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Sample records for hot-rolled steel strip

  1. Model for prediction of strip temperature in hot strip steel mill

    International Nuclear Information System (INIS)

    Panjkovic, Vladimir

    2007-01-01

    Proper functioning of set-up models in a hot strip steel mill requires reliable prediction of strip temperature. Temperature prediction is particularly important for accurate calculation of rolling force because of strong dependence of yield stress and strip microstructure on temperature. A comprehensive model was developed to replace an obsolete model in the Western Port hot strip mill of BlueScope Steel. The new model predicts the strip temperature evolution from the roughing mill exit to the finishing mill exit. It takes into account the radiative and convective heat losses, forced flow boiling and film boiling of water at strip surface, deformation heat in the roll gap, frictional sliding heat, heat of scale formation and the heat transfer between strip and work rolls through an oxide layer. The significance of phase transformation was also investigated. Model was tested with plant measurements and benchmarked against other models in the literature, and its performance was very good

  2. Model for prediction of strip temperature in hot strip steel mill

    Energy Technology Data Exchange (ETDEWEB)

    Panjkovic, Vladimir [BlueScope Steel, TEOB, 1 Bayview Road, Hastings Vic. 3915 (Australia)]. E-mail: Vladimir.Panjkovic@BlueScopeSteel.com

    2007-10-15

    Proper functioning of set-up models in a hot strip steel mill requires reliable prediction of strip temperature. Temperature prediction is particularly important for accurate calculation of rolling force because of strong dependence of yield stress and strip microstructure on temperature. A comprehensive model was developed to replace an obsolete model in the Western Port hot strip mill of BlueScope Steel. The new model predicts the strip temperature evolution from the roughing mill exit to the finishing mill exit. It takes into account the radiative and convective heat losses, forced flow boiling and film boiling of water at strip surface, deformation heat in the roll gap, frictional sliding heat, heat of scale formation and the heat transfer between strip and work rolls through an oxide layer. The significance of phase transformation was also investigated. Model was tested with plant measurements and benchmarked against other models in the literature, and its performance was very good.

  3. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions; FINAL

    International Nuclear Information System (INIS)

    Yi-Wen Cheng; Patrick Purtscher

    1999-01-01

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills

  4. 75 FR 19369 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products from Brazil: Preliminary Results of...

    Science.gov (United States)

    2010-04-14

    .... Hot-rolled dual phase steel, phase-hardened, primarily with a ferritic-martensitic microstructure.... See Preliminary Results of Antidumping Duty Administrative Review: Stainless Steel Sheet and Strip in... Antidumping Duty Administrative Review: Stainless Steel Sheet and Strip in Coils From France, 68 FR 69379...

  5. Image recognition of shape defects in hot steel rolling

    NARCIS (Netherlands)

    Balmashnova, E.; Bruurmijn, L.C.M.; Dissanayake, R.; Duits, R.; Kampmeijer, L.; Noorden, van T.L.; Boon, M.A.A.

    2013-01-01

    A frequently occurring issue in hot rolling of steel is so-called tail pinching. Prominent features of a pinched tail are ripple-like defects and a pointed tail. In this report two algorithms are presented to detect those features accurately in 2D gray scale images of steel strips. The two ripple

  6. Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

    International Nuclear Information System (INIS)

    Muhin, U.; Belskij, S.; Makarov, E.; Koinov, T.

    2013-01-01

    Full text: A mathematical model of the thermal state of the metal on the run-out roller table of a continuous wide hot-strip mill is presented. The mathematical model takes into account the heat generation during the polymorphic γ → α transformation of super cooled austenite phase and the influence of chemical composition on the physical properties of the steel. The model allows the calculation of modes of accelerated cooling of strips on the run-out roller table of a continuous wide hot strip mill. Winding temperature calculation error does not exceed 20 °C for 98.5 % of the strips from low-carbon and low-alloyed steels. key words: hot rolled, wide-strip, accelerated cooling, run-out roller table, polymorphic transformation, mathematical modeling

  7. The Influence of Vanadium Microalloying on the Production of Thin Slab Casting and Direct Rolled Steel Strip

    Science.gov (United States)

    Li, Yu; Milbourn, David

    Vanadium microalloying is highly effective in high strength strip steels produced by thin slab casting and direct rolled process. Because of the high solubility of V(C,N) in austenite, vanadium is likely to remain in solution during casting, equalisation and rolling. Vanadium microalloyed steels have better hot ductility and are less prone to transverse cracking than niobium containing steels. Despite a coarse as-cast austenite grain size before rolling, significant grain refinement can be achieved in vanadium microalloyed steels by repeated recrystallization during rolling, resulting in a fine uniform ferrite microstructure in final strip. Almost all vanadium present in microalloyed steels is available to precipitate in ferrite as very fine particles, contributing to precipitation strengthening. Vanadium microalloyed steels show less sensitivity to rolling process variables and exhibit excellent combination of strength and toughness.

  8. Review of the continuous casting of steel by strip casting technology. Twin roll method system

    International Nuclear Information System (INIS)

    Ibarrondo, I.

    2008-01-01

    In order to compete in the future steel market and to maintain market share, the steel makers will need to use new efficient technologies capable of supplying steel strip products of high quality at low cost. In this way, the strip casting technology by twin rol method is one of the most important research are in the iron and steel industry today. This review makes a general description of the strip casting technology as well as its different steps, such us; metal delivery and casting, solidification process, hot rolling reduction step, etc. Through mathematical and physical models, the influence on microstructure texture surface quality and mechanical properties of the materials obtained by this method are described as a function of processing parameters, specially the roughness of the rolls. the manufacturing of carbon, stainless and electrical steels involves smaller capital and operating cost, lower gas emissions, and an opportunity to create new grades due to a faster solidification rate that leads to a different solidification structures. In sight of all this it is likely that Strip Casting technology will make a profound impact on the manufacturing landscape of the 21 s t century. (Author) 177 refs

  9. Rolling process simulation of a pair-crossed hot strip mill

    International Nuclear Information System (INIS)

    Chen Shaojie; Xu Jianzhong; Liu Xianghua; Wang Guodong

    2000-01-01

    Process simulation can help optimize the operating parameters aiming to improve the quality of rolled products. In this paper, software in Visual Basic language is developed to simulate the hot rolling process of a pair-crossed mill. The strip temperature is calculated by considering air cooling, water cooling, heat generation and conduction.The production parameters including rolling speeds, resistance to deformation, rolling forces, drive torques and powers are evaluated by mathematical models and their parameter identification support tools. The deformation of roll stack is calculated by influential function method. The roll temperature and expansion are calculated by finite differential method, and the roll wear is described by empirical formula. Based on these calculations as well as the effect of heredity is taken into account, the strip crown and flatness then can be obtained. The results show that the simulation software has friendly user interface, high accuracy and practicability. It can be served as a basis for the mill design and optimization of process parameters to acquire high quality of hot rolled strip. (author)

  10. A novel ultra-low carbon grain oriented silicon steel produced by twin-roll strip casting

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yang, E-mail: wy069024019@163.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Zhang, Yuan-Xiang; Lu, Xiang; Fang, Feng; Xu, Yun-Bo; Cao, Guang-Ming; Li, Cheng-Gang [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials and Biomedical Engineering, University of Texas at El Paso, TX 79968 (United States); Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

    2016-12-01

    A novel ultra-low carbon grain oriented silicon steel was successfully produced by strip casting and two-stage cold rolling method. The microstructure, texture and precipitate evolution under different first cold rolling reduction were investigated. It was shown that the as-cast strip was mainly composed of equiaxed grains and characterized by very weak Goss texture ({110}<001>) and λ-fiber (<001>//ND). The coarse sulfides of size ~100 nm were precipitated at grain boundaries during strip casting, while nitrides remained in solution in the as-cast strip and the fine AlN particles of size ~20–50 nm, which were used as grain growth inhibitors, were formed in intermediate annealed sheet after first cold rolling. In addition, the suitable Goss nuclei for secondary recrystallization were also formed during intermediate annealing, which is totally different from the conventional process that the Goss nuclei originated in the subsurface layer of the hot rolled sheet. Furthermore, the number of AlN inhibitors and the intensity of desirable Goss texture increased with increasing first cold rolling reduction. After secondary recrystallization annealing, very large grains of size ~10–40 mm were formed and the final magnetic induction, B{sub 8}, was as high as 1.9 T. - Highlights: • A novel chemical composition base on strip casting silicon steel was proposed. • The ultra-low carbon design could shorten the processing routes. • The novel composition and processes were beneficial to obtain more inhibitors. • The magnetic induction of grain oriented silicon steel was significantly improved.

  11. The Role of Nano-TiO2 Lubricating Fluid on the Hot Rolled Surface and Metallographic Structure of SS41 Steel

    Directory of Open Access Journals (Sweden)

    Yanan Meng

    2018-02-01

    Full Text Available In this paper, nano-TiO2lubricating fluid was chosen as an advanced rolling lubricant to investigate its effect on the hot rolled surface and metallographic structure of SS41 steel strips. The tribological performances of nano-TiO2 lubricating fluid were measured by a four-ball tribotester. The hot rolling experiments under different lubrication conditions were carried out by a four-high rolling mill. The surface morphology, oxide scales and metallographic structure after hot rolling were observed using a confocal laser scanning microscope and scanning electron microscope (SEM, respectively. The composition of surface attachments was analyzed with X-ray photoelectron spectroscopy (XPS. The results indicate that the nano-TiO2 lubricating fluid has a better tribological performance. The surface defects on the hot rolled surface could be decreased. The phase composition of the surface still appears as a mixture of ferrite and pearlite. The surface of steel strips is not micro-alloyed with titanium as predicted. Additionally, the grain size of rolled steel strips which were lubricated with the nano-TiO2lubricating fluid decreased by nearly 50%, compared with traditional lubricating fluid. Furthermore, it was found that the thickness of the oxide layers on the surface reduced, whilst the Rockwell hardness of the oxide layers was enhanced as nano-TiO2 lubricating fluid was applied.

  12. Effect of asymmetric hot rolling on texture, microstructure and magnetic properties in a non-grain oriented electrical steel

    International Nuclear Information System (INIS)

    Chen, S.; Butler, J.; Melzer, S.

    2014-01-01

    In this study, both asymmetric hot rolling (AHR) and conventional hot rolling (CHR) were carried out to study the effect of the hot rolling conditions on the evolution of the texture and microstructure in a non-grain oriented (NGO) steel. The microstructure and texture in the subsequent processing stages were characterised and related to the final magnetic properties. The results show that AHR, compared with CHR, tends to homogenise texture through thickness of the hot band strips. AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips, which are favourable features in relation to the magnetic properties of the strip. However, the favourable features observed in hot rolled AHR strips are eliminated after cold rolling and annealing. Contrarily, the required θ-fibre is decreased and the unwanted γ-fibre is intensified in the AHR sheet after cold rolling and their strength is maintained in the subsequent process steps. On the other hand, AHR does not produce a discernible change in the grain size in the hot band annealed strip and in the final annealed sheet, except that the magnetic anisotropy in the AHR is improved after skin pass and extra annealing as the result of the redistribution of the texture components within the θ-fibre, no significant improvement of the magnetic properties as a direct consequence of the application of asymmetric hot rolling has been observed under the current AHR experimental conditions. - Highlights: • Asymmetrical hot rolling (AHR) produces more uniform distribution of texture through the thickness of the hot rolled strips and of the hot band annealed strips when compared with conventional hot rolling (CHR). • AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips. The θ-fibre is decreased but the γ-fibre is intensified in the AHR sheet after cold rolling

  13. Effect of asymmetric hot rolling on texture, microstructure and magnetic properties in a non-grain oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Chen, S., E-mail: Shangping.chen@tatasteel.com [Tata Steel, 1970 CA IJmuiden (Netherlands); Butler, J. [Tata Steel, S60 3AR South Yorkshire (United Kingdom); Melzer, S. [Tata Steel, 1970 CA IJmuiden (Netherlands)

    2014-11-15

    In this study, both asymmetric hot rolling (AHR) and conventional hot rolling (CHR) were carried out to study the effect of the hot rolling conditions on the evolution of the texture and microstructure in a non-grain oriented (NGO) steel. The microstructure and texture in the subsequent processing stages were characterised and related to the final magnetic properties. The results show that AHR, compared with CHR, tends to homogenise texture through thickness of the hot band strips. AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips, which are favourable features in relation to the magnetic properties of the strip. However, the favourable features observed in hot rolled AHR strips are eliminated after cold rolling and annealing. Contrarily, the required θ-fibre is decreased and the unwanted γ-fibre is intensified in the AHR sheet after cold rolling and their strength is maintained in the subsequent process steps. On the other hand, AHR does not produce a discernible change in the grain size in the hot band annealed strip and in the final annealed sheet, except that the magnetic anisotropy in the AHR is improved after skin pass and extra annealing as the result of the redistribution of the texture components within the θ-fibre, no significant improvement of the magnetic properties as a direct consequence of the application of asymmetric hot rolling has been observed under the current AHR experimental conditions. - Highlights: • Asymmetrical hot rolling (AHR) produces more uniform distribution of texture through the thickness of the hot rolled strips and of the hot band annealed strips when compared with conventional hot rolling (CHR). • AHR results in a higher fraction of the θ-fibre ({0 0 1}) and a lower fraction of the γ-fibre ({1 1 1}) in the hot band strips. The θ-fibre is decreased but the γ-fibre is intensified in the AHR sheet after cold rolling

  14. 75 FR 42782 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2010-07-22

    ...)] Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... Brazil and Japan, and the suspended investigation on hot-rolled steel from Russia. SUMMARY: The... Japan, and the suspended investigation on hot-rolled steel from Russia would be likely to lead to...

  15. 75 FR 62566 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2010-10-12

    ...)] Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... antidumping duty investigation on hot-rolled steel from Russia. SUMMARY: The Commission hereby gives notice of... suspended investigation on hot-rolled steel from Russia would be likely to lead to continuation or...

  16. Roll force prediction of high strength steel using foil rolling theory in cold skin pass rolling

    International Nuclear Information System (INIS)

    Song, Gil Ho; Jung, Jae Chook

    2013-01-01

    Skin pass rolling is a very important process for applying a certain elongation to a strip in the cold rolling and annealing processes, which play an important role in preventing the stretching of the yield point when the material is processed. The exact prediction of the rolling force is essential for obtaining a given elongation with the steel grade and strip size. Unlike hot rolling and cold rolling, skin pass rolling is used to apply an elongation of within 2% to the strip. Under a small reduction, it is difficult to predict the rolling force because the elastic deformation behavior of the rolls is complicated and a model for predicting the rolling force has not yet been established. Nevertheless, the exact prediction of the rolling force in skin pass rolling has gained increasing importance in recent times with the rapid development of high strength steels for use in automobiles. In this study, the possibility of predicting the rolling force in skin pass rolling for producing various steel grades was examined using foil rolling theory, which is known to have similar elastic deformation behavior of rolls in the roll bite. It was found that a noncircular arc model is more accurate than a circular model in predicting the roll force of high strength steel below TS 980 MPa in skin pass rolling

  17. Metallurgical analysis of spalled work roll of hot strip mill

    International Nuclear Information System (INIS)

    Khan, M.M.; Khan, M.A.

    1993-01-01

    In this study failure analysis of four work roll of the Hot Strip Mill is carried out. The microstructure is correlated with the chemical composition of shell and roll-life. It was concluded that for the longer service of the roll, cementite, graphite and martensite should be balanced (as per working requirement of the mill). (author)

  18. Properties of hot rolled steels for enamelling

    International Nuclear Information System (INIS)

    Gavrilovski, Dragica; Gavrilovski, Milorad

    2003-01-01

    The results of an investigation of the structure and properties of experimental produced hot rolled steels suitable for enamelling are presented in the paper. Hot rolled steels for enamelling represent a special group of the steels for conventional enamelling. Their quality has to be adapted to the method and conditions of enamelling. Therefore, these steels should meet some specific requirements. In addition to usual investigation of the chemical composition and mechanical properties, microstructure and quality of the steel surface also were investigated. The basic aim was to examine steels capability for enamelling, i. e. steels resistance to the fish scales phenomena, by trial enamelling, as well as quality of the steel - enamel contact surface, to evaluate the binding. Also, the changes of the mechanical properties, especially the yield point, during thermal treatment, as a very specific requirement, were investigated, by simplified method. Good results were obtained confirming the steels capability for enamelling. (Original)

  19. 75 FR 64246 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Correction to Notice of...

    Science.gov (United States)

    2010-10-19

    ...-Rolled Carbon-Quality Steel Products From Brazil: Correction to Notice of Antidumping Duty Order AGENCY... certain hot-rolled flat-rolled carbon-quality steel products from Brazil. See Antidumping Duty Order: Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, 67 FR 11093 (March 12, 2002...

  20. Application of powder metallurgy and hot rolling processes for manufacturing aluminum/alumina composite strips

    Energy Technology Data Exchange (ETDEWEB)

    Zabihi, Majed, E-mail: m.zabihi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Toroghinejad, Mohammad Reza, E-mail: toroghi@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shafyei, Ali, E-mail: shafyei@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2013-01-10

    In this study, aluminum matrix composites (AMC) with 2, 4, 6 and 10 wt% alumina were produced using powder metallurgy (PM), mechanical milling (MM) and vacuum hot pressing (VHP) techniques; then, this was followed by the hot-rolling process. During hot rolling, AMCs with 6 and 10 wt% Al{sub 2}O{sub 3} were fractured whereas strip composites with 2 and 4 wt% Al{sub 2}O{sub 3} were produced successfully. Microstructure and mechanical properties of the samples were investigated by optical and scanning electron microscopes and tensile and hardness tests, respectively. Microscopic evaluations of the hot-rolled composites showed a uniform distribution of alumina particles in the aluminum matrix. It was found that with increasing alumina content in the matrix, tensile strength (TS) and hardness increased and the percentage of elongation also decreased. Scanning electron microscope (SEM) was used to investigate aluminum/alumina interfaces and fracture surfaces of the hot rolled specimens after tensile test. SEM observations demonstrated that the failure mode in the hot-rolled Al-2 wt% Al{sub 2}O{sub 3} composite strips is a typical ductile fracture, while the failure mode was shear ductile fracture with more flat surfaces in Al-4 wt% Al{sub 2}O{sub 3} strips.

  1. Service behaviour of high speed steel rolling rolls used in hot strip mills; Comportamiento en servicio de los aceros rapidos utilizados en la fabricacion de los cilindros de trabajo de los trenes de bandas en caliente

    Energy Technology Data Exchange (ETDEWEB)

    Ziadi, A.; Belzunce, F. J.; Rodriguez, C.; Fernandez, I.

    2005-07-01

    Work rolls used in hot strip mills may be able to carry out severe actions: very high thermal stresses and wear, along with mechanical stresses due to normal rolling loads, which develop in the presence of cracks, produced by the former actions. The microstructure and the mechanical behaviour (strength and toughness) of high speed steels, which recently have been introduced in this applications, were studied in this work in comparison with high chromium cast irons. (Author) 7 refs.

  2. 75 FR 32160 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil: Extension of Time Limit...

    Science.gov (United States)

    2010-06-07

    ...-Rolled Carbon-Quality Steel Products from Brazil: Extension of Time Limit for Preliminary Results of...-quality steel products from Brazil. See Agreement Suspending the Countervailing Duty Investigation on Hot... duty order on certain hot-rolled flat-rolled carbon-quality steel products from Brazil. See Initiation...

  3. Hot coiled steel strip with elevated niobium content for pipelines and its weldability

    International Nuclear Information System (INIS)

    Brozda, J.; Zeman, M.

    2010-01-01

    Examinations and tests have been performed on thermomechanically rolled and hot coiled 14 mm thick steel strips with a low carbon and elevated niobium content, assigned for the production of pipelines. There were examined basic mechanical properties of the steels, brittle fracture resistance of the parent material and simulated HAZ's, susceptibility to cold cracking as well as properties of MMA and GMA welded joints. It was found that the tested steels are characterized by a good weldability, are not prone to cold cracking, have a low brittle fracture transition temperature and the HAZ of welded joints shows a sufficient high brittle fracture resistance. (authors)

  4. Development of TRIP-Aided Lean Duplex Stainless Steel by Twin-Roll Strip Casting and Its Deformation Mechanism

    Science.gov (United States)

    Zhao, Yan; Zhang, Weina; Liu, Xin; Liu, Zhenyu; Wang, Guodong

    2016-12-01

    In the present work, twin-roll strip casting was carried out to fabricate thin strip of a Mn-N alloyed lean duplex stainless steel with the composition of Fe-19Cr-6Mn-0.4N, in which internal pore defects had been effectively avoided as compared to conventional cast ingots. The solidification structure observed by optical microscope indicated that fine Widmannstatten structure and coarse-equiaxed crystals had been formed in the surface and center, respectively, with no columnar crystal structures through the surface to center of the cast strip. By applying hot rolling and cold rolling, thin sheets with the thickness of 0.5 mm were fabricated from the cast strips, and no edge cracks were formed during the rolling processes. With an annealing treatment at 1323 K (1050 °C) for 5 minutes after cold rolling, the volume fractions of ferrite and austenite were measured to be approximately equal, and the distribution of alloying elements in the strip was further homogenized. The cold-rolled and annealed sheet exhibited an excellent combination of strength and ductility, with the ultimate tensile strength and elongation having been measured to be 1000 MPa and 65 pct, respectively. The microstructural evolution during deformation was investigated by XRD, EBSD, and TEM, indicating that ferrite and austenite had different deformation mechanisms. The deformation of ferrite phase was dominated by dislocation slipping, and the deformation of austenite phase was mainly controlled by martensitic transformation in the sequence of γ→ ɛ-martensite→ α'-martensite, leading to the improvement of strength and plasticity by the so-called transformation-induced plasticity (TRIP) effect. By contrast, lean duplex stainless steels of Fe-21Cr-6Mn-0.5N and Fe-23Cr-7Mn-0.6N fabricated by twin-roll strip casting did not show TRIP effects and exhibited lower strength and elongation as compared to Fe-19Cr-6Mn-0.4N.

  5. Texture evolution of experimental silicon steel grades. Part I: Hot rolling

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval Robles, J.A., E-mail: jsandoval.uanl@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, Ave. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66450 (Mexico); Salas Zamarripa, A.; Guerrero Mata, M.P. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, Ave. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66450 (Mexico); Cabrera, J. [Universitat Politècnica de Catalunya, Departament de Ciència dels Materials I Enginyeria Metal-lúrgica, Av. Diagonal 647, Barcelona 08028 (Spain)

    2017-05-01

    The metallurgical understanding of the deformation processes during the fabrication of non-oriented electrical steels plays a key role in improving their final properties. Texture control and optimization is critical in these steels for the enhancement of their magnetic properties. The aim of the present work is to study the texture evolution of six non-oriented experimental silicon steel grades during hot rolling. These steels were low carbon steel with a silicon content from 0.5 to 3.0 wt%. The first rolling schedule was performed in the austenitic (γ-Fe) region for the steel with a 0.5 wt% of silicon content, while the 1.0 wt% silicon steel was rolled in the two-phase (α+γ) region. Steels with higher silicon content were rolled in the ferritic (α-Fe) region. The second rolling schedule was performed in the α-Fe region. Samples of each stage were analyzed by means of Electron Backscatter Diffraction (EBSD). Findings showed that the texture was random and heterogeneous in all samples after 60% of rolling reduction, which is due to the low deformation applied during rolling. After the second rolling program, localized deformation and substructured grains near to surface were observed in all samples. The Goss {110}<001>texture-component was found in the 0.5 and 1.0 wt.-%silicon steels. This is due to the thermomechanical conditions and the corresponding hot band microstructure obtained after the first program. Moreover, the α<110>//RD and the γ <111>//ND fiber components of the texture presented a considerable increment as the silicon content increases. Future research to be published soon will be related to the texture evolution during the cold-work rolling process. - Highlights: • We analyze six silicon steel experimental grades alloys trough the rolling process. • Material was subjected to a hot deformation process in the α-γ region. • No recrystalization was observed during-after the rolling schedules. • Rise of the magnetic texture components

  6. 75 FR 77828 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Extension of Time Limit...

    Science.gov (United States)

    2010-12-14

    ...-Rolled Carbon-Quality Steel Products From Brazil: Extension of Time Limit for Final Results of...-Rolled Carbon Quality Steel Products From Brazil: Preliminary Results of Countervailing Duty... administrative review of the countervailing duty order on certain hot-rolled flat-rolled carbon- quality steel...

  7. Microstructure and properties of hot roll bonding layer of dissimilar metals. 2. Bonding interface microstructure of Zr/stainless steel by hot roll bonding and its controlling

    International Nuclear Information System (INIS)

    Yasuyama, Masanori; Ogawa, Kazuhiro; Taka, Takao; Nakasuji, Kazuyuki; Nakao, Yoshikuni; Nishimoto, Kazutoshi.

    1996-01-01

    The hot roll bonding of zirconium and stainless steel inserted with tantalium was investigated using the newly developed rolling mill. The effect of hot rolling temperatures of zirconium/stainless steel joints on bonding interface structure was evaluated. Intermetallic compound layer containing cracks was observed at the bonding interface between stainless steel and tantalium when the rolling temperature was above 1373K. The hardness of the bonding layer of zirconium and tantalium bonded above 1273K was higher than tantalium or zirconium base metal in spite of absence of intermetallic compound. The growth of reaction layer at the stainless steel and tantalium interface and at the tantalium and zirconium interface was conforming a parabolic low when that was isothermally heated after hot roll bonding, and the growth rate was almost same as that of static diffusion bonding without using hot roll bonding process. It is estimated that the strain caused by hot roll bonding gives no effect on the growth of reaction layer. It was confirmed that the dissimilar joint of zirconium and stainless steel with insert of tantalium having the sound bonding interface were obtained at the suitable bonding temperature of 1173K by the usage of the newly developed hot roll bonding process. (author)

  8. Properties of Galvanized and Galvannealed Advanced High Strength Hot Rolled Steels

    Energy Technology Data Exchange (ETDEWEB)

    V.Y. Guertsman; E. Essadiqi; S. Dionne; O. Dremmailova; R. Bouchard; B. Voyzelle; J. McDermid; R. Fourmentin

    2008-04-01

    The objectives of the project were (i) to develop the coating process information to achieve good quality coatings on 3 advanced high strength hot rolled steels while retaining target mechanical properties, (ii) to obtain precise knowledge of the behavior of these steels in the various forming operations and (iii) to establish accurate user property data in the coated conditions. Three steel substrates (HSLA, DP, TRIP) with compositions providing yield strengths in the range of 400-620 MPa were selected. Only HSLA steel was found to be suitable for galnaizing and galvannealing in the hot rolled condition.

  9. Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

    Directory of Open Access Journals (Sweden)

    E.Makarov

    2016-07-01

    Full Text Available A mathematical model of the thermal state of the metal in the run-out roller table continuous wide hot strip mill. The mathematical model takes into account heat generation due to the polymorphic γ → α transformation of supercooled austenite phase state and the influence of the chemical composition of the steel on the physical properties of the metal. The model allows calculation of modes of accelerated cooling strips on run-out roller table continuous wide hot strip mill. Winding temperature calculation error does not exceed 20°C for 98.5 % of strips of low-carbon and low-alloy steels

  10. Microstructure Engineering in Hot Strip Mills, Part 1 of 2: Integrated mathematical Model

    Energy Technology Data Exchange (ETDEWEB)

    J.K. Brimacombe; I.V. Samaraseker; E.B. Hawbolt; T.R. Meadowcroft; M. Militzer; W.J. Pool; D.Q. Jin

    1998-09-30

    This report describes the work of developing an integrated model used to predict the thermal history, deformation, roll forces, microstructural evaluation and mechanical properties of steel strip in a hot-strip mill. This achievement results from a join research effort that is part of the American Iron and Steel Institute's (AISI) Advanced Process Control Program, a collaboration between the U.S. DOE and fifteen North American steel makers.

  11. Influence of cold rolling direction on texture, inhibitor and magnetic properties in strip-cast grain-oriented 3% silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Fang, F., E-mail: fangfengdbdx@163.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Lu, X.; Zhang, Y.X.; Wang, Y.; Jiao, H.T.; Cao, G.M.; Yuan, G.; Xu, Y.B. [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials and Biomedical Engineering, University of Texas at El Paso, EL Paso, TX 79968 (United States); Wang, G.D. [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China)

    2017-02-15

    An unconventional cold rolling scheme (inclined rolling at 0°, 30°, 45°, 90° during second-stage cold rolling process) was adopted to process grain-oriented silicon steel based on strip casting process. The influences of inclination angles on microstructure, texture, inhibitor and magnetic properties were studied by a combination of EBSD, XRD and TEM. It was found that the α-fiber texture was weakened and γ-fiber was strengthened in cold rolled sheet with increase in inclination angle. The primary recrystallization sheet exhibited more homogeneous microstructure with relatively strong γ-fiber, medium α-fiber texture, weak λ-fiber texture and Goss component at high inclination angles. Fine and homogeneous inhibitors were obtained after primary annealing with increase in inclination angle from 0° to 90° because of more uniform deformation after inclined rolling. The grain-oriented silicon steel experienced completely secondary recrystallization at various inclination angles after final annealing process, with superior magnetic properties at 0° and 90°. Furthermore, Goss nuclei capable of final secondary recrystallization in strip casting process newly formed both in-grain shear bands and grain boundaries region during second-stage cold rolling and subsequent annealing process, which is different from the well-accepted results that Goss texture originated from the subsurface layer of the hot rolled sheet or during intermediate annealing process. In addition, the Goss texture that nucleated in-grain shear bands was weaker but more accurate as compared to that in grain boundaries region. - Highlights: • Inclined cold rolling was adopted to process strip-cast grain-oriented silicon steel. • Influence of inclination angles on texture, inhibitor and magnetic properties was studied. • The initial texture was changed with respect to the inclination angle. • Homogeneous inhibitors were obtained after primary annealing at various inclination angles.

  12. 78 FR 11901 - Hot-Rolled Steel Products From China, India, Indonesia, Taiwan, Thailand, and Ukraine; Notice of...

    Science.gov (United States)

    2013-02-20

    ... 906-908 (Second Review)] Hot-Rolled Steel Products From China, India, Indonesia, Taiwan, Thailand, and... determine whether revocation of the countervailing duty orders on hot-rolled steel products from India, Indonesia, and Thailand and the revocation of the antidumping duty orders on hot-rolled steel products from...

  13. Effects of hot rolled microstructure after twin-roll casting on microstructure, texture and magnetic properties of low silicon non-oriented electrical steel

    International Nuclear Information System (INIS)

    Liu, Hai-Tao; Wang, Yin-Ping; An, Ling-Zi; Wang, Zhao-Jie; Hou, Dao-Yuan; Chen, Jun-Mou; Wang, Guo-Dong

    2016-01-01

    In this work, a 0.71 wt%Si+0.44 wt%Al as-cast strip was produced by novel twin-roll casting. Some as-cast samples were respectively reheated and hot rolled at different temperatures in order to obtain different microstructure prior to cold rolling and annealing. The effects of the hot rolled microstructure on microstructure, texture evolution and magnetic properties were investigated in detail. A coarse deformed microstructure with λ-fiber texture was formed after hot rolling at 850–1050 °C, finally leading to an inhomogeneous recrystallization microstructure with strong λ-fiber, Goss and extremely weak γ-fiber texture. By contrast, a fine transformed microstructure was formed after hot rolling at 1150–1250 °C, finally leading to a fine and homogeneous recrystallization microstructure with stronger α-fiber, γ-fiber and much weaker λ-fiber texture. It should be noted that both the magnetic induction and core loss non-monotonically decreased or increased according to the hot rolling temperature. The unfavorable α-fiber and γ-fiber textures in the annealed sheets were much weaker than those of the conventional products regardless of the hot rolling temperature, thus contributing to a much higher magnetic induction. However, the average grain size in the annealed sheets was much lower than those of the conventional products regardless of the hot rolling temperature, thus leading to a higher core loss except the case of 1050 °C. Hence, it is underscored that better integrated magnetic properties than those of the conventional products can be obtained by optimizing the hot rolled microstructure to produce final desirable recrystallization microstructure and texture. - Highlights: • Non-oriented silicon steel was fabricated using twin-roll casting route. • Microstructure and texture evolution were clarified. • Effects of the hot rolled microstructure were investigated in detail. • Formation mechanism of the recrystallization texture was explored.

  14. Effects of hot rolled microstructure after twin-roll casting on microstructure, texture and magnetic properties of low silicon non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn; Wang, Yin-Ping; An, Ling-Zi; Wang, Zhao-Jie; Hou, Dao-Yuan; Chen, Jun-Mou; Wang, Guo-Dong

    2016-12-15

    In this work, a 0.71 wt%Si+0.44 wt%Al as-cast strip was produced by novel twin-roll casting. Some as-cast samples were respectively reheated and hot rolled at different temperatures in order to obtain different microstructure prior to cold rolling and annealing. The effects of the hot rolled microstructure on microstructure, texture evolution and magnetic properties were investigated in detail. A coarse deformed microstructure with λ-fiber texture was formed after hot rolling at 850–1050 °C, finally leading to an inhomogeneous recrystallization microstructure with strong λ-fiber, Goss and extremely weak γ-fiber texture. By contrast, a fine transformed microstructure was formed after hot rolling at 1150–1250 °C, finally leading to a fine and homogeneous recrystallization microstructure with stronger α-fiber, γ-fiber and much weaker λ-fiber texture. It should be noted that both the magnetic induction and core loss non-monotonically decreased or increased according to the hot rolling temperature. The unfavorable α-fiber and γ-fiber textures in the annealed sheets were much weaker than those of the conventional products regardless of the hot rolling temperature, thus contributing to a much higher magnetic induction. However, the average grain size in the annealed sheets was much lower than those of the conventional products regardless of the hot rolling temperature, thus leading to a higher core loss except the case of 1050 °C. Hence, it is underscored that better integrated magnetic properties than those of the conventional products can be obtained by optimizing the hot rolled microstructure to produce final desirable recrystallization microstructure and texture. - Highlights: • Non-oriented silicon steel was fabricated using twin-roll casting route. • Microstructure and texture evolution were clarified. • Effects of the hot rolled microstructure were investigated in detail. • Formation mechanism of the recrystallization texture was explored.

  15. Cold-Rolled Strip Steel Stress Detection Technology Based on a Magnetoresistance Sensor and the Magnetoelastic Effect.

    Science.gov (United States)

    Guan, Ben; Zang, Yong; Han, Xiaohui; Zheng, Kailun

    2018-05-21

    Driven by the demands for contactless stress detection, technologies are being used for shape control when producing cold-rolled strips. This paper presents a novel contactless stress detection technology based on a magnetoresistance sensor and the magnetoelastic effect, enabling the detection of internal stress in manufactured cold-rolled strips. An experimental device was designed and produced. Characteristics of this detection technology were investigated through experiments assisted by theoretical analysis. Theoretically, a linear correlation exists between the internal stress of strip steel and the voltage output of a magneto-resistive sensor. Therefore, for this stress detection system, the sensitivity of the stress detection was adjusted by adjusting the supply voltage of the magnetoresistance sensor, detection distance, and other relevant parameters. The stress detection experimental results showed that this detection system has good repeatability and linearity. The detection error was controlled within 1.5%. Moreover, the intrinsic factors of the detected strip steel, including thickness, carbon percentage, and crystal orientation, also affected the sensitivity of the detection system. The detection technology proposed in this research enables online contactless detection and meets the requirements for cold-rolled steel strips.

  16. 76 FR 34101 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2011-06-10

    ...] Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia Determinations On...-quality steel products from Russia would be likely to lead to continuation or recurrence of material injury to an industry in the United States within a reasonably foreseeable time. The Commission further...

  17. Cold-rolled steel strip X-ray thickness gauge

    International Nuclear Information System (INIS)

    Tong Jianmin; Cong Peng; Li Litao

    2010-01-01

    This paper introduces a cold-rolled steel strip X-ray thickness gauge. This gauge uses two-detector construction including penetrating ionization chamber and measuring ionization chamber. Standard magazine box is composed of three rotating plates driving by stepper motor, including 13 pieces of standard sample to build up 154 thickness value, obtaining standard sample curve covering thickness range of 0.1 mm to 5 mm. Automation system include Siemens S7-200 PLC as key controlling unit, embedded controlling system for data acquisition and computing, and PC as man-machine interface, and employ Ethernet (TCP/IP) or RS485/232 as communication protocol. Reversing Cold mill AGC closed-loop control operation test demonstrates that the gauge can adapt to the severe production environment, operate stably and reliably, measurement precision can reached to ±0.19%, reproducibility to ±0.09%, and stability to ±0.06%, response time range from 4 ms to 200 ms and be adjustable. So it can meet the high demanding of cold-rolled plate/strip production. (authors)

  18. Application of the Finite Element Method to Reveal the Causes of Loss of Planeness of Hot-Rolled Steel Sheets during Laser Cutting

    Science.gov (United States)

    Garber, E. A.; Bolobanova, N. L.; Trusov, K. A.

    2018-01-01

    A finite element technique is developed to simulate the stresses and the strains during strip flattening to reveal the causes of the cutting-assisted loss of planeness of hot-rolled steel sheets processed in roller levelers. The loss of planeness is found to be caused by a nonuniform distribution of the flattening-induced longitudinal tensile stresses over the strip thickness and width. The application of tensile forces to a strip in a roller leveler decreases this nonuniformity and prevents loss of planeness in cutting.

  19. Effects of microalloying on hot-rolled and cold-rolled Q&P steels

    Science.gov (United States)

    Azevedo de Araujo, Ana Luiza

    Third generation advanced high strength steels (AHSS) have been a major focus in steel development over the last decade. The premise of these types of steel is based on the potential to obtain excellent combinations of strength and ductility with low-alloy compositions by forming mixed microstructures containing retained austenite (RA). The development of heat treatments able to achieve the desired structures and properties, such as quenching and partitioning (Q&P) steels, is driven by new requirements to increase vehicle fuel economy by reducing overall weight while maintaining safety and crashworthiness. Microalloying additions of niobium (Nb) and vanadium (V) in sheet products are known to provide strengthening via grain refinement and precipitation hardening and may influence RA volume fraction and transformation behavior. Additions of microalloying elements in Q&P steels have not been extensively studied to date, however. The objective of the present study was to begin to understand the potential roles of Nb and V in hot-rolled and cold-rolled Q&P steel. For that, a common Q&P steel composition was selected as a Base alloy with 0.2C-1.5Si-2.0Mn (wt. %). Two alloys with an addition of Nb (0.02 and 0.04 wt. %) and one with an addition of V (0.06 wt. %) to the Base alloy were investigated. Both hot-rolled and cold-rolled/annealed Q&P simulations were conducted. In the hot-rolled Q&P study, thermomechanical processing was simulated via hot torsion testing in a GleebleRTM 3500, and four coiling temperatures (CT) were chosen. Microstructural evaluation (including RA measurements via electron backscattered diffraction - EBSD) and hardness measurements were performed for all alloys and coiling conditions. The analysis showed that Nb additions led to overall refinement of the prior microstructure. Maximum RA fractions were measured at the 375 °C CT, and microalloying was associated with increased RA in this condition when compared to the Base alloy. A change in

  20. ABOUT RATIONING MAXIMUM ALLOWABLE DEFECT DEPTH ON THE SURFACE OF STEEL BILLETS IN PRODUCTION OF HOT-ROLLED STEEL

    Directory of Open Access Journals (Sweden)

    PARUSOV E. V.

    2017-01-01

    Full Text Available Formulation of the problem. Significant influence on the quality of rolled steel have various defects on its surface, which in its turn inherited from surface defects of billet and possible damage to the surface of rolled steel in the rolling mill line. One of the criteria for assessing the quality indicators of rolled steel is rationing of surface defects [1; 2; 3; 6; 7]. Current status of the issue. Analyzing the different requirements of regulations to the surface quality of the rolled high-carbon steels, we can conclude that the maximum allowable depth of defects on the surface of billet should be in the range of 2.0...5.0 mm (depending on the section of the billet, method of its production and further the destination Purpose. Develop a methodology for calculating the maximum allowable depth of defects on the steel billet surface depending on the requirements placed on the surface quality of hot-rolled steel. Results. A simplified method of calculation, allowing at the rated depth of defects on the surface of the hot-rolled steel to make operatively calculation of the maximum allowable depth of surface defects of steel billets before heating the metal in the heat deformation was developed. The findings shows that the maximum allowable depth of surface defects is reduced with increasing diameter rolled steel, reducing the initial section steel billet and degrees of oxidation of the metal in the heating furnace.

  1. Effects of alloying elements on sticking occurring during hot rolling of ferritic stainless steels

    International Nuclear Information System (INIS)

    Ha, Dae Jin; Kim, Yong Jin; Lee, Yong Deuk; Lee, Sung Hak; Lee, Jong Seog

    2008-01-01

    In this study, effects of alloying elements on the sticking occurring during hot rolling of five kinds of ferritic STS430J1L stainless steels were investigated by analyzing high-temperature hardness and oxidation behavior of the rolled steels. Hot-rolling simulation tests were conducted by a high-temperature wear tester which could simulate actual hot rolling. The simulation test results revealed that the sticking process proceeded with three stages, i.e., nucleation, growth, and saturation. Since the hardness continuously decreased as the test temperature increased, whereas the formation of Fe-Cr oxides in the rolled steel surface region increased, the sticking of five stainless steels was evaluated by considering both the high-temperature hardness and oxidation effects. The addition of Zr, Cu, or Si had a beneficial effect on the sticking resistance, while the Ni addition did not show any difference in the sticking. Particularly in the case of the Si addition, Si oxides formed first in the initial stage of high-temperature oxidation, worked as initiation sites for Fe-Cr oxides, accelerated the formation of Fe-Cr oxides, and thus raised the sticking resistance by about 10 times in comparison with the steel without Si content

  2. Microstructural evolution in warm-rolled and cold-rolled strip cast 6.5 wt% Si steel thin sheets and its influence on magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xianglong, E-mail: 215454278@qq.com; Liu, Zhenyu, E-mail: zyliu@mail.neu.edu.cn; Li, Haoze; Wang, Guodong

    2017-07-01

    Highlights: • The experimental materials used in the study are based on strip casting. • Magnetic properties between warm rolled and cold rolled sheets are investigated. • Cold rolled 6.5% Si sheet has better magnetic properties than warm rolled sheet. • The γ and λ-fiber recrystallization textures can be optimized after cold rolling. • Cold rolling should be more suitable for fabricating 6.5% Si steel thin sheets. - Abstract: 6.5 wt% Si steel thin sheets were usually fabricated by warm rolling. In our previous work, 6.5 wt% Si steel thin sheets with good magnetic properties had been successfully fabricated by cold rolling based on strip casting. In the present work, the main purposes were to find out the influences of warm rolling and cold rolling on microstructures and magnetic properties of the thin sheets with the thickness of 0.2 mm, and to confirm which rolling method was more suitable for fabricating 6.5 wt% Si steel thin sheets. The results showed that the cold rolled sheet could obtain good surface quality and flatness, while the warm rolled sheet could not. The intensity of γ-fiber rolling texture (<1 1 1>//ND) of cold rolled specimen was weaker than that of the warm rolled specimen, especially for the {1 1 1}<1 1 2> component at surface layer and {1 1 1}<1 1 0> component at center layer. After the same annealing treatment, the cold rolled specimen, which had higher stored energy and weaker intensity of γ-fiber rolling texture, could obtain smaller recrystallization grain size, weaker intensity of γ-fiber recrystallization texture and stronger intensity of λ-fiber recrystallization texture. Therefore, due to the good surface quality, smaller recrystallization grain size and optimum recrystallization texture, the cold rolled specimen possessed improved magnetic properties, and cold rolling should be more suitable for fabricating 6.5 wt% Si steel thin sheets.

  3. Evolution of Oxide Inclusions in Si-Mn Killed Steels During Hot-Rolling Process

    Science.gov (United States)

    Yang, Wen; Guo, Changbo; Zhang, Lifeng; Ling, Haitao; Li, Chao

    2017-10-01

    The evolution of oxide inclusions in Si-Mn killed steels refined by slags of different basicity during a four-pass industrial hot-rolling process was investigated using an automated microscopy system. High-basicity refining slag induced the formation of CaO- and Al2O3-containing inclusions, while refining slag with 0.8 basicity induced dominant inclusions of SiO2 and MnO-SiO2. CaO-SiO2-Al2O3 inclusions mainly formed endogenously during solidification and cooling of Ca-containing steels, where Ca originated from slag-steel reactions. However, the larger-sized higher-CaO inclusions originated from slag entrainment. Different inclusions presented different hot-rolling behaviors. The inclusion composition changed by deformation and new phase formation. The dominant oxide types were unchanged under refinement by low-basicity slag; however, they changed under refinement with high-basicity slag. The deformation index of inclusions decreased with increasing accumulated reduction (AR) of the steel. The difference in deformation index between different inclusion types was the largest in the first rolling stage and decreased in subsequent stages. SiO2-CaO and SiO2-MnO-CaO inclusions had larger deformation indices during hot rolling but smaller indices in the last two stages. High-basicity slag increased inclusion complexity; from the perspective of cold-drawing performance, low-basicity refining slag is better for the industrial production of tire-cord steels.

  4. Closure behavior of spherical void in slab during hot rolling process

    Science.gov (United States)

    Cheng, Rong; Zhang, Jiongming; Wang, Bo

    2018-04-01

    The mechanical properties of steels are heavily deteriorated by voids. The influence of voids on the product quality should be eliminated through rolling processes. The study on the void closure during hot rolling processes is necessary. In present work, the closure behavior of voids at the center of a slab at 800 °C during hot rolling processes has been simulated with a 3D finite element model. The shape of the void and the plastic strain distribution of the slab are obtained by this model. The void decreases along the slab thickness direction and spreads along the rolling direction but hardly changes along the strip width direction. The relationship between closure behavior of voids and the plastic strain at the center of the slab is analyzed. The effects of rolling reduction, slab thickness and roller diameter on the closure behavior of voids are discussed. The larger reduction, thinner slab and larger roller diameter all improve the closure of voids during hot rolling processes. Experimental results of the closure behavior of a void in the slab during hot rolling process mostly agree with the simulation results..

  5. Adaptive neural network controller for the molten steel level control of strip casting processes

    International Nuclear Information System (INIS)

    Chen, Hung Yi; Huang, Shiuh Jer

    2010-01-01

    The twin-roll strip casting process is a steel-strip production method which combines continuous casting and hot rolling processes. The production line from molten liquid steel to the final steel-strip is shortened and the production cost is reduced significantly as compared to conventional continuous casting. The quality of strip casting process depends on many process parameters, such as molten steel level in the pool, solidification position, and roll gap. Their relationships are complex and the strip casting process has the properties of nonlinear uncertainty and time-varying characteristics. It is difficult to establish an accurate process model for designing a model-based controller to monitor the strip quality. In this paper, a model-free adaptive neural network controller is developed to overcome this problem. The proposed control strategy is based on a neural network structure combined with a sliding-mode control scheme. An adaptive rule is employed to on-line adjust the weights of radial basis functions by using the reaching condition of a specified sliding surface. This surface has the on-line learning ability to respond to the system's nonlinear and time-varying behaviors. Since this model-free controller has a simple control structure and small number of control parameters, it is easy to implement. Simulation results, based on a semi experimental system dynamic model and parameters, are executed to show the control performance of the proposed intelligent controller. In addition, the control performance is compared with that of a traditional Pid controller

  6. Annealing effects on the microstructure and mechanical properties of hot-rolled 14Cr-ODS steel

    Science.gov (United States)

    Gao, R.; Zhang, T.; Ding, H. L.; Jiang, Y.; Wang, X. P.; Fang, Q. F.; Liu, C. S.

    2015-10-01

    The oxide dispersion strengthened ferritic steels with nominal composition (weight percent) of Fe-14Cr-2W-0.5Ti-0.06Si-0.2V-0.1Mn-0.05Ta-0.03C-0.3Y2O3 were fabricated by sol-gel method, mechanical alloying, and hot isostatic pressing techniques. The evolution of microstructure and mechanical properties of the hot-rolled specimens with heat treatment was investigated. Tensile strength and hardness of hot-rolled ODS steel are significantly enhanced due to the formation of mechanical twins and high density dislocations. Uniformly dispersed oxide particles (10-40 nm) and fine-grained structure (200-400 nm) are responsible for the superior mechanical properties of the hot-rolled specimen annealed between 650 °C and 850 °C. With further increasing annealing temperature, the grain size of the hot-rolled specimens increases while the size of oxide particles decreases, which leads to lower strength and hardness but better ductility. The tensile strength and total elongation of samples in the rolling direction are higher than those in the transverse direction after the same treatments owing to the grain anisotropy induced by the large mechanical deformation.

  7. Rolling force prediction for strip casting using theoretical model and artificial intelligence

    Institute of Scientific and Technical Information of China (English)

    CAO Guang-ming; LI Cheng-gang; ZHOU Guo-ping; LIU Zhen-yu; WU Di; WANG Guo-dong; LIU Xiang-hua

    2010-01-01

    Rolling force for strip casting of 1Cr17 ferritic stainless steel was predicted using theoretical model and artificial intelligence.Solution zone was classified into two parts by kiss point position during casting strip.Navier-Stokes equation in fluid mechanics and stream function were introduced to analyze the rheological property of liquid zone and mushy zone,and deduce the analytic equation of unit compression stress distribution.The traditional hot rolling model was still used in the solid zone.Neural networks based on feedforward training algorithm in Bayesian regularization were introduced to build model for kiss point position.The results show that calculation accuracy for verification data of 94.67% is in the range of+7.0%,which indicates that the predicting accuracy of this model is very high.

  8. Microstructure and texture evolution of ultra-thin grain-oriented silicon steel sheet fabricated using strip casting and three-stage cold rolling method

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hong-Yu; Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn; Wang, Yin-Ping; Wang, Guo-Dong

    2017-03-15

    A 0.1 mm-thick grain-oriented silicon steel sheet was successfully produced using strip casting and three-stage cold rolling method. The microstructure, texture and inhibitor evolution during the processing was briefly analyzed. It was found that Goss texture was absent in the hot rolled sheet because of the lack of shear deformation. After normalizing, a large number of dispersed MnS precipitates with the size range of 15–90 nm were produced. During first cold rolling, dense shear bands were generated in the deformed ferrite grains, resulting in the intense Goss texture after first intermediate annealing. The microstructure was further refined and homogenized during the subsequent cold rolling and annealing processes. After primary recrystallization annealing, a homogeneous microstructure consisting of fine and equiaxed grains was produced while the associated texture was characterized by a strong γ-fiber texture. Finally, a complete secondary recrystallization microstructure consisting of entirely large Goss grains was produced. The magnetic induction B{sub 8} and iron loss P{sub 10/400} was 1.79 T and 6.9 W/kg, respectively. - Highlights: • Ultra-thin grain-oriented silicon steel was produced by strip casting process. • Microstructure, texture and inhibitor evolution was briefly investigated. • Goss texture was absent in primary recrystallization annealed sheet. • MnS precipitates with a size range of 15–90 nm formed after normalizing. • A complete secondary recrystallization microstructure was produced.

  9. Texture and magnetic properties of non-oriented electrical steels processed by an unconventional cold rolling scheme

    Energy Technology Data Exchange (ETDEWEB)

    He, Youliang, E-mail: youliang.he@canada.ca [CanmetMATERIALS, Natural Resources Canada, Hamilton, ON (Canada); Hilinski, Erik J. [Formerly Research and Technology Centre, United States Steel Corporation, Munhall, PA (United States); Now Tempel Steel Co., Chicago, IL (United States)

    2016-05-01

    Two non-oriented electrical steels containing 0.9 wt% and 2.8 wt% of silicon were processed using an unconventional cold rolling scheme, i.e. the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) so that the initial texture before cold rolling and the rotation paths of crystals during cold deformation were both altered as compared to conventional cold rolling along the original HRD. The cold-rolled steel strips were then annealed, skin-pass rolled and final annealed. The texture and microstructure of the materials were characterized by X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and optical microscopy, and considerable differences in average grain size and texture were observed at different inclination angles. The magnetic properties of the steel strips were measured at 400 Hz and 1.0 T/1.5 T using a specially designed Epstein frame, and apparent differences were also noticed at various angles. The magnetic quality of texture was evaluated using different texture factors/parameters and compared to the measured magnetic properties. Although apparent improvement on the magnetic quality of texture can be noted by inclining the CRD to HRD, the trend does not match the measured magnetic properties at 400 Hz, which may have been affected by other parameters in addition to crystallographic texture. - Highlights: • The cold rolling direction is inclined an angle to the hot rolling direction. • The deformation and annealing textures are both changed by the inclined rolling. • Magnetic quality of texture is improved at specific inclination angles. • Low silicon steel is more sensitive in texture change than high silicon steel. • High frequency core loss does not follow the computed magnetic quality of texture.

  10. Rietveld and impedance analysis of cold and hot rolled duplex and lean duplex steels for application in paper and pulp industry

    Energy Technology Data Exchange (ETDEWEB)

    Esteves, Luiza; Lins, Vanessa de Freitas Cunha, E-mail: luizaeq@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Quimica; Paiva, Paulo Renato Perdigao [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET), Belo Horizonte, MG (Brazil); Viana, Adolfo Kalergis do Nascimento [APERAM South America, Timoteo, MG (Brazil)

    2017-01-15

    In this study, X-Ray Diffraction (XRD) and Rietveld Refinement were performed to identify and quantify the ferrite and austenite phase of cold and hot rolled duplex stainless steels (UNS S31803) and lean duplex stainless steels (UNS S32304). Electrochemical impedance spectroscopy (EIS) was applied to evaluate the chemical behavior of duplex and lean duplex stainless steels in white, green, and black liquors of paper and pulp industry. Rietveld analysis results showed a higher austenite content than the standard limit for duplex steels in the hot rolled condition. The hot rolling condition plays a major role in improving corrosion resistance in white liquor mainly for the lean duplex steel. (author)

  11. Rietveld and impedance analysis of cold and hot rolled duplex and lean duplex steels for application in paper and pulp industry

    International Nuclear Information System (INIS)

    Esteves, Luiza; Lins, Vanessa de Freitas Cunha; Viana, Adolfo Kalergis do Nascimento

    2017-01-01

    In this study, X-Ray Diffraction (XRD) and Rietveld Refinement were performed to identify and quantify the ferrite and austenite phase of cold and hot rolled duplex stainless steels (UNS S31803) and lean duplex stainless steels (UNS S32304). Electrochemical impedance spectroscopy (EIS) was applied to evaluate the chemical behavior of duplex and lean duplex stainless steels in white, green, and black liquors of paper and pulp industry. Rietveld analysis results showed a higher austenite content than the standard limit for duplex steels in the hot rolled condition. The hot rolling condition plays a major role in improving corrosion resistance in white liquor mainly for the lean duplex steel. (author)

  12. Effects by the microstructure after hot and cold rolling on the texture and grain size after final annealing of ferritic non-oriented FeSi electrical steel

    Science.gov (United States)

    Schneider, J.; Stöcker, A.; Franke, A.; Kawalla, R.

    2018-04-01

    The magnetic properties of fully processed non-oriented FeSi electrical steel are characterized by their magnetization behavior and specific magnetic losses. The magnetic properties are determined by the texture and microstructure. Less gamma fiber intensity and a high intensity of preferable texture components, especially cube fiber texture, are desirable to obtain an excellent magnetizing behavior. Furthermore, large grain sizes are necessary to reach low values of the specific magnetic losses. The fabrication route of the fully processed non-oriented electrical steels comprises a heavy cold rolling of the hot rolled material before final annealing. To fulfill the requirements on large grain size for low loss materials, grain growth, which appears after complete recrystallization, plays an important role. In this paper we will analyze the influence of different microstructures of the hot strip and the resulting microstructure after cold rolling on the appearance of recrystallization and grain growth after final annealing. The evolution of texture reflects the present ongoing softening processes: recovery, recrystallization and finally grain growth at the given annealing conditions. It will be shown that the image of texture at recrystallization is remarkable different from the texture at grain growth. Substantially grain growth is obtained at lower annealing temperatures for an optimum microstructure of the hot rolled material.

  13. Effects by the microstructure after hot and cold rolling on the texture and grain size after final annealing of ferritic non-oriented FeSi electrical steel

    Directory of Open Access Journals (Sweden)

    J. Schneider

    2018-04-01

    Full Text Available The magnetic properties of fully processed non-oriented FeSi electrical steel are characterized by their magnetization behavior and specific magnetic losses. The magnetic properties are determined by the texture and microstructure. Less gamma fiber intensity and a high intensity of preferable texture components, especially cube fiber texture, are desirable to obtain an excellent magnetizing behavior. Furthermore, large grain sizes are necessary to reach low values of the specific magnetic losses. The fabrication route of the fully processed non-oriented electrical steels comprises a heavy cold rolling of the hot rolled material before final annealing. To fulfill the requirements on large grain size for low loss materials, grain growth, which appears after complete recrystallization, plays an important role. In this paper we will analyze the influence of different microstructures of the hot strip and the resulting microstructure after cold rolling on the appearance of recrystallization and grain growth after final annealing. The evolution of texture reflects the present ongoing softening processes: recovery, recrystallization and finally grain growth at the given annealing conditions. It will be shown that the image of texture at recrystallization is remarkable different from the texture at grain growth. Substantially grain growth is obtained at lower annealing temperatures for an optimum microstructure of the hot rolled material.

  14. Annealing effects on the microstructure and mechanical properties of hot-rolled 14Cr-ODS steel

    International Nuclear Information System (INIS)

    Gao, R.; Zhang, T.; Ding, H.L.; Jiang, Y.; Wang, X.P.; Fang, Q.F.; Liu, C.S.

    2015-01-01

    The oxide dispersion strengthened ferritic steels with nominal composition (weight percent) of Fe–14Cr–2W-0.5Ti-0.06Si-0.2V-0.1Mn-0.05Ta-0.03C-0.3Y_2O_3 were fabricated by sol–gel method, mechanical alloying, and hot isostatic pressing techniques. The evolution of microstructure and mechanical properties of the hot-rolled specimens with heat treatment was investigated. Tensile strength and hardness of hot-rolled ODS steel are significantly enhanced due to the formation of mechanical twins and high density dislocations. Uniformly dispersed oxide particles (10–40 nm) and fine-grained structure (200–400 nm) are responsible for the superior mechanical properties of the hot-rolled specimen annealed between 650 °C and 850 °C. With further increasing annealing temperature, the grain size of the hot-rolled specimens increases while the size of oxide particles decreases, which leads to lower strength and hardness but better ductility. The tensile strength and total elongation of samples in the rolling direction are higher than those in the transverse direction after the same treatments owing to the grain anisotropy induced by the large mechanical deformation.

  15. Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

    International Nuclear Information System (INIS)

    Raab, A. E.; Berger, E.; Freudenthaler, J.; Leomann, F.; Walch, C.

    2011-01-01

    Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesive and abrasive tool wear.First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test.All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.

  16. Tribology and Tool Wear of Hot Dip Galvanized Zinc Magnesium Alloys on Cold Rolled Steel Sheets

    Science.gov (United States)

    Raab, A. E.; Berger, E.; Freudenthaler, J.; Leomann, F.; Walch, C.

    2011-05-01

    Recently zinc based coatings on cold rolled steel with improved functionality in terms of forming and/or corrosion behaviour have been intensively investigated in the steel industry1,2,3. One of the most promising products are zinc magnesium alloys produced in hot dip galvanizing process. These coatings were already introduced in construction industry a few years ago1. With some modifications the improved properties of the coating are also interesting for automotive industry. In the present work the tribological potential of hot dip galvanized zinc magnesium coatings (HDG/ZM) produced at an industrial line under regular production, was studied in terms of sliding properties, adhesive and abrasive tool wear. First a short introduction into surface morphology of HDG/ZM will be given. For the tribological characterization of the material, which is the main topic of the contribution, different tests were performed on hot dip galvanised zinc magnesium material and results were compared with classic hot dip galvanized zinc coating (HDG/Z). The investigations are mainly based on the strip draw test which allows the determination of the friction coefficient directly by using a constant contact pressure. Deep drawing property was tested by forming model cups. The abrasive tool wear was tested using a standard test for material used in automotive industry. The adhesive tool wear was investigated by characterizing the coating material transferred to the tool in the strip draw test. All performed tests show an improved drawability of HDG/ZM compared to classical HDG/Z reference material. However the most promising difference between HDG/ZM and HDG/Z is that galling was found to be less for HDG/ZM than for HDG/Z. Therefore HDG/ZM is an interesting system not only with respect to corrosion protection but also in terms of tribology and provides clear advantages in formability.

  17. Promoting Ti{sub 4}C{sub 2}S{sub 2} strain induced precipitation during asymmetrical hot rolling to improve r value and advantaged texture in Ti stabilized IF steel

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Futao, E-mail: dongft@sina.com [College of Metallurgy and Energy, Hebei United University, Tangshan 063000 (China); Xue, Fei [College of Electrical Engineering, Hebei United University, Tangshan 063000 (China); Du, Linxiu; Liu, Xianghua [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

    2015-01-25

    Highlights: • We study Ti{sub 4}C{sub 2}S{sub 2} strain induced precipitation in Ti stabilized IF steel. • The PTT diagram is obtained by plotting 1/A{sub r}–time curves. • Hot rolling at the nose of P{sub s} line effectively promotes Ti{sub 4}C{sub 2}S{sub 2} precipitation. • Annealed sheet with promoted Ti{sub 4}C{sub 2}S{sub 2} exhibits higher r value and stronger γ fiber texture. • Adverse impact of tiny TiC has been significantly mitigated. - Abstract: The kinetic of Ti{sub 4}C{sub 2}S{sub 2} strain induced precipitation in a Ti stabilized IF steel was investigated using two stage interrupted compression test with high true strain (0.5). The PTT (precipitation–time–temperature) diagram was obtained by plotting 1/A{sub r}–time curves. TEM (transmission electron microscopy) observation confirmed that the evolution of Ti{sub 4}C{sub 2}S{sub 2} precipitate in the quenched samples of thermal simulation is in good agreement with the PTT diagram. Hot strips were produced at three different rolling temperatures with high strain and slight shear deformation. It was found that hot rolling at the nose temperature of the P{sub s} line of the PTT diagram can effectively promote the precipitation of Ti{sub 4}C{sub 2}S{sub 2} and retard the precipitation of TiC. Cold rolled and annealed sheets from hot strip containing higher volume fraction of Ti{sub 4}C{sub 2}S{sub 2} exhibited higher r value and stronger γ fiber texture with equal {1 1 1}〈1 1 2〉 and {1 1 1}〈1 1 0〉 components. By contrast, cold rolled and annealed sheets from hot strips containing lower volume fraction of Ti{sub 4}C{sub 2}S{sub 2} represented lower r values and weaker γ fiber texture with significant drops from {1 1 1}〈1 1 2〉 to {1 1 1}〈1 1 0〉 component.

  18. AISI/DOE Advanced Process Control Program Vol. 3 of 6 Microstructure Engineering in Hot Strip Mills, Part 1 of 2: Integrated Mathematical Model

    Energy Technology Data Exchange (ETDEWEB)

    J.K. Brimacombe; I.V. Samarasekera; E.B. Hawbolt; T.R. Meadowcroft; M. Militzer; W.J. Pool; D.Q. Jin

    1999-07-31

    This report describes the work of developing an integrated model used to predict the thermal history, deformation, roll forces, microstructural evolution and mechanical properties of steel strip in a hot-strip mill. This achievement results from a joint research effort that is part of the American Iron and Steel Institute's (AIS) Advanced Process Control Program, a collaboration between the U.S. DOE and fifteen North American Steelmakers.

  19. Evolution of microstructure, texture and inhibitor along the processing route for grain-oriented electrical steels using strip casting

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Yao, Sheng-Jie [School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, 264209 (China); Sun, Yu; Gao, Fei; Song, Hong-Yu; Liu, Guo-Huai [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Li, Lei; Geng, Dian-Qiao [Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Liu, Zhen-Yu; Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China)

    2015-08-15

    In the present work, a regular grade GO sheet was produced successively by strip casting, hot rolling, normalizing annealing, two-stage cold rolling with intermediate annealing, primary recrystallization annealing, secondary recrystallization annealing and purification. The aim of this paper was to characterize the evolution of microstructure, texture and inhibitor along the new processing route by comprehensive utilization of optical microscopy, X-ray diffraction and transmission electron microscopy. It was found that a fine microstructure with the ferrite grain size range of 7–12 μm could be obtained in the primary recrystallization annealed sheet though a very coarse microstructure was produced in the initial as-cast strip. The main finding was that the “texture memory” effect on Goss texture started on the through-thickness intermediate annealed strip after first cold rolling, which was not similar to the “texture memory” effect on Goss texture starting on the surface layers of the hot rolled strip in the conventional production route. As a result, the origin of Goss nuclei capable of secondary recrystallization lied in the grains already presented in Goss orientation in the intermediate annealed strip after first cold rolling. Another finding was that fine and dispersive inhibitors (mainly AlN) were easy to be produced in the primary recrystallization microstructure due to the initial rapid solidification during strip casting and the subsequent rapid cooling, and the very high temperature reheating usually used before hot rolling in the conventional production route could be avoided. - Highlights: • A regular grade grain-oriented electrical steel was produced. • Evolution of microstructure, texture and inhibitor was characterized. • Origin of Goss nuclei lied in the intermediate annealed strip. • A fine primary recrystallization microstructure could be produced. • Effective inhibitors were easy to be obtained in the new processing route.

  20. Numerical cooling strategy design for hot rolled dual phase steel

    Energy Technology Data Exchange (ETDEWEB)

    Suwanpinij, Piyada; Prahl, Ulrich; Bleck, Wolfgang [RWTH Aachen (DE). Dept. of Ferrous Metallurgy (IEHK); Togobytska, Nataliya; Weiss, Wolf; Hoemberg, Dietmar [Weierstrass-Institut fuer Angewandte Analysis und Stochastik (WIAS) im Forschungsverbund Berlin e.V. (Germany)

    2010-10-21

    In this article, the Mo-Mn dual phase steel and its process parameters in hot rolling are discussed. The process window was derived by combining the experimental work in a hot deformation dilatometer and numerical calculation of process parameters using rate law models for ferrite and martensite transformation. The ferrite formation model is based on the Leblond and Devaux approach while martensite formation is based on the Koistinen- Marburger (K-M) formula. The carbon enrichment during ferrite formation is taken into account for the following martensite formation. After the completion of the parameter identification for the rate law model, the evolution of phases in multiphase steel can be addressed. Particularly, the simulations allow for predicting the preferable degree of retained strain and holding temperature on the run out table (ROT) for the required ferrite fraction. (orig.)

  1. Forming of High-strength Steels Using a Hot-melt Dry Lubricant

    DEFF Research Database (Denmark)

    Hörnström, Sven-Erik; Karlsson, Erik; Olsson, Mikael

    2008-01-01

    during forming resulting in seizure of the tool/steel sheet contact and extensive scratching of the steel sheet surface. As a result, a number of concepts have been developed in order to reduce the tendency to galling in metal forming, including the development of new dry lubricants, new forming tool...... steel grades and improved surface engineering treatments such as the deposition of low friction CVD and PVD coatings. In the present study the performance of a hot-melt dry lubricant in the forming of hot and cold rolled and hot-dip galvanized high strength steel has been evaluated and compared...... with a conventional rust protection oil using four different tests methods, i.e. a strip reduction test, a bending under tension test, a stretch-forming test and a pin-on disc test. In the tests, two different cold work tool steels, a conventional steel grade and a nitrogen alloyed PM steel grade were evaluated...

  2. Hot forging of roll-cast high aluminum content magnesium alloys

    Science.gov (United States)

    Kishi, Tomohiro; Watari, Hisaki; Suzuki, Mayumi; Haga, Toshio

    2017-10-01

    This paper reports on hot forging of high aluminum content magnesium alloy sheets manufactured using horizontal twin-roll casting. AZ111 and AZ131 were applied for twin-roll casting, and a hot-forging test was performed to manufacture high-strength magnesium alloy components economically. For twin-roll casting, the casting conditions of a thick sheet for hot forging were investigated. It was found that twin-roll casting of a 10mm-thick magnesium alloy sheet was possible at a roll speed of 2.5m/min. The grain size of the cast strip was 50 to 70µm. In the hot-forging test, blank material was obtained from as-cast strip. A servo press machine with a servo die cushion was used to investigate appropriate forging conditions (e.g., temperature, forging load, and back pressure) for twin-roll casts (TRCs) AZ111 and AZ131. It was determined that high aluminum content magnesium alloy sheets manufactured using twin-roll casting could be forged with a forging load of 150t and a back pressure of 3t at 420 to 430°C. Applying back pressure during hot forging effectively forged a pin-shaped product.

  3. Control of surface thermal scratch of strip in tandem cold rolling

    Science.gov (United States)

    Chen, Jinshan; Li, Changsheng

    2014-07-01

    The thermal scratch seriously affects the surface quality of the cold rolled stainless steel strip. Some researchers have carried out qualitative and theoretical studies in this field. However, there is currently a lack of research on effective forecast and control of thermal scratch defects in practical production, especially in tandem cold rolling. In order to establish precise mathematical model of oil film thickness in deformation zone, the lubrication in cold rolling process of SUS410L stainless steel strip is studied, and major factors affecting oil film thickness are also analyzed. According to the principle of statistics, mathematical model of critical oil film thickness in deformation zone for thermal scratch is built, with fitting and regression analytical method, and then based on temperature comparison method, the criterion for deciding thermal scratch defects is put forward. Storing and calling data through SQL Server 2010, a software on thermal scratch defects control is developed through Microsoft Visual Studio 2008 by MFC technique for stainless steel in tandem cold rolling, and then it is put into practical production. Statistics indicate that the hit rate of thermal scratch is as high as 92.38%, and the occurrence rate of thermal scratch is decreased by 89.13%. Owing to the application of the software, the rolling speed is increased by approximately 9.3%. The software developed provides an effective solution to the problem of thermal scratch defects in tandem cold rolling, and helps to promote products surface quality of stainless steel strips in practical production.

  4. Characterizing the stretch-flangeability of hot rolled multiphase steels

    International Nuclear Information System (INIS)

    Pathak, N.; Butcher, C.; Worswick, M.; Gao, J.

    2013-01-01

    Hole expansion tests are commonly used to characterize the edge stretching limit of a material. Traditionally, a conical punch is used to expand a punched hole until a through-thickness crack appears. However, many automotive stretch flanging operations involve in-plane edge stretching that is best captured with a flat punch. In this paper, hole expansion tests were carried out on two different hot-rolled multiphase steels using both flat and conical punches. The fracture mechanisms for both punch types were investigated using scanning electron microscopy (SEM)

  5. Development of high strength hot rolled low carbon copper-bearing steel containing nanometer sized carbides

    Energy Technology Data Exchange (ETDEWEB)

    Phaniraj, M.P. [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Shin, Young-Min [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Lee, Joonho [Department of Materials Science and Engineering, Korea University, Seoul 136-701 (Korea, Republic of); Goo, Nam Hoon [Sheet Product Design Group, Hyundai Steel Co., North Industrial Street 1400, 343-823, DangJin 343-823 (Korea, Republic of); Kim, Dong-Ik; Suh, Jin-Yoo; Jung, Woo-Sang [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Shim, Jae-Hyeok, E-mail: jhshim@kist.re.kr [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Choi, In-Suk, E-mail: insukchoi@kist.re.kr [High Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of)

    2015-05-01

    A low carbon ferritic steel was alloyed with Ti, Mo and Cu with the intention of achieving greater increment in strength by multiple precipitate strengthening. The steel is hot rolled and subjected to interrupted cooling to enable precipitation of Ti–Mo carbides and copper. Thermodynamic calculations were carried out to determine equilibrium phase fractions at different temperatures. Microstructure characterization using transmission electron microscopy and composition analysis revealed that the steel contains ~5 nm size precipitates of (Ti,Mo)C. Precipitation kinetics calculations using MatCalc software showed that mainly body centered cubic copper precipitates of size < 5nm form under the cooling conditions in the present study. The steel has the high tensile strength of 853 MPa and good ductility. The yield strength increases by 420 MPa, which is more than that achieved in hot rolled low carbon ferritic steels with only copper precipitates or only carbide precipitates. The precipitation and strengthening contribution of copper and (Ti,Mo)C precipitates and their effect on the work hardening behavior is discussed.

  6. Enhancement of strength properties of hot rolled 10KHSND steel

    International Nuclear Information System (INIS)

    Nasibov, A.G.; Popova, L.V.; Pikulin, S.A.; Globa, N.I.

    1989-01-01

    To find out the reasons of low hot rolling yield for 10KhSND steel sheets in mechanical properties, titanium effect in the range of 0.008-0.03% concentrations is studied. It is established that the titanium content in a solid solution is conserved within 0.003-0.005%, the rest of titanium is bound to carbonitrides Ti(C, N). It is shown that alloys with 0.025-0.03% titanium content possess the increased values of ultimate and yield strength the necessary level of impact strength and good wealdability. The good steel yield, when the titanium content is sustained at the given level, increases from 40 to 85%

  7. Spray rolling aluminum alloy strip

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kevin M.; Delplanque, J.-P.; Johnson, S.B.; Lavernia, E.J.; Zhou, Y.; Lin, Y

    2004-10-10

    Spray rolling combines spray forming with twin-roll casting to process metal flat products. It consists of atomizing molten metal with a high velocity inert gas, cooling the resultant droplets in flight and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets teams with conductive cooling at the rolls to rapidly remove the alloy's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly solidified product. While similar in some ways to twin-roll casting, spray rolling has the advantage of being able to process alloys with broad freezing ranges at high production rates. This paper describes the process and summarizes microstructure and tensile properties of spray-rolled 2124 and 7050 aluminum alloy strips. A Lagrangian/Eulerian poly-dispersed spray flight and deposition model is described that provides some insight into the development of the spray rolling process. This spray model follows droplets during flight toward the rolls, through impact and spreading, and includes oxide film formation and breakup when relevant.

  8. Effect of carbon content on microstructure and mechanical properties of hot-rolled low carbon 12Cr-Ni stainless steel

    International Nuclear Information System (INIS)

    Zheng, H.; Ye, X.N.; Li, J.D.; Jiang, L.Z.; Liu, Z.Y.; Wang, G.D.; Wang, B.S.

    2010-01-01

    Research highlights: → Hot-rolled ultra low carbon martensite is characterized by dislocation cells substructure. → The formation of dislocation cells is attributed to high Ms and low interstitial atoms content. → Hot-rolled ultra low carbon 12Cr-Ni stainless steel has excellent impact toughness. → Delta ferrite deteriorates the impact toughness of hot-rolled 12Cr-Ni stainless steel. - Abstract: 12Cr-Ni stainless steels containing different carbon contents from 0.004 wt.% to 0.034 wt.% were hot-rolled and air-cooled. Their corresponding microstructures were observed with optical microscope and transmission electron microscope, and the Vickers hardness, tensile and impact tests were also carried out. It was found that the martensitic morphology was significantly influenced by carbon content. The as-received ultra low carbon martensite in the steel containing 0.004 wt.% C is characterized by dislocation cells substructure. The formation of dislocation cells is attributed to high martensite finishing point (above 400 deg. C) and low interstitial atoms content. On the other hand, the martensite in the steel containing 0.034 wt.% C consists mainly of typical martensite laths because of low martensite finishing point and high interstitial atoms content which hinder dislocation motion. Furthermore, carbon content has an evident effect on the mechanical properties of 12Cr-Ni steels. The hardness and strength of the as-received steels increase with an increase in carbon content, but their elongation and impact toughness decrease with the carbon content. The steel containing 0.004 wt.% C has excellent impact toughness due to the ultra low carbon content in the martensite composed of dislocation cells.

  9. 78 FR 16252 - Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia, and Thailand: Final Results...

    Science.gov (United States)

    2013-03-14

    ... Indonesia P.T. Krakatau Steel 10.21 All Others 10.21 Thailand Sahaviriya Steel Industries Public Company...] Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia, and Thailand: Final Results of... products (``HR steel'') from India, Indonesia, and Thailand pursuant to section 751(c) of the Tariff Act of...

  10. Advanced cold rolled steels for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Harald; Mattissen, Dorothea; Schaumann, Thomas Wilhelm [ThyssenKrupp Steel AG, Center of Materials Excellence, Dortmund (Germany)

    2009-01-15

    Advanced high-strength steels offer a great potential for the further development of automobile bodies-in-white due to their combined mechanical properties of high formability and strength. They represent the first choice in material selection for strength and crash-relevant parts with challenging geometries. The intensive development of multiphase steels by ThyssenKrupp Steel has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex-phase steels are currently produced in addition to cold rolled dual phase (DP) and retained austenite (RA) or transformation induced plasticity (TRIP) steels. New continuously annealed grades of steel are being developed with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for the high demands of structural automobile components. These steels make use of the classic advantages of microalloying as well as the principles of DP steels and RA / TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. (orig.)

  11. Study of mechanism on microstructure refinement during compact strip production process

    International Nuclear Information System (INIS)

    Yu Hao; Kang Yonglin; Wang Kelu; Fu Jie; Wang Zhongbing; Liu Delu

    2003-01-01

    In this study, microstructures of 1.9 mm hot strip steel produced by compact strip production (CSP) are investigated by using optical metallograph observation and electron back-scattered diffraction (EBSD) data to deduce the status of hot rolled austenite before phase transformation, because the evolution of hot rolled austenite is important to provide information for the microstructure refinement. The experimental results show that the finishing hot rolled microstructure is a mixture of recrystallized and deformed austenite, and the percentage of recrystallized austenite is greater than that of the deformed austenite. At last, microstructure evolution of austenite is modeled based on chemical compositions and techniques of producing 1.9 mm hot strip. The simulation results agree well with experimental data. Analysis shows that microstructure refinement, recrystallization and supercooling rate are the primary causes to fine microstructure

  12. Fabrication and properties of strip casting 4.5 wt% Si steel thin sheet

    Energy Technology Data Exchange (ETDEWEB)

    Zu, Guoqing, E-mail: gz854@uowmail.edu.au [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Zhang, Xiaoming [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Zhao, Jingwei [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Wang, Yuqian [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Yan, Yi [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Li, Chengang; Cao, Guangming [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Jiang, Zhengyi [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia)

    2017-02-15

    Three 4.5 wt% Si steel thin sheets with different thicknesses were efficiently fabricated by twin-roll strip casting, warm rolling and cold rolling followed by final annealing. A comprehensive investigation from the workability of the as-cast strip to the magnetic property of the produces was performed to illustrate the superiority of the new materials. The results show that the as-cast strip, which has a much lower Vickers hardness than that of the 6.5 wt% Si steel, is suitable for rolling processing. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies confirm that no ordering phase exists in the as-cast strip. The cold-rolled thin sheets exhibit good surface quality without edge cracks. Furthermore, all the three 4.5 wt% Si steel thin sheets possess relative strong <100>//ND texture and present high magnetic inductions and low iron losses after finial annealing. - Highlights: • 4.5 wt% Si as-cast sheet with excellent workability was produced by strip casting. • Three 4.5 wt% Si thin sheets were effectively fabricated by warm and cold rolling. • The microstructure and macro-texture of the thin sheets were elucidated. • High magnetic inductions and low iron losses were achieved simultaneously.

  13. Microstructure, texture evolution and magnetic properties of strip-casting non-oriented 6.5 wt.% Si electrical steel doped with cerium

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze, E-mail: lhzqq83@163.com; Liu, Hai-Tao; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn; Wang, Guo-Dong

    2015-05-15

    A 0.3 mm thick non-oriented 6.5 wt.% Si electrical steel sheet doped with cerium is produced by twin-roll strip casting, hot rolling, warm rolling and annealing. A detailed study of the cerium precipitates in the as-cast strip, microstructure and texture evolution at different processing stages is carried out by electron probe micro-analysis, optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. Grain interior distributing precipitates identified as Ce-oxides, Ce-oxysulfides and Ce-phosphides, and boundary distributing Ce-oxides and Ce-phosphides are observed in the as-cast strip. The initial as-cast strip is characterized by a much finer solidification microstructure and dominated by obvious < 001 >//ND texture through the strip thickness. After hot and warm rolling, inhomogeneous microstructure containing large amounts of in-grain shear bands is characterized by mixed < 110 >//RD and < 111 >//ND textures. The texture of the annealed sheet with a relatively large average grain size is far more optimized by the domination of the beneficial cube, rotated cube, (001)< 120 > to (001)< 130 > and Goss texture components, and the elimination of the detrimental γ-fiber texture, leading to a superior magnetic induction and improved iron loss. - Highlights: • An Fe–6.5 wt.% Si as-cast strip doped with cerium was produced. • A thin warm rolled sheet with limited edge cracks was obtained. • Microstructure and texture evolution at each stage were investigated. • Strong λ-fiber and Goss recrystallization textures were formed. • The magnetic properties of the annealed sheet were significantly improved.

  14. THE METHOD OF ROLL SURFACE QUALITY MEASUREMENT FOR CONTINUOUS HOT DIP ZINC COATED STEEL SHEET PRODUCTION LINE

    Directory of Open Access Journals (Sweden)

    Ki Yong Choi

    2015-01-01

    Full Text Available The present paper describes a developed analyzing system of roll surface during the process of continuous hot dip zinc coated steel sheet production line, in particular, adhering problem by transferred inclusions from roll to steel sheet surface during annealing process so called the pickup. The simulated test machine for coated roll surface in processing line has been designed and performed. The system makes it possible to analyze roll surface condition according to pickup phenomena from various roll coatings concerning operating conditions of hearth rolls in annealing furnace. The algorithm of fast pickup detection on surface is developed on the base of processing of several optical images of surface. The parameters for quality estimation of surface with pickups were developed. The optical system for images registration and image processing electronics may be used in real time and embed in processing line.

  15. 78 FR 24435 - Hot-Rolled Steel Products From China, India, Indonesia, Taiwan, Thailand, and Ukraine

    Science.gov (United States)

    2013-04-25

    ... Ukraine Scheduling of full five-year reviews concerning the countervailing duty orders on hot-rolled steel... China, India, Indonesia, Taiwan, Thailand, and Ukraine. AGENCY: United States International Trade..., India, Indonesia, Taiwan, Thailand, and Ukraine would be likely to lead to continuation or recurrence of...

  16. ANALYSIS ON THE BEHAVIOR OF PRECIPITATES IN ULTRA-THIN HOT STRIP OF PLAIN LOW CARBON STEEL PRODUCED BY COMPACT STRIP PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    H. Yu; Y.L. Kang; H.B. Dong; D.L. Liu; J. Fu

    2002-01-01

    This paper investigated the mechanism of precipitation and its influence upon prop-erties of ultra-thin hot strips of low carbon steel produced by CSP techniques usingexperiment and thermodynamics theory. The experimental results show that thereare lots of fine and dispersive precipitates in microstructures. By analysis, most ofaluminum nitrides are in grains, while coexisted precipitates of MnS are along grainboundaries. Coexisted precipitates compose cation-vacancy type oxides such as Al2O3in the core, while MnS is at the fringe of surface. The precipitation behavior of AlNand MnS in the hot strip is studied by thermodynamic calculation. At last, implica-tions between strengthening effect and techniques are analyzed using obtained solubilityproducts.

  17. 76 FR 48143 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Preliminary...

    Science.gov (United States)

    2011-08-08

    ..., 75 FR 81565 (December 28, 2010). \\3\\ Certain Oil Country Tubular Goods from the People's Republic of..., from Steven Hampton, International Trade Analyst, ``Certain Hot-Rolled Carbon Steel Flat Products from...

  18. 76 FR 31938 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Preliminary Results of 2009...

    Science.gov (United States)

    2011-06-02

    ... the File from Christopher Hargett, International Trade Compliance Analyst, through Melissa Skinner... Skinner, Office Director, concerning ``Certain Hot-Rolled Carbon Steel Flat Products from India: Customs...

  19. 76 FR 42679 - Certain Hot-Rolled Carbon Steel Flat Products From India: Final Results of Antidumping Duty...

    Science.gov (United States)

    2011-07-19

    .... Steel''), Nucor Corporation (``Nucor''), and ArcelorMittal USA Inc. DATES: Effective Date: July 19, 2011..., 2011. We received briefs from U.S. Steel and Nucor and a rebuttal brief from Tata.\\5\\ On May 17, the... India, dated April 14, 2011; Letter from Nucor to the Department, regarding Certain Hot-Rolled Carbon...

  20. Effect of Hot Rolling on the Microstructure and Mechanical Properties of Nitrogen Alloyed Austenitic Stainless Steel

    Science.gov (United States)

    Chenna Krishna, S.; Karthick, N. K.; Jha, Abhay K.; Pant, Bhanu; Cherian, Roy M.

    2018-05-01

    In the present investigation, the effect of multi-pass hot rolling in the temperature range of 700-1000 °C on the microstructure and mechanical properties of nitrogen alloyed austenitic stainless steel was studied with the aid of optical microscopy, tensile testing and x-ray diffraction measurements. The microstructural changes that occurred in the hot rolled specimens were elongation of grains in rolling direction, nucleation of new grains at the grain boundaries of elongated grains and growth of nucleated grains to form fully recrystallized grains. Elongated grains formed at lower rolling temperature (700-800 °C) due to inadequate strain/temperature for the initiation of dynamic recrystallization. At higher rolling temperature (900-1000 °C), fine grains formed due to dynamic recrystallization. Tensile properties showed strong dependency on the rolling temperature. Tensile strength increased with the decrease in the rolling temperature at the cost of ductility. Maximum strength was observed in samples hot rolled at 700 °C with yield strength of 917 MPa and ductility of 25%. This variation in the tensile properties with the rolling temperature is attributed to changes in the dislocation density and grain structure. The estimated yield strength from the dislocation density, solid solution and grain boundary strengthening closely matched with experimentally determined yield strength confirming the role of dislocation density and grain size in the strengthening.

  1. Development of microstructure and texture in strip casting grain oriented silicon steel

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yang; Xu, Yun-Bo, E-mail: yunbo_xu@126.com; Zhang, Yuan-Xiang; Fang, Feng; Lu, Xiang; Liu, Hai-Tao; Wang, Guo-Dong

    2015-04-01

    Grain oriented silicon steel was produced by strip casting and two-stage cold rolling processes. The development of microstructure and texture was investigated by using optical microscopy, X-ray diffraction and electron backscattered diffraction. It is shown that the microstructure and texture evolutions of strip casting grain oriented silicon steel are significantly distinct from those in the conventional processing route. The as-cast strip is composed of coarse solidification grains and characterized by pronounced 〈001〉//ND texture together with very weak Goss texture. The initial coarse microstructure enhances {111} shear bands formation during the first cold rolling and then leads to the homogeneously distributed Goss grains through the thickness of intermediate annealed sheet. After the secondary cold rolling and primary annealing, strong γ fiber texture with a peak at {111}〈112〉 dominates the primary recrystallization texture, which is beneficial to the abnormal growth of Goss grain during the subsequent high temperature annealing. Therefore, the secondary recrystallization of Goss orientation evolves completely after the high temperature annealing and the grain oriented silicon steel with a good magnetic properties (B{sub 8}=1.94 T, P{sub 1.7/50}=1.3 W/kg) can be prepared. - Highlights: • Grain oriented silicon steel was developed by a novel ultra-short process. • Many evenly distributed Goss “seeds” were originated from cold rolled shear bands. • More MnS inhibitors were obtained due to the rapid cooling of strip casing. • The magnetic induction of grain oriented silicon steel was significantly improved.

  2. Fabrication of high permeability non-oriented electrical steels by increasing 〈0 0 1〉 recrystallization texture using compacted strip casting processes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, PO Box 105, Shenyang 110819 (China); Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Schneider, J. [Institut für Metallformung, Technische Universität Bergakademie Freiberg, Bernhard-von-Cotta-Str. 4, D-09596 Freiberg (Germany); Li, Hua-Long [Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Sun, Yu; Gao, Fei; Lu, Hui-Hu; Song, Hong-Yu [State Key Laboratory of Rolling and Automation, Northeastern University, PO Box 105, Shenyang 110819 (China); Li, Lei; Geng, Dian-Qiao [Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110819 (China); Liu, Zhen-Yu; Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, PO Box 105, Shenyang 110819 (China)

    2015-01-15

    In this paper we will report on the application of the twin-roll casting technique to get a 2 mm thick material of Fe-3.2%Si alloy, which was finally hot rolled, cold rolled and annealed. After a mild hot rolling to a thickness of 1 mm and a mild cold rolling to a thickness of 0.35 mm, we obtained a high intensity of λ-fiber (〈0 0 1〉|| ND) and η-fiber (〈0 0 1〉|| RD) texture concentrated on cube ({0 0 1}〈0 1 0〉) component and a diminishing intensity of the γ-fiber (〈1 1 1〉|| ND) texture, and a large average grain size in the final processed material. The experimental results for the evolution of the microstructure and texture along the used processing routes were described within the paper in detail. The formation mechanism for the desired recrystallization textures were explained in terms of oriented nucleation, micro-growth selection, accumulated deformation stored energy, geometric softening and orientation pinning. It will be demonstrated that this new processing route using the compact strip casting offers the possibility to fabricate high permeability non-oriented electrical steels without additional fabrication steps like hot band annealing or two step cold rolling with intermediate annealing as in the case of conventional processing route. - Highlights: • High permeability non-oriented electrical steel was fabricated by strip casting processes. • Hot band annealing or two step cold rolling with intermediate annealing was eliminated. • Prevailing of 〈0 0 1〉|| ND and 〈0 0 1〉|| RD textures over diminishing 〈1 1 1〉|| ND texture was realized. • Evolution of microstructure and texture along the used processing routes were described.

  3. Hot rolling of chromium - nickel - manganese stainless steel containing nitrogen and boron

    International Nuclear Information System (INIS)

    Khorosh, V.A.; Bulat, S.I.; Mukhina, M.A.; Sorokina, N.A.; Yushchenko, K.A.; Tsentral'nyj Nauchno-Issledovatel'skij Inst. Chernoj Metallurgii, Moscow; AN Ukrainskoj SSR, Kiev. Inst. Ehlektrosvarki)

    1976-01-01

    The strength of stainless steel of the 03Kh2ON16AG6 type increases perceptibly with an increase in the nitrogen content from 0.11 to 0.37%. At the same time, however, its ductility in the region of hot deformation temperatures (red brittleness range of 800 to 1,000 deg C) decreases. Microalloying with boron (0.002 to 0.005% by calculation) permits enhancing the hot ductility to an acceptable level without adversely affecting the working properties. The mechaniusm of boron effect is analyzed. The temperature at which ingots are heated prior to rolling to achieve the desired effect must be sufficiently low. Optimum condition for two stage heating of 6.2-ton ingots are recommeded

  4. 78 FR 64008 - Hot-Rolled Steel Products From China, India, Indonesia, Taiwan, Thailand, and Ukraine; Revised...

    Science.gov (United States)

    2013-10-25

    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-405, 406, and 408 and 731-TA-899-901 and 906-908 (Second Review)] Hot-Rolled Steel Products From China, India, Indonesia, Taiwan, Thailand, and Ukraine; Revised Schedule for the Subject Five Year Reviews AGENCY: United States International Trade...

  5. Microstructural research on hot strips of low carbon steel produced by a compact strip production line under different thermal histories

    International Nuclear Information System (INIS)

    Yu Hao; Chen Qixiang; Kang Yonglin; Sun Yi

    2005-01-01

    Coupons with the same composition and thickness (4.0 mm nominal gauge) obtained from hot strips of low carbon steel underwent a series of investigations to analyze the microstructural characteristics and mechanisms responsible for their differences in mechanical properties. Two different industrial technologies were adopted, although the strips used in this research were produced on the same Compact Strip Production (CSP) line. One of the strips was produced with a routine γ→α CSP thermal history, but the other with a γ→α→γ* conventional thermal history. The only difference between them was that one technology had a α→γ* thermal history. Different specimens of both types of strips were prepared for metallographic observation, tensile tests, electron back-scattered diffraction tests and positron annihilation technique tests. Experimental results showed that the differences in mechanical properties could be ascribed to dissimilarities not only in the grain size and textural components but also in dislocation density

  6. Investigation of Hot Rolling Influence on the Explosive-Welded Clad Plate

    Directory of Open Access Journals (Sweden)

    Guanghui ZHAO

    2016-11-01

    Full Text Available The microstructure, the shear strength and tensile strength of stainless steel explosive-welded clad plate at different rolling reduction were studied. The mechanical properties of the explosive-welded and explosive-rolled clad plates were experimentally measured. Simultaneously, the microstructures of the clad plate were investigated by the Ultra deep microscope and the tensile fracture surface were observed by the scan electron microscope (SEM. It was observed that the tensile strength has been increased considerably, whereas the elongation percentage has been reduced with the increase of hot rolling reduction. In the tensile shear test, the bond strength is higher than the strength of the ferritic stainless steel layer and meets the relevant known standard criterion. Microstructural evaluations showed that the grain of the stainless steel and steel refined with the increase of thickness reduction. Examination of the tensile fracture surfaces reveal that, after hot rolling, the fracture in the low alloy steel and ferritic stainless steel clad plates is of the ductile type.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12409

  7. Development of dissimilar metal transition joint by hot bond rolling

    International Nuclear Information System (INIS)

    Kurokawa, Hiroyuki; Nakasuji, Kazuyuki; Kajimura, Haruhiko; Nagai, Takayuki; Takeda, Seiichiro.

    1997-01-01

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) to stainless steel piping are required for nuclear fuel reprocessing plants. The authors have developed dissimilar transition joints made of stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot bond rolling process of clad bars and clad pipes, using a newly developed mill called 'rotary reduction mill'. This report presents the manufacturing process of dissimilar transition joints produced from the clad pipe with three layers by the hot bond rolling. First, the method of hot bond rolling of clad pipe is proposed. Then, the mechanical and corrosion properties of the dissimilar transition joints are evaluated in detail by carrying out various tests. Finally, the rolling properties in the clad pipe method are discussed. (author)

  8. Evaluation of factors affecting the edge formability of two hot rolled multiphase steels

    Science.gov (United States)

    Mukherjee, Monideepa; Tiwari, Sumit; Bhattacharya, Basudev

    2018-02-01

    In this study, the effect of various factors on the hole expansion ratio and hence on the edge formability of two hot rolled multiphase steels, one with a ferrite-martensite microstructure and the other with a ferrite-bainite microstructure, was investigated through systematic microstructural and mechanical characterization. The study revealed that the microstructure of the steels, which determines their strain hardening capacity and fracture resistance, is the principal factor controlling edge formability. The influence of other factors such as tensile strength, ductility, anisotropy, and thickness, though present, are secondary. A critical evaluation of the available empirical models for hole expansion ratio prediction is also presented.

  9. Development and industrial mastering hot rolling procedure for low-ductile steels and alloys

    International Nuclear Information System (INIS)

    Degterenko, V.K.; Sokolov, V.A.

    1980-01-01

    The technique for the development of the sheet hot rolling procedure for low-ductile steels and alloys (0Kh17N14M2, 12Kh21N5T, 20Kh25N20C2,40Kh13, 36NKhTYu etc.) is proposed, using plastometer which permits to obtain the data on the deformation resistance in the wide range of temperatures (800-1300 deg C), of deformation degrees (0.1-0.3) and deformation rates (0.001-300 c -1 ). With the help of the plastometric data processed on the computer the calculation of the rolling regimes for the sheet with improved surface quality is carried out at the more uniform loading on the mill stands

  10. Microstructure and Mechanical Properties of Fe-18Mn-18Cr-0.5N Austenitic Nonmagnetic Stainless Steel in Asymmetric Hot Rolling

    Science.gov (United States)

    Song, Y. L.; Li, C. S.; Ma, B.; Han, Y. H.

    2017-05-01

    Asymmetric hot rolling (ASHR) with a mismatch speed ratio of 1.15 in a single pass was applied to Fe-18Mn-18Cr-0.5N steel and was compared with symmetric hot rolling (SHR). The results indicated that a through-thickness microstructure gradient was formed in the plate due to the shear strain (0.36) introduced by ASHR. A fine-grained layer with the average size of 3 μm was achieved at the top surface of ASHR plate, while numerous elongated grains with a few recrystallized grains were presented at the center layer. The texture was distributed randomly at the top surface of ASHR plate, and a weaker intensity of typical hot-rolled texture in austenitic steel was obtained at the center layer of ASHR plate compared to SHR plate. An excellent combination of microhardness, strength and ductility was obtained in the ASHR plate, which was attributed to gradient microstructure induced by ASHR.

  11. Mechanical properties and hot-rolled microstructures of a low carbon bainitic steel with Cu-P alloying

    International Nuclear Information System (INIS)

    Cui, W.F.; Zhang, S.X.; Jiang, Y.; Dong, J.; Liu, C.M.

    2011-01-01

    Highlights: → Mechanical properties and microstructures of low carbon bainite steel are examined. → Cu-P alloying promotes strengthening and uniform plastic deformation. → Cu-P alloying delays recovery process during rolling interval. → Lowering rolling temperature is favorable to increasing toughness. - Abstract: A low carbon bainitic steel with Cu-P alloying was developed. The new steel aims to meet the demand of high strength, high toughness and resistance to chloride ion corrosion for the components used in the environment of sea water and oceanic atmosphere. Mechanical properties of the steel were tested and strengthening and toughening mechanisms were analyzed by comparing hot-rolled microstructures of the low carbon bainitic steels with and without Cu-P alloying. The results show that Cu-P alloying provided strong solution strengthening with weak effect on ductility. The toughness loss caused by Cu-P alloying could be balanced by increasing the amount of martensite/remained austenite (M/A island) at lower finishing temperature. The static recovery process during rolling interval was delayed by the interaction of phosphorous, copper atoms with dislocations, which was favorable to the formation of bainitic plates. Super-fine Nb(C, N) particles precipitated on dislocations had coherency with bainite ferrite at 830 deg. C finishing temperature. Raising finishing temperature to 880 deg. C, Nb(C, N) particles were prone to coarsening and losing coherency. It was also found that no accurate lattice match relationship among retained austenite, martensite and bainite in granular bainitic microstructure.

  12. Mechanical properties and hot-rolled microstructures of a low carbon bainitic steel with Cu-P alloying

    Energy Technology Data Exchange (ETDEWEB)

    Cui, W.F., E-mail: wenfangcui@yahoo.com.cn [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China); Zhang, S.X. [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China); Technology Center of Laiwu Iron and Steel (Group) Co. Ltd., Laiwu 271104 (China); Jiang, Y. [School of Chemical Engineering, University of Queensland, Brisbane 4072 (Australia); Dong, J. [Technology Center of Laiwu Iron and Steel (Group) Co. Ltd., Laiwu 271104 (China); Liu, C.M. [Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110004 (China)

    2011-08-15

    Highlights: {yields} Mechanical properties and microstructures of low carbon bainite steel are examined. {yields} Cu-P alloying promotes strengthening and uniform plastic deformation. {yields} Cu-P alloying delays recovery process during rolling interval. {yields} Lowering rolling temperature is favorable to increasing toughness. - Abstract: A low carbon bainitic steel with Cu-P alloying was developed. The new steel aims to meet the demand of high strength, high toughness and resistance to chloride ion corrosion for the components used in the environment of sea water and oceanic atmosphere. Mechanical properties of the steel were tested and strengthening and toughening mechanisms were analyzed by comparing hot-rolled microstructures of the low carbon bainitic steels with and without Cu-P alloying. The results show that Cu-P alloying provided strong solution strengthening with weak effect on ductility. The toughness loss caused by Cu-P alloying could be balanced by increasing the amount of martensite/remained austenite (M/A island) at lower finishing temperature. The static recovery process during rolling interval was delayed by the interaction of phosphorous, copper atoms with dislocations, which was favorable to the formation of bainitic plates. Super-fine Nb(C, N) particles precipitated on dislocations had coherency with bainite ferrite at 830 deg. C finishing temperature. Raising finishing temperature to 880 deg. C, Nb(C, N) particles were prone to coarsening and losing coherency. It was also found that no accurate lattice match relationship among retained austenite, martensite and bainite in granular bainitic microstructure.

  13. Solutions for Safe Hot Coil Evacuation and Coil Handling in Case of Thick and High Strength Steel

    Directory of Open Access Journals (Sweden)

    Sieberer Stefan

    2016-01-01

    Full Text Available Currently hot rolling plants are entering the market segment for thick gauges and high strength steel grades where the elastic bending property of the strip leads to internal forces in the coil during coiling operation. The strip tends to open. Primetals is investigating several possibilities to facilitate safe coil evacuation and coil handling under spring-back conditions. The contribution includes finite element models of such mechanical solutions. Results of parameter variation and stability limits of case studies are presented in the paper.

  14. Microstructural characterization and formation mechanism of abnormal segregation band of hot rolled ferrite/pearlite steel

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Rui [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Engineering Research Center of Large Size Alloy Structural Steel Bars of Shandong Province, Jinan 250061 (China); School of Materials Science and Engineering, Shandong University of Technology, Zibo 255049 (China); Li, Shengli, E-mail: lishengli@sdu.edu.cn [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Engineering Research Center of Large Size Alloy Structural Steel Bars of Shandong Province, Jinan 250061 (China); Zhu, Xinde [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Ao, Qing [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China); Engineering Research Center of Large Size Alloy Structural Steel Bars of Shandong Province, Jinan 250061 (China)

    2015-10-15

    In order to further reveal the microstructural characterization and formation mechanism of abnormal segregation band of hot rolled ferrite/pearlite steel, the microstructure of this type steel was intensively studied with Scanning Auger Microprobe (SAM), etc. The results show that severe C–Mn segregation exists in the abnormal segregation band region at the center of hot rolled ferrite/pearlite steel, which results from the Mn segregation during solidification process of the continuous casting slab. The C–Mn segregation causes relative displacement of pearlite transformation curve and bainite transformation curve of C curve in the corresponding region, leading to bay-like shaped C curve. The bay-like shaped C curve creates conditions for the transformation from supercooling austenite to bainite at relatively lower cooling rate in this region. The Fe–Mn–C Atomic Segregation Zone (FASZ) caused by C–Mn segregation can powerfully retard the atomic motion, and increase the lattice reconstruction resistance of austenite transformation. These two factors provide thermodynamic and kinetic conditions for the bainite transformation, and result in the emergence of granular bainitic abnormal segregation band at the center of steel plate, which leads to lower plasticity and toughness of this region, and induces the layered fracture. - Highlights: • Scanning Auger Microprobe (SAM) is applied in the fracture analysis. • The abnormal segregation band region appears obvious C–Mn segregation. • The C–Mn segregation leads to bay-like shaped C curve. • The C–Mn segregation leads to Fe–Mn–C Atomic Segregation Zone.

  15. Hot rolling and annealing effects on the microstructure and mechanical properties of ODS austenitic steel fabricated by electron beam selective melting

    Science.gov (United States)

    Gao, Rui; Ge, Wen-jun; Miao, Shu; Zhang, Tao; Wang, Xian-ping; Fang, Qian-feng

    2016-03-01

    The grain morphology, nano-oxide particles and mechanical properties of oxide dispersion strengthened (ODS)-316L austenitic steel synthesized by electron beam selective melting (EBSM) technique with different post-working processes, were explored in this study. The ODS-316L austenitic steel with superfine nano-sized oxide particles of 30-40 nm exhibits good tensile strength (412 MPa) and large total elongation (about 51%) due to the pinning effect of uniform distributed oxide particles on dislocations. After hot rolling, the specimen exhibits a higher tensile strength of 482 MPa, but the elongation decreases to 31.8% owing to the introduction of high-density dislocations. The subsequent heat treatment eliminates the grain defects induced by hot rolling and increases the randomly orientated grains, which further improves the strength and ductility of EBSM ODS-316L steel.

  16. A model for prediction of profile and flatness of hot and cold rolled flat products in four-high mills

    Science.gov (United States)

    Overhagen, Christian; Mauk, Paul Josef

    2018-05-01

    For flat rolled products, the thickness profile in the transversal direction is one of the most important product properties. For further processing, a defined crown of the product is necessary. In the rolling process, several mechanical and thermal influences interact with each other to form the strip shape at the roll gap exit. In the present analysis, a process model for rolling of strip and sheet is presented. The core feature of the process model is a two-dimensional stress distribution model based on von Karman's differential equation. Sub models for the mechanical influences of work roll flattening as well as work and backup roll deflection and the thermal influence of work roll expansion have been developed or extended. The two-dimensional stress distribution serves as an input parameter for the roll deformation models. For work roll flattening, a three-dimensional model based on the Boussinesq problem is adopted, while the work and backup roll deflection, including contact flattening is calculated by means of finite beam elements. The thermal work roll crown is calculated with help of an axisymmetric numerical solution of the heat equation for the work roll, considering azimuthal averaging for the boundary conditions at the work roll surface. Results are presented for hot rolling of a strip in a seven-stand finishing train of a hot strip mill, showing the calculated evolution of the strip profile. A variation of the strip profile from the first to the 20th rolled strip is shown. This variation is addressed to the progressive increase of work roll temperature during the first 20 strips. It is shown that a CVC® system can lead to improvements in strip profile and therefore flatness.

  17. The Effects of Finish Rolling Temperature and Niobium Microalloying on the Microstructure and Properties of a Direct Quenched High-Strength Steel

    Directory of Open Access Journals (Sweden)

    Kaijalainen A.

    2017-06-01

    Full Text Available This paper comprehends the effects of finish rolling temperature (FRT and Nb-microalloying on the microstructural evolution and resultant properties of a low carbon direct quenched steel in the yield strength category of ≥900 MPa. Results indicate that a decrease in FRT close to Ar3 temperature significantly influenced the microstructure following phase transformation, especially at the subsurface (~50-400 μm of the rolled strip. On decreasing the FRT, the subsurface microstructure revealed a fine mixture of ferrite and bainite obviously as a result of strain-induced transformation, whereas the structure at the centreline remained essentially martensitic. Further, Nb-microalloying promoted the formation of ferrite and bainite even at higher FRTs, thus influencing the mechanical properties. The microstructures of the hot-rolled strips were further corroborated with the aid of CCT diagrams.

  18. Precipitation Strengthening by Induction Treatment in High Strength Low Carbon Microalloyed Hot-Rolled Plates

    Science.gov (United States)

    Larzabal, G.; Isasti, N.; Rodriguez-Ibabe, J. M.; Uranga, P.

    2018-03-01

    The use of microalloyed steels in the production of thick plates is expanding due to the possibility of achieving attractive combinations of strength and toughness. As market requirements for high strength plates are increasing and new applications require reduced weight and innovative designs, novel approaches to attaining cost-effective grades are being developed. The mechanism of precipitation strengthening has been widely used in thin strip products, since the optimization of the coiling strategy offers interesting combinations in terms of final properties and microalloying additions. Precipitation strengthening in thick plates, however, is less widespread due to the limitation of interphase precipitation during continuous cooling after hot rolling. With the main objective of exploring the limits of this strengthening mechanism, laboratory thermomechanical simulations that reproduced plate hot rolling mill conditions were performed using low carbon steels microalloyed with Nb, NbMo, and TiMo additions. After continuous cooling to room temperature, a set of heat treatments using fast heating rates were applied simulating the conditions of induction heat treatments. An important increase of both yield and tensile strengths was measured after induction treatment without any important impairment in toughness properties. A significant precipitation hardening is observed in Mo-containing grades under specific heat treatment parameters.

  19. A feasibility study on different NDT techniques used for testing bond quality in cold roll bonded Al-Sn alloy/steel bimetal strips

    Directory of Open Access Journals (Sweden)

    Tallafuss Philipp Johannes

    2017-01-01

    Full Text Available This paper presents non-destructive testing (NDT results for the detection of bond defects in aluminium-tin (Al-Sn alloy/steel bimetal strips. Among all types of bimetal strip that are used in the automotive industry for plain journal engine bearings, Al-Sn alloys cold roll bonded (CRB onto steel backing is the most common type. The difficulty to evaluate the metallurgical bond between the two dissimilar metals is a major industrial concern, which comprises the risk that bearings fail in the field. Considering the harsh performance requirements, 100% online non-destructive testing would be desirable to significantly reduce the business risk. Nowadays bimetal strip manufacturers still rely on destructive testing through different peel-off tests. This work offers the results from four independent NDT studies, using active thermography, shearography, ultrasound and guided wave electromagnetic acoustic transducers (EMATs and samples with different artificially implanted defects, to explore the feasibility to qualitatively indicate the occurrence of bond defects. A destructive peel off test was used to correlate the NDT results with known bond quality. The studies were done under laboratory conditions, and in case of ultrasound also online under production conditions. During the ultrasound online test, the requirements that a NDT technique has to fulfil for online inspection of Al-Sn alloy/steel bimetal strip were established. For active thermography, shearography and guided wave EMAT techniques, it was theoretically analysed, if the laboratory test results could be transferred to testing under production conditions. As a result, guided waves using EMATs, among the four tested methods, are best suited for online inspection of Al-Sn alloy/steel bimetal strip. This research was carried out in collaboration with MAHLE Engine Systems UK Ltd., an Al-Sn alloy/steel bimetal strip manufacturer for the automotive industry.

  20. Manufacture of thin-walled clad tubes by pressure welding of roll bonded sheets

    Science.gov (United States)

    Schmidt, Hans Christian; Grydin, Olexandr; Stolbchenko, Mykhailo; Homberg, Werner; Schaper, Mirko

    2017-10-01

    Clad tubes are commonly manufactured by fusion welding of roll bonded metal sheets or, mechanically, by hydroforming. In this work, a new approach towards the manufacture of thin-walled tubes with an outer diameter to wall thickness ratio of about 12 is investigated, involving the pressure welding of hot roll bonded aluminium-steel strips. By preparing non-welded edges during the roll bonding process, the strips can be zip-folded and (cold) pressure welded together. This process routine could be used to manufacture clad tubes in a continuous process. In order to investigate the process, sample tube sections with a wall thickness of 2.1 mm were manufactured by U-and O-bending from hot roll bonded aluminium-stainless steel strips. The forming and welding were carried out in a temperature range between RT and 400°C. It was found that, with the given geometry, a pressure weld is established at temperatures starting above 100°C. The tensile tests yield a maximum bond strength at 340°C. Micrograph images show a consistent weld of the aluminium layer over the whole tube section.

  1. Mechanical Properties of a Bainitic Steel Producible by Hot Rolling

    Directory of Open Access Journals (Sweden)

    Rana R.

    2017-12-01

    Full Text Available A carbide-free bainitic microstructure is suitable for achieving a combination of ultra high strength and high ductility. In this work, a steel containing nominally 0.34C-2Mn-1.5Si-1Cr (wt.% was produced via industrial hot rolling and laboratory heat treatments. The austenitization (900°C, 30 min. and austempering (300-400°C, 3 h treatments were done in salt bath furnaces. The austempering treatments were designed to approximately simulate the coiling step, following hot rolling and run-out-table cooling, when the bainitic transformation would take place and certain amount of austenite would be stabilized due to suppression of carbide precipitation. The microstructures and various mechanical properties (tensile properties, bendability, flangeability, and room and subzero temperature impact toughness relevant for applications were characterized. It was found that the mechanical properties were highly dependent on the stability of the retained austenite, presence of martensite in the microstructure and the size of the microstructural constituents. The highest amount of retained austenite (~ 27 wt.% was obtained in the sample austempered at 375°C but due to lower austenite stability and coarser overall microstructure, the sample exhibited lower tensile ductility, bendability, flangeability and impact toughness. The sample austempered at 400°C also showed poor properties due to the presence of initial martensite and coarse microstructure. The best combination of mechanical properties was achieved for the samples austempered at 325-350°C with a lower amount of retained austenite but with the highest mechanical stability.

  2. Method of making steel strapping and strip

    Energy Technology Data Exchange (ETDEWEB)

    Robert D. Reilly

    2000-02-16

    procedure would simulate proposed processing line conditions however variations in test results have necessitated further investigations into the nature of cold rolled steel vs. hot rolled steel and electric furnace steel vs. basic oxygen furnace steel as it may apply to heat treating procedures and selection of appropriate steel chemistry for the process.

  3. Effect of Strength Coefficient of Bainite on Micromechanical Deformation and Failure Behaviors of Hot-Rolled 590FB Steel during Uniaxial Tension

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Young; Choi, Shi-Hoon [Sunchon National University, Suncheon (Korea, Republic of); Kim, Sung Il [POSCO Technical Research Laboratories, Gwangyang (Korea, Republic of)

    2016-11-15

    The effect of the strength coefficient (K{sub B}) of bainite on micromechanical deformation and failure behaviors of a hot-rolled 590MPa steel (590FB) during uniaxial tension was simulated using the elasto-plastic finite element method (FEM). The spatial distribution of the constituent phases was obtained using a phase identification technique based on optical microstructure. Empirical equations which depend on chemical composition were used to determine the stress-strain relationship of the constituent phases of the 590FB steel. The stress-strain partitioning and failure behavior were analyzed by increasing the K{sub B} of bainite. The elasto-plastic FEM results revealed that effective strain in the ferrite-bainite boundaries, and maximum principal stress in fibrous bainite, were enhanced as the K{sub B} increased. The elasto-plastic FEM results also demonstrated that the K{sub B} significantly affects the micromechanical deformation and failure behaviors of the hot-rolled 590FB steel during uniaxial tension.

  4. Refinement of the microstructure of steel by cross rolling

    International Nuclear Information System (INIS)

    Tsay, Kira; Arbuz, Alexandr; Gusseynov, Nazim; Nemkaeva, Renata; Ospanov, Nurlan; Krupen'kin, Ivan

    2016-01-01

    One of the most effective ways for refinement of metal microstructure is a severe plastic deformation. The cross rolling is the one of most perspective methods of severe plastic deformation, because it allows to get the long billets, unlike equal angular pressing and other popular methods. This fact provides some industrial expectation for this method. However, deformation and motion path of the metal is very heterogeneous across the section of the rolled piece. This paper presents the finite element modeling of hot cross rolling of steel in the software package DEFORM-3D features implemented and studied the stress-strain state. An experimental study of the effect of the cross rolling on a three-roll mill on the microstructure of structural alloy steel and stainless steel AISI321 in different zones of the bar. Analysis of microsections made after rolling with high total stretch and the final pass temperature 700°C, shows the formation of equiaxial ultrafinegrain structure on the periphery of an elongated rod and “rolling” texture in the central zone. The resulting microstructure corresponds to that obtained in models of stress-strain state. Keywords: cross rolling, ultra-fine grain structure, steel.

  5. Investigation of the structure dependence of diffusivity, solubility and permeability of hydrogen in hot-rolled low-carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Forcey, K S; Ross, D K [Birmingham Univ. (UK). Dept. of Physics; Iordanova, I A [Sofia Univ. (Bulgaria). Dept. of Solid State Physics

    1989-01-01

    A time-lag method for estimating the diffusivity, permeability and solubility of hydrogen in low-carbon hot-rolled steels has been applied. Oriani's model has been used to investigate and explain the effects of microstructure on the trapping of hydrogen. The results show that the initial microstructure of steel significantly affects the behaviour of hydrogen atoms. Of the three sites, namely: Dislocations, interstitial atoms and particles, the most effective traps seem to be interfaces between coarse particles and the matrix. (orig.).

  6. Investigation of the structure dependence of diffusivity, solubility and permeability of hydrogen in hot-rolled low-carbon steels

    International Nuclear Information System (INIS)

    Forcey, K.S.; Ross, D.K.; Iordanova, I.A.

    1989-01-01

    A time-lag method for estimating the diffusivity, permeability and solubility of hydrogen in low-carbon hot-rolled steels has been applied. Oriani's model has been used to investigate and explain the effects of microstructure on the trapping of hydrogen. The results show that the initial microstructure of steel significantly affects the behaviour of hydrogen atoms. Of the three sites, namely: Dislocations, interstitial atoms and particles, the most effective traps seem to be interfaces between coarse particles and the matrix. (orig.)

  7. Hot ductility of continuously cast structural steels

    International Nuclear Information System (INIS)

    Pytel, S.M.

    1995-01-01

    The objective of this investigation was to explain the hot ductility of the structural steels characterized by different amount of carbon and morphology of sulfides. Two different rolling processes were simulated under computer controlled, high temperature deformation MTS system. Results of this study show that morphology of sulfides as well as temperature and amount of deformation are responsible for level of hot ductility of the steel tested. (author)

  8. Application of MMC model on simulation of shearing process of thick hot-rolled high strength steel plate

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Liang; Li, Shuhui [Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, Shanghai Jiao Tong University, Shanghai 200240 (China); Yang, Bing; Gao, Yongsheng [Automotive Steel Research Institute, R and D Center, BaoShan Iron and Steel Co.,Ltd, Shanghai 201900 (China)

    2013-12-16

    Shear operation is widely used as the first step in sheet metal forming to cut the sheet or plate into the required size. The shear of thick hot-rolled High Strength Steel (HSS) requires large shearing force and the sheared edge quality is relatively poor because of the large thickness and high strength compared with the traditional low carbon steel. Bad sheared edge quality will easily lead to edge cracking during the post-forming process. This study investigates the shearing process of thick hot-rolled HSS plate metal, which is generally exploited as the beam of heavy trucks. The Modified Mohr-Coulomb fracture criterion (MMC) is employed in numerical simulation to calculate the initiation and propagation of cracks during the process evolution. Tensile specimens are designed to obtain various stress states in tension. Equivalent fracture strains are measured with Digital Image Correlation (DIC) equipment to constitute the fracture locus. Simulation of the tension test is carried out to check the fracture model. Then the MMC model is applied to the simulation of the shearing process, and the simulation results show that the MMC model predicts the ductile fracture successfully.

  9. Application of MMC model on simulation of shearing process of thick hot-rolled high strength steel plate

    International Nuclear Information System (INIS)

    Dong, Liang; Li, Shuhui; Yang, Bing; Gao, Yongsheng

    2013-01-01

    Shear operation is widely used as the first step in sheet metal forming to cut the sheet or plate into the required size. The shear of thick hot-rolled High Strength Steel (HSS) requires large shearing force and the sheared edge quality is relatively poor because of the large thickness and high strength compared with the traditional low carbon steel. Bad sheared edge quality will easily lead to edge cracking during the post-forming process. This study investigates the shearing process of thick hot-rolled HSS plate metal, which is generally exploited as the beam of heavy trucks. The Modified Mohr-Coulomb fracture criterion (MMC) is employed in numerical simulation to calculate the initiation and propagation of cracks during the process evolution. Tensile specimens are designed to obtain various stress states in tension. Equivalent fracture strains are measured with Digital Image Correlation (DIC) equipment to constitute the fracture locus. Simulation of the tension test is carried out to check the fracture model. Then the MMC model is applied to the simulation of the shearing process, and the simulation results show that the MMC model predicts the ductile fracture successfully

  10. In-Situ Characterization of Deformation and Fracture Behavior of Hot-Rolled Medium Manganese Lightweight Steel

    Science.gov (United States)

    Zhao, Zheng-zhi; Cao, Rong-hua; Liang, Ju-hua; Li, Feng; Li, Cheng; Yang, Shu-feng

    2018-02-01

    The deformation and fracture behavior of hot-rolled medium manganese lightweight (0.32C-3.85Mn-4.18Al-1.53Si) steel was revealed by an in situ tensile test. Deformed δ-ferrite with plenty of cross-parallel deformation bands during in situ tensile tests provides δ-ferrite of good plasticity and ductility, although it is finally featured by the cleavage fracture. The soft and ductile δ-ferrite and high-volume fraction of austenite contribute to the superior mechanical properties of medium manganese lightweight steel heated at 800°C, with a tensile strength of 924 MPa, total elongation of 35.2% and product of the strength and elongation of 32.5 GPa %.

  11. Effects of rolling temperature on microstructure, texture, formability and magnetic properties in strip casting Fe-6.5 wt% Si non-oriented electrical steel

    International Nuclear Information System (INIS)

    Liu, Hai-Tao; Li, Hao-Ze; Li, Hua-Long; Gao, Fei; Liu, Guo-Huai; Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin; Cao, Guang-Ming; Liu, Zhen-Yu; Wang, Guo-Dong

    2015-01-01

    Fe-6.5 wt% Si non-oriented electrical steel sheets with a thickness of 0.50 mm were produced by using a new processing route: strip casting followed by hot rolling, intermediate temperature (150–850 °C) rolling and final annealing. The present study focused on exploring the effects of rolling temperature varying from 150 to 850 °C on the microstructure and texture evolution, the formability and final magnetic properties. The microstructure and texture evolution at the various processing steps were investigated in detail by using OM, XRD, EBSD and TEM. It was found that the formability during rolling, the microstructure and texture before and after annealing and final magnetic properties highly depended on rolling temperature. The formability during rolling was gradually improved with increasing rolling temperature due to the slipping of dislocation. In particular, the rolling temperature dominated the formation of in-grain shear bands in the rolled microstructure, which played an important role in the development of final recrystallization microstructure and texture. In the case of lower temperature (150–450 °C) rolling, an inhomogeneous microstructure with a large amount of in-grain shear bands was formed in the rolled sheets, which finally resulted in a fine and inhomogeneous annealing microstructure dominated by mild λ-fiber texture composed of cube and {001}〈210〉 components and α*-fiber texture concentrated on {115}〈5–10 1〉 component. By contrast, in the case of higher temperature (650–850 °C) rolling, a relatively homogeneous microstructure without in-grain shear bands was formed instead in the rolled sheets, which finally led to a coarse and relatively homogeneous annealing microstructure characterized by strong α-fiber and γ-fiber texture. Accordingly, on the whole, both the magnetic induction (B 8 and B 50 ) and iron loss (P 15/50 and P 10/400 ) decreased with raising rolling temperature. - Highlights: • Fe−6.5 wt% Si sheet was

  12. Effects of rolling temperature on microstructure, texture, formability and magnetic properties in strip casting Fe-6.5 wt% Si non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Li, Hao-Ze [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Li, Hua-Long [Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Gao, Fei; Liu, Guo-Huai [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin [National Engineering Research Center for Silicon Steel, Wuhan Iron & Steel (Group) Corp, Wuhan 430083 (China); Cao, Guang-Ming; Liu, Zhen-Yu; Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China)

    2015-10-01

    Fe-6.5 wt% Si non-oriented electrical steel sheets with a thickness of 0.50 mm were produced by using a new processing route: strip casting followed by hot rolling, intermediate temperature (150–850 °C) rolling and final annealing. The present study focused on exploring the effects of rolling temperature varying from 150 to 850 °C on the microstructure and texture evolution, the formability and final magnetic properties. The microstructure and texture evolution at the various processing steps were investigated in detail by using OM, XRD, EBSD and TEM. It was found that the formability during rolling, the microstructure and texture before and after annealing and final magnetic properties highly depended on rolling temperature. The formability during rolling was gradually improved with increasing rolling temperature due to the slipping of dislocation. In particular, the rolling temperature dominated the formation of in-grain shear bands in the rolled microstructure, which played an important role in the development of final recrystallization microstructure and texture. In the case of lower temperature (150–450 °C) rolling, an inhomogeneous microstructure with a large amount of in-grain shear bands was formed in the rolled sheets, which finally resulted in a fine and inhomogeneous annealing microstructure dominated by mild λ-fiber texture composed of cube and {001}〈210〉 components and α*-fiber texture concentrated on {115}〈5–10 1〉 component. By contrast, in the case of higher temperature (650–850 °C) rolling, a relatively homogeneous microstructure without in-grain shear bands was formed instead in the rolled sheets, which finally led to a coarse and relatively homogeneous annealing microstructure characterized by strong α-fiber and γ-fiber texture. Accordingly, on the whole, both the magnetic induction (B{sub 8} and B{sub 50}) and iron loss (P{sub 15/50} and P{sub 10/400}) decreased with raising rolling temperature. - Highlights: • Fe−6

  13. Effects of Cold Rolling Reduction and Initial Goss Grains Orientation on Texture Evolution and Magnetic Performance of Ultra-thin Grain-oriented Silicon Steel

    Directory of Open Access Journals (Sweden)

    LIANG Rui-yang

    2017-06-01

    Full Text Available The ultra-thin grain-oriented silicon steel strips with a thickness of 0.06-0.12mm were produced by one-step-rolling methods with different Goss-orientation of grain-oriented silicon steel sheets. The effect of cold rolling reduction and initial Goss-orientation of samples on texture evolution and magnetic performance of ultra-thin grain-oriented silicon steel strips was studied by EBSD. The result shows that with the increase of cold rolling reduction and decrease of strips thickness, the recrystallization texture is enhanced after annealing.When the cold rolling reduction is 70%,RD//〈001〉 recrystallization texture is the sharpest, and the magnetic performance is the best. The higher degree of Goss orientation in initial sample is, the better magnetic performance of ultra-thin grain-oriented silicon steel.Therefore, for producing an ultra-thin grain-oriented silicon steel with high performance, a material with a concentrated orientation of Goss grains can be used.

  14. Overall model of the dynamic behaviour of the steel strip in an annealing heating furnace on a hot-dip galvanizing line

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-de-Pison, F.J.; Pernia, A.; Jimenez-Macias, E.; Fernandez, R.

    2010-07-01

    Predicting the temperature of the steel strip in the annealing process in a hot-dip galvanizing line (HDGL) is important to ensure the physical properties of the processed material. The development of an accurate model that is capable of predicting the temperature the strip will reach according to the furnaces variations in temperature and speed, its dimensions and the steels chemical properties, is a requirement that is being increasingly called for by industrial plants of this nature. This paper presents a comparative study made between several types of algorithms of Data Mining and Artificial Intelligence for the design of an efficient and overall prediction model that will allow determining the strips variation in temperature according to the physico-chemical specifications of the coils to be processed, and fluctuations in temperature and speed that are recorded within the annealing process. The ultimate goal is to find a model that is effectively applicable to coils of new types of steel or sizes that are being processed for the first time. This model renders it possible to fine-tune the control model in order to standardise the treatment in areas of the strip in which there is a transition between coils of different sizes or types of steel. (Author).

  15. Influence of hot rolling and high speed hydrostatic extrusion on the microstructure and mechanical properties of RAF ODS steel

    International Nuclear Information System (INIS)

    Oksiuta, Z.; Kurzydlowski, K.J.; Baluc, N.

    2009-01-01

    Argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti oxide dispersion strengthened (ODS) ferritic steel powder was mechanically alloyed with 0.3Y2O3 (wt.%) nano-particles in attritor ball mill and consolidated by hot isostatic pressing (HIP) at 1150 deg. C under pressure of 200 MPa for 3 hrs. To improve mechanical properties of as HIPped ODS ingots the material was undergone further thermo-mechanical treatment (TMT), namely: hot rolling (HR) at 850 deg. C or high speed hot extrusion (HSHE) at 850 deg. C. After TMT both materials were annealed at 1050 deg. C for 1 h in vacuum. Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment exhibited elongated in a longitudinal direction grains with an average size of 75 μm. However, an equiaxed, smaller than 500 nm grains were also found in the microstructure of both materials. Different size and morphology of oxides particles were also observed. Bigger, about 150 nm Ti-Al-O particles were usually located at grain boundaries whereas Y-Ti-O nanoclusters of about 5 nm were uniformly distributed in ODS steel matrix. The Charpy impact tests revealed significantly better about 90% (5.8 J) upper shelf energy (USE) of material after HSHE but ductile to brittle transition temperature (DBTT) of both alloys was unsatisfactory. As-HR ODS steel has shown DBTT of about 55 deg. C whereas HSHE ODS steel has about 75 deg. C. This relatively high values of transition temperature were probably caused by oxides particles present at grain boundaries of the ODS alloys which decreased fracture properties of the ODS steels. High temperature tensile properties of both ODS alloys are found to be satisfactory in full range of the testing temperature from 23 up to 750 deg. C. However, about 15% better UTS and YS0.2 (1350 MPa and 1285 MPa, respectively) as well as ductility were measured in the case of the as-HSHE ODS steel. These results indicates that HSHE process of the ODS steel can be considered as more

  16. Examining the microtexture evolution in a hole-edge punched into 780 MPa grade hot-rolled steel

    Energy Technology Data Exchange (ETDEWEB)

    Shin, J.H.; Kim, M.S. [Department of Printed Electronics Engineering, Sunchon National University, 315 Maegok, Sunchon, Jeonnam 540-950 (Korea, Republic of); Kim, S.I.; Seo, S.J. [POSCO Technical Research Laboratories, Gwangyang 545-090 (Korea, Republic of); Choi, S.-H., E-mail: shihoon@sunchon.ac.kr [Department of Printed Electronics Engineering, Sunchon National University, 315 Maegok, Sunchon, Jeonnam 540-950 (Korea, Republic of)

    2016-08-15

    The deformation behavior in the hole-edge of 780 MPa grade hot-rolled steel during the punching process was investigated via microstructure characterization and computational simulation. Microstructure characterization was conducted to observe the edges of punched holes through the thickness direction, and electron back-scattered diffraction (EBSD) was used to analyze the heterogeneity of the deformation. Finite element analysis (FEA) that could account for a ductile fracture criterion was conducted to simulate the deformation and fracture behaviors of 780 MPa grade hot-rolled steel during the punching process. Calculation of rotation rate fields at the edges of the punched holes during the punching process revealed that metastable orientations in Euler space were confined to specific orientation groups. Rotation-rate fields effectively explained the stability of the initial texture components in the hole-edge region during the punching process. A visco-plastic self-consistent (VPSC) polycrystal model was used to calculate the microtexture evolution in the hole-edge region during the punching process. FEA revealed that the heterogeneous effective strain was closely related to the heterogeneity of the Kernel average misorientation (KAM) distribution in the hole-edge region. A simulation of the deformation microtexture evolution in the hole-edge region using a VPSC model was in good agreement with the experimental results. - Highlights: •We analyzed the microstructure in a hole-edge punched in HR 780HB steel. •Rotation rate fields revealed the stability of the initial texture components. •Heterogeneous effective stain was closely related to the KAM distribution. •VPSC model successfully simulated the deformation microtexture evolution.

  17. Hot rolled composite billet for nuclear control rods

    International Nuclear Information System (INIS)

    Miller, G.E.

    1976-01-01

    This invention relates to a composite plate shaped billet, useful in the fabrication of nuclear control rods, which comprises a core of stainless steel containing about 2 percent boron 10, a thin coating of zirconia on the surfaces of said core, and said zirconia coating being completely encased in a jacket of mild steel, said composite having been hot rolled between about 1075 0 and about 1165 0 C. 1 claim, 8 figures

  18. Splitting in Dual-Phase 590 high strength steel plates

    International Nuclear Information System (INIS)

    Yang Min; Chao, Yuh J.; Li Xiaodong; Tan Jinzhu

    2008-01-01

    Charpy V-notch impact tests on 5.5 mm thick, hot-rolled Dual-Phase 590 (DP590) steel plate were evaluated at temperatures ranging from 90 deg. C to -120 deg. C. Similar tests on 2.0 mm thick DP590 HDGI steel plate were also conducted at room temperature. Splitting or secondary cracks was observed on the fractured surfaces. The mechanisms of the splitting were then investigated. Fracture surfaces were analyzed by optical microscope (OM) and scanning electron microscope (SEM). Composition of the steel plates was determined by electron probe microanalysis (EPMA). Micro Vickers hardness of the steel plates was also surveyed. Results show that splitting occurred on the main fractured surfaces of hot-rolled steel specimens at various testing temperatures. At temperatures above the ductile-brittle-transition-temperature (DBTT), -95 deg. C, where the fracture is predominantly ductile, the length and amount of splitting decreased with increasing temperature. At temperatures lower than the DBTT, where the fracture is predominantly brittle, both the length and width of the splitting are insignificant. Splitting in HDGI steel plates only appeared in specimens of T-L direction. The analysis revealed that splitting in hot-rolled plate is caused by silicate and carbide inclusions while splitting in HDGI plate results from strip microstructure due to its high content of manganese and low content of silicon. The micro Vickers hardness of either the inclusions or the strip microstructures is higher than that of the respective base steel

  19. Research on the Microstructures and Mechanical Properties of Ti Micro-Alloyed Cold Rolled Hot-Dip Galvanizing DP980 Steel

    Science.gov (United States)

    Han, Yun; Kuang, Shuang; Qi, Xiumei; Xie, Chunqian; Liu, Guanghui

    Effects of galvanizing simulation parameters on microstructures and mechanical properties of Ti-microalloyed cold rolled hot-dip galvanizing DP980 steel were investigated in this study by optical microscopy (OM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and tensile test. Moreover, the precipitation behavior of Ti in the experimental steel was also studied. The results show that, as the heating temperature increases, the tensile strength of experimental galvanizing DP980 steel decreases while the yield ratio and elongation of the steel are enhanced. The microstructures of experimental steels exhibit typical dual phase steel character and the volume fractions of MA islands are almost 30%. In addition, lots of nano-sized TiC precipitates can be found in the ferrite grains.

  20. The effect of heat treatment on recrystallized microstructure, precipitation and ductility of hot-rolled Fe–Cr–Al–REM ferritic stainless steel sheets

    International Nuclear Information System (INIS)

    Qu, H.P.; Lang, Y.P.; Yao, C.F.; Chen, H.T.; Yang, C.Q.

    2013-01-01

    This study presents research works about the effects of heat treatment on recrystallized equiaxed grain size, precipitation, room temperature (RT) toughness and ductile to brittle transition temperature (DBTT) of Fe–Cr–Al–REM ferritic stainless steel (FSS) hot-rolled sheet. Results showed that the recrystallization of hot-rolled Fe–Cr–Al–REM FSS sheet could be completed after annealing treatment at 750 °C for 15 min with the equiaxed grain diameter of approximately 50 μm. Inappropriate annealing treatment would inevitably leads to the unexpected grain coarsening. On the other hand, a great deal of needle-like or spot-like fine aluminum–lanthanum compound Al 11 La 3 precipitates were observed in the ferrite matrix after 1 h aging treatment at 750 °C. The microstructure observation results associated with the impact test definitely illustrated that the Al 11 La 3 precipitates was the reason for the brittle crack in the as-casted ingot and as-forged slab. The real DBTT of the annealed Fe–Cr–Al–REM FSS sheet with average grain size of about 50 μm was −4 °C. Meanwhile, the DBTT of the hot-rolled Fe–Cr–Al–REM stainless steel sheet was evidently increased as the recrystallized grain size increased.

  1. The effect of heat treatment on recrystallized microstructure, precipitation and ductility of hot-rolled Fe-Cr-Al-REM ferritic stainless steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Qu, H.P., E-mail: quhuapeng0926@163.com [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China); Lang, Y.P. [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China); Yao, C.F. [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China); Zhuozhou Works, Central Iron and Steel Research Institute (CISRI), 2 HuoJuNan Road, Zhuozhou 072750, Hebei (China); Chen, H.T.; Yang, C.Q. [Institute for Special Steels (Formerly Institute for Structural Materials), Central Iron and Steel Research Institute (CISRI), 76 HaiDianNan Road, Beijing 100081 (China)

    2013-02-01

    This study presents research works about the effects of heat treatment on recrystallized equiaxed grain size, precipitation, room temperature (RT) toughness and ductile to brittle transition temperature (DBTT) of Fe-Cr-Al-REM ferritic stainless steel (FSS) hot-rolled sheet. Results showed that the recrystallization of hot-rolled Fe-Cr-Al-REM FSS sheet could be completed after annealing treatment at 750 Degree-Sign C for 15 min with the equiaxed grain diameter of approximately 50 {mu}m. Inappropriate annealing treatment would inevitably leads to the unexpected grain coarsening. On the other hand, a great deal of needle-like or spot-like fine aluminum-lanthanum compound Al{sub 11}La{sub 3} precipitates were observed in the ferrite matrix after 1 h aging treatment at 750 Degree-Sign C. The microstructure observation results associated with the impact test definitely illustrated that the Al{sub 11}La{sub 3} precipitates was the reason for the brittle crack in the as-casted ingot and as-forged slab. The real DBTT of the annealed Fe-Cr-Al-REM FSS sheet with average grain size of about 50 {mu}m was -4 Degree-Sign C. Meanwhile, the DBTT of the hot-rolled Fe-Cr-Al-REM stainless steel sheet was evidently increased as the recrystallized grain size increased.

  2. Controlled rolling process for dual phase steels and application to rod, wire, sheet and other shapes

    Science.gov (United States)

    Thomas, Gareth; Ahn, Jae-Hwan; Kim, Nack-Joon

    1986-01-01

    An improved, energy efficient, hot rolling method for direct production of cold formable dual-phase steel is provided. The steel is heated to completely austenitize it and then continuously hot rolled and cooled down into the ferrite-austenite two phase region to a temperature which is just below the effective Ar.sub.3 temperature. The hot rolled steel is then rapidly quenched to provide an alloy containing strong, tough lath martensite (fibers) in a ductile soft ferrite matrix. The method is particularly useful for providing rods in which form the alloy is capable of being drawn into high strength wire or the like in a cold drawing operation without any intermediate annealing or patenting, and has excellent strength, ductility and fatigue characteristics.

  3. Influence of ring growth rate on damage development in hot ring rolling

    NARCIS (Netherlands)

    Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

    2015-01-01

    As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For

  4. Advanced cold rolled steels for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, H. [ThyssenKrupp Steel AG, Eberhardstrasse 12, 44145 Dortmund (Germany); Mattissen, D.; Schaumann, T.W. [ThyssenKrupp Steel AG, Duisburg (Germany)

    2006-09-15

    Advanced multiphase steels offer a great potential for bodies-in-white through their combination of formability and achievable component strength levels. They are first choice for strength and crash-relevant parts of challenging geometry. The intensive development of high-strength multiphase steels by ThyssenKrupp has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex phase steels are currently produced in addition to cold rolled DP and RA steels. New continuously annealed grades with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for applications mainly in the field of structural automobile elements make use of the classic advantages of microalloying as well as the principles of DP and TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [German] Fortschrittliche Multiphasen-Staehle eroeffnen wegen der inzwischen erreichbaren Kombination aus Umformbarkeit und Bauteilfestigkeit ein enormes Potenzial fuer Rohkarosserien. Sie stellen eine erste Wahl dar, wenn es um Festigkeit und um Crashsicherheit geht und besondere Anforderungen an die Bauteilgeometrien gestellt werden. Bei ThyssenKrupp hat die Entwicklung hochfester Multiphasen-Staehle in Verbindung mit dem Feuerverzinken zur Realisierung von Blechhalbzeugen gefuehrt, die hervorragend formbar sind. Es werden heute feuerverzinkte Komplexphasenstaehle neben den bewaehrten kaltgewalzten Dualphasen(DP) - und Retained Austenit(RA)-Staehlen produziert. Die neuen kontinuierlich gegluehten Stahlvarianten mit Festigkeiten bis zu 1000 MPa in Kombination mit der bei Strukturbauteilen im Automobilbau geforderten Duktilitaet nutzen sowohl die klassischen Vorteile des Mikrolegierens aus und dazu die Prinzipien, die man bei DP- und TRIP-Staehlen anwendet. Eine weitere Verbesserung des Eigenschaftsprofils wird mit dem

  5. Evolution of microstructure at hot band annealing of ferritic FeSi steels

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Jürgen, E-mail: juergen.schneider@t-online.de [Institute of Metal Forming, Technische Universität Bergakademie Freiberg, Bernhard-von Cotta-Str. 4, D-09596 Freiberg (Germany); Stahlzentrum Freiberg e.V., Leipziger Straße 34, D-09599 Freiberg (Germany); Li, Guangqiang [State Key Lab. of Refractories and Metallurgy, Wuhan University of Science and Technology, No. 947 Heping Avenue, Qingshan District, Wuhan 430081 (China); Franke, Armin [Stahlzentrum Freiberg e.V., Leipziger Straße 34, D-09599 Freiberg (Germany); Zhou, Bowen [State Key Lab. of Refractories and Metallurgy, Wuhan University of Science and Technology, No. 947 Heping Avenue, Qingshan District, Wuhan 430081 (China)

    2017-02-15

    The magnetic properties of the finally fabricated nonoriented FeSi steels critically depend on the microstructure and on the occurring crystallographic texture. The fabrication route comprises hot rolling, coiling and cooling, hot band annealing before cold rolling (optional), cold rolling and the final thermal treatment. As well known there is an interplay between the microstructure and texture during the various processing steps. For that reason, it is of interest to know more on the evolution of the microstructure at hot band annealing of hot band prepared in different ways. In this paper we will summarize our recent results on the evolution of microstructure during thermal annealing of hot band: thermal treatment following immediately the last pass of hot rolling or a hot band annealing as a separate processing step before cold rolling.

  6. Formability of high-alloy dual-phase Cr-Ni steels

    International Nuclear Information System (INIS)

    Elfmark, J.

    2004-01-01

    The formability of dual-phase high-alloy Cr-Ni steel within the temperature range from 900 to 1250 C was studied using laboratory tensile and torsion tests. The dual-phase steels on 24% Cr basis are characterized by poor hot formability due to very low stable deformation values and slow recrystallization. Mathematical description of deformation stability exhaustion was derived, as well as a model of formability control based on analysis of the gradual diffuse deformation stability from the stability limit to the moment when the deformation starts to concentrate in a small volume of the test piece. Rolling simulation of dual-phase steel strip was used as an example demonstrating the draught scheme optimization technique which avoids the danger of crack occurrence during the rolling of dual-phase steel strip. (orig.)

  7. The Work Softening by Deformation-Induced Disordering and Cold Rolling of 6.5 wt pct Si Steel Thin Sheets

    Science.gov (United States)

    Wang, Xianglong; Li, Haoze; Zhang, Weina; Liu, Zhenyu; Wang, Guodong; Luo, Zhonghan; Zhang, Fengquan

    2016-09-01

    As-cast strip of 6.5 wt pct Si steel was fabricated by twin-roll strip casting. After hot rolling at 1323 K (1050 °C), thin sheets with the thickness of 0.35 mm were produced by warm rolling at 373 K (100 °C) with rolling reductions of 15, 25, 35, 45, 55, and 65 pct. Influence of warm rolling reduction on ductility was investigated by room temperature bending test. The measurement of macro-hardness showed that "work softening" could begin when the warm rolling reduction exceeded 35 pct. The room temperature ductility of the thin sheets gradually increased with the increase of warm rolling reductions, and the plastic deformation during bending began to form when the warm rolling reduction was greater than 45 pct, the 65 pct rolled thin sheet exhibited the maximum plastic deformation of about 0.6 pct during bending at room temperature, with a few small dimples having been observed on the fracture surfaces. B2-ordered domains were formed in the 15, 25, 35, 45, and 55 pct rolled specimens, and their average size decreased with the increase of warm rolling reductions. By contrast, no B2-ordered domain could be found in the 65 pct rolled specimen. It had been observed that large-ordered domains could be split into several small parts by the slip of partial super-dislocations during warm rolling, which led to significant decrease of the order degree to cause the phenomenon of deformation-induced disordering. On the basis of these results, cold rolling schedule was developed to successfully fabricate 0.25-mm-thick sheets with good surface qualities and magnetic properties from warm rolled sheets.

  8. The hot working characteristics of a boron bearing and a conventional low carbon steel

    International Nuclear Information System (INIS)

    Stumpf, Waldo; Banks, Kevin

    2006-01-01

    Constitutive hot working constants were determined for an 11 ppm boron low carbon strip steel and compared from 875 to 1140 deg. C and strain rates of 0.001-2.5 s -1 to a high nitrogen low carbon strip steel. The boron steel showed a different hot working behaviour than the conventional steel with the steady state flow stress about 50-60% higher, the peak strain more than 50% higher and the eventual ferrite grain size about 40% smaller, if compared at the same temperature compensated strain rates or Z values. This difference persisted where the soaking temperature before compression was varied between 1140 and 1250 deg. C, proving that undissolved AlN in the boron-bearing steel was not responsible. With systematically varied linear cooling rates after hot working, the final ferrite grain size in the boron steel is finer and is independent of the two Z values applied during hot working. Retarded softening by dynamic recrystallisation during hot working in the boron containing steel is probably caused by boron solute drag of moving grain boundaries

  9. Effect of rolling temperature on 12Kh18N10T steel tube hardening

    International Nuclear Information System (INIS)

    Yushkevich, P.M.; Stepanovich, V.E.; Manankova, L.V.; Usenko, V.N.; Semenov, I.A.

    1984-01-01

    Mechanical properties and substructure of tubes at the constant reduction degree k(the ratio of deformation over wall thickness to deformation over diameter), depending on strain degree during cold and hot tube rolling, have been studied. The investigations are carried out using hot-rolled tubes with the dimensions 88x8 mm of 12Kh1hN10T steel. With the decrease of strain over the wall of the tube, produced of 12Kh18N10T steel as to strain over diameter the values of yield strength and ultimate strength increase with simultaneous decrease in ductility during warm rolling and yield strength and ultimate strength decrease with the increase in ductility-during cold rolling. During warm rolling of the tubes at 250 deg C the hardening of 12Kh18N10T steel is higher, than at the rolling temperature 150 deg C. The optimum temperature range of warm rolling is 120-150 deg C. Grain orientation in the metal of the tubes and degree of texture perfection increase with the temperature increase of the tube warm drolling as compared with col rolli

  10. Tribological study in roll forming of lean duplex stainless steel sheets

    DEFF Research Database (Denmark)

    Nielsen, Peter Søe; Nielsen, Morten Strogaard; Bay, Niels

    2012-01-01

    . Production tests show that galling can be a problem but pick-up formation on the tools seems to reach a consistent level. Improvements to tool surfaces and lubricant quality are proposed with a view to optimizing the tribo-system in order to increase the produced length before galling initiates and tool...... are relatively low and surface expansion is more or less non-existent, long roll forming production runs imply large sliding/contact lengths due to relative movement between steel strip and rolls. This requires an efficient tribological system to prevent pick-up formation on the forming tools. The present work...... focus on tribological issues are galling and pick-up formation as well as tool life in roll forming of stainless duplex steel sheets. The roll forming process is exemplified by production of an s-shaped profile used in interlock carcass production for flexible pipes used in off-shore oil extraction...

  11. Phenomenological Model Describing the Formation of Peeling Defects on Hot-Rolled Duplex Stainless Steel 2205

    Science.gov (United States)

    Yong-jun, Zhang; Hui, Zhang; Jing-tao, Han

    2017-05-01

    The chemical composition, morphology, and microstructure of peeling defects formed on the surface of sheets from steel 2205 under hot rolling are studied. The microstructure of the surface is analyzed using scanning electron and light microscopy. The zones affected are shown to contain nonmetallic inclusions of types Al2O3 and CaO - SiO2 - Al2O3 - MgO in the form of streak precipitates and to have an unfavorable content of austenite, which causes decrease in the ductility of the area. The results obtained are used to derive a five-stage phenomenological model of formation of such defects.

  12. Development of dissimilar metal transition joint by hot roll bonding technique

    International Nuclear Information System (INIS)

    Nagai, Takayuki; Takeda, Seiichiro; Tanaka, Yasumasa; Ogawa, Kazuhiro; Nakasuji, Kazuyuki; Ikenaga, Yoshiaki.

    1994-01-01

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) with stainless steel piping is needed for nuclear fuel reprocessing plants. The authors have developed dissimilar metal transition joints between stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot roll bonding process, using the newly developed mill called 'rotary reduction mill'. In the R and D program, appropriate bonding conditions in the manufacturing process of the joints were established. This report presents the structure of transition joints and the manufacturing process by the hot roll bonding technique. Then, the evaluation of mechanical and corrosion properties and the results of demonstration test of joints for practical use are described. (author)

  13. Development of dissimilar metal transition joint by hot roll bonding technique

    International Nuclear Information System (INIS)

    Nagai, Takayuki; Takeuchi, Masayuki; Takeda, Seiichiro; Shikakura, Sakae; Ogawa, Kazuhiro; Nakasuji, Kazuyuki; Kajimura, Haruhiko.

    1995-01-01

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) with stainless steel piping is needed for nuclear fuel reprocessing plants. The authors have developed dissimilar metal transition joints between stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot roll bonding process, using the newly developed mill called 'rotary reduction mill'. In the R and D program, appropriate bonding conditions in the manufacturing process of the joints were established. This report presents the structure of transition joints and the manufacturing process by hot roll bonding technique. Then, the evaluation of mechanical and corrosion properties and the results of demonstration test of joints for practical use are described. (author)

  14. Effect of microstructural anisotropy on fracture toughness of hot rolled 13Cr ODS steel - The role of primary and secondary cracking

    Science.gov (United States)

    Das, A.; Viehrig, H. W.; Bergner, F.; Heintze, C.; Altstadt, E.; Hoffmann, J.

    2017-08-01

    ODS steels have been known to exhibit anisotropic fracture behaviour and form secondary cracks. In this work, the factors responsible for the anisotropic fracture behaviour have been investigated using scanning electron microscopy and electron backscatter microscopy. Fracture toughness of hot rolled 13Cr ODS steel was determined using unloading compliance method for L-T and T-L orientations at various temperatures. L-T orientation had higher fracture toughness than T-L orientation and also contained more pronounced secondary cracking. Secondary cracks appeared at lower loads than primary cracks in both orientations. Primary crack propagation was found to be preferentially through fine grains in a bimodal microstructure. Grains were aligned and elongated the most towards rolling direction followed by T and S directions resulting in fracture anisotropy. Crystallographic texture and preferential alignment of Ti enriched particles parallel to rolling direction also contributed towards fracture anisotropy.

  15. Characterization of microstructure, texture and magnetic properties in twin-roll casting high silicon non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze; Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn; Lu, Hui-Hu; Song, Hong-Yu; Wang, Guo-Dong

    2014-02-15

    An Fe-6.5 wt.% Si-0.3 wt.% Al as-cast sheet was produced by twin-roll strip casting process, then treated with hot rolling, warm rolling and annealing. A detailed study of the microstructure and texture evolution at different processing stages was carried out by optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. The initial as-cast strip showed strong columnar grains and pronounced < 001 >//ND texture. The hot rolled and warm rolled sheets were characterized by large amounts of shear bands distributed through the thickness together with strong < 110 >//RD texture and weak < 111 >//ND texture. After annealing, detrimental < 111 >//ND texture almost disappeared while beneficial (001)<210 >, (001)<010 >, (115)<5 − 10 1 > and (410) < 001 > recrystallization textures were formed, thus the magnetic induction of the annealed sheet was significantly improved. The recrystallization texture in the present study could be explained by preferred nucleation and grain growth mechanism. - Highlights: • A high silicon as-cast strip with columnar structure was produced. • A thin warm rolled sheet without large edge cracks was obtained. • Microstructure and texture evolution at each stage were investigated. • Beneficial (001)<210 >, (001)<010 >, (410)<001 > recrystallization textures were formed. • The magnetic induction of annealed sheet was significantly improved.

  16. Transformation kinetics of microalloyed steels after hot controlled ...

    African Journals Online (AJOL)

    Transformation kinetics of austenite into ferrite after controlled hot rolling has been investigated in three microalloyed steels (Nb, Nb-Ti and C-Mn-V) using hot interrupted compression tests on the Gleeble 1500 within the testing temperature range of 875°C-1100°C. Holding times were varied between 0.5 and 30s, strain ...

  17. Determination of residual stresses in roll compacted titanium strips

    CSIR Research Space (South Africa)

    Mothosi, KL

    2017-01-01

    Full Text Available residual stresses using x-ray diffraction (XRD) surface probing technique. Preliminary results were obtained for the surface residual stress at the center of the titanium strips for the 100 and 325 mesh strips rolled at 0.1 roll gap for 20 and 50 mm set...

  18. Effect of intercritical deformation on microstructure and mechanical properties of a low-silicon aluminum-added hot-rolled directly quenched and partitioned steel

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Xiao-Dong, E-mail: tan.x@mpie.de [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf (Germany); Xu, Yun-Bo, E-mail: yunbo_xu@126.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Ponge, Dirk [Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf (Germany); Yang, Xiao-Long; Hu, Zhi-Ping; Peng, Fei [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Ju, Xiao-Wei [CERI LONG PRODUCT CO., LTD., Beijing 100176 (China); Wu, Di [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Raabe, Dierk [Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Str. 1, 40237 Düsseldorf (Germany)

    2016-02-22

    Here, we applied hot-rolling in conjunction with direct quenching and partitioning (HDQ&P) processes with different rolling schedules to a low-C low-Si Al-added steel. Ferrite was introduced into the steel by intercritical rolling and air cooling after hot-rolling. The effect of intercritcal deformation on the microstructure evolution and mechanical properties was investigated. The promotion of austenite stabilization and the optimization of the TRIP effect due to a moderate degree of intercritical deformation were systematically explored. The results show that the addition of 1.46 wt% of Al can effectively promote ferrite formation. An intercritical deformation above 800 °C can result in a pronounced bimodal grain size distribution of ferrite and some elongated ferrite grains containing sub-grains. The residual strain states of both austenite and ferrite and the occurrence of bainite transformation jointly increase the retained austenite fraction due to its mechanical stabilization and the enhanced carbon partitioning into austenite from its surrounding phases. An intercritical deformation below 800 °C can profoundly increase the ferrite fraction and promote the recrystallization of deformed ferrite. The formation of this large fraction of ferrite enhances the carbon enrichment in the untransformed austenite and retards the bainite transformation during the partitioning process and finally enhances martensite transformation and decreases the retained austenite fraction. The efficient TRIP effect of retained austenite and the possible strain partitioning of bainite jointly improve the work hardening and formability of the steel and lead to the excellent mechanical properties with relatively high tensile strength (905 MPa), low yield ratio (0.60) and high total elongation (25.2%).

  19. Rolling-element fatigue life of silicon nitride balls. [as compared to that of steel, ceramic, and cermet materials

    Science.gov (United States)

    Parker, R. J.; Zaretsky, E. V.

    1974-01-01

    The five-ball fatigue tester was used to evaluate silicon nitride as a rolling-element bearing material. Results indicate that hot-pressed silicon nitride running against steel may be expected to yield fatigue lives comparable to or greater than those of bearing quality steel running against steel at stress levels typical rolling-element bearing application. The fatigue life of hot-pressed silicon nitride is considerably greater than that of any ceramic or cermet tested. Computer analysis indicates that there is no improvement in the lives of 120-mm-bore angular--contact ball bearings of the same geometry operating at DN values from 2 to 4 million where hot-pressed silicon nitride balls are used in place of steel balls.

  20. FATIGUE BEHAVIOR OF HOT-ROLLED STEEL INTENDED FOR COLD FORMING

    Directory of Open Access Journals (Sweden)

    Gejza Rosenberg

    2011-07-01

    Full Text Available In the work, there are presented measured tension and fatigue properties of eight low-carbon steels moulded in form of 20 kg ingots that were processed by controlled regime of rolling /cooling and then exposed to simulated effect of two coiling temperatures. The experimental results presented in the work show, that steels with ferrite-martensite or ferrite-bainitic microstructure have in comparison to ferrite-pearlitic or ferrite-carbidic microstructure better strength-plastic properties, but worse resistance to cyclic loading.

  1. A Study on the Low Temperature Brittleness by Cyclic Cooling-Heating of Low Carbon Hot Rolled Steel Plate

    International Nuclear Information System (INIS)

    Lee, Hyo Bok

    1979-01-01

    The ductile-brittle transition phenomenon of low carbon steel has been investigated using the standard Charpy V-notch specimen. Dry ice and acetone were used as refrigerants. Notched specimens were cut from the hot rolled plate produced at POSCO for the Olsen impact test. The effect of cyclic cooling and heating of 0.14% carbon steel on the embrittlement was extensively examined. The ductile-brittle transition temperature was found to be approximately-30 .deg. C. The transition temperature was gradually increased as the number of cooling-heating cycles increased. On a typical V-notch fracture surface it was found that the ductile fracture surface showed a thick and fibrous structure, while the brittle fracture surface a small and light grain with irregular disposition. As expected, the transition temperature was also increased as the carbon content of steel increased. Compared with the case of 0.14% carbon steel, the transition temperature of 0.17% carbon steel was found to be increased about 12 .deg. C

  2. Effect of decreased hot-rolling reduction treatment on fracture toughness of low-alloy structural steels

    Science.gov (United States)

    Tomita, Yoshiyuki

    1990-09-01

    Commercial low-alloy structural steels, 0.45 pct C (AISI 1045 grade), 0.40 pct C-Cr-Mo (AISI 4140 grade), and 0.40 pct C-Ni-Cr-Mo (AISI 4340 grade), have been studied to determine the effect of the decreased hot-rolling reduction treatment (DHRRT) from 98 to 80 pct on fracture toughness of quenched and highly tempered low-alloy structural steels. The significant conclusions are as follows: (1) the sulfide inclusions were modified through the DHRRT from a stringer (mean aspect ratio: 16.5 to 17.6) to an ellipse (mean aspect ratio: 3.8 to 4.5), independent of the steels studied; (2) the DHRRT significantly improved J Ic in the long-transverse and shorttransverse orientations, independent of the steels studied; and (3) the shelf energy in the Charpy V-notch impact test is also greatly improved by the DHRRT, independent of testing orientation and steels studied; however, (4) the ductile-to-brittle transition temperature was only slightly affected by the DHRRT. The beneficial effect on the J Ic is briefly discussed in terms of a crack extension model involving the formation of voids at the inclusion sites and their growth and eventual linking up through the rupture of the intervening ligaments by local shear.

  3. Influence of some additives to the kinetics of Zn-crystal growth onto continuous hot dip galvanized steel

    International Nuclear Information System (INIS)

    Arsovski, Angel; Sekuloski, Predrag; Georgievski, Mile; Mickovski, Jovan

    2003-01-01

    In this work we made attempt on determination of the gefree, of influence, of the different types of additives on zinc spangle growth during forming of zinc coating, at the process of continues hot deep galvanizing of steel strip. All investigations were made at cold rolling mill plant 'Ladna Valavnica'-Skopje - HDG line, Additives were implied manually using hand pump directly on full hard strip, just before annealing furnace. Three types of additives were used in unchanged state as well as their mixtures. Analysis of the results included macro photograph of the surface, microphotograph of the zinc coating as well as different attempts of mathematical models. During investigation all technological parameters (cleanness of the strip from the emulsion marks, temperatures of the different zones of the furnace, temperature of the molten zinc and chemical composition of the zinc pot) remained at their constant values. (Original)

  4. Evaluation of the mechanical properties after thermal treatment of a structural hot rolled multiphase steel

    Directory of Open Access Journals (Sweden)

    Asensio-Lozano, J.

    2007-12-01

    Full Text Available The present paper corresponds to the experimental study conducted on a hot rolled (HR multiphase (MP steel, in which hardness, tensile and toughness properties were measured after the application of a series of subcritical and intercritical heat treatments (HT to the hot rolled stock. The aforementioned values were compared to the corresponding ones in the as-rolled state and after normalizing. The microstructure in the longitudinal plane of the strip was analyzed by light optical microscopy in the as-rolled state and in the HT samples. Longitudinal (L and transverse (T tensile and toughness specimens were cut to characterize every condition studied. Toughness properties were evaluated by means of Charpy V-notch tests conducted at 20 °C, 0 °C, –20 °C, –40 °C, –60 °C and –80 °C . It was observed that the yield stress increased with the increase in the heat treatment temperature in the subcritical range, while the tensile strength decreased slightly over the same range of temperatures. Uniform and total elongation only showed a slight improvement when the treatment was conducted at 620 °C and 700 °C, while the best toughness response corresponded to the sample treated at 500 °C for operating temperatures comprised between –40 °C and room temperature (RT.

    El presente estudio corresponde al trabajo experimental desarrollado en un acero multifase laminado en caliente, en el que se evaluaron las propiedades de dureza, tracción y tenacidad a impacto, tras realizar tratamientos térmicos subcríticos e intercríticos al material laminado en caliente. Los valores precedentes se comparan con el material de partida laminado en caliente y tras tratamiento de normalizado. Se analiza la microestructura en microscopía óptica de reflexión, en el plano longitudinal tanto en el estado laminado como en las muestras tratadas térmicamente. Se estudiaron los comportamientos longitudinales y transversales en tracción y frente a impacto

  5. The influence of the hardening coolant agent on the properties of hot rolled bars of the steel 42CrMo4

    Directory of Open Access Journals (Sweden)

    M. Stańczyk

    2014-10-01

    Full Text Available In the work the influence results of two different hardening coolant agents on the basic mechanical proprieties and microstructure of the round hot rolled bars were presented. The bars of 42CrMo4 steel were exposed to analysis, and for those bars in the hardening process, water and modern pro-ecological polymer cooling agents Aqua Quench MK were used.

  6. Evolution of recrystallization microstructure and texture during rapid annealing in strip-cast non-oriented electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Feng [The State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Xu, Yun-Bo, E-mail: yunbo_xu@126.com [The State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Zhang, Yuan-Xiang; Wang, Yang; Lu, Xiang [The State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China); Misra, R.D.K [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials Research and Innovation and Department of Metallurgical and Materials Engineering, University of Texas at El Paso, 500W, University Avenue, El Paso, TX 79968 (United States); Wang, Guo-Dong [The State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang 110819 (China)

    2015-05-01

    Non-oriented electrical steel as-cast strip was produced by twin roll strip casting process, and subsequently cold rolled and annealed at heating rates in the range of 3–450 °C/s with the aim to elucidate the effect of heating rate on the evolution of recrystallized microstructure and texture. The average grain size was rapidly increased when the heating rate was increased from 3 to 25 °C/s, and decreased when the heating rate was greater than 25 °C/s. The average grain size did not increase linearly with heating rate, which was related to different degree of nucleation and growth rate. The recrystallization texture exhibited pronounced improvement during rapid annealing. At high heating rate, the Goss and Cube had a higher probability of nucleation of shear bands with high stored energy, while the intensity of the γ-fiber texture was significantly reduced. The highest B{sub 50} value attained was 1.803 T at a heating rate of 300 °C/s. The study indicates that rapid heating has strong effect on the recrystallization behavior in non-oriented electrical steels, which facilitates optimization of microstructure and texture, especially in the coarse-grained structure. - Highlights: • The effects of heating rate on the microstructure and texture of non-oriented steel were investigated. • The average grain size did not change monotonically with heating rate. • Recrystallization texture exhibited pronounced improvement in the as-cast strip. • Superior magnetic properties were obtained in twin-rolled strip casting process.

  7. Fabrication of cold-rolled bands of the alloy-ehi 702 in rolls

    International Nuclear Information System (INIS)

    Zhuchin, V.N.; Gindin, A.Sh.; Shaburov, V.E.; Vladimirov, S.M.; Sokolov, V.A.; Shavkun, V.V.; Perepelitsa, I.V.; Markov, V.V.; Naymov, E.P.; Evstaf'ev, P.P.

    1977-01-01

    The questions are discussed, connected with the manufacture of cold-rolled strip of alloy EI702 in reels from strip blanks. It has been established that in the manufacture of hot-rolled stock from EI702 slabs it is necessary to use powerful rolling equipment because of high resistance to deformation. The reel method for manufacturing EI702 alloy improves the rolled stock and increases percentage of serviceable stock, as well as the output

  8. Effect of skin pass rolling reduction rate on the texture evolution of a non-oriented electrical steel after inclined cold rolling

    Energy Technology Data Exchange (ETDEWEB)

    Mehdi, Mehdi [CanmetMATERIALS, Natural Resources Canada, Hamilton, ON L8P 0A5 (Canada); Department of Mechanical, Automotive, and Materials Engineering, University of Windsor, Windsor, ON N9B 3P4 (Canada); He, Youliang, E-mail: youliang.he@canada.ca [CanmetMATERIALS, Natural Resources Canada, Hamilton, ON L8P 0A5 (Canada); Hilinski, Erik J. [Tempel Steel Co., Chicago, IL 60640-1020 (United States); Edrisy, Afsaneh [Department of Mechanical, Automotive, and Materials Engineering, University of Windsor, Windsor, ON N9B 3P4 (Canada)

    2017-05-01

    In order to promote the magnetically favourable <001>//ND texture (θ-fibre) and minimize the unfavourable <111>//ND fibre (γ-fibre) in non-oriented electrical steel, an unconventional cold rolling scheme was employed in this study, in which the cold rolling was carried out at an angle (i.e. 30°, 45°, 60°, and 90°) to the hot rolling direction (HRD). After annealing, two steel sheets (i.e. those after cold rolling at 60° and 45° to the HRD) were found to have considerably different textures from other sheets, i.e. showing the strongest and the weakest θ-fibre textures, respectively. These two sheets were then subjected to skin pass rolling to various reduction rates from 5–20% to investigate the effect of rolling reduction on the evolution of texture. It was found that during skin pass rolling, the cube texture ({001}<100>) was gradually weakened and the rotated cube orientation ({001}<110>) was strengthened. With the increase of the reduction rate, the {112}<110> orientation on the α-fibre became a major component. Upon final annealing, the cube texture was slightly restored, but the volume fraction was considerably lower than that before skin pass rolling. - Highlights: • Inclined cold rolling optimizes the textures of non-oriented electrical steels. • A 60° angle to the hot rolling direction results in the largest improvement of the favorable texture. • Skin pass rolling weakens the cube texture and promotes the {112}<110> texture. • Final annealing restores some of the cube texture and strengthens the rotated cube texture. • Low Taylor factor of the cube orientation leads to its easy deformation in skin pass rolling.

  9. Experimental determination of heat transfer coefficients in roll bite and air cooling for computer simulations of 1100 MPa carbon steel rolling

    Science.gov (United States)

    Leinonen, Olli; Ilmola, Joonas; Seppälä, Oskari; Pohjonen, Aarne; Paavola, Jussi; Koskenniska, Sami; Larkiola, Jari

    2018-05-01

    In modeling of hot rolling pass schedules the heat transfer phenomena have to be known. Radiation to ambient, between rolls and a steel slab as well as heat transfer in contacts must be considered to achieve accurate temperature distribution and thereby accurate material behavior in simulations. Additional heat is generated by friction between the slab and the work roll and by plastic deformation. These phenomena must be taken into account when the effective heat transfer coefficient is determined from experimental data. In this paper we determine the effective heat transfer coefficient at the contact interface and emissivity factor of slab surface for 1100MPa strength carbon steel for hot rolling simulations. Experimental pilot rolling test were carried out and slab temperatures gathered right below the interface and at the mid thickness of the slab. Emissivity factor tests were carried out in the same manner but without rolling. Experimental data is utilized to derive contact heat transfer coefficient at the interface and emissivity factor of slab surface. Pilot rolling test is reproduced in FE-analysis to further refine the heat transfer coefficient and emissivity factor. Material mechanical properties at rolling temperatures were determined by Gleeble™ thermo-mechanical simulator and IDS thermodynamic-kinetic-empirical software.

  10. A Study on Compressive Anisotropy and Nonassociated Flow Plasticity of the AZ31 Magnesium Alloy in Hot Rolling

    Directory of Open Access Journals (Sweden)

    Guoqiang Wang

    2014-01-01

    Full Text Available Effect of anisotropy in compression is studied on hot rolling of AZ31 magnesium alloy with a three-dimensional constitutive model based on the quadratic Hill48 yield criterion and nonassociated flow rule (non-AFR. The constitutive model is characterized by compressive tests of AZ31 billets since plastic deformations of materials are mostly caused by compression during rolling processes. The characterized plasticity model is implemented into ABAQUS/Explicit as a user-defined material subroutine (VUMAT based on semi-implicit backward Euler's method. The subroutine is employed to simulate square-bar rolling processes. The simulation results are compared with rolled specimens and those predicted by the von Mises and the Hill48 yield function under AFR. Moreover, strip rolling is also simulated for AZ31 with the Hill48 yield function under non-AFR. The strip rolling simulation demonstrates that the lateral spread generated by the non-AFR model is in good agreement with experimental data. These comparisons between simulation and experiments validate that the proposed Hill48 yield function under non-AFR provides satisfactory description of plastic deformation behavior in hot rolling for AZ31 alloys in case that the anisotropic parameters in the Hill48 yield function and the non-associated flow rule are calibrated by the compressive experimental results.

  11. Tensile property improvement of TWIP-cored three-layer steel sheets fabricated by hot-roll-bonding with low-carbon steel or interstitial-free steel

    Science.gov (United States)

    Park, Jaeyeong; Kim, Jung-Su; Kang, Minju; Sohn, Seok Su; Cho, Won Tae; Kim, Hyoung Seop; Lee, Sunghak

    2017-01-01

    TWIP-cored three-layer steel sheets were newly fabricated by hot rolling of TWIP steel sheet surrounded by low-carbon (LC) or interstitial-free (IF) steel sheets. TWIP/LC or TWIP/IF interfaces were well bonded without pores or voids, while a few pearlites were thinly formed along the interfaces. The strengths and elongation of the TWIP-cored sheets increased as the volume fraction of TWIP-cored region increased, and were also well matched with the ones calculated by a rule of mixtures based on volume fraction or force fraction. According to digital image correlation and electron back-scatter diffraction analyses, very high strain hardening effect in the initial deformation stage and active twin formation in the interfacial region beneficially affected the overall homogeneous deformation in the TWIP-cored sheets without any yield point phenomenon occurring in the LC sheet and serrations occurring in the TWIP sheet, respectively. These TWIP-cored sheets can cover a wide range of yield strength, tensile strength, and ductility levels, e.g., 320~498 MPa, 545~878 MPa, and 48~54%, respectively, by controlling the volume fraction of TWIP-cored region, and thus present new applications to multi-functional automotive steel sheets requiring excellent properties.

  12. Non-Metallic Inclusions and Hot-Working Behaviour of Advanced High-Strength Medium-Mn Steels

    Directory of Open Access Journals (Sweden)

    Grajcar A.

    2016-06-01

    Full Text Available The work addresses the production of medium-Mn steels with an increased Al content. The special attention is focused on the identification of non-metallic inclusions and their modification using rare earth elements. The conditions of the thermomechanical treatment using the metallurgical Gleeble simulator and the semi-industrial hot rolling line were designed for steels containing 3 and 5% Mn. Hot-working conditions and controlled cooling strategies with the isothermal holding of steel at 400°C were selected. The effect of Mn content on the hot-working behaviour and microstructure of steel was addressed. The force-energetic parameters of hot rolling were determined. The identification of structural constituents was performed using light microscopy and scanning electron microscopy methods. The addition of rare earth elements led to the total modification of non-metallic inclusions, i.e., they replaced Mn and Al forming complex oxysulphides. The Mn content in a range between 3 and 5% does not affect the inclusion type and the hot-working behaviour. In contrast, it was found that Mn has a significant effect on a microstructure.

  13. A Study of the Batch Annealing of Cold-Rolled HSLA Steels Containing Niobium or Titanium

    Science.gov (United States)

    Fang, Chao; Garcia, C. Isaac; Choi, Shi-Hoon; DeArdo, Anthony J.

    2015-08-01

    The batch annealing behavior of two cold-rolled, microalloyed HSLA steels has been studied in this program. One steel was microalloyed with niobium while the other with titanium. A successfully batch annealed steel will exhibit minimum variation in properties along the length of the coil, even though the inner and outer wraps experience faster heating and cooling rates and lower soaking temperatures, i.e., the so-called "cold spot" areas, than the mid-length portion of the coil, i.e., the so-called "hot spot" areas. The variation in strength and ductility is caused by differences in the extent of annealing in the different areas. It has been known for 30 years that titanium-bearing HSLA steels show more variability after batch annealing than do the niobium-bearing steels. One of the goals of this study was to try to explain this observation. In this study, the annealing kinetics of the surface and center layers of the cold-rolled sheet were compared. The surface and center layers of the niobium steel and the surface layer of the titanium steel all showed similar annealing kinetics, while the center layer of the titanium steel exhibited much slower kinetics. Metallographic results indicate that the stored energy of the cold-rolled condition, as revealed by grain center sub-grain boundary density, appeared to strongly influence the annealing kinetics. The kinetics were followed by the Kernel Average Misorientation reconstruction of the microstructure at different stages on annealing. Possible pinning effects caused by microalloy precipitates were also considered. Methods of improving uniformity and increasing kinetics, involving optimizing both hot-rolled and cold-rolled microstructure, are suggested.

  14. 75 FR 65453 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Flat Products From Brazil: Notice of...

    Science.gov (United States)

    2010-10-25

    ... Nucor Corporation (Nucor) and United States Steel Corporation (U.S. Steel), domestic producers of hot..., the Department received requests from Nucor and U.S. Steel (collectively, domestic producers), that... July 6, 2010 (CBP Memo). On July 22, 2010, and July 23, 2010, respectively, Nucor and U.S. Steel timely...

  15. Low carbon manganese-nickel-niobium steel

    International Nuclear Information System (INIS)

    Heisterkamp, F.; Hulka, K.

    1983-11-01

    Experimental heats of a low carbon-manganese-0.5% nickel-0.15% niobium steel have been rolled to plates between 13.5 and 50 mm thickness and to a 16 mm hot strip. Various combinations of soaking temperatures form 1100 0 C to 1300 0 C and of finish rolling temperatures between 710 0 C and 930 0 C have been investigated. From mechanical properties obtained, one can conclude that the investigated steel composition provides very good properties e.g. for pipe steels X65 to X75. In particular, the toughness at low temperature is outstanding despite relaxed rolling conditions. Metalographic and special investigations such as electron microscopy, texture evaluation and chemical extraction, correlated with applied rolling schedules and the mechanical properties obtained resulted in a comprehensive understanding about the benefits of high niobium metallurgy combined with nickel addition. All practically applied welding processes generated mechanical properties, in particular toughness of the weldment, that meet arctic specifications.(Author) [pt

  16. Microstructure, texture and magnetic properties of strip-cast 1.3% Si non-oriented electrical steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yuanxiang, E-mail: yunboxu@126.com [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China); Xu Yunbo; Liu Haitao; Li Chenggang; Cao Guangming; Liu Zhenyu; Wang Guodong [State Key Laboratory of Rolling Technology and Automation, Northeastern University, Shenyang (China)

    2012-10-15

    In this work, the evolution of microstructure, texture and magnetic properties of non-oriented 1.3% silicon steel processed using the twin-roll strip casting was investigated, especially under different solidification structures. A number of microstructures about the as-cast strips show that the initial solidification structure of casting a strip can be controlled by the melt superheats. The microstructures with the average grain size of {approx}100-400 {mu}m can be obtained in strips when the melt superheats are from 20 to 60 Degree-Sign C. A nearly random, diffuse, homogeneous texture under a low melt superheat, but comparatively developed {l_brace}100{r_brace} oriented grains are formed under a high melt superheat through the cast strip thickness. The relatively low core loss and high magnetic induction can be obtained in the cold rolled and annealed sheets when increasing the initial grain size of cast-strip. The textures in annealed sheets with coarse initial grain size are characterized by the relatively strong Goss component and {l_brace}001{r_brace} fiber but weak {gamma}-fiber component, which lead to the high permeability. - Highlights: Black-Right-Pointing-Pointer The superheat has an evident effect on the grain size and orientation of strip. Black-Right-Pointing-Pointer Developed Cube and Goss textures were formed in the annealed sheet. Black-Right-Pointing-Pointer High magnetic properties were obtained in the twin-rolled strip casting process.

  17. Hot-rolled Process of Multilayered Composite Metal Plate

    Directory of Open Access Journals (Sweden)

    YU Wei

    2017-02-01

    Full Text Available For multi-layer plate, it is a difficult problem to increase product yield rate and improve bonding interface quality. A high yield hot-rolled method of multilayered plate was proposed. The raw strips and plate were fixed by argon arc welding. The combined billet was put into a metal box and vacuum pumped, and then heated and rolled by multi passes at the temperature of 1000-1200℃. The 67 layered plate with the thickness of 2.5mm was successfully produced. The interfacial microstructures and diffusion behavior were investigated and analyzed by optical microscopy and scan electronic microscopy. The tensile and shear strength were tested,and the shear fractures were analyzed. The results show that the multilayered plate yield rate is more than 90% by two steps billet combination method and rolling process optimization. The good bonding interface quality is obtained, the shear strength of multilayered plate reaches 241 MPa. Nickel interlayer between 9Cr18 and 1Cr17 can not only prevent the diffusion of carbon, but also improve the microstructure characteristics.

  18. Effect of Cooling Rate on the Microstructure and Mechanical Properties of C-Mn-Al-Si-Nb Hot-Rolled TRIP Steels

    Science.gov (United States)

    Fu, B.; Y Lu, M.; Y Yang, W.; Li, L. F.; Y Zhao, Z.

    2017-12-01

    A novel thermomechanical process to manufacture hot-rolled TRIP steels has been proposed based on dynamic transformation of undercooled austenite (DTUA). The cooling rate between DTUA and isothermal bainitic treatment in the novel process is important. In the present study, effect of this cooling rate on the final microstructures and mechanical properties of a C-Mn-Al-Si-Nb TRIP steel was investigated. The results showed that the volume fractions of acicular ferrite and retained austenite were increased with the increment of cooling rate. As a consequence, higher yield strength and larger total elongation were obtained for the investigated steel with higher cooling rate. In addition, a value of 30.24 GPa% for the product of tensile strength and total elongation was acquired when the cooling rate was 25 K/s. This value has met the standard of the “Third Generation” of advanced high strength sheet steels.

  19. Thin slab processing of acicular ferrite steels with high toughness

    Energy Technology Data Exchange (ETDEWEB)

    Reip, Carl-Peter; Hennig, Wolfgang; Hagmann, Rolf [SMS Demag Aktiengesellschaft, Duesseldorf (Germany); Sabrudin, Bin Mohamad Suren; Susanta, Ghosh; Lee, Weng Lan [Megasteel Sdn Bhd, Banting (Malaysia)

    2005-07-01

    Near-net-shape casting processes today represent an important option in steelmaking. High productivity and low production cost as well as the variety of steel grades that can be produced plus an excellent product quality are key factors for the acceptance of such processes in markets all over the world. Today's research focuses on the production of pipe steel with special requirements in terms of toughness at low temperatures. The subject article describes the production of hot strip made from acicular ferritic / bainitic steel grades using the CSP thin-slab technology. In addition, the resulting strength and toughness levels as a function of the alloying concepts are discussed. Optimal control of the CSP process allows the production of higher-strength hot-rolled steel grades with a fine-grain acicular-ferritic/bainitic microstructure. Hot strip produced in this way is characterized by a high toughness at low temperatures. In a drop weight tear test, transition temperatures of up to -50 deg C can be achieved with a shear-fracture share of 85%. (author)

  20. Fatigue crack growth behaviors in hot-rolled low carbon steels: A comparison between ferrite–pearlite and ferrite–bainite microstructures

    International Nuclear Information System (INIS)

    Guan, Mingfei; Yu, Hao

    2013-01-01

    The roles of microstructure types in fatigue crack growth behaviors in ferrite–pearlite steel and ferrite–bainite steel were investigated. The ferrite–bainite dual-phase microstructure was obtained by intermediate heat treatment, conducted on ferrite–pearlite hot-rolled low carbon steel. This paper presents the results from investigation using constant stress-controlled fatigue tests with in-situ scanning electron microscopy (SEM), fatigue crack growth (FCG) rate tests, and fatigue fractography analysis. Microscopy images arrested by in-situ SEM showed that the fatigue crack propagation in F–P steel could become unstable more ealier compared with that in F–B steel. The fatigue cracks in ferrite–pearlite were more tortuous and could propagate more freely than that in ferrite–bainite microstructures. However, frequent crack branching were observed in ferrite–bainite steel and it indicated that the second hard bainite phase effectively retarded the crack propagation. The variation of FCG rate (da/dN) with stress intensity factor range (ΔK) for F–P and F–B steels was discussed within the Paris region. It was shown that FCG rate of F–P steel was higher than that of F–B steel. Moreover, the fatigue fracture surface analysis proved that grain boundaries could also play a role in the resistance of crack propagation.

  1. The effect of microstructure on the sheared edge quality and hole expansion ratio of hot-rolled 700 MPa steel

    Science.gov (United States)

    Kaijalainen, A.; Kesti, V.; Vierelä, R.; Ylitolva, M.; Porter, D.; Kömi, J.

    2017-09-01

    The effects of microstructure on the cutting and hole expansion properties of three thermomechanically rolled steels have been investigated. The yield strength of the studied 3 mm thick strip steels was approximately 700 MPa. Detailed microstructural studies using laser scanning confocal microscopy (LCSM), FESEM and FESEM-EBSD revealed that the three investigated materials consist of 1) single-phase polygonal ferrite, 2) polygonal ferrite with precipitates and 3) granular bainite. The quality of mechanically sheared edges were evaluated using visual inspection and LSCM, while hole expansion properties were characterised according to the methods described in ISO 16630. Roughness values (Ra and Rz) of the sheet edge with different cutting clearances varied between 12 µm to 21 µm and 133 µm to 225 µm, respectively. Mean hole expansion ratios varied from 28.4% to 40.5%. It was shown that granular bainite produced the finest cutting edge, but the hole expansion ratio remained at the same level as in the steel comprising single-phase ferrite. This indicates that a single-phase ferritic matrix enhances hole expansion properties even with low quality edges. A brief discussion of the microstructural features controlling the cutting quality and hole expansion properties is given.

  2. Influence of Al content on the corrosion resistance of micro-alloyed hot rolled steel as a function of grain size

    Science.gov (United States)

    Qaban, Abdullah; Naher, Sumsun

    2018-05-01

    High-strength low-alloy steel (HSLA) has been widely used in many applications involving automobiles, aerospace, construction, and oil and gas pipelines due to their enhanced mechanical and chemical properties. One of the most critical elements used to improve these properties is Aluminium. This work will explore the effect of Al content on the corrosion behaviour of hot rolled high-strength low-alloy steel as a function of grain size. The method of investigation employed was weight loss technique. It was obvious that the increase in Al content enhanced corrosion resistance through refinement of grain size obtained through AlN precipitation by pinning grain boundaries and hindering their growth during solidification which was found to be beneficial in reducing corrosion rate.

  3. Influence of the Radiation Shield on the Temperature of Rails Rolled in the Reversing Mill

    Directory of Open Access Journals (Sweden)

    Gołdasz A.

    2015-04-01

    Full Text Available The paper presents a mathematical model of heat transfer during cooling of hot-rolled rails in the reversing mill. The influence of the radiation shield on the temperature of rolled rails has been analyzed. The heat transfer model for cooling a strip covered by the thermal shield has been presented. The two types of shields build of steel and aluminum sheets separated with insulating layer have been studded. Calculations have been performed with self developed software which utilizes the finite element method.

  4. Improvement of impact toughness by modified hot working and heat treatment in 13%Cr martensitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Srivatsa, Kulkarni, E-mail: srivatsa.kulkarni@kcssl.com; Srinivas, Perla; Balachandran, G.; Balasubramanian, V.

    2016-11-20

    Improvement of the general mechanical properties and in particular sub-zero impact toughness in a 0.2%C-13%Cr martensitic stainless steel has been explored by varying the hot deformation and heat treatment conditions. The deformation conditions include hot rolling an ingot in one case and cogging the ingot to a semis followed by hot rolling in another case. The bars made from both routes were subjected to a single hardening heat treatment at 980 °C and 1040 °C oil quenched and a double hardening heat treatment at 1040 °C followed by 980 °C oil quenched. The hardened steels were subjected to a standard two stage tempering at 710 °C followed by 680 °C. The impact toughness was found to be doubled in the cogged and rolled steel in double hardened condition. Other processing conditions show varying impact toughness levels. The toughness observed was correlated to the grain size and the carbide distribution in the matrix and the fractography features.

  5. Advanced automobile steels subjected to plate rolling at 773 K or 1373 K

    Science.gov (United States)

    Torganchuk, Vladimir; Belyakov, Andrey; Kaibyshev, Rustam

    2017-12-01

    The high manganese steels exhibiting the effects of twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) demonstrate an excellent combination of enhanced formability, strength and ductility. Such unique mechanical properties make high-manganese steel the most attractive material for various applications, including the segment of advanced automobile steels. The strain hardening in such steels can be achieved through martensitic transformation, when the stacking fault energy (SFE) is about 10 mJ m-2, and/or twinning, when SFE is about 20 to 50 mJ m-2. The actual mechanical properties of high-Mn steels could vary, depending on the conditions of thermo-mechanical processing. In the present study, the effect of rolling temperature on the microstructure and mechanical properties of 18% Mn steels was clarified. The steels hot rolled at 1373 K were characterized by uniform almost equiaxed grains with near random crystallographic orientations that resulted in relatively low yield strengths of 300-360 MPa, followed by pronounced strain hardening that led to the total elongation above 60%. In contrast, the steels warm rolled at 773 K were characterized by flattened grains with a strong rolling texture and high yield strengths of 850-950 MPa combined with a total elongation of about 30%.

  6. 75 FR 64254 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Products From Brazil; Final Results of...

    Science.gov (United States)

    2010-10-19

    ...-Rolled Carbon Quality Steel Products From Brazil; Final Results of Antidumping Duty Administrative Review... for the Final Results, 75 FR 19369 (April 14, 2010) (Preliminary Results). This review covers sales of... Products from Brazil,'' dated June 22, 2010 (USIMINAS Sales Verification Report). Following the release of...

  7. Fabrication of Hadfield-Cored Multi-layer Steel Sheet by Roll-Bonding with 1.8-GPa-Strength-Grade Hot-Press-Forming Steel

    Science.gov (United States)

    Chin, Kwang-Geun; Kang, Chung-Yun; Park, Jaeyeong; Lee, Sunghak

    2018-05-01

    An austenitic Hadfield steel was roll-bonded with a 1.8-GPa-strength-grade martensitic hot-press-forming (HPF) steel to fabricate a multi-layer steel (MLS) sheet. Near the Hadfield/HPF interface, the carburized and decarburized layers were formed by the carbon diffusion from the Hadfield (1.2%C) to HPF (0.35%C) layers, and could be regarded as kinds of very thin multi-layers of 35 μm in thickness. The tensile test and fractographic data indicated that the MLS sheet was fractured abruptly within the elastic range by the intergranular fracture occurred in the carburized layer. This was because C was mainly segregated at prior austenite grain boundaries in the carburized layer, which weakened grain boundaries to induce the intergranular fracture. In order to solve the intergranular facture problem, the MLS sheet was tempered at 200 °C. The stress-strain curve of the tempered MLS sheet lay between those of the HPF and Hadfield sheets, and a rule of mixtures was roughly satisfied. Tensile properties of the MLS sheet were dramatically improved after the tempering, and the intergranular fracture was erased completely. In particular, the yield strength up to 1073 MPa along with the high strain hardening and excellent ductility of 32.4% were outstanding because the yield strength over 1 GPa was hardly achieved in conventional austenitic steels.

  8. Structural and spectroscopic characterisations of the surface oxide scales and inclusions present on edge-burst hot-rolled steel coils

    International Nuclear Information System (INIS)

    Chowdhury, Anirban; Iyyappan, Ramasamy; Majumdar, Dipanwita; Singha, Achintya

    2014-01-01

    Detailed structural and spectroscopic characterisations have been carried out on the inclusions and the surface oxides present on edge-burst hot-rolled steel coils. Surface scales were characterised through X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. Evidence of different types of regular and non-stoichiometric Fe-oxides was found on the cracked surface of the steel wire. Along with the surface scales inclusions with calcium aluminate and spinel was characterized using Raman spectroscopy. The usefulness of Raman spectroscopy has been explored in detail for the characterisation of these inclusions; especially when XRD information ceases to be a limiting tool. The samples collected from the clogged nozzle area were found to be of grossite (CaO·2Al 2 O 3 ) phase and this was also observed in the inclusions in the finished coils. It was found that this particular calcium aluminate phase has a detrimental effect on casting and final finished steel products. - Highlights: • First investigation and surface study report on edge-bursting issue of steel coils. • Detailed characterisations of the inclusions and surface oxide scales in steel. • Influence of a particular type of calcium aluminate phase on process chemistry

  9. Possible influences on textures in unalloyed steels and their effects on steel properties

    International Nuclear Information System (INIS)

    Grossterlinden, R.; Imlau, K.P.; Kawalla, R.; Lotter, U.; Reip, C.-P.

    1996-01-01

    Textures in steels play an essential role for applications where anisotropic properties are favourable. For the example of deep-drawing steel sheet the correlation between parameters characterising the behaviour in the deep-drawing process, as Lankford r-value and planar anisotropy Δr, and the crystallographic texture is considered. Furthermore, the development of texture in the course of manufacturing cold strip is followed for unalloyed and microalloyed deep-drawing grades. For representation of typical features of textures the method of orientation distribution functions (ODF) together with the description of texture by characteristic fibres is used. In detail, the parameters influencing textures, such as chemical composition, finishing temperature in the hot-rolling mill (in relation to the austenite or ferrite region), transformation behaviour, cold-rolling reduction and the course of temperature during recrystallizing annealing, are discussed. From the given survey it may be concluded, that in the manufacturing process there are many possibilities to control the texture of the finished product. Finally, it is shown that the impact of textures on the r-value can be calculated with high precision. On the other hand, the formation of texture itself, particularly during hot-rolling, transformation and recrystallization after cold-rolling, at present can be calculated and modelled only in simple cases. (orig.)

  10. Effect of heating and deformation conditions on the depth of surface defects in alloyed steel rolling

    International Nuclear Information System (INIS)

    Malygin, R.Z.; Karyakin, B.P.; Grosman, A.B.; Simovskikh, V.N.; Storozhev, V.I.

    1978-01-01

    The effect of heating and deformation conditions on the depth change of artificial defects in the 50 KhFA alloyed steel rolling on the 850 blooming and 450 section mill was studied. Quite a definite regularity in the arrangement of defects (cracks and hairlines) along the circumference of the round steel bar and obvious relation with the defect distribution on the bloom faces are established. Oxidation is shown to diminish defect depth while ingot and billet heating especially on the faces under direct firing. Blooms should be placed in the furnace with 90 deg canting in relation to the faces position while ingot heating. Round rolling must be performed with one or several 45 deg strip cantings. The defect depth for the ingots to be rolled without chipping is set up

  11. Microstructure and microtexture evolutions of deformed oxide layers on a hot-rolled microalloyed steel

    International Nuclear Information System (INIS)

    Yu, Xianglong; Jiang, Zhengyi; Zhao, Jingwei; Wei, Dongbin; Zhou, Cunlong; Huang, Qingxue

    2015-01-01

    Highlights: • Microtexture development of deformed oxide layers is investigated. • Magnetite shares the {0 0 1} fibre texture with wustite. • Hematite develops the {0 0 0 1} basal fibre parallel to the oxide growth. • Stress relief and ion vacancy diffusion mechanism for magnetite seam. - Abstract: Electron backscatter diffraction (EBSD) analysis has been presented to investigate the microstructure and microtexture evolutions of deformed oxide scale formed on a microalloyed steel during hot rolling and accelerated cooling. Magnetite and wustite in oxide layers share a strong {0 0 1} and a weak {1 1 0} fibres texture parallel to the oxide growth. Trigonal hematite develops the {0 0 0 1} basal fibre parallel to the crystallographic plane {1 1 1} in magnetite. Taylor factor estimates have been conducted to elucidate the microtexture evolution. The fine-grained magnetite seam adjacent to the substrate is governed by stress relief and ions vacancy diffusion mechanism

  12. A Coupled Model for Work Roll Thermal Contour with Subsectional Cooling in Aluminum Strip Cold Rolling

    Directory of Open Access Journals (Sweden)

    Shao Jian

    2014-10-01

    Full Text Available Little attention had been given to the evaluation of subsectional cooling control ability under complicated working conditions. In this paper, heat generation was calculated by using finite difference method. Strip hardening, work roll elastic deformation and elastic recovery of strip were taken into account. The mean coefficient of convective heat transfer on work roll surface was simulated by FLUENT. Calculation model had used the alternative finite difference scheme, which improved the model stability and computing speed. The simulation result shows that subsectional cooling control ability is different between different rolling passes. Positive and negative control abilities are roughly the same in the same pass. The increase of rolled length, working pressure of header and friction coefficient has positive effect on subsectional cooling control ability, and the rolling speed is on the contrary. On the beginning of the pass, when work roll surface has not reached the stable temperature, control ability of subsectional cooling is mainly affected by rolled length. The effect of mean coefficient of convective heat transfer and coefficient of friction is linear. When rolling speed is over 500 m/min, control ability of subsectional cooling becomes stable.

  13. Microstructural characterization of Zr1Nb alloy after hot rolling

    Energy Technology Data Exchange (ETDEWEB)

    Souza, A.C. [Universidade Estadual do Mato Grosso do Sul (UEMS), MS (Brazil); Rossi, J.L.; Martinez, L.G.; Mucsi, C.S. [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Tsakiropoulos, P. [University of Sheffield (United Kingdom); Ceoni, F.C.; Grandini, C.R. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), SP (Brazil)

    2016-07-01

    Full text: The different research lines within the scope in engineering and materials science have developed new materials that can be used in different industrial sectors, such as, energy, health and transportation. For the nuclear industry, for example, the Zr alloys, are of great interest due to its good mechanical properties, excellent corrosion resistance and above all, the high permeability to thermal neutrons. In the health sector, the zirconium poses one of the lowest Young's modulus when compared to other metallic biomaterials, e.g., pure Zr is 68 GPa, bone mineral hydroxyapatite is 80 GPa, for Ti alloys is 90 GPa and above, for Nb is 105 GPa and stainless steels above 189 GPa. This is particularly important for implants in bones, whose elasticity modulus can reach 30 GPa and it is desirable an as close match as possible. However, the zirconium alloys, have great chemical affinity with oxygen and nitrogen. Moreover, oxides and nitrides may form during the melting process, heat treatment and hot rolling, changing the physic-chemical properties of the alloy. This experimental work shows the results of the evolution of the microstructure after hot rolling of the Zr1Nb alloy. It was possible to confirm the absence of formation of oxides and nitrides, thus confirming the of the experimental method of melting and hot rolling of the Zr1Nb alloy. (author)

  14. Plasticity of low carbon steel in a hot state

    Energy Technology Data Exchange (ETDEWEB)

    Konovalov, V P; Rizol' , A I; Shram, N N [Ural' skij Nauchno-Issledovatel' skij Inst. Chernykh Metallov, Sverdlovsk (USSR)

    1977-07-01

    The hot ductility (in tapered-specimen piersing test and the in wedge-shaped specimen rolling test) is studied of the Armeo-type low carbon steel produced by vacuum induction and open hearth techniques. The variations of the chemical composition within specified ranges, particularly as regards sulphur, oxygen and the Mn/S ratio, have a marked effect on the processing ductility. The temperature range of brittle fracture and acceptable hot working reductions as functions of the chemical composition have been revealed.

  15. Plasticity of low carbon steel in a hot state

    International Nuclear Information System (INIS)

    Konovalov, V.P.; Rizol', A.I.; Shram, N.N.

    1977-01-01

    The hot ductility (in tapered-specimen piersing test and the in wedge-shaped specimen rolling test) is studied of the Armeo-type low carbon steel produced by vacuum induction and open hearth techniques. The variations of the chemical composition within specified ranges, particularly as regards sulphur, oxygen and the Mn/S ratio, have a marked effect on the processing ductility. The temperature range of brittle fracture and acceptable hot working reductions as functions of the chemical composition have been revealed

  16. Multilayer Steel Materials Deformation Resistance and Roll Force Measurement

    Directory of Open Access Journals (Sweden)

    A. G. Kolesnikov

    2014-01-01

    Full Text Available To create new types of cars, raise their reliability, gain operational life, and decrease in metal consumption of products it is necessary to improve mechanical, physical, and also special properties of the constructional materials applied in mechanical engineering. Presently, there are intensive researches and developments under way to create materials with ultrafine-grained structure (the sizes of grains in their crystal lattice make less than 1 micron in one of the measurements.BMSTU developed a manufacturing technology of multilayer steel sheets with steady ultrafine-grained structure based on the multiple hot rolling of billet as a composition consisting of the alternating metal sheets. A principled condition for implementation of such technology is existence of different crystallographic modifications in the adjoining sheets of the composition at specified temperature of rolling.Power parameters of rolling are important technical characteristics of the process. Usually, to determine a deformation resistance value when rolling the diverse multilayer materials, is used the actual resistance value averaging in relation to the components of the composition. The aim of this work is a comparative analysis of known calculated dependences with experimental data when rolling the 100-layer samples. Objects of research were the 100-layer compositions based on the alternating layers of steel 08H18N10 and U8.Experimental samples represented the vacuumized capsules with height, width, and length of 53 mm x 53 mm x 200 mm, respectively, in which there were the 100-layer packs from sheets, each of 0.5 mm, based on the composition of steels (U8+08H18N10. Rolling was made on the double-high mill with rolls of 160 mm in diameter during 19 passes to the thickness of 7 mm with the speed of 0,1 m/s. Relative sinking in each pass was accepted to be equal 10±2,5%. Rolling forces were measured by the strain-gauging method using the measuring cells, located under

  17. Effect of two-step intercritical annealing on microstructure and mechanical properties of hot-rolled medium manganese TRIP steel containing δ-ferrite

    International Nuclear Information System (INIS)

    Xu, Yun-bo; Hu, Zhi-ping; Zou, Ying; Tan, Xiao-dong; Han, Ding-ting; Chen, Shu-qing; Ma, De-gang; Misra, R.D.K.

    2017-01-01

    The microstructure-properties relationship, work-hardening behavior and retained austenite stability have been systematically investigated in a hot-rolled medium manganese transformation-induced-plasticity (TRIP) steel containing δ-ferrite subjected to one-step and two-step intercritical annealing. The steel exhibited tensile strength of 752 MPa and total elongation of 52.7% for one-step intercritical annealing at 740 °C, tensile strength of 954 MPa and total elongation of 39.2% in the case of intercritical quenching at 800 °C and annealing at 740 °C. The austenite obtained by two-step annealing mostly consists of refined lath structures and increased fraction of block-type particles existing at various kinds of sites, which is highly distinguished from those characterized by long lath morphology and small amounts of granular shape in one-step annealed samples. In spite of a higher C and Mn content in austenite and finer austenite laths, two-step annealing can lead to an active and continuous TRIP effect provided by a mixed blocky and lath-type austenitic structure with lower stability, contributing to a higher UTS. In contrast, one-step annealing gave rise to a less active but sustained TRIP effect given by the dominant lath-like austenite having higher stability, leading to a very high elongation. The further precipitation of vanadium carbides and the presence of both dislocation substructure and fine equiaxed grain in ferrite matrix facilitate the increase of yield strength after double annealing. - Highlights: • A novel two-step process was applied to a hot-rolled Fe-0.2C-6.5Mn-3Al steel. • The interplay between different microstructures and mechanical properties was studied. • Two-step annealing led to an active and continuous TRIP. • An outstanding combination of strength of 954 MPa and elongation of 39.2% was obtained.

  18. Effect of two-step intercritical annealing on microstructure and mechanical properties of hot-rolled medium manganese TRIP steel containing δ-ferrite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yun-bo [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, People' s Republic China (China); Hu, Zhi-ping, E-mail: huzhiping900401@126.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, People' s Republic China (China); Zou, Ying; Tan, Xiao-dong; Han, Ding-ting; Chen, Shu-qing [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819, People' s Republic China (China); Ma, De-gang [Tangshan Iron and Steel Company, Tangshan 063000, People' s Republic China (China); Misra, R.D.K. [Laboratory for Excellence in Advanced Steel Research, Department of Metallurgical, Materials and Biomedical Engineering, University of Texas at El Paso, TX 79968 (United States)

    2017-03-14

    The microstructure-properties relationship, work-hardening behavior and retained austenite stability have been systematically investigated in a hot-rolled medium manganese transformation-induced-plasticity (TRIP) steel containing δ-ferrite subjected to one-step and two-step intercritical annealing. The steel exhibited tensile strength of 752 MPa and total elongation of 52.7% for one-step intercritical annealing at 740 °C, tensile strength of 954 MPa and total elongation of 39.2% in the case of intercritical quenching at 800 °C and annealing at 740 °C. The austenite obtained by two-step annealing mostly consists of refined lath structures and increased fraction of block-type particles existing at various kinds of sites, which is highly distinguished from those characterized by long lath morphology and small amounts of granular shape in one-step annealed samples. In spite of a higher C and Mn content in austenite and finer austenite laths, two-step annealing can lead to an active and continuous TRIP effect provided by a mixed blocky and lath-type austenitic structure with lower stability, contributing to a higher UTS. In contrast, one-step annealing gave rise to a less active but sustained TRIP effect given by the dominant lath-like austenite having higher stability, leading to a very high elongation. The further precipitation of vanadium carbides and the presence of both dislocation substructure and fine equiaxed grain in ferrite matrix facilitate the increase of yield strength after double annealing. - Highlights: • A novel two-step process was applied to a hot-rolled Fe-0.2C-6.5Mn-3Al steel. • The interplay between different microstructures and mechanical properties was studied. • Two-step annealing led to an active and continuous TRIP. • An outstanding combination of strength of 954 MPa and elongation of 39.2% was obtained.

  19. 77 FR 70142 - Initialed Draft Revision to the Agreement Suspending the Antidumping Investigation on Certain Hot...

    Science.gov (United States)

    2012-11-23

    ... the Agreement Suspending the Antidumping Investigation on Certain Hot-Rolled Flat-Rolled Carbon... revision to the Agreement Suspending the Antidumping Investigation on Certain Hot-Rolled Flat-Rolled Carbon...'') investigation on hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from the Russian...

  20. Hot-rolling metals in vacuum. Information circular

    International Nuclear Information System (INIS)

    Beall, R.A.; Worthington, R.B.; Blickensderfer, R.

    1979-01-01

    The process of hot-rolling metals, alloys, and composites in vacuum is studied. First, a comprehensive review of the literature is presented, including the advantages and disadvantages of using vacuum. Next, details of hot-rolling titanium, chromium, and molybdenum-iron bimetal are given. Finally, the design of new equipment is described

  1. 75 FR 47541 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil and Japan: Final Results of...

    Science.gov (United States)

    2010-08-06

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-351-828, A-588-846] Hot-Rolled Flat..., Department of Commerce. SUMMARY: On April 1, 2010, the Department of Commerce (the Department) initiated... Department has conducted expedited (120-day) sunset reviews for both orders pursuant to 19 CFR 351.218(e)(1...

  2. Effect of Rolling and Subsequent Annealing on Microstructure, Microtexture, and Properties of an Experimental Duplex Stainless Steel

    Science.gov (United States)

    Mandal, Arka; Patra, Sudipta; Chakrabarti, Debalay; Singh, Shiv Brat

    2017-12-01

    A lean duplex stainless steel (LDSS) has been prepared with low-N content and processed by different thermo-mechanical schedules, similar to the industrial processing that comprised hot-rolling, cold-rolling, and annealing treatments. The microstructure developed in the present study on low-N LDSS has been compared to that of high-N LDSS as reported in the literature. As N is an austenite stabilizer, lower-N content reduced the stability of austenite and the austenite content in low-N LDSS with respect to the conventional LDSS. Due to low stability of austenite in low-N LDSS, cold rolling resulted in strain-induced martensitic transformation and the reversion of martensite to austenite during subsequent annealing contributed to significant grain refinement within the austenite regions. δ-ferrite grains in low-N LDSS, on the other hand, are refined by extended recovery mechanism. Initial solidification texture (mainly cube texture) within the δ-ferrite region finally converted into gamma-fiber texture after cold rolling and annealing. Although MS-brass component dominated the austenite texture in low-N LDSS after hot rolling and cold rolling, that even transformed into alpha-fiber texture after the final annealing. Due to the significant grain refinement and formation of beneficial texture within both austenite and ferrite, good combination of strength and ductility has been achieved in cold-rolled and annealed sample of low-N LDSS steel.

  3. Analysis of the strengthening mechanisms in pipeline steels as a function of the hot rolling parameters

    International Nuclear Information System (INIS)

    Carretero Olalla, V.; Bliznuk, V.; Sanchez, N.; Thibaux, P.; Kestens, L.A.I.; Petrov, R.H.

    2014-01-01

    The yield strength of different pipeline steel grades, rolled under four different conditions, was correlated with calculated strengthening contributions. Slabs with the same composition were rolled under identical roughing conditions but varied finish rolling temperature (FRT). Two cooling routes, consisting of accelerated water cooling condition (ACC) followed by slow cooling in an oven to simulate coiling and air cooling were applied after the last rolling pass. The microstructures obtained after each thermo mechanical controlled process (TMCP) schedule, were characterized using Transmission Electron Microscopy (TEM), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Electron backscatter diffraction (EBSD). The mechanical properties of the plates were determined by means of tensile tests and Charpy V-notch impact test. It was confirmed that a combination of fast cooling rate and low finish rolling temperature produces higher strength than the slow cooling rate and high finish rolling temperature. Contributions to the strengthening arising from the various microstructural features like solid solution strengthening, grain size, dislocation density and precipitation hardening, were analyzed using Taylor, Hall–Petch and Ashby–Orowan approaches. The root of the sum of the squares method was applied to link the experimental with the model-predicted strength. It is believed that this approach provides a better understanding of the effect of TMCP parameters on the microstructure and strengthening mechanisms in pipeline steels

  4. A study of roll-bonding MS90 alloy to steel utilizing chromized interlayer

    International Nuclear Information System (INIS)

    Tolaminejad, B.; Arabi, H.

    2008-01-01

    This article describes a study of the application of a roll bonding technique to MS90(CuZn10) alloy strips and steel sheets using a chromized interlayer. It was found that the overall bond between these two metals resulted from two different types of bonds: a block bond, linking the MS90 alloy strips and chromium topcoat layer, and a blank bond, linking the MS90 alloy strips and bare steel surface in the area where the chromium coating has been fragmented. This study investigated the effects of plating time on the thickness of the coating layers and of the area fraction of the blank bond on the bond strength. The overall bond strength depends mainly on the strength and the area fraction of the blank bond. A linear relationship model exists between the overall bond strength and the area fraction of the blank bond. The bond strength of the blank bond was eight times greater than that of the block bond. The area fraction of the blank bond increased with increasing the coating thickness up to 55 μm, but thereafter decreased due to the rotation of the chromium blocks

  5. Effect of melt conditioning on heat treatment and mechanical properties of AZ31 alloy strips produced by twin roll casting

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sanjeev, E-mail: sanjeevdas80@gmail.com [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); Barekar, N.S. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); El Fakir, Omer; Wang, Liliang [Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Prasada Rao, A.K.; Patel, J.B.; Kotadia, H.R.; Bhagurkar, A. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); Dear, John P. [Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Fan, Z. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom)

    2015-01-03

    In the present investigation, magnesium strips were produced by twin roll casting (TRC) and melt conditioned twin roll casting (MC-TRC) processes. Detailed optical microscopy studies were carried out on as-cast and homogenized TRC and MC-TRC strips. The results showed uniform, fine and equiaxed grain structure was observed for MC-TRC samples in as-cast condition. Whereas, coarse columnar grains with centreline segregation were observed in the case of as-cast TRC samples. The solidification mechanisms for TRC and MC-TRC have been found completely divergent. The homogenized TRC and MC-TRC samples were subjected to tensile test at elevated temperature (250–400 °C). At 250 °C, MC-TRC sample showed significant improvement in strength and ductility. However, at higher temperatures the tensile properties were almost comparable, despite of TRC samples having larger grains compared to MC-TRC samples. The mechanism of deformation has been explained by detailed fractures surface and sub-surface analysis carried out by scanning electron and optical microscopy. Homogenized MC-TRC samples were formed (hot stamping) into engineering component without any trace of crack on its surface. Whereas, TRC samples cracked in several places during hot stamping process.

  6. 77 FR 26600 - WTO Dispute Settlement Proceeding Regarding United States-Countervailing Measures on Certain Hot...

    Science.gov (United States)

    2012-05-04

    ... Proceeding Regarding United States-- Countervailing Measures on Certain Hot-Rolled Carbon Steel Flat Products... certain hot-rolled carbon steel flat products from India. That request may be found at www.wto.org... requested consultations concerning countervailing measures regarding certain hot-rolled carbon steel flat...

  7. Effects of initial microstructure and texture on microstructure, texture evolution and magnetic properties of non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Li, Hua-Long [Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Wang, Hui [Science and Technology on Surface Physics and Chemistry Laboratory, P.O. Box No. 9-35, Huafengxincun, Jiangyou City, Sichuan Province 621908 (China); National Key Laboratory for Nuclear Fuel and Materials, Nuclear Power Institute of China, Chengdu 610041 (China); Liu, Yi; Gao, Fei; An, Ling-Zi; Zhao, Shi-Qi; Liu, Zhen-Yu; Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China)

    2016-05-15

    An equiaxed grained as-cast strip and a columnar grained as-cast strip was produced by using twin-roll strip casting, respectively. Both as-cast strips mainly containing 0.71 wt%Si and 0.44 wt%Al were cold rolled and annealed with or without the hot rolling prior to cold rolling. Microstructure, texture evolution along the whole processing routes and the magnetic properties were investigated in detail. It was found that the equiaxed grained strip was characterized by almost random texture while the columnar grained strip was dominated by strong λ-fiber (<001>‖ND) texture. After cold rolling and annealing, all the final sheets of both the as-cast strips showed extremely weak γ-fiber (<111>‖ND) recrystallization texture. In addition, the finally annealed sheets of the equiaxed grained strip were dominated by relatively weak λ-fiber and strong Goss ({110}<001>) recrystallization texture while those of the columnar grained strip were dominated by much stronger λ-fiber and much weaker Goss recrystallization texture regardless of whether the hot rolling was adopted before cold rolling, thus the former showed much lower magnetic induction than the latter. On the other hand, even though the finally annealed sheets of the equiaxed grained strip showed a little more homogeneous recrystallization microstructure with a little bigger grain size than those of the columnar grained strip in the case of no hot rolling, a much higher iron loss was displayed. By contrast, in the case of hot rolling, the former exhibited a little lower iron loss than the latter as a result of the more significant increase in grain size and λ-fiber recrystallization texture. The introduction of the hot rolling could increase the grain size, strengthen λ-fiber texture and weaken Goss texture of the finally annealed sheets of both the as-cast strips, leading to a much improvement in both the magnetic induction and iron loss. - Highlights: • Equiaxed and columnar grained as-cast strips were

  8. Microstructure analysis of AISI 304 stainless steel produced by twin-roll thin strip casting process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microstructure of AISI 304 austenite stainless steel fabricated by the thin strip casting process were investigated using optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD).The microstructures of the casting strips show a duplex structure consisting of delta ferrite and austenite. The volume fraction of the delta ferrite is about 9.74vol% at the center and 6.77vol% at the surface of the casting thin strip, in vermicular and band shapes. On account of rapid cooling and solidification in the continuous casting process, many kinds of inclusions and precipitates have been found. Most of the inclusions and precipitates are spherical complex compounds consisting of oxides, such as, SiO2, MnO, Al2O3,Cr2O3,and FeO or their multiplicity oxides of MnO·Al2O3,2FeO·SiO2, and 2MnO·SiO2. Many defects including dislocations and stacking faults have also formed during the rapid cooling and solidification process, which is helpful to improve the mechanical properties of the casting strips.

  9. 77 FR 49477 - WTO Dispute Settlement Proceeding Regarding United States-Countervailing Measures on Certain Hot...

    Science.gov (United States)

    2012-08-16

    ... Proceeding Regarding United States-- Countervailing Measures on Certain Hot-Rolled Carbon Steel Flat Products... certain hot-rolled carbon steel flat products from India. That request may be found at www.wto.org... countervailing measures regarding certain hot-rolled carbon steel flat products from India (Investigation C-533...

  10. Influence of structure and properties of tubular billets of the 12 Kh 18N10T steel on deformability of tubes at cold-rolling mills

    International Nuclear Information System (INIS)

    Vil'yams, O.S.; Bol'shova, N.M.; Olejnik, O.V.; Velikotnaya, E.S.

    1979-01-01

    Metallographic analysis of the defects of the ''oblique cracks'' type on the surface of hot-rolled tubes of the 12Kh18N10T steel has been carried out. Recommended is the complex of mechanical properties and the structure factors (grain size) of conversion hot-rolled tubes, providing the combination of ductility and high rapture strength during rolling at pilger mills. At a grain size not coarser than number 5, a billet must have σsub(T) 5 >=40 %. Hot-rolled coarse-grained billet is not recommended for warm rolng because of high strain hardening

  11. 78 FR 15703 - Certain Hot-Rolled Carbon Steel Flat Products From India, Indonesia, the People's Republic of...

    Science.gov (United States)

    2013-03-12

    ... Others 20.28 Thailand Sahaviriya Steel Industries 7.35 Public Co., Ltd. Siam Strip Mill Public Co., 20.30... People's Republic of China, Taiwan, Thailand, and Ukraine; Final Results of the Expedited Second Sunset... steel flat products from India, Indonesia, the People's Republic of China (PRC), Taiwan, Thailand, and...

  12. Numerical simulation of springback of medium-thick plates in local hot rolling

    Directory of Open Access Journals (Sweden)

    XIE Dong

    2017-10-01

    Full Text Available [Objectives] In order to understand the factors of springback in the local hot rolling of medium-thick steel plates,[Methods] a 3D thermal-elastic-plastic analysis is conducted to investigate the factors affecting the amount of springback. Through a series of numerical analyses,the influence of deformation temperature,temperature field distribution,plate size and local loading are examined. [Results] The results show that when the deformation temperature exceeds a certain level at which material yield stress begins to decrease significantly,the springback will reduce markedly with the increase in temperature. Due to the distribution characteristics of the deformation area,the influence of temperature distribution on springback where the local deformation scale is larger is dominated by the three dimensions of temperature field distribution. Changes in the length and width of the plate have a certain influence on the springback,in which changes to the length of a plate where the local deformation scale is larger have a more obvious influence on springback. The springback of the plate decreases with the increase of local loading. [Conclusions] The results of this study can assist in the optimization of parameters in the automatic hot rolling of thick plates,while also having a basic guiding effect on the further study of springback in the local hot rolling of thick plates.

  13. Optimization of the process of steel strip perforation and nickel platting for the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strip

    Directory of Open Access Journals (Sweden)

    Petrović Aleksandra B.

    2009-01-01

    Full Text Available In the production of pocket type electrodes for Ni-Cd batteries perforation of proper steel strips and then nickel platting of perforated steel strips were made. In the nickel platting process, the organic solvent, trichloroethylene, has previously been used for cleaning. Due to the carcinogenic nature of trichloroethylene and the many operations previously required during cleaning, it was considered to do cleaning of perforated steel strips without use of the mentioned organic solvent. In the purpose of elimination of trichloroethylene from the cleaning process of perforated steel strips, the tests of perforation of steel strips with use of oils of different viscosity were made. It was shown that there was no dysfunction during the work of the perforation plants, meaning there was no additional heating of the strips, deterring of the steel filings, nor excessive wearing of the perforation apparatus. The perforation percent was the same irrelevant of the viscosity of the used oil. Before being perforated using the oils with different viscosity, the nickel platting steel strips were cleaned in different degreasers (based on NaOH as well as on KOH. It was shown that efficient cleaning without the use of trichloroethylene is possible with the use of oil with smaller viscosity in the perforated steel strips process and the degreaser based on KOH in the cleaning process, before nickel platting. It also appeared that the alkali degreaser based on KOH was more efficient, bath corrections were made less often and the working period of the baths was longer, which all in summary means less quantity of chemicals needed for degreasing of perforated steel strips.

  14. Properties isotropy of magnesium alloy strip workpieces

    Directory of Open Access Journals (Sweden)

    Р. Кавалла

    2016-12-01

    Full Text Available The paper discusses the issue of obtaining high quality cast workpieces of magnesium alloys produced by strip roll-casting. Producing strips of magnesium alloys by combining the processes of casting and rolling when liquid melt is fed continuously to fast rolls is quite promising and economic. In the process of sheet stamping considerable losses of metal occur on festoons formed due to anisotropy of properties of foil workpiece, as defined by the macro- and microstructure and modes of rolling and annealing. The principal causes of anisotropic mechanical properties of metal strips produced by the combined casting and rolling technique are the character of distribution of intermetallic compounds in the strip, orientation of phases of metal defects and the residual tensions. One of the tasks in increasing the output of fit products during stamping operations consists in minimizing the amount of defects. To lower the level of anisotropy in mechanical properties various ways of treating the melt during casting are suggested. Designing the technology of producing strips of magnesium alloys opens a possibility of using them in automobile industry to manufacture light-weight body elements instead of those made of steel.

  15. PECULIAR FEATURES PERTAINING TO STRIP FORMATION FROM BAR

    Directory of Open Access Journals (Sweden)

    G. N. Zdor

    2010-01-01

    Full Text Available The paper describes results of calculations and presents experimental substantiation of the dependence of a strip width being rolled out of a 10-mm diameter bar on its final thickness. It has been shown that the formation technology of thin steel strips out of a round bar makes it possible without any difficulties to obtain rolled products with the given cross-section dimensions due to proper selection of single drafting.

  16. Secondary recrystallization behavior in a twin-roll cast grain-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Song, Hong-Yu; Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn; Wang, Yin-Ping; Wang, Guo-Dong

    2017-04-15

    The microstructure and texture evolution along the processing was investigated with a particular focus on the secondary recrystallization behavior in a 0.23 mm-thick twin-roll cast grain-oriented electrical steel. A striking feature is that Goss orientation originated during twin-roll casting as a result of shear deformation and it was further enhanced during hot rolling and normalizing. After primary recrystallization annealing, a homogeneous microstructure associated with a sharp γ-fiber texture was produced. During secondary recrystallization annealing, the γ-fiber texture was first strengthened and weakened with increasing temperature prior to the onset of secondary recrystallization. Goss grains always exhibited more 20–45° misoriented boundaries than the matrix. The matrix was quite stable during secondary recrystallization with the aid of dense inhibitors. Finally, a complete secondary recrystallization microstructure consisting of large Goss grains was produced. The grain boundary characteristics distribution indicated that the high energy model was responsible for the abnormal growth of Goss grains under the present conditions. - Highlights: • A 0.23 mm twin-roll cast grain-oriented silicon steel sheet was produced. • Goss orientation originated during twin-roll casting. • Secondary recrystallization behavior was briefly investigated. • γ-fiber texture was enhanced prior to the onset of secondary recrystallization. • A complete secondary recrystallization microstructure was produced.

  17. Microstructural changes after control rolling and interrupted accelerated cooling simulations in pipeline steel

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Mourino, Nuria; Petrov, Roumen [Department of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052 Ghent (Belgium); Bae, Jin-Ho; Kim, Kisoo [Sheet Products and Process Research Group, POSCO, Jeonnam, 545-090 (Korea, Republic of); Kestens, Leo A.I. [Department of Materials Science and Engineering, Ghent University, Technologiepark Zwijnaarde 903, B-9052 Ghent (Belgium); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD, Delft (Netherlands)

    2011-04-15

    The {gamma}-{alpha} transformation and final microstructure in pipeline steel was studied by carrying out a number of physical simulations of industrial hot rolling schedules. Particularly, the effect of the reheating temperature, deformation and cooling parameters on the transformation temperatures and final grain size were considered with a goal to obtain an appropriate thermo-mechanical processing route which will generate appropriate microstructures for pipeline applications. The CCT diagram of the steel was derived experimentally by means of dilatometric tests. Hot torsion experiments were applied in a multi-deformation cycle at various temperatures in the austenite region to simulate industrial rolling schedules. By variation of the reheating temperature, equivalent strain, and accelerated cooling, different types of microstructures were obtained. It was found that the deformation increases the transformation temperatures whereas the higher cooling rates after deformation decrease them. Post-deformation microstructure consists of fine bainitic-ferrite grains with dispersed carbides and small amount of dispersed martensite/austenite islands which can be controlled by varying the reheating temperature, deformation and post-deformation cooling. The detailed microstructure characteristics obtained from the present work could be used to optimize the mechanical properties, strength and toughness of pipeline steel grades by an appropriate control of the thermo-mechanical processing. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. Hot rolling of thick uranium molybdenum alloys

    Science.gov (United States)

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  19. 3-D Transient Heat Transfer Analysis of Slab Heating Characteristics in a Reheating Furnace in Hot Strip Mills

    OpenAIRE

    J. Y. Jang; Y. W. Lee; C. N. Lin; C. H. Wang

    2015-01-01

    The reheating furnace is used to reheat the steel slabs before the hot-rolling process. The supported system includes the stationary/moving beams, and the skid buttons which block some thermal radiation transmitted to the bottom of the slabs. Therefore, it is important to analyze the steel slab temperature distribution during the heating period. A three-dimensional mathematical transient heat transfer model for the prediction of temperature distribution within the slab ha...

  20. Microstructure evolution during spray rolling and heat treatment of 2124 Al

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, K.M. [Industrial Technology Department, Idaho National Laboratory, Idaho Falls, ID 83415-2050 (United States)], E-mail: kevin.mchugh@inl.gov; Lin, Y.; Zhou, Y.; Johnson, S.B.; Delplanque, J.-P.; Lavernia, E.J. [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616 (United States)

    2008-03-25

    Spray rolling is a strip-casting technology that combines elements of spray forming and twin-roll casting. It consists of atomizing molten metal with a high velocity inert gas, quenching the resultant droplets in flight, and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets and conduction heat transfer at the rolls rapidly remove the metal's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly-solidified strip. Spray rolling operates at a higher solidification rate than conventional twin-roll casting and is able to process a broader range of alloys at high production rates. A laboratory-scale strip caster was constructed and used to evaluate the interplay of processing parameters and strip quality for strips up to 200 mm wide and 1.6-6.4 mm thick. This paper examines microstructure evolution during spray rolling and explores how gas-to-metal mass flow ratio influences the microstructure and mechanical properties of spray-rolled 2124 Al. The influences of solution heat treatment and cold rolling on grain structure and constituent particle spheroidization are also examined.

  1. METHOD OF HOT ROLLING URANIUM METAL

    Science.gov (United States)

    Kaufmann, A.R.

    1959-03-10

    A method is given for quickly and efficiently hot rolling uranium metal in the upper part of the alpha phase temperature region to obtain sound bars and sheets possessing a good surface finish. The uranium metal billet is heated to a temperature in the range of 1000 deg F to 1220 deg F by immersion iii a molten lead bath. The heated billet is then passed through the rolls. The temperature is restored to the desired range between successive passes through the rolls, and the rolls are turned down approximately 0.050 inch between successive passes.

  2. Multivariable H force/level control of the twin-roller strip caster

    International Nuclear Information System (INIS)

    Cavazos, A.; Edwards, J.B.

    2005-01-01

    Twin-roller steel strip casters may offer some advantages with respect to classical continuous casting hot rolling processes. Some works have reported control aspects of this process and although the process has been found to be highly interactive and non-linear, little or no attention has been given to its multivariable characteristics. The purpose of this work is to design a multivariable control capable of decoupling the system. This paper presents some important aspects of the strip caster modeling and reports the simulation results of the application of the multivariable H-optimal control for nominal performance to force/level control. Various controllers have been designed for different pool level heights and it is shown that they can decouple the system, allowing the application of PI decentralized controllers to considerably improve performance. (author)

  3. Refinement of ferrite grain size during hot direct rolling of hsla steel

    International Nuclear Information System (INIS)

    Ajmal, M.

    2001-01-01

    Steel ingots containing 0.04 wt % Nb and varying contents of carbon were made in laboratory, that simulated thin slab casting. Mn and Si content were kept constant at 1.35 % and 0.25 % respectively. After each casting the mould assembly was transferred to the rolling mill and the temperature of the ingot was monitored. Each ingot was rolled to 4mm thickness in three passes. The first pass of 43% reduction for all the ingots were given at 1140 degree C. The second pass (reduction, 35 %) for all the ingots were given at 1040 degree C. However the temperature for third pass (reduction, 30 %) was varied to retain more strain in the austenite prior to transformation. It was shown that third pass at lower temperature i.e. 810 degree C in the austenite range yields a ferrite grains size of 2-3 micrometer. A yield strength of 465 Mpa and tensile strength of 530 Mpa can also be achieved in these plates. (author)

  4. Development of Low Carbon Niobium Bearing High Strength F-B Dual Phase Steel with High Hole Expansion Property

    Science.gov (United States)

    Zhang, Lin; Xia, Ming-sheng; Xiong, Zi-liu; Du, Yan-bing; Qiao, Zhi-ming; Zhang, Hong-bo

    In the study a low carbon niobium bearing high strength F-B dual phase automobile steel with high hole expansion property has been investigated. Steels of different chemical composition have been investigated by simulation experiments of controlled rolling and cooling process to study the influences of chemical elements, especially for C,Nb and Ti, and cooling pattern on the mechanical properties, flangeability and microstructure of strips. So-called 3-stages cooling pattern was adopted in simulation experiments, combining ultra fast cooling in first stage, air cooling in middle stage and fast cooling in the last stage, and at the end of run-out table the temperature of rolled pieces drop to below Bs point. Optical microstructure and SEM morphology have been observed. Results indicate that it is possible to obtain dual phase microstructure of polygonal ferrite plus bainite in adopting 3-stages cooling pattern. The low temperature coiling method using 3-step controlled cooling pattern after hot rolling is effective to produce low carbon Nb bearing steel with high balance of strength-ductility-flangeability, in addition, higher carbon content of steel tend to be detrimental to flangeability of steel, due to much carbide precipitation at ferrite boundary. Based on the results of simulation experiments mill trial has been carried out and hot rolled high strength steel with tensile strength higher as 600Mpa and hole expansion ratio higher as 100% has been developed successfully.

  5. [Factors influencing electrocardiogram results in workers exposed to noise in steel-making and steel-rolling workshops of an iron and steel plant].

    Science.gov (United States)

    Li, Y H; Yu, S F; Gu, G Z; Chen, G S; Zhou, W H; Wu, H; Jiao, J

    2016-02-20

    To investigate the factors influencing the electrocardiogram results in the workers exposed to noise in steel-making and steel rolling workshops of an iron and steel plant. From September to December, 2013, cluster sampling was used to select 3 150 workers exposed to noise in the steel-making and steel-rolling workshops of an iron and steel plant, and a questionnaire survey and physical examinations were performed. The number of valid workers was 2 915, consisting of 1 606 workers in the steel-rolling workshop and 1 309 in the steel-making workshop. The electrocardiogram results of the workers in steel-making and steel-rolling workshops were analyzed. The overall abnormal rate of electrocardiogram was 26.35%, and the workers in the steel-making workshop had a significantly higher abnormal rate of electrocardiogram than those in the steel-rolling workshop(32.24% vs 21.54%, Pelectrocardiogram than female workers(27.59% vs 18.61%, Pelectrocardiogram than those who did not drink(28.17% vs 23.75%, Pelectrocardiogram than those who were not exposed to high temperature(29.43% vs 20.14%, Pelectrocardiogram in the workers with cumulative noise exposure levels of electrocardiogram results. High cumulative noise exposure, alcohol consumption, and high temperature may affect the abnormal rate of electrocardiogram in the workers exposed to noise in steel-making and steel-rolling workshops.

  6. Effect of hot rolling on the structure and the mechanical properties of nitrogen-bearing austenitic-martensitic 14Kh15AN4M steel

    Science.gov (United States)

    Bannykh, O. A.; Betsofen, S. Ya.; Lukin, E. I.; Blinov, V. M.; Voznesenskaya, N. M.; Tonysheva, O. A.; Blinov, E. V.

    2016-04-01

    The effect of the rolling temperature and strain on the structure and the properties of corrosionresistant austenitic-martensitic 14Kh15AN4M steel is studied. The steel is shown to exhibit high ductility: upon rolling in the temperature range 700-1100°C at a reduction per pass up to 80%, wedge steel specimens are uniformly deformed along and across the rolling direction without cracking and other surface defects. Subsequent cold treatment and low-temperature tempering ensure a high hardness of the steel (50-56 HRC). Austenite mainly contributes to the hardening upon rolling in the temperature range 700-800°C at a reduction of 50-70%, and martensite makes the main contribution at higher temperatures and lower strains. Texture does not form under the chosen deformation conditions, which indicates dynamic recrystallization with the nucleation and growth of grains having no preferential orientation.

  7. Microstructure and texture evolution of different high manganese cast steels during hot deformation and subsequent treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lima, M.N.S.; Andrade, C.D.; Abreu, H.F.G. de; Klug, J.; Masoumi, M., E-mail: mohammad@alu.ufc.br [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Depto. de Engenharia Metalurgica e de Materiais; Ferreira, W.M. [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Curso de Engenharia Mecanica

    2016-07-01

    Microstructure and texture evolution were studied in two different austenitic high manganese cast steels in each processing condition. Special attention was paid to the effects of hot deformation and subsequent treatment on grain orientation behavior. The roles of Mn and C elements as well as heat treatment processes were investigated by Thermo-Calc. The texture evolutions in the as-cast, solution heat treatment, as-rolled and subsequent treatment were explored via orientation distribution function. The results showed that face-centred cube austenite was developed in steels. Strong {110}<115> texture component was characterized in as-cast in both alloys. Then, the inhomogeneity microstructure and the pronounced microsegregations were removed by annealing and Brass {110}<112>, {110}<111> and {221}<102> components were formed. Finally, cube {001}<100> component was developed during hot rolling in samples. (author)

  8. Microstructure and texture evolution of different high manganese cast steels during hot deformation and subsequent treatment

    International Nuclear Information System (INIS)

    Lima, M.N.S.; Andrade, C.D.; Abreu, H.F.G. de; Klug, J.; Masoumi, M.; Ferreira, W.M.

    2016-01-01

    Microstructure and texture evolution were studied in two different austenitic high manganese cast steels in each processing condition. Special attention was paid to the effects of hot deformation and subsequent treatment on grain orientation behavior. The roles of Mn and C elements as well as heat treatment processes were investigated by Thermo-Calc. The texture evolutions in the as-cast, solution heat treatment, as-rolled and subsequent treatment were explored via orientation distribution function. The results showed that face-centred cube austenite was developed in steels. Strong {110}<115> texture component was characterized in as-cast in both alloys. Then, the inhomogeneity microstructure and the pronounced microsegregations were removed by annealing and Brass {110}<112>, {110}<111> and {221}<102> components were formed. Finally, cube {001}<100> component was developed during hot rolling in samples. (author)

  9. Simple Heat Treatment for Production of Hot-Dip Galvanized Dual Phase Steel Using Si-Al Steels

    Science.gov (United States)

    Equihua-Guillén, F.; García-Lara, A. M.; Muñíz-Valdes, C. R.; Ortíz-Cuellar, J. C.; Camporredondo-Saucedo, J. E.

    2014-01-01

    This work presents relevant metallurgical considerations to produce galvanized dual phase steels from low cost aluminum-silicon steels which are produced by continuous strip processing. Two steels with different contents of Si and Al were austenized in the two-phase field ferrite + austenite (α + γ) in a fast manner to obtain dual phase steels, suitable for hot-dip galvanizing process, under typical parameters of continuous annealing processing line. Tensile dual phase properties were obtained from specimens cooled from temperature below Ar3, held during 3 min, intermediate cooling at temperature above Ar1 and quenching in Zn bath at 465 °C. The results have shown typical microstructure and tensile properties of galvanized dual phase steels. Finally, the synergistic effect of aluminum, silicon, and residual chromium on martensite start temperature ( M s), critical cooling rate ( C R), volume fraction of martensite, and tensile properties has been studied.

  10. Effects of thermo-mechanical treatment and microalloying with Cr, Nb and Ti on phase transformation in C-Mn steel strips produced by compact strip production process

    International Nuclear Information System (INIS)

    Zhu, Y.Z.; Liang, D.M.; Li, J.C.; Xu, J.P.; Xue, Z.L.

    2011-01-01

    Highlights: → The order of solid solution of carbides influences phase transformation of C-Mn steel in cooling. → Evidences of early stage of solid solution of carbides were provides in the paper. → Transitional state evidences such as carbon enriched regions were observed in this study. - Abstract: The C-Mn steel strips microalloyed with Cr, Nb, Ti was produced by compact strip production process and then heat-treated under different conditions. Optical microscopy, scanning electron microscopy, energy dispersive spectroscopy and transmission electron microscopy were used to investigate phase transformations in the steel after different treatments. It was revealed that the phase transformations upon quenching were greatly affected by the austenization temperature and time. When the steel was annealed at 950 deg. C, carbides of Cr, Mn and Fe were dissolved dramatically, while carbides of Nb and Ti are relatively stable at this temperature. When the temperature increases to 1100 deg. C, the carbides of Nb were dissolved rapidly, while the carbides of Ti still show somewhat stable (partial dissolution). Annealing time influences both the amount and the shapes of carbides in the steel, which leads to different phase transformations in the following air cooling processes. Grain growth in the steel in annealing process strongly depends on the dissolution of carbides on grain boundaries. Additionally, a subsequent rolling after annealing treatment at 950 deg. C lead to obvious precipitation of carbides of Ti and Nb in the steel.

  11. Adaptive Automatic Gauge Control of a Cold Strip Rolling Process

    Directory of Open Access Journals (Sweden)

    ROMAN, N.

    2010-02-01

    Full Text Available The paper tackles with thickness control structure of the cold rolled strips. This structure is based on the rolls position control of a reversible quarto rolling mill. The main feature of the system proposed in the paper consists in the compensation of the errors introduced by the deficient dynamics of the hydraulic servo-system used for the rolls positioning, by means of a dynamic compensator that approximates the inverse system of the servo-system. Because the servo-system is considered variant over time, an on-line identification of the servo-system and parameter adapting of the compensator are achieved. The results obtained by numerical simulation are presented together with the data taken from real process. These results illustrate the efficiency of the proposed solutions.

  12. Research and Development Trend of Shape Control for Cold Rolling Strip

    Science.gov (United States)

    Wang, Dong-Cheng; Liu, Hong-Min; Liu, Jun

    2017-09-01

    Shape is an important quality index of cold rolling strip. Up to now, many problems in the shape control domain have not been solved satisfactorily, and a review on the research progress in the shape control domain can help to seek new breakthrough directions. In the past 10 years, researches and applications of shape control models, shape control means, shape detection technology, and shape control system have achieved significant progress. In the aspect of shape control models, the researches in the past improve the accuracy, speed and robustness of the models. The intelligentization of shape control models should be strengthened in the future. In the aspect of the shape control means, the researches in the past focus on the roll optimization, mill type selection, process optimization, local strip shape control, edge drop control, and so on. In the future, more attention should be paid to the coordination control of both strip shape and other quality indexes, and the refinement of control objective should be strengthened. In the aspects of shape detection technology and shape control system, some new types of shape detection meters and shape control systems are developed and have successfully industrial applications. In the future, the standardization of shape detection technology and shape control system should be promoted to solve the problem of compatibility. In general, the four expected development trends of shape control for cold rolling strip in the future are intelligentization, coordination, refinement, and standardization. The proposed research provides new breakthrough directions for improving shape quality.

  13. Medium carbon steel deep drawing: A study on the evolution of mechanical properties, texture and simulations, from cold rolling to the end product

    Energy Technology Data Exchange (ETDEWEB)

    Plaut, Ronald L. [University of Sao Paulo, Sao Paulo (Brazil)], E-mail: rlplaut@usp.br; Padilha, Angelo F. [University of Sao Paulo, Sao Paulo (Brazil); Lima, N.B. [IPEN-CNEN/SP, Sao Paulo (Brazil); Herrera, Clara [Max-Planck-Institut fuer Eisenforschung (Germany); Filho, Antenor Ferreira [Industrial Director, Brasmetal Waelzholz S/A, Diadema (Brazil); Yoshimura, Leandro H. [CCS Consulting, Sao Paulo (Brazil)

    2009-01-15

    Medium carbon steels are mostly used for simple applications; nevertheless new applications have been developed for which good sheet formability is required. This class of steels has an inherent low formability. A medium carbon hot rolled SAE 1050 steel has been selected for this study. It has been cold rolled with reductions in the 7-80% range. Samples have been used to assess the cold work hardening curve. For samples with a 50 and 80% thickness reduction, an annealing heat treatment has been performed to obtain recrystallization. The material has been characterized in the 'as received', cold rolled and annealed conditions, using several methods: optical microscopy, X-ray diffraction (texture), Vickers hardness and tensile testing. The 50% cold rolled and recrystallized material has been further studied in terms of sheet metal formability and texture evolution during the actual stamping of a steel toecap that has been used to validate the finite element simulations.

  14. Effect of nano-sized precipitates on the crystallography of ferrite in high-strength strip steel

    Institute of Scientific and Technical Information of China (English)

    Jing-jing Yang; Run Wu; Wen Liang; Meng-xia Tang

    2014-01-01

    For strip steel with the thickness of 1.6 mm, the yield and tensile strengths as high as 760 and 850 MPa, respectively, were achieved using the compact strip production technology. Precipitates in the steel were characterized by scanning and transmission electron microscopy to elucidate the strengthening mechanism. In addition, intragranular misorientation, Kernel average misorientation, and stored energy were measured using electron backscatter diffraction for crystallographic analysis of ferrite grains containing precipitates and their neighbors without precipitates. It is found that precipitates in specimens primarily consist of TiC and Ti4C2S2. Ferrite grains containing pre-cipitates exhibit the high Taylor factor as well as the crystallographic orientations with{012},{011},{112}, or{221}plane parallel to the rolling plane. Compared with the intragranular orientation of adjoining grains, the intragranular misorientation of grains containing precipi-tates fluctuates more frequently and more mildly as a function of distance. Moreover, the precipitates can induce ferrite grains to store a rela-tively large amount of energy. These results suggest that a correlation exists between precipitation in ferrite grains and grain crystallographic properties.

  15. Effect of the cold-rolling parameters and the yield strength of the strip material on the friction stresses in a deformation zone

    Science.gov (United States)

    Garber, E. A.; Yagudin, I. V.; Ermilov, V. V.; Traino, A. I.

    2009-10-01

    The reliability of the methods of determining the friction coefficient is analyzed, since the friction stresses in the deformation zone during cold rolling significantly affect the quality of cold-rolled sheets and the energy consumption. The well-known experimental data and empirical dependences are shown to contradict each other, and the statistical assurance of these dependences is absent. A database on the interrelated technological and energy-force parameters of a five-stand cold-rolling mill, which includes a wide range of steel grades and strip sizes and shapes, is analyzed. Regression analysis is used to obtain a statistically reliable regression dependence of the friction coefficient in the deformation zone on the most significant technological parameters. The application of this dependence decreases the error of energy-force calculations by more than two times.

  16. Cold-rolled sheets production of stainless martensite-ageing steel smelted by vacuum arc and electroslag techniques

    Energy Technology Data Exchange (ETDEWEB)

    Rivkin, A A; Grishkov, A I; Suslin, A P; Nesterenko, A A; Lola, V N [Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR)

    1975-05-01

    In cooperation with a number of metallurgical works the production of a high strength sheet stainless maraging steel EHP678 (000KH11N10M2T) has been tested by rolling cylindrical ingots of vacuum arc smelting at the blooming (the mass of rough ingots was 5.1 to 6.0 t, that of cleaned ingots - 3.8 to 5.1 t) or rectangular ingots of electroslag smelting (13 t) at the slabbing. The recommended regimes of heating and deformation are much similar to those used for the steel-KH18N10T. The output of valid cold-rolled sheets proved to be rather low (0.24 t/t for the vacuum arc smelting and 0.30 t/t for the electroslag smelting) mainly due to the losses on cleaning and a considerable portion of wrong-size slabs. The data are presented on the steel-EHP678 properties after various heat treatments. For the production of wide cold-rolled sheets of the steel EHP678 it is recommended to use steelmaking procedure with electroslag smelting including open-hearth melting in arc furnaces, rolling of ingots at the slabbing with heating up to 1260-1280 deg C (hold-up of 4.5 to 5 hrs); electroslag smelting for rectangular section slabs, rolling of ingots of electroslag smelting at the slabbing with their heating up to 1250 deg C (hold-up of 5.5 to 6 hrs), rolling at the 1680-type mill with heating up to 1250-1260 deg C (hold-up of 4 to 4.5 hrs ensuring the rolling temperature after a rough group not below 1100 deg C), quenching of hot-rolled sheets heating up to 920-940 deg C (hold-up of 3 to 3.5 min/mm), shot peening of sheets for descaling (provided the respective equipment is available) with a subsequent short-time pickling in an acid solution and cold rolling with a summary deformation of 35 to 45 %. The steelmaking with the electroslag smelting is much more profitable as regards to the fine technology of number of the main procedures, convenient cooperation of the works and a considerably greater output of the final products out of one ton of the steel produced.

  17. The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (Ⅲ) - Comparison on Laser Weldability of Boron Steel and Hot -Stamped Steel-

    Energy Technology Data Exchange (ETDEWEB)

    Choi, So Young; Kim, Jong Do [Korea Maritime and Ocean University, Busan (Korea, Republic of); Kim, Jong Su [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-01-15

    This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and that of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained.

  18. The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (Ⅲ) - Comparison on Laser Weldability of Boron Steel and Hot -Stamped Steel-

    International Nuclear Information System (INIS)

    Choi, So Young; Kim, Jong Do; Kim, Jong Su

    2015-01-01

    This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and that of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained

  19. Influence of hot rolling and high speed hydrostatic extrusion on the microstructure and mechanical properties of an ODS RAF steel

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Z., E-mail: oksiuta@pb.edu.pl [Bialystok Technical University, Faculty of Mechanical Engineering, Wiejska 45c, 15-352 Bialystok (Poland); Lewandowska, M.; Kurzydlowski, K.J. [Warsaw University of Technology, Faculty of Materials Science and Engineering, Woloska 141, 02-504 Warsaw (Poland); Baluc, N. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, 5232 Villigen PSI (Switzerland)

    2011-02-15

    An argon gas atomized, pre-alloyed Fe-14Cr-2W-0.3Ti (wt.%) reduced activation ferritic (RAF) steel powder was mechanically alloyed with 0.3wt.% Y{sub 2}O{sub 3} nano-particles in an attritor ball mill and consolidated by hot isostatic pressing at 1150 {sup o}C under a pressure of 200 MPa for 3 h. In the aim to improve its mechanical properties the ODS steel was then submitted to a thermo-mechanical treatment (TMT): hot rolling (HR) at 850 deg. C or high speed hydrostatic extrusion (HSHE) at 900 deg. C, followed by heat treatment (HT). Transmission electron microscopy (TEM) observations of the ODS alloys after TMT and heat treatment revealed the presence of elongated grains in the longitudinal direction, with an average width of 8 {mu}m and an average length of 75 {mu}m, and equiaxed grains, a few microns in diameter, in the transverse direction. Two populations of oxide particles were observed by TEM: large Ti-Al-O particles, up to 250 nm in diameter, usually located at the grain boundaries and small Y-Ti-O nanoclusters, about 2.5 nm in diameter, uniformly distributed in the matrix. Charpy impact tests revealed that the HSHE material exhibits a larger upper shelf energy (5.8 J) than the HR material (2.9 J). The ductile-to-brittle transition temperature of both alloys is relatively high, in the range of 55-72 deg. C. Tensile mechanical properties of both ODS alloys were found satisfactory over the full range of investigated temperatures (23-750 deg. C). The HSHE material exhibits better tensile strength and ductility than the HR material. These results indicate that HSHE can be considered as a promising TMT method for improving the mechanical properties of ODS RAF steels.

  20. On rolling of alloyed steels on the continuous light-section mill 250

    International Nuclear Information System (INIS)

    Grigor'ev, V.K.; Antipov, V.F.; Zamotin, V.M.; Kuznetsov, Yu.M.

    1976-01-01

    Using the method of computed ratios, the expected loads (torques) have been calculated in the rolling of alloyed steels on the light-section mill 250 of the Chelyabinsk metallurgical works. The deviation of the computed torques from those measured for steels 35GS and St5ps does not exceed -6%. Data are given on changes in torques during the rolling of alloyed steels in the different stands as compared with the actual data for the rolling of ordinary steel. Calculations show, and experimental data confirm, that, according to the torque value, it is possible to roll alloyed steels of sufficiently wide assortment on mill 250

  1. AIS/DOE Technology Roadmap Program: Strip Casting: Anticipating New Routes To Steel Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Prof. Alan W. Camb; Prof. Anthony Rollett

    2001-08-31

    To determine the potential for strip casting in the steel industry and to develop the fundamental knowledge necessary to allow the role of strip casting in the modern steel industry to be understood. Based upon a study of carbon steel strip castings that were either produced for the program at British Steel or were received from a pre-commercial production machine, the following conclusions were made. Strip casting of carbon steels is technically feasible for sheet material from slightly less than 1 mm thick to 3 mm thick, and, assuming that it is economically viable, it will be first applied in carbon steel markets that do not require stringent surface quality or extensive forming. The potential of strip casting as a casting process to be developed for steel castings is very high as the cast strip has some very novel characteristics. Direct cast carbon strip has better surface quality, shape and profile than any other casting process currently available. The more rapidly solidified structure of direct cast strip tends to be strong with low ductility; however, with adequate thermal treatment, it is possible to develop a variety of properties from the same grade. The process is more amenable at this time to production tonnages per year of the order of 500,000 tons and as such will first find niche type applications. This technology is an additional technology for steel production and will be in addition to, rather than a replacement for, current casting machines.

  2. Fabrication of high edge-definition steel-tape gratings for optical encoders

    Science.gov (United States)

    Ye, Guoyong; Liu, Hongzhong; Yan, Jiawei; Ban, Yaowen; Fan, Shanjin; Shi, Yongsheng; Yin, Lei

    2017-10-01

    High edge definition of a scale grating is the basic prerequisite for high measurement accuracy of optical encoders. This paper presents a novel fabrication method of steel tape gratings using graphene oxide nanoparticles as anti-reflective grating strips. Roll-to-roll nanoimprint lithography is adopted to manufacture the steel tape with hydrophobic and hydrophilic pattern arrays. Self-assembly technology is employed to obtain anti-reflective grating strips by depositing the graphene oxide nanoparticles on hydrophobic regions. A thin SiO2 coating is deposited on the grating to protect the grating strips. Experimental results confirm that the proposed fabrication process enables a higher edge definition in making steel-tape gratings, and the new steel tape gratings offer better performance than conventional gratings.

  3. Investigation of the influence of the chemical composition of HSLA steel grades on the microstructure homogeneity during hot rolling in continuous rolling mills using a fast layer model

    International Nuclear Information System (INIS)

    Schmidtchen, M; Kawalla, R; Rimnac, A; Bragin, S; Linzer, B; Warczok, P; Kozeschnik, E; Bernhard, C

    2016-01-01

    The newly developed LaySiMS simulation tool provides new insight for inhomogeneous material flow and microstructure evolution in an endless strip production (ESP) plant. A deepened understanding of the influence of inhomogeneities in initial material state, temperature profile and material flow and their impact on the finished product can be reached e.g. by allowing for variable layer thickness distributions in the roll gap. Coupling temperature, deformation work and work hardening/recrystallization phenomena accounts for covering important effects in the roll gap. The underlying concept of the LaySiMS approach will be outlined and new insight gained regarding microstructural evolution, shear and inhomogeneous stress and strain states in the roll gap as well as local residual stresses will be presented. For the case of thin slab casting and direct rolling (TSDR) the interrelation of inhomogeneous initial state, micro structure evolution and dissolution state of micro alloying elements within the roughing section of an ESP line will be discussed. Special emphasis is put on the influence of the local chemical composition arising from direct charging on throughthickness homogeneity of the final product. It is concluded that, due to the specific combination of large reductions in the high reduction mills (HRM) and the highly inhomogeneous inverse temperature profile, the ESP-concept provides great opportunities for homogenizing the microstructure across the strip thickness. (paper)

  4. Influence of precipitation behavior on mechanical properties and hydrogen induced cracking during tempering of hot-rolled API steel for tubing

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Joonoh, E-mail: mjo99@kims.re.kr [Ferrous Alloy Department, Advanced Metallic Materials Division, Korea Institute of Materials Science, 797 Changwondae-ro, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Choi, Jongmin; Han, Seong-Kyung; Huh, Sungyul; Kim, Seong-Ju [Sheet Products Design Team, Technical Research Center, Hyundai Steel Company, 1480 Bukbusaneop-ro, Dangjin, Chungnam 343-823 (Korea, Republic of); Lee, Chang-Hoon; Lee, Tae-Ho [Ferrous Alloy Department, Advanced Metallic Materials Division, Korea Institute of Materials Science, 797 Changwondae-ro, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of)

    2016-01-15

    Precipitation behavior and its effect on hydrogen embrittlement during tempering process of hot-rolled API steel designed with 0.4 wt% Cr and 0.25 wt% Mo were investigated. The base steel was normalized and then tempered at 650 °C for up to 60 min. The precipitation behavior of the examined steel was explored using transmission electron microscopy (TEM) analysis, and it was found that the precipitation sequence during tempering at 650 °C were as follows: MX+M{sub 3}C→MX→MX+M{sub 7}C{sub 3}+M{sub 23}C{sub 6}. The change of particle fraction was measured by electrolytic extraction technique. At the early stage of tempering, the particle fraction greatly decreased due to dissolution of M{sub 3}C particle, and increased after 10 min by the precipitation of M{sub 7}C{sub 3} and M{sub 23}C{sub 6} particles. The particle fraction showed a peak at 30 min tempering and decreased again due to the dissolution of M{sub 7}C{sub 3} particle. Vickers hardness tests of base steel and tempered samples were carried out, and then the hardness was changed by accompanying with the change of particle fraction. The sensitivity of hydrogen embrittlement was evaluated through hydrogen induced cracking (HIC) tests, and the results clearly proved that HIC resistance of tempered samples was better than that of base steel due to the formation of tempered martensite, and then the HIC resistance changed depending on the precipitation behavior during tempering, i.e., the precipitation of coarse M{sub 23}C{sub 6} and M{sub 7}C{sub 3} particles deteriorated the HIC resistance.

  5. Influence of precipitation behavior on mechanical properties and hydrogen induced cracking during tempering of hot-rolled API steel for tubing

    International Nuclear Information System (INIS)

    Moon, Joonoh; Choi, Jongmin; Han, Seong-Kyung; Huh, Sungyul; Kim, Seong-Ju; Lee, Chang-Hoon; Lee, Tae-Ho

    2016-01-01

    Precipitation behavior and its effect on hydrogen embrittlement during tempering process of hot-rolled API steel designed with 0.4 wt% Cr and 0.25 wt% Mo were investigated. The base steel was normalized and then tempered at 650 °C for up to 60 min. The precipitation behavior of the examined steel was explored using transmission electron microscopy (TEM) analysis, and it was found that the precipitation sequence during tempering at 650 °C were as follows: MX+M_3C→MX→MX+M_7C_3+M_2_3C_6. The change of particle fraction was measured by electrolytic extraction technique. At the early stage of tempering, the particle fraction greatly decreased due to dissolution of M_3C particle, and increased after 10 min by the precipitation of M_7C_3 and M_2_3C_6 particles. The particle fraction showed a peak at 30 min tempering and decreased again due to the dissolution of M_7C_3 particle. Vickers hardness tests of base steel and tempered samples were carried out, and then the hardness was changed by accompanying with the change of particle fraction. The sensitivity of hydrogen embrittlement was evaluated through hydrogen induced cracking (HIC) tests, and the results clearly proved that HIC resistance of tempered samples was better than that of base steel due to the formation of tempered martensite, and then the HIC resistance changed depending on the precipitation behavior during tempering, i.e., the precipitation of coarse M_2_3C_6 and M_7C_3 particles deteriorated the HIC resistance.

  6. Force prediction in cold rolling mills by polynomial methods

    Directory of Open Access Journals (Sweden)

    Nicu ROMAN

    2007-12-01

    Full Text Available A method for steel and aluminium strip thickness control is provided including a new technique for predictive rolling force estimation method by statistic model based on polynomial techniques.

  7. Model of mechanical properties change of steel during rolling with use of hightemperature thermomechanical treatment

    International Nuclear Information System (INIS)

    Zhadan, V.T.; Gubenko, V.T.; Bernshtejn, M.L.; Binarskij, M.S.

    1975-01-01

    A mathematical model is proposed of changes in the mechanical properties of the steel-50KHGA in the process of rolling with application of a high-temperature thermomechanical treatment (HTTMT). The model accounts for all the main particularities of the structure formation processes during a high temperature deformation of metals and alloys. The nonmonotonic dependence of the steel mechanical properties on the deformation velocity can be presented as a result of a summary effect of three parallel processes on the formation of these properties: hot working, softening and substructural hardening. The mathematical model has been constructed by the iteration method

  8. Effect of hot band grain size on development of textures and magnetic properties in 2.0% Si non-oriented electrical steel sheet

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.M. [Department of Materials Science and Engineering, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Huh, M.Y., E-mail: myhuh@korea.ac.kr [Department of Materials Science and Engineering, Korea University, 5-1, Anam-dong, Sungbuk-Gu, Seoul 136-701 (Korea, Republic of); Lee, H.J.; Park, J.T.; Kim, J.S. [Electrical Steel Sheet Research Group, Technical Research Laboratories, POSCO, Goedong-dong, Pohang (Korea, Republic of); Shin, E.J. [Korea Atomic Energy Research Institute, Neutron Science Division, Daejeon 305-353 (Korea, Republic of); Engler, O. [Hydro Aluminium Rolled Products GmbH, Research and Development Bonn, P.O. Box 2468, D-53014 Bonn (Germany)

    2015-12-15

    The effect of hot band grain size on the development of crystallographic texture and magnetic properties in non-oriented electrical steel sheet was studied. After cold rolling the samples with different initial grain sizes displayed different microstructures and micro-textures but nearly identical macro-textures. The homogeneous recrystallized microstructure and micro-texture in the sample having small grains caused normal continuous grain growth. The quite irregular microstructure and micro-texture in the recrystallized sample with large initial grain size provided a preferential growth of grains in 〈001〉//ND and 〈113〉//ND which were beneficial for developing superior magnetic properties. - Highlights: • We produced hot bands of electrical steel with different grain size but same texture. • Hot band grain size strongly affected cold rolling and subsequent annealing textures. • Homogeneous recrystallized microstructure caused normal continuous grain growth. • Irregular recrystallized microstructure led to selective growth of <001>//ND grains. • Hot band with large grains was beneficial for superior magnetic properties.

  9. Hot ductility of a microalloyed steel in the intermediate temperature range

    International Nuclear Information System (INIS)

    Darsouni, A.; Bouzabata, B.; Montheillet, F.

    1995-01-01

    In this study hot ductility has been determined from tensile tests for two states of a microalloyed steel: after casting and after rolling processes. Hot deformations were carried out at speeds varying from 10 -4 s -1 to 10 -2 s -1 and temperatures from 750 C to 1100 C. Two heat treatments were chosen before hot deformation. A ferrite precipitation is observed at austenitic grain boundaries in the intercritical temperature range, causing intergranular embrittlement. Ductility trough is deeper in the as-cast samples due to the growth of large grain size. Also, precipitation makes the hot ductility curve wider and deeper around 900 C. The results show a decrease in hot ductility. Minimum values of hot ductility are determined for (ITC) treatment at 900 C and for (DTC) treatment at 800 C. For this second treatment another decrease in hot ductility was observed at 900 C. We can explain hot ductility losses by the presence of precipitates in the austenitic region and the presence of the two-phase structure in the intercritical region. (orig.)

  10. Recent Developments in On-Line Assessment of Steel Strip Properties

    International Nuclear Information System (INIS)

    Meilland, P.; Kroos, J.; Buchholtz, O. W.; Hartmann, H.-J.

    2006-01-01

    On-line non-destructive assessment of steel strip properties is a subject of growing interest amongst European manufacturers, as it provides information all along the products length, without slowing down the production. Arcelor, Salzgitter and TKS recently undertook a collective effort to assess the performance of 3 systems for flat carbon steel strips mechanical properties at the exit of galvanizing lines

  11. New progress of FEM simulation and AI application in rolling at RAL

    International Nuclear Information System (INIS)

    Liu Xianghua; Wang Guodong; Zhao Kun

    2000-01-01

    New progresses on FEM simulation and AI application in rolling have been achieved at RAL recently. The existence and uniqueness of the extreme point of total functional for rolling problem has been proved. Different rolling processes, such as H-beam rolling, ribbing strip rolling, slab sizing, have been solved by our in-house FEM software package. The simulation results have been put into production use to improve the precision of math models. The Artificial Neural Network has been used to predict rolling force, coiling temperature, microstructure and properties of the rolled products. An expert system for deviation diagnoses of strip thickness has been developed for industry use. Synergetic Artificial Intelligence has also been applied to rolling scheduling. We are making continuous efforts to develop AI applications for rolling line co-operating in China steel industry. (author)

  12. INFLUENCE OF MICRO-SEGREGATION IN PB-S-ALLOYED FREE MACHINING STEELS ON THE SURFACE QUALITY OF THE ROLLED WIRE-ROD

    OpenAIRE

    Leuschke, U.; Rajesh Puvvada, N.; Puvvada, Rajesh

    2008-01-01

    Free machining steel billets were manufactured at the continuous casting machine. The manufactured billets did not exhibit any kind of surface defects but surface cracks and slivers appeared when the billets were rolled into wires and rods at the wire-rod mill. The defects on rolled wire-rod have been detected by a hot eddy current system. Further investigations in these defects with the help of microprobe analysis system and scanning electron microscope equipped with image analysis system re...

  13. Analysis of hot rolling and hot forging effects on mechanical properties and microstructure of ZrNbMoGe alloy

    International Nuclear Information System (INIS)

    AH Ismoyo; Parikin; Bandriyana

    2014-01-01

    Research on formation technique by a combined method of rolling and forging has been carried out in order to improve the mechanical properties of ZrNbMoGe alloy to be used as fuel cladding in NPP (Nuclear Power Plant) application. The effects of rolling and forging were analyzed several tests. The tests were conducted for zirconium alloy specimen with a composition of (in % wt.) 97% Zr, 0,5% Mo, 2% Nb and 0,5% Ge, where the specimen was melted with an arc-furnace. The hot rolling and forging were conducted at 900 °C and 950 °C respectively. Hardness test was carried out by using a microhardness testing machine, while microstructure examination and crystal structure analysis were conducted with an optical microscope and an X-ray diffractometer. The results show that the hardness of the alloy increase from 141.21 HV (starting material) to 210.47 HV (hot rolled material) and 365.75 HV (hot forged material). Texturing phenomenon is clearly figured on the microstructure due to hot rolling and forging process. Analysis by diffractogram also indicates that the hot rolling and forging process has influence on the crystal orientation of dominant preferred direction in the reflection plane of (10ī1), recorded from the rise of intensity counting from about 2500 to 3000. In summary, hot forging and rolling process can change the mechanical properties (hardness and texture) and microstructure of materials. (author)

  14. Surface conditioning of a cold-rolled dual-phase steel by annealing in nitriding atmospheres prior to hot-dip galvanizing

    Energy Technology Data Exchange (ETDEWEB)

    Luther, F.; Beste, D.; Bleck, W. [Institute for Ferrous Metallurgy (IEHK), RWTH Aachen (Germany); Dimyati, A.; Mayer, J. [Central Facility for Electron Microscopy (GFE), RWTH Aachen (Germany)

    2007-04-15

    The development of steel grades for automotive applications in the recent years has been driven on by two trends: lightweight and improved crash safety. By using steels like DP (dual phase) the goals of passenger safety, fuel efficiency and environmental friendliness can be met at reasonable price. The favorite corrosion protection method for sheet steels in the car industry is the hot-dip galvanizing process. Here, an approach was made to reduce the surface enrichment of critical alloying elements of a dual phase steel grade by reactive annealing in ammonia containing atmospheres. The effects of this treatment on mechanical properties and hot-dip coating behavior are reported. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  15. Effects of S and Mn on the hot workability of STS 316L and 309S steels

    International Nuclear Information System (INIS)

    Lee, Soo Chan; Kim, Young Hwan; Lee, Yun Yong

    1998-01-01

    Effects of sulfur and manganese on the hot workability of STS 316L and 309S steels have been investigated. From the results of hot workability test, the hot ductility was decreased with increasing sulfur content and reheating temperature. This is considered to be caused by sulfur segregations and sulfide precipitates at grain boundaries. Sulfur would be dissolved under the reheating conditions and reprecipitated with decreasing temperatures during hot rolling. The content of reprecipitated sulfur is decreased with increasing manganese content and decreasing reheating temperature. Therefore, the hot ductility is increased with increasing manganese content. It was also found that the hot ductility is increased with decreasing reheating temperature

  16. Experiment and simulation analysis of roll-bonded Q235 steel plate

    International Nuclear Information System (INIS)

    Zhao, G.; Huang, Q.; Zhou, C.; Zhang, Z.; Ma, L.; Wang, X.

    2016-01-01

    Heavy-gauge Q235 steel plate was roll bonded, and the process was simulated using MARC software. Ultrasonic testing results revealed the presence of cracks and lamination defects in an 80-mm clad steel sheet, especially at the head and tail of the steel plate. There were non-uniform ferrite + pearlite microstructures and unbound areas at a bond interface. Through scanning electron microscopy analysis, long cracks and additional inclusions in the cracks were observed at the interface. A fracture analysis revealed non-uniform inclusions that pervaded the interface. Moreover, MARC simulations demonstrated that there was little equivalent strain at the centre of the slab during the first rolling pass. The equivalent centre increased to 0.5 by the fourth rolling pass. Prior to the final pass, the equivalent strain was not consistent across the thickness direction, preventing bonding interfaces from forming consistent deformation and decreasing the residual stress. The initial rolling reduction rate should not be very small (e.g. 5%) as it is averse to the coordination of rolling deformation. Such rolling processes are averse to the rolling bond. (Author)

  17. Engineering of rolled constructional microalloyed steel products

    International Nuclear Information System (INIS)

    Adamczyk, J.

    2003-01-01

    Flexibility of the microalloyed steels on manufacturing of products with high mechanical and technological properties at not exaggerated production costs, it caused of their application for different constructions and machines in many branches of economy. It is a reason of the big interest of this steel group and the improvement of metallurgical and technological processing. In the work the examples of applications of C-Mn microalloyed steels with V and N microadditions for production of long shape products of R p0.2 > 650 MPa and KCU2 > 57 Jcm -2 are presented. They are manufactured in the controlled rolling process. Moreover this work presents liquid metal treatment in ladlemann process and influence of ingots solidification conditions, controlled rolling of weldable plates with Nb, Ti, V and B microadditions which after quenching and tempering have R p0.2 > 870 MPa, KV -50 o C > 27 J and plastic strain ratio equals 1.2. This work also presents the energy saving rolling technology with controlled recrystallization (method of thermomechanical treatment) of improved Weldox 960 steel plates with Mb, Ti, V and B microadditions which have after high-temperature tempering R p0.2 > 100 MPa, KV -50 o C >90 J and plastic strain ratio is less than 1.2. The introduction of microalloyed constructional steels and the appropriate technology in the domestic industry will contribute to high-processed products with properties competitive to products manufactured in high-industrialized countries. Thanks to that it will be possible to increase the technical level as well as to reduce production costs and import. (author)

  18. Effects of Niobium Microalloying on Microstructure and Properties of Hot-Dip Galvanized Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Mohrbacher, Hardy [NiobelCon bvba, Brussels (Belgium)

    2010-04-15

    Niobium microalloying is effective in hot-rolled and cold-rolled steels by providing a fine-grained microstructure resulting in increased strength. To optimize the strengthening effect, alloy design and hot-rolling conditions have to be adapted. As a key issue the dissolution and precipitation characteristics of Nb are discussed in particular with regard to the run-out table conditions. It is then considered how the hot-rolled microstructure and the solute state of Nb interact with the hot-dip galvanizing cycle. The adjusted conditions allow controlling the morphology and distribution of phases in the cold-rolled annealed material. Additional precipitation hardening can be achieved as well. The derived options can be readily applied to produce conventional HSLA and IF high strength steels as well as to modem multiphase steels. It will be explained how important application properties such as strength, elongation, bendability, weldability and delayed cracking resistance can be influenced in a controlled and favorable way. Examples of practical relevance and experience are given.

  19. Precipitation characteristic of high strength steels microalloyed with titanium produced by compact strip production

    Institute of Scientific and Technical Information of China (English)

    Jian Zhou; Yonglin Kang; Xinping Mao

    2008-01-01

    Transmission electron microscopy (TEM) and physics-chemical phase analysis were employed to investigate the precipitates in high strength steels microalloyed with Ti produced by compact strip production (CSP). It was seen that precipitates in Ti mieroalloyed steels mainly included TiN, Ti4C2S2, and TiC. The size of TiN particles varied from 50 to 500 nm, and they could precipitate during or before soaking. The Ti4C2S>2 with the size of 40-100 nm might precipitate before rolling, and the TiC particles with the size of 5-50 nm precipitated heterogeneously. High Ti content would lead to the presence of bigger TiC particles that precipitated in austenite, and by contrast, TiC particles that precipitated in ferrite and the transformation of austenite to ferrite was smaller. They were less than 30 nm and mainly responsible for precipitate strengthening. It should be noted that the TiC particles in higher Ti content were generally smaller than those in the steel with a lower Ti content.

  20. Effects of thermomechanical processing on titanium aluminide strip cast by the melt overflow process

    Energy Technology Data Exchange (ETDEWEB)

    Gaspar, T.A. (Ribbon Technology Corporation, PO Box 30758, Columbus, OH 43230 (United States)); Hackman, L.E. (Ribbon Technology Corporation, PO Box 30758, Columbus, OH 43230 (United States)); Batawi, E. (Sulzer-Innotec, Division 1511, PO Box 65, Winterthur 8404 (Switzerland)); Peters, J.A. (Sulzer-Innotec, Division 1511, PO Box 65, Winterthur 8404 (Switzerland))

    1994-05-01

    The objective of this research project was to investigate the feasibility of producing titanium aluminide foils from direct cast strip using ribbon technology''s plasma melt overflow process. Niobium-modified Ti[sub 3]Al alloys were melted in a cold copper crucible using a transferred plasma arc and then direct cast into strip on a rotating chill roll.Samples cut from the as-cast Ti[sub 3]Al-Nb ([alpha][sub 2]) titanium aluminide strip were encapsulated into a pack. The packs were heated to the rolling temperature and then hot rolled at low strain rates. Foils 70 [mu]m (0.003 in) thick, having a uniform [alpha][sub 2]-B2 microstructure with oxygen contents as low as 900 wt.ppm were obtained after pack rolling. The strips and foils were characterized in terms of microstructure and chemical composition in the as-received, heat-treated and pack-rolled conditions.The results indicated that it was technically feasible to produce foils from direct cast titanium aluminide strip using pack-rolling technology. The advantage of this technology lies in its cost-effectiveness, since the relatively low cost direct-cast titanium aluminide strip was thermomechanically processed into foil with the desired microstructure without any intermediate processing steps. ((orig.))

  1. Finite-element model to predict roll-separation force and defects during rolling of U-10Mo alloys

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub; Burkes, Douglas E.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean

    2017-10-01

    This study used a finite element code, LSDYNA, as a predictive tool to optimize the rolling process. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel were conducted following two different schedules. Model predictions of the roll-separation force and roll pack thicknesses at different stages of the rolling process were compared with experimental measurements. The study reported here discussed various attributes of the rolled coupons revealed by the model (e.g., waviness and thickness non-uniformity like dog boning). To investigate the influence of the cladding material on these rolling defects, other cases were simulated:  hot rolling with alternative can materials, namely, 304 stainless steel and Zircaloy-2, and bare-rolling.

  2. IMPACT OF STRAIN RATE ON MICROALLOYED STEEL SHEET BREAKING

    Directory of Open Access Journals (Sweden)

    Mária Mihaliková

    2014-08-01

    Full Text Available Strain rate is a significant external factor and its influence on material behavior in forming process is a function of its internal structure. The contribution is analysis of the impact of loading rate from 1.6 x 10-4 ms-1 to 24 ms-1 to changes in the fracture of steel sheet used for bodywork components in cars. Experiments were performed on samples taken from HC420LA grade strips produced by cold rolling and hot dip galvanizing. Material strength properties were compared based on measured values, and changes to fracture surface character were observed.

  3. Experimental study and calculation of boiling heat transfer on steel plates during runout table operation

    International Nuclear Information System (INIS)

    Liu, Z.D.; Fraser, D.; Samarasekera, I.V.

    2002-01-01

    Within a hot strip steel mill, red hot steel is hot rolled into a long continuous slab that is led onto what is called the runout table. Temperatures of the steel at the beginning of this table are around 900 o C. Above and below the runout table are banks of water jets, sprays or water curtains that rapidly cool the steel slab. The heat transfer process itself may be considered one of the most complicated in the industrial world. The cooling process that occurs on the runout table is crucial and governs the final mechanical properties and flatness of a steel strip. However, very limited data of industrial conditions has been available and that which is available is poorly understood. To study heat transfer during runout table cooling, an industrial scale pilot runout table facility was constructed at the University of British Columbia (UBC). This paper describes the experimental details, data acquisition and data handling techniques for steel plates during water jet impingement cooling by one circular water jet from industrial headers. The effect of cooling water temperature and initial steel plate temperature as well as varying water jet diameters on heat transfer was systematically investigated. A two-dimensional finite element scheme based inverse heat conduction model was developed to calculate surface heat transfer coefficients along the impinging surface. Heat flux curves at the stagnation area were obtained for selected tests. A quantitative relationship between adjustable processing parameters and heat transfer coefficients along the impinging surface during runout table operation is discussed. The results of the study were used to upgrade an extensive process model developed at UBC. The model ties in the cooling rate and hence two dimensional temperature gradients to the resulting microstructure and final mechanical properties of the steel. This process model is widely used by major steel industries in Canada and the United States. (author)

  4. Engineering study for a melting, casting, rolling and fabrication facility for recycled contaminated stainless steel

    International Nuclear Information System (INIS)

    1994-01-01

    This Preliminary Report is prepared to study the facilities required for recycling contaminated stainless steel scrap into plate which will be fabricated into boxes suitable for the storage of contaminated wastes and rubble. The study is based upon the underlying premise that the most cost effective way to produce stainless steel is to use the same processes employed by companies now in production of high quality stainless steel. Therefore, the method selected for this study for the production of stainless steel plate from scrap is conventional process using an Electric Arc Furnace for meltdown to hot metal, a Continuous Caster for production of cast slabs, and a Reversing Hot Mill for rolling the slabs into plate. The fabrication of boxes from the plate utilizes standard Shears, Punch Presses and welding equipment with Robotic Manipulators. This Study presumes that all process fumes, building dusts and vapors will be cycled through a baghouse and a nuclear grade HEPA filter facility prior to discharge. Also, all process waste water will be evaporated into the hot flue gas stream from the furnace utilizing a quench tank; so there will be no liquid discharges from the facility and all vapors will be processed through a HEPA filter. Even though HEPA filters are used today in controlling radioactive contamination from nuclear facilities there is a sparsity of data concerning radioactivity levels and composition of waste that may be collected from contaminated scrap steel processing. This report suggests some solutions to these problems but it is recommended that additional study must be given to these environmental problems

  5. Microstructure and partitioning behavior characteristics in low carbon steels treated by hot-rolling direct quenching and dynamical partitioning processes

    International Nuclear Information System (INIS)

    Li, Yun-jie; Li, Xiao-lei; Yuan, Guo; Kang, Jian; Chen, Dong; Wang, Guo-dong

    2016-01-01

    In this work, a new process and composition design are proposed for “quenching and partitioning” or Q&P treatment. Three low carbon steels were treated by hot-rolling direct quenching and dynamical partitioning processes (DQ&P). The effects of proeutectoid ferrite and carbon concentration on microstructure evolution and mechanical properties were investigated. The present work obtained DQ&P prototype steels with good mechanical properties and established a new notion on compositions for Q&P processing. Microstructures were characterized by means of electro probe microanalyzer (EPMA), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD), especially the morphology and size of retained austenite. Mechanical properties were measured by uniaxial tensile tests. The results indicated that introducing proeutectoid ferrite can increase the volume fraction of retained austenite and thus improve mechanical properties. TEM observation showed that retained austenite included the film-like inter-lath austenite and blocky austenite located in martensite/ferrite interfaces or surrounded by ferrites. It was interesting that when the carbon concentration is as low as ~ 0.078%, the film-like inter-lath untransformed austenite cannot be stabilized to room temperature and almost all of them transformed into twin martensite. The blocky retained austenite strengthened the interfaces and transformed into twin martensite during the tensile deformation process. The PSEs of specimens all exceeded 20 GPa.%. - Highlights: •This study focused on a new process: Q&P process applying dynamical partitioning. •Ferrite can increase the volume fraction of retained austenite. •The film-like austenite and the blocky austenite were observed. •The low carbon steels treated by new process reached PSEs higher than 20 GPa.%.

  6. Application of MySQL in instantaneous profile gauge system

    International Nuclear Information System (INIS)

    Guo Xiaojing; Miao Jichen; Wu Zhifang

    2011-01-01

    As equipment in the hot rolling plate plant for online measurement of strip steel, the instantaneous profile gauge is used to measure instant crown of hot rolling strips and feed back the crown to the rolling mill to adjust strip profile. During the measurement, a large amount of data need to be stored reasonably for query, display, computation and other processing, while a database management software can make it happen. Based on such features of MySQL as small size, fast speed, low cost and open source codes, a database function was implemented in the instantaneous profile gauge for data storage, query and maintenance, by applying MySQL database management system and integrating with the control interface. (authors)

  7. Rolling Process Modeling Report: Finite-Element Prediction of Roll Separating Force and Rolling Defects

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-04-23

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).

  8. Continuum Mechanical Modelling of Skin-pass Rolling

    DEFF Research Database (Denmark)

    Kijima, Hideo; Bay, Niels

    2007-01-01

    The special contact conditions in skin-pass rolling of steel strip is analyzed by studying plane strain upsetting of thin sheet with low reduction applying long narrow tools and dry friction conditions. An extended sticking region is estimated by an elasto-plastic FEM analysis of the plane strain...

  9. Assessment of recovery and recrystallisation behaviours of cold rolled IF steel through non-destructive electromagnetic characterisation

    Science.gov (United States)

    Roy, Rajat K.; Dutta, Siuli; Panda, Ashis K.; Rajinikanth, V.; Das, Swapan K.; Mitra, Amitava; Strangwood, M.; Davis, Claire L.

    2018-07-01

    The recovery and recrystallisation behaviours of cold rolled IF steel have been investigated by destructive (optical microscopy and hardness) and non-destructive electromagnetic sensor, (which allows direct measurement of strip samples with no surface preparation) techniques. The onset and completion of recrystallisation are clearly monitored through destructive techniques of optical microscopy and hardness measurements. The nucleation of new recrystallised grains is observed in the sample annealed at 600 °C/15 min, while completion of recrystallisation takes place at 700 °C/15 min. The destructive techniques are not very accurate in monitoring recovery, for example, changes in hardness of accounting for ≈60% change in the coercivity value. Therefore, the measurement of magnetic softening through an electromagnetic sensor acts a crucial role for understanding recovery and recrystallisation behaviours of steels during industrial processing. The present investigation is aimed not only for controlling product quality but also saving characterisation time through off line monitoring during steel processing at industry.

  10. Study of aluminum nitride precipitation in Fe- 3%Si steel

    Directory of Open Access Journals (Sweden)

    F.L. Alcântara

    2013-01-01

    Full Text Available For good performance of electrical steels it is necessary a high magnetic induction and a low power loss when submitted to cyclic magnetization. A fine dispersion of precipitates is a key requirement in the manufacturing process of Fe- 3%Si grain oriented electrical steel. In the production of high permeability grain oriented steel precipitate particles of copper and manganese sulphides and aluminium nitride delay normal grain growth during primary recrystallization, causing preferential growth of grains with Goss orientation during secondary recrystallization. The sulphides precipitate during the hot rolling process. The aluminium nitride particles are formed during hot rolling and the hot band annealing process. In this work AlN precipitation during hot deformation of a high permeability grain oriented 3%Si steel is examined. In the study, transfer bar samples were submitted to controlled heating, compression and cooling treatments in order to simulate a reversible hot rolling finishing. The samples were analyzed using the transmission electron microscope (TEM in order to identify the precipitates and characterize size distribution. Precipitate extraction by dissolution method and analyses by inductively coupled plasma optical emission spectrometry (ICP-OES were used to quantify the precipitation. The results allowed to describe the precipitation kinetics by a precipitation-time-temperature (PTT diagram for AlN formation during hot rolling.

  11. The Influence of Hot-Rolled Temperature on Plasma Nitriding Behavior of Iron-Based Alloys

    Science.gov (United States)

    El-Hossary, F. M.; Khalil, S. M.; Lotfy, Kh.; Kassem, M. A.

    2009-07-01

    Experiments were performed with an aim of studying the effect of hot-rolled temperature (600 and 900°C) on radio frequency (rf) plasma nitriding of Fe93Ni4Zr3 alloy. Nitriding was carried out for 10 min in a nitrogen atmosphere at a base pressure of 10-2 mbarr. Different continuous plasma processing powers of 300-550 W in steps 50 W or less were applied. Nitrided hot-rolled specimens were characterized by optical microscopy (OM), X-ray diffraction (XRD) and microhardness measurements. The results reveal that the surface of hot-rolled rf plasma nitrided specimens at 600°C is characterized with a fine microstructure as a result of the high nitrogen solubility and diffusivity. Moreover, the hot-rolled treated samples at 600°C exhibit higher microhardness value than the associated values of hot-rolled treated samples at 900°C. The enhancement of microhardness is due to precipitation and predominance of new phases ( γ and ɛ phases). Mainly, this conclusion has been attributed to the high defect densities and small grain sizes of the samples hot-rolled at 600°C. Generally, the refinement of grain size plays a dramatic role in improvement of mechanical properties of tested samples.

  12. 75 FR 59744 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Science.gov (United States)

    2010-09-28

    ...)] Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan AGENCY: United States... duty orders on stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico, and Taiwan... stainless steel sheet and strip from Germany, Italy, Japan, Korea, Mexico, and Taiwan would be likely to...

  13. 78 FR 25701 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Second Amended Final Results...

    Science.gov (United States)

    2013-05-02

    ... Essar I, the CIT remanded Commerce's AFA determination that Essar benefited from the CIP.\\10\\ The CIT... DEPARTMENT OF COMMERCE International Trade Administration [C-533-821] Certain Hot-Rolled Carbon... Commerce. SUMMARY: On April 9, 2013, the United States Court of International Trade (CIT) sustained the...

  14. Dimensional ranges and rolling efficiency in a tandem cold rolling mill

    Energy Technology Data Exchange (ETDEWEB)

    Larkiola, J.

    1997-12-31

    In this work, physical models and a neural network theory have been combined in order to predict the properties of a steel strip and to optimise the process parameters in cold rolling. The prediction of the deformation resistance of the material and the friction parameter is based on the physical model presented by Bland, Ford and Ellis and artificial neural network computing (ANN). The accuracy of these models has been tested and proved by using a large amount of the measured data. With the aid of these models it has been shown that (a) the small change to the relative reduction distribution can have a clear effect upon the rolling efficiency, (b) the dimensional ranges of the tandem cold roll mill can be determined and optimised and (c) the possibility to cold roll a new product of new width, strength or thickness can be determined and the parameters of the tandem cold rolling process can be optimised. (orig.) 43 refs.

  15. A computer system to aid in the planning of steel rolls cuts

    Directory of Open Access Journals (Sweden)

    Nelson Maculan

    2007-03-01

    Full Text Available The planning of cuts in steel rolls is a combinatory optimization problem. Some companies of the metallurgical industry use the steel cold lamination process so that it acquires the necessary physical properties. In this case, the cutting patterns should consist of compartments of items compatible with the lamination process, hindering the task of cuts planning. A compartment represents an intermediate roll to be laminated, so that it is possible to combine intermediate rolls with different lamination needs in the same roll of the stock. In this work the prototype of the RollCut System will be presented to aid with the cuts planning.

  16. Microstructure control during twin roll casting of an AZ31 magnesium alloy

    International Nuclear Information System (INIS)

    Huang, Y; Bayandorian, I; Fan, Z

    2012-01-01

    The existing twin roll casting technique for magnesium alloys suffers heterogeneity in both microstructure and chemistry and downstream processing is required to improve the strip quality, resulting in cost rise. In the present work, twin roll casting was carried out using an AZ31 magnesium alloy, with the application of intensive shearing melt conditioning prior to casting. The effect of process parameters such as pouring temperature and casting speed on microstructure control during casting and subsequent downstream processing was studied. Experimental results showed that the melt conditioning treatment allowed the production of AZ31 strips with uniform and refined microstructure free of centreline segregations. It was also shown that an optimized combination of pouring temperature and casting speed, in conjunction with a strip thickness control operation, resulted in uniformly distributed stored energies due to enhanced plastic deformation, which promoted recrystallization during casting and subsequent heat treatment. Strips prepared by twin roll casting and homogenization developed similar microstructural features to those prepared by twin roll casting followed by lengthy downstream processing by homogenization, hot rolling and annealing and displayed a weaker basal texture, exhibiting a potentially better formability.

  17. State parameter-based modelling of microstructure evolution in micro-alloyed steel during hot forming

    International Nuclear Information System (INIS)

    Buken, H; Kozeschnik, E

    2016-01-01

    In steel production, thermo-mechanical treatment at elevated temperatures is an inevitable step for controlling the microstructure and, thus, the mechanical-technological properties of the final product. One of the main goals in modelling microstructure evolution is the prediction of progress and interaction of hardening and softening mechanism at temperatures, where reheating, hot rolling, finish rolling and coiling are typically carried out. The main mechanisms that need to be accounted for are precipitation, grain growth, solute drag, recovery, recrystallization and phase transformation, which are to be described as functions of temperature, external loading and chemical composition of the material. In the present work, we present a new approach for dealing with these problems and apply it to the thermal and mechanical loading of microalloyed steel. Within this model, we quantitatively predict, for instance, the phenomenon of recrystallization stop in the presence of precipitation. The computational treatment is verified against experimental data from literature, where good agreement is achieved. (paper)

  18. Rolling contact fatigue of low hardness steel for slewing ring application

    Science.gov (United States)

    Knuth, Jason A.

    This thesis discusses the rolling contact fatigue of steel utilized in anti-friction bearings, also referred to as slewing bearings. These slewing bearings are utilized in cranes, excavators, wind turbines and other similar applications. Five materials composed of two different material types were tested. The two material types were high carbon steel and medium carbon alloy steel. The test specimens were processed from forged rolled rings. Two machines were evaluated a ZF-RCF and 3-Ball test machine. The evaluation was to determine which machine can best simulate the application in which the slewing bearing is utilized. Initially, each specimen will be pretested to determine the appropriate testing direction from within the forged rolled rings. Pretesting is needed in order to establish consistent failure modes between samples. The primary goal of the test is to understand the life differences and failure modes between high carbon steel and medium carbon alloy steel. The high carbon steel ring was cut into two sections, one of which was stress relieved and the other was quenched and tempered. The medium carbon alloy steel was cut into three sections, all of which were quenched and tempered to different hardness levels. The test program was dynamically adjusted based upon the previous sample's life and load. An S-N curve was then established from the 5 materials tested at two target loads. The samples were run until the first sign of a crack was detected by an eddy current. At the completion of the rolling contact test, select sample's microstructure was evaluated for crack initiation location. The selected samples were divided into four groups which represent different maximum shear stress levels. These samples displayed indications of material deformation in which the high carbon steel experienced an increased amount of cold work when compared to medium carbon alloy steel. The life of the high carbon steel was nearly equivalent to the expected life of the medium

  19. Finite-element model to predict roll-separation force and defects during rolling of U-10Mo alloys

    Science.gov (United States)

    Soulami, Ayoub; Burkes, Douglas E.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean

    2017-10-01

    A major goal of the Convert Program of the U.S. Department of Energy's National Nuclear Security Administration (DOE/NNSA) is to enable high-performance research reactors to operate with low-enriched uranium rather than the high-enriched uranium currently used. To this end, uranium alloyed with 10 wt% molybdenum (U-10Mo) represents an ideal candidate because of its stable gamma phase, low neutron caption cross section, acceptable swelling response, and predictable irradiation behavior. However, because of the complexities of the fuel design and the need for rolled monolithic U-10Mo foils, new developments in processing and fabrication are necessary. This study used a finite-element code, LS-DYNA, as a predictive tool to optimize the rolling process. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel were conducted following two different schedules. Model predictions of the roll-separation force and roll pack thicknesses at different stages of the rolling process were compared with experimental measurements. The study reported here discussed various attributes of the rolled coupons revealed by the model (e.g., waviness and thickness non-uniformity like dog-boning). To investigate the influence of the cladding material on these rolling defects, other cases were simulated: hot rolling with alternative can materials, namely, 304 stainless steel and Zircaloy-2, and bare-rolling. Simulation results demonstrated that reducing the mismatch in strength between the coupon and can material improves the quality of the rolled sheet. Bare-rolling simulation results showed a defect-free rolled coupon. The finite-element model developed and presented in this study can be used to conduct parametric studies of several process parameters (e.g., rolling speed, roll diameter, can material, and reduction).

  20. Flow behavior of polymers during the roll-to-roll hot embossing process

    International Nuclear Information System (INIS)

    Deng, Yujun; Yi, Peiyun; Peng, Linfa; Lai, Xinmin; Lin, Zhongqin

    2015-01-01

    The roll-to-roll (R2R) hot embossing process is a recent advancement in the micro hot embossing process and is capable of continuously fabricating micro/nano-structures on polymers, with a high efficiency and a high throughput. However, the fast forming of the R2R hot embossing process limits the time for material flow and results in complicated flow behavior in the polymers. This study presents a fundamental investigation into the flow behavior of polymers and aims towards the comprehensive understanding of the R2R hot embossing process. A three-dimensional (3D) finite element (FE) model based on the viscoelastic model of polymers is established and validated for the fabrication of micro-pyramids using the R2R hot embossing process. The deformation and recovery of micro-pyramids on poly(vinyl chloride) (PVC) film are analyzed in the filling stage and the demolding stage, respectively. Firstly, in the analysis of the filling stage, the temperature distribution on the PVC film is discussed. A large temperature gradient is observed along the thickness direction of the PVC film and the temperature of the top surface is found to be higher than that of the bottom surface, due to the poor thermal conductivity of PVC. In addition, creep strains are demonstrated to depend highly on the temperature and are also observed to concentrate on the top layer of the PVC film because of high local temperature. In the demolding stage, the recovery of the embossed micro-pyramids is obvious. The cooling process is shown to be efficient for the reduction of recovery, especially when the mold temperature is high. In conclusion, this research advances the understanding of the flow behavior of polymers in the R2R hot embossing process and might help in the development of the highly accurate and highly efficient fabrication of microstructures on polymers. (paper)

  1. Overall model of the dynamic behaviour of the steel strip in an annealing heating furnace on a hot-dip galvanizing line

    Directory of Open Access Journals (Sweden)

    Fernández, R.

    2010-10-01

    Full Text Available Predicting the temperature of the steel strip in the annealing process in a hot-dip galvanizing line (HDGL is important to ensure the physical properties of the processed material. The development of an accurate model that is capable of predicting the temperature the strip will reach according to the furnace’s variations in temperature and speed, its dimensions and the steel’s chemical properties, is a requirement that is being increasingly called for by industrial plants of this nature. This paper presents a comparative study made between several types of algorithms of Data Mining and Artificial Intelligence for the design of an efficient and overall prediction model that will allow determining the strip’s variation in temperature according to the physico-chemical specifications of the coils to be processed, and fluctuations in temperature and speed that are recorded within the annealing process. The ultimate goal is to find a model that is effectively applicable to coils of new types of steel or sizes that are being processed for the first time. This model renders it possible to fine-tune the control model in order to standardise the treatment in areas of the strip in which there is a transition between coils of different sizes or types of steel.La predicción de la temperatura de la banda de acero dentro del proceso de recocido de una planta de galvanizado continuo en caliente es importante para garantizar las propiedades físicas del material procesado. El desarrollo de un modelo preciso que sea capaz de predecir la temperatura que va a alcanzar la banda según las variaciones de temperaturas y velocidades del horno, y sus dimensiones y propiedades químicas del acero, es una necesidad cada vez más demandada por este tipo de plantas industriales. En el presente estudio se muestra una comparativa realizada entre diversos tipos de algoritmos deMinería de Datos e Inteligencia Artificial para el desarrollo de un modelo de predicci

  2. Microstructural characterization of Cu82.3Al8.3Mn9.4 shape memory alloy after rolling

    Directory of Open Access Journals (Sweden)

    Mirko Gojić

    2017-09-01

    Full Text Available In this paper, the microstructure of Cu82.3Al8.3Mn9.4 (in wt. % shape memory alloy after hot and cold rolling was investigated. The Cu82.3Al8.3Mn9.4 alloy was produced by a vertical continuous casting method in the form a cylinder rod of 8 mm in diameter. After the casting, hot and cold rolling was performed. By hot rolling a strip with a thickness of 1.75 mm was obtained, while by cold rolling a strip with a thickness of 1.02 mm was produced. After the rolling process, heat treatment was performed. Heat treatment was carried out by solution annealing at 900 °C held for 30 minutes and water quenched immediately after heating. The microstructure characterization of the investigated alloy was carried out by optical microscopy (OM, scanning electron microscopy (SEM equipped with a device for energy dispersive spectroscopy (EDS. Phase transformation temperatures and fusion enthalpies were determined by differential scanning calorimetry (DSC method. The homogenous martensite microstructure was confirmed by OM and SEM micrographs after casting. During rolling the two-phase microstructure occurred. Results of DSC analysis showed martensite start (Ms, martensite finish (Mf, austenite start (As and austenite finish (Af temperatures.

  3. Simulation of Bimetallic Bush Hot Rolling Bonding Process

    Directory of Open Access Journals (Sweden)

    Yaqin Tian

    2015-01-01

    Full Text Available Three-dimensional model of bimetallic bush was established including the drive roller and the core roller. The model adopted the appropriate interface assumptions. Based on the bonding properties of bimetallic bush the hot rolling process was analyzed. The optimum reduction ratio of 28% is obtained by using the finite element simulation software MARC on the assumption of the bonding conditions. The stress-strain distribution of three dimensions was research assumptions to interface deformation of rolling. At the same time, based on the numerical simulation, the minimum reduction ratio 20% is obtained by using a double metal composite bush rolling new technology from the experiment research. The simulation error is not more than 8%.

  4. Additional grain refinement in recrystallization controlled rolling of Ti-microalloyed steels processed by near-net-shape casting technology

    International Nuclear Information System (INIS)

    Arribas, M.; Lopez, B.; Rodriguez-Ibabe, J.M.

    2008-01-01

    This paper analyzes the recrystallization kinetics in Ti-microalloyed steels processed using 'beam blank' casting technology. The faster solidification rates associated with this technology brings a finer precipitation of TiN particles which are very effective in controlling austenite grain growth during hot working. Furthermore, these small precipitates have been shown to delay static and dynamic recrystallization. The finer the precipitates the higher the delay in recrystallization. Nevertheless, beyond particle size and distribution, the level of delay is very dependent on microstructure (above all austenite grain size) and deformation conditions (strain and temperature). This paper studies the effects of this recrystallization delay on the microstructure evolution during hot rolling. Special attention was paid to the study of the occurrence of partial recrystallization during the final stages of rolling, which could lead to the presence of mixed microstructures before transformation. The possibility of achieving an additional austenite grain size refinement prior to transformation was evaluated

  5. Non-Contact Thickness and Profile Measurements of Rolled Aluminium Strip Using EMAT

    International Nuclear Information System (INIS)

    Hobbis, A.; Aruleswaran, A.

    2006-01-01

    Accurate measurement of strip thickness is a very high priority for the aluminium rolled product industry. This paper presents the findings of trials to measure the thickness of aluminium strip using a send-receive, radially polarised Electromagnetic Acoustic Transducer (EMAT). A broadband EMAT system, developed at Warwick University, UK with a centre frequency of approximately 5 MHz and frequency content up to 12 MHz was used. The resultant ultrasonic waveforms have been processed using Fourier analysis. Static measurements of aluminium alloy samples in the thickness range between 0.28 mm to 2.8 mm have been measured using this non-contact approach at stand-offs of up to 2 mm. Measurements across the aluminium strip width to evaluate its profile for quality control was also carried out successfully. Some of the experiments and results obtained are described in detail

  6. Surface finishing and levelling of thermomechanically hardened rolled steel

    International Nuclear Information System (INIS)

    Grosval'd, V.G.; Bashchenko, A.P.; Grishkov, A.I.; Gutnik, M.V.; Kanevskij, B.L.; Nikozov, A.I.; Sedov, N.D.; Prosin, K.A.; Safonov, L.I.

    1975-01-01

    The finishing of high-strength merchant shapes from alloy steel was tried out under industrial conditions with the equipment of metallurgical plants. After thermomechanical hardening in the production line of the rolling mill, 30KhGSN2A and 40Kh1NVA steel rounds 32 and 31 mm in diameter were straightened on a two-roller straightening machine designed by the All-Union Scientific Research Institute for Metallurgical Machinery (VNII Metmash). This made possible subsequent turning and grinding of the rods. The conditions of straightening, turning and grinding have been worked so as to obtain thermomechanically strengthened and ground rolled products approximating the gauged and ground metal in shape geometry and surface finish. It is shown that the labour-consuming operation of turning can be eliminated by reducing the machining pass of the rolled product, and this lowers the labour required for the finishing operations by 75%. After grinding with 40- and 25-grain abrasive wheels, high strength rolled shapes were obtained with a diameter of 30-0.20 mm and a surface finish of class 6-5 satisfying the technical specifications. (author)

  7. Regularities of ferritic-pearlitic structure formation during subcooled austenite decomposition

    International Nuclear Information System (INIS)

    Shkatov, V.V.; Frantsenyuk, L.I.; Bogomolov, I.V.

    1997-01-01

    Relationships of ferrite-pearlite structure parameters to austenite grain size and cooling conditions during γ -> α transformation are studied for steel 3 sp. A mathematical description has been proposed for grain evolution in carbon and low alloy steel cooling after hot rolling. It is shown that ferrite grain size can be controlled by changing temperature range of water spraying when the temperatures of rolling completion and strip coiling are the same

  8. IMPROVEMENT PROCESS FOR ROLLING MILL THROUGH THE DMAIC SIX SIGMA APPROACH

    Directory of Open Access Journals (Sweden)

    Kunal Ganguly

    2012-09-01

    Full Text Available This project aims to address the problems that are facing a large aluminum company in a Developing Hot Rolling Mill Capabilities for Wider Widths Hard Alloys Rolling and b Eliminate down time due to strip /coil slippage during hard alloys 5xxx rolling at Hot Mill. The challenge for the company was to cater the fast changing export demand for Flat Rolled products with its existing resources. By applying Six Sigma principles, the team identified the current situation that the rolling mills operations were in. Si x Sigma DMAIC methodologies were use d in the project to determine the project's CTQ characteristics, defining the possible causes, Identifying the variation sources, establishing variable relationships and Implementing Control Plans. The project can be useful for any company that needs to fi nd the most cost efficient way to improve and utilize its resources.

  9. Dominant root locus in state estimator design for material flow processes: A case study of hot strip rolling.

    Science.gov (United States)

    Fišer, Jaromír; Zítek, Pavel; Skopec, Pavel; Knobloch, Jan; Vyhlídal, Tomáš

    2017-05-01

    The purpose of the paper is to achieve a constrained estimation of process state variables using the anisochronic state observer tuned by the dominant root locus technique. The anisochronic state observer is based on the state-space time delay model of the process. Moreover the process model is identified not only as delayed but also as non-linear. This model is developed to describe a material flow process. The root locus technique combined with the magnitude optimum method is utilized to investigate the estimation process. Resulting dominant roots location serves as a measure of estimation process performance. The higher the dominant (natural) frequency in the leftmost position of the complex plane the more enhanced performance with good robustness is achieved. Also the model based observer control methodology for material flow processes is provided by means of the separation principle. For demonstration purposes, the computer-based anisochronic state observer is applied to the strip temperatures estimation in the hot strip finishing mill composed of seven stands. This application was the original motivation to the presented research. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Through-process characterization of local anisotropy of Non-oriented electrical steel using magnetic Barkhausen noise

    Science.gov (United States)

    He, Youliang; Mehdi, Mehdi; Hilinski, Erik J.; Edrisy, Afsaneh

    2018-05-01

    Magnetic Barkhausen noise (MBN) signals were measured on a non-oriented electrical steel through all the thermomechanical processing stages, i.e. hot rolling, hot band annealing, cold rolling and final annealing. The temperature of the final annealing was varied from 600 °C to 750 °C so that the steel consisted of partially or completely recrystallized microstructures and different levels of residual stresses. The angular MBNrms (root mean square) values were compared to the texture factors in the same directions, the latter being calculated from the crystallographic texture measured by electron backscatter diffraction (EBSD). It was found that, in the cold-rolled, hot-rolled and completely recrystallized steels, the angular MBNrms followed a cosine function with respect to the angle of magnetization, while in partially recrystallized state such a relation does not exist. After cold rolling, the maximum MBNrms was observed in the rolling direction (RD) and the minimum MBNrms was in the transverse direction (TD), which was inconsistent with the magnetocrystalline anisotropy as indicated by the texture factor. After hot rolling, the maximum and minimum MBNrms values were observed in the TD and RD, respectively, exactly opposite to the cold-rolled state. If the steel was completely recrystallized, the maximum MBNrms was normally observed at a direction that was 15-30° from the minimum texture factor. If the steel was partially recrystallized, both the magnetocrystalline anisotropy of the material and the residual stress contributed to the angular MBNrms, which resulted in the deviation of the relationship from a cosine function. The relative strength of the two factors determined which factor would dominate the overall magnetic anisotropy.

  11. Microscopic analysis and simulation of check-mark stain on the galvanized steel strip

    Science.gov (United States)

    So, Hongyun; Yoon, Hyun Gi; Chung, Myung Kyoon

    2010-11-01

    When galvanized steel strip is produced through a continuous hot-dip galvanizing process, the thickness of adhered zinc film is controlled by plane impinging air gas jet referred to as "air-knife system". In such a gas-jet wiping process, stain of check-mark or sag line shape frequently appears. The check-mark defect is caused by non-uniform zinc coating and the oblique patterns such as "W", "V" or "X" on the coated surface. The present paper presents a cause and analysis of the check-mark formation and a numerical simulation of sag lines by using the numerical data produced by Large Eddy Simulation (LES) of the three-dimensional compressible turbulent flow field around the air-knife system. It was found that there is alternating plane-wise vortices near the impinging stagnation region and such alternating vortices move almost periodically to the right and to the left sides on the stagnation line due to the jet flow instability. Meanwhile, in order to simulate the check-mark formation, a novel perturbation model has been developed to predict the variation of coating thickness along the transverse direction. Finally, the three-dimensional zinc coating surface was obtained by the present perturbation model. It was found that the sag line formation is determined by the combination of the instantaneous coating thickness distribution along the transverse direction near the stagnation line and the feed speed of the steel strip.

  12. Static recrystallisation and precipitation after hot deformation of austenitic stainless steels containing molybdenum and niobium

    International Nuclear Information System (INIS)

    Lombry, R.; Rossard, C.; Thomas, B.J.

    1981-01-01

    In general the hot workability of austenite depends on the work hardening during deformation and the kinetics of the dynamic and static restoration processes. Static recrystallisation is a very important factor in the case of hot rolling. The present work was undertaken to determine the effect of additions of molybdenum or niobium on the kinetics of static recrystallisation. The results show that the rate of static recrystallisation of type 304, 316 and 347 stainless steels decreases in this order for a given amount of prior deformation (epsilon=0,44). The differences in the rates of recrystallisation increases as the temperature is lowered towards 900 deg C. The effect of molybdenum appears to be attribuable to a solute drag effect on the mobility of dislocations, subgrain boundaries or grain boundaries whereas niobium additions lead to the formation of NbC precipitates on the dislocation cell walls and sub boundaries. It is also shown that in the case of type 316 and type 347 steels the dynamic recrystallisation process (observed in type 304 steels at all temperatures above 900 deg C) is replaced by dynamic recovery at temperatures egal to or below about 1000 deg C [fr

  13. ADVANTAGES OF RAPID METHOD FOR DETERMINING SCALE MASS AND DECARBURIZED LAYER OF ROLLED COIL STEEL

    Directory of Open Access Journals (Sweden)

    E. V. Parusov

    2016-08-01

    Full Text Available Purpose. To determine the universal empirical relationships that allow for operational calculation of scale mass and decarbonized layer depth based on the parameters of the technological process for rolled coil steel production. Methodology. The research is carried out on the industrial batches of the rolled steel of SAE 1006 and SAE 1065 grades. Scale removability was determined in accordance with the procedure of «Bekaert» company by the specifi-cations: GA-03-16, GA-03-18, GS-03-02, GS-06-01. The depth of decarbonized layer was identified in accordance with GOST 1763-68 (M method. Findings. Analysis of experimental data allowed us to determine the rational temperature of coil formation of the investigated steel grades, which provide the best possible removal of scale from the metal surface, a minimal amount of scale, as well as compliance of the metal surface color with the require-ments of European consumers. Originality. The work allowed establishing correlation of the basic quality indicators of the rolled coil high carbon steel (scale mass, depth of decarbonized layer and inter-laminar distance in pearlite with one of the main parameters (coil formation temperature of the deformation and heat treatment mode. The re-sulting regression equations, without metallographic analysis, can be used to determine, with a minimum error, the quantitative values of the total scale mass, depth of decarbonized layer and the average inter-lamellar distance in pearlite of the rolled coil high carbon steel. Practical value. Based on the specifications of «Bekaert» company (GA-03-16, GA-03-18, GS-03-02 and GS-06-01 the method of testing descaling by mechanical means from the surface of the rolled coil steel of low- and high-carbon steel grades was developed and approved in the environment of PJSC «ArcelorMittal Kryvyi Rih». The work resulted in development of the rapid method for determination of total and remaining scale mass on the rolled coil steel

  14. Influence of surface defects on the fatigue crack initiation in pearlitic steel

    Directory of Open Access Journals (Sweden)

    Toribio Jesús

    2014-06-01

    Full Text Available Tensile fatigue tests were performed under load control, with constant stress range Δσ on pearlitic steel wires, from the hot rolled bar to the commercial prestressing steel wire (which has undergone seven cold drawing steps. Results show that fatigue cracks in pearlitic steels initiate at the wire surface starting from small defects, whose size decreases with the drawing process. Fatigue cracks created from defects (initiation phase exhibit a fractographic appearance consisting of ductile microtearing events which can be classified as tearing topography surface or TTS, and exhibit a remarkably lower spacing in the prestressing steel wire than in the hot rolled bar. In addition, some S-N tests were performed in both material forms under a stress range of about half the yield strength. In these tests, the main part of the fatigue life corresponds to the propagation stage in the hot rolled bar whereas such a main part of the life is associated with the initiation stage in the case of the prestressing steel wire.

  15. Flow control inside a molten Zn pot for improving surface quality of zinc plated strips

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.H. [Samsung Techwin Co., Ltd. (Korea); Koh, M.S.; Kim, S. [Pohang University of Science and Technology Graduate School, Pohang (Korea)

    2001-10-01

    The flow fields inside a molten Zn pot of continuous hot-chip galvanizing process were investigated experimentally. With varying several parameters including the strip speed V{sub s}, flow rate Q of induction heater, scrapper location and baffle configuration, instantaneous velocity fields were measured using a PIV velocity field measurement technique. Inside the strip region, counter-clockwise rotating flow is dominant. The general flow pattern inside the strip region is nearly not influenced by the trip speed V{sub 2}, flow rate Q and the scrapper location. In the exit region, the flow separated from the moving strip due to the existence of a stabilizing roll ascends to the free surface, for the cases of no scrapper and scrapper detached form the roll. On the other hand, the ascending flow to the free surface is decreased, as the flow rate Q of induction heater increases. By installing a baffle around the uprising strip, the flow moving up to the stabilizing roll decreases. In addition, B-type baffle is better than A-type baffle in reducing speed of flow around the stabilizing rolls. However, the flow ascended to the free surface is largely influenced by changing the flow rate Q, and the scrapper location, irrespective of the baffle type. (author). 14 refs., 11 figs.

  16. Mathematical Modelling of Carbonitride Precipitation during Hot Working in Nb Microalloyed Steels

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on thermodynamics and kinetics, precipitation behavior of microalloyed steels was analyzed. Deformation greatly promotes isothermal carbonitride precipitation and makes C-curve shift leftwards. The position and shape of C-curve also depend on the content of Nb and N. C-curve shifts leftwards a little when N content increases and the nose temperature is raised with increasing Nb content. Deformation shortened precipitation start time during continuous cooling, raised precipitation start temperature, accelerated precipitation kinetics of carbonitrides. With decreasing the finishing temperature and coiling temperature, the precipitates volume fraction increases and strength increment is raised during hot rolling. The simulated results are in agreementwith experiment results.

  17. Impact of as-cast structure on structure and properties of twin-roll cast AA8006 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Slamova, M.; Ocenasek, V. [Vyzkumny Ustav Kovu, Panenske Brezany (Czechoslovakia); Juricek, Z.

    2000-07-01

    Sheet production by twin-roll casting (TRC) process is a well established practice in the aluminium industry because it offers several advantages in comparison with DC casting and hot rolling, esp. lower production and investment costs. Thin strips exhibiting a combination of good strength and high ductility are required for various applications and for this reason alloys with higher Fe and Mn content such as AA 8006 displace AA 1xxx or AA 8011 alloys. However, TRC of AA 8006 strips involves several problems, e.g. casting conditions and subsequent treatment procedures need fine tuning. The results of an investigation of the effect of casting conditions on structure and properties of AA 8006 strips are presented. The influence of casting speed, grain refiner addition, molten metal level in the tundish, tip setback and roll separating force was investigated. The impact of imperfect as-cast structure on structure and properties of thin strips in H22 and O tempers was evaluated and compared with strips from good as-cast material. (orig.)

  18. Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

    Science.gov (United States)

    Shen, Wenning; Feng, Lajun; Feng, Hui; Cao, Ying; Liu, Lei; Cao, Mo; Ge, Yanfeng

    The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel.

  19. X-ray diffraction analysis of cold rolled strip from jewelry 585 gold alloy

    Directory of Open Access Journals (Sweden)

    Karastojković Zoran

    2017-01-01

    Full Text Available Here is investigated an golden alloy 585 as one of widely used gold alloy in jewelry production. Insufficient data, even in nowadays, exist about the production schedule of gold alloys, including melting, rolling and heat treatment regimes. The structures of complex alloys, such as used golden alloy, are less known and/or investigated. Principally, the constitutional diagram of Au-Ag-Cu system is known, as a (metastable equilibrium diagram. But, after relatively fast cooling from liquid state during casting will be obtained polycrystalline grains, different from equilibrium conditions. Such polycrystalline material frequently undergoes to rolling for obtaining a desired shape of (semiproduct. Those processes, casting and rolling, will show the influence on the final structure to be obtained, also on properties of such treated alloy. The structural changes and obtained phases in metal working processes of 585 gold alloy still are not well examined, so here is provided an XRD examination after heavy reduction at cold rolling of a strip. The castings were in the flat form in dimension of 4,5x50x50mm, than cold rolled to 1,5mm, intermediate annealed and finally cold rolled to thickness of 0,5mm with height reduction of 66,7%.

  20. Performance of Flow and Heat Transfer in a Hot-Dip Round Coreless Galvanizing Bath

    Science.gov (United States)

    Yue, Qiang; Zhang, Chengbo; Xu, Yong; Zhou, Li; Kong, Hui; Wang, Jia

    2017-04-01

    Flow field in a coreless hot-dip galvanizing pot was investigated through a water modeling experiment. The corresponding velocity vector was measured using an acoustic Doppler velocimeter. The flow field of molten zinc in the bath was also analyzed. Steel strip velocities from 1.7 to 2.7 m/s were adopted to determine the effect of steel strip velocity on the molten zinc flow in the bath. A large vortex filled the space at the right side of the sink roll, under linear speed from 1.0 to 2.7 m/s and width from 1.0 to 1.3 m of the steel strip, because of the effects of wall and shear stress. The results of the water modeling experiment were compared with those of numerical simulations. In the simulation, Maxwell equations were solved using finite element method to obtain magnetic flux density, electromagnetic force, and Joule heating. The Joule heating rate reached the maximum and minimum values near the side wall and at the core of the bath, respectively, because of the effect of skin and proximity. In an industrial-sized model, the molten zinc flow and temperature fields driven by electromagnetic force and Joule heating in the inductor of a coreless galvanizing bath were numerically simulated. The results indicated that the direction of electromagnetic force concentrated at the center of the galvanizing pot horizontal planes and exerted a pinch effect on molten zinc. Consequently, molten zinc in the pot was stirred by electromagnetic force. Under molten zinc flow and electromagnetic force stirring, the temperature of the molten zinc became homogeneous throughout the bath. This study provides a basis for optimizing electromagnetic fields in coreless induction pot and fine-tuning the design of steel strip parameters.

  1. Electrochemical Corrosion Behavior of Carbon Steel and Hot Dip Galvanized Steel in Simulated Concrete Solution with Different pH Values

    Directory of Open Access Journals (Sweden)

    Wanchen XIE

    2017-08-01

    Full Text Available Hot dip galvanizing technology is now widely used as a method of protection for steel rebars. The corrosion behaviors of Q235 carbon steel and hot galvanized steel in a Ca(OH2 solution with a pH from 10 to 13 was investigated by electrode potential and polarization curves testing. The results indicated that carbon steel and hot galvanized steel were all passivated in a strong alkaline solution. The electrode potential of hot dip galvanized steel was lower than that of carbon steel; thus, hot dip galvanized steel can provide very good anodic protection for carbon steel. However, when the pH value reached 12.5, a polarity reversal occurred under the condition of a certain potential. Hot dip galvanized coating became a cathode, and the corrosion of carbon steel accelerated. The electrochemical behaviors and passivation abilities of hot dip galvanized steel and carbon steel were affected by pH. The higher the pH value was, the more easily they were passivated.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16675

  2. Numerical simulation of the roll levelling of third generation fortiform 1050 steel using a nonlinear combined hardening material model

    Science.gov (United States)

    Galdos, L.; Saenz de Argandoña, E.; Mendiguren, J.; Silvestre, E.

    2017-09-01

    The roll levelling is a flattening process used to remove the residual stresses and imperfections of metal strips by means of plastic deformations. During the process, the metal sheet is subjected to cyclic tension-compression deformations leading to a flat product. The process is especially important to avoid final geometrical errors when coils are cold formed or when thick plates are cut by laser. In the last years, and due to the appearance of high strength materials such as Ultra High Strength Steels, machine design engineers are demanding reliable tools for the dimensioning of the levelling facilities. Like in other metal forming fields, finite element analysis seems to be the most widely used solution to understand the occurring phenomena and to calculate the processing loads. In this paper, the roll levelling process of the third generation Fortiform 1050 steel is numerically analysed. The process has been studied using the MSC MARC software and two different material laws. A pure isotropic hardening law has been used and set as the baseline study. In the second part, tension-compression tests have been carried out to analyse the cyclic behaviour of the steel. With the obtained data, a new material model using a combined isotropic-kinematic hardening formulation has been fitted. Finally, the influence of the material model in the numerical results has been analysed by comparing a pure isotropic model and the later combined mixed hardening model.

  3. About the influence of the topography of the steel surface on faults during hot galvanizing of part loads; Zum Einfluss der Topographie der Stahloberflaeche auf Fehler beim Stueckgut-Feuerverzinken

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.D. [Institut fuer Korrosionsschutz GmbH, Dresden (Germany); Schubert, P.

    2002-03-01

    The topography of the steel surface can influence the formation of layers during hot galvanizing in many ways. Information is given on galvanizing faults caused by impressions in the steel surface (rolling and drawing ridges). Flux remainders accumulated in these impressions can be encapsulated in the zinc coating during hot galvanizing. This leads to cavities and pores in the coating or to sponge-like zinc raisings at its surface. The flux remainders from the zinc coating can boil during powder coating and lead to blisters and pimple-like rises in the coating. Therefore, steel surfaces designed for galvanizing should be even or only have flat impressions. (orig.)

  4. Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

    Directory of Open Access Journals (Sweden)

    Wenning Shen

    Full Text Available The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel. Keywords: Stainless steel, Carbon steel, Anti-corrosion, Conductivity, Electrochemical, EIS

  5. Hot ductility behavior of boron microalloyed steels

    International Nuclear Information System (INIS)

    Lopez-Chipres, E.; Mejia, I.; Maldonado, C.; Bedolla-Jacuinde, A.; Cabrera, J.M.

    2007-01-01

    The current study analyses the influence of boron contents (between 29 and 105 ppm) on the hot ductility of boron microalloyed steels. For this purpose, hot tensile tests were carried out at different temperatures (700, 800, 900 and 1000 deg. C) at a constant true strain rate of 0.001 s -1 . In general, results revealed an improvement of the hot ductility of steels at increasing boron content. At 700, 900 and 1000 deg. C the ductility is higher than at 800 deg. C, where boron microalloyed steels exhibit a region of ductility loss (trough region). Likewise, dynamic recrystallization only occurred at 900 and 1000 deg. C. The fracture surfaces of the tested steels at temperatures giving the high temperature ductility regime show that the fracture mode is a result of ductile failure, whereas it is ductile-brittle failure in the trough region. Results are discussed in terms of dynamic recrystallization and boron segregation towards austenite grain boundaries, which may retard the formation of pro-eutectoid ferrite and increase grain boundary cohesion

  6. Characterization of a hot-rolled Cu--Al--Ni--Ti shape memory alloy

    International Nuclear Information System (INIS)

    Segui, C.; Pons, J.; Cesari, E.

    1999-01-01

    The changes in the martensitic transformation of a Cu-Al-Ni-Ti alloy hot-rolled at different temperatures have been studied in detail, covering different aspects such as ageing in the parent phase at temperatures ranging between 250 and 350 o C, stabilisation of the martensite and betatization of the previously hot-rolled specimens. Besides the evolution of transformation temperatures upon different thermal treatments, special attention has been paid to the changes in mechanical properties of the alloy, such as elastic modulus and internal friction. These results are analysed in relation to the microstructural changes as observed by transmission electron microscopy. (orig.)

  7. 76 FR 46323 - Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan

    Science.gov (United States)

    2011-08-02

    ...)] Stainless Steel Sheet and Strip From Germany, Italy, Japan, Korea, Mexico, and Taiwan Determination On the... injury to an industry in the United States within a reasonably foreseeable time and that revocation of... antidumping duty orders on stainless steel sheet and strip from Japan, Korea, and Taiwan \\3\\ would be likely...

  8. Quality Parameters Defined by Chebyshev Polynomials in Cold Rolling Process Chain

    International Nuclear Information System (INIS)

    Judin, Mika; Nylander, Jari; Larkiola, Jari; Verho, Martti

    2011-01-01

    The thickness profile of hot strip is of importance to profile, flatness and shape of the final cold rolled product. In this work, strip thickness and flatness profiles are decomposed into independent components by solving Chebyshev polynomials coefficients using matrix calculation. Four terms are used to characterize most common shapes of thickness and flatness profile. The calculated Chebyshev coefficients from different line measurements are combined together and analysed using neural network tools. The most common types of shapes are classified.

  9. Direct strip casting of steel - historical perspective and future direction

    International Nuclear Information System (INIS)

    Manohar, P.A.; Hunter, A.; Ferry, M.

    2000-01-01

    The commercialisation of direct strip casting (DSC) of steel represents the realisation of a dream cherished by engineers for over one hundred and fifty years. The story of the global competition for DSC of steel, that has ingredients of romanticism of chasing of a dream, adventure and intrigue, is being played out across continents over dozens of decades with an interplay of setbacks and successes. At this stage, DSC is set to make a profound impact on the steelmaking landscape. This paper reviews the important milestones in this compelling story, presents the current status and then gazes into the crystal ball in an attempt to predict which turn the story may take in the near future. The constraints and critical challenges for the successful commercialisation of DSC are highlighted. Recent results are discussed relating the production process to quality control and properties of unalloyed, low carbon strip-cast steels. future metallurgical challenges include a better understanding of solidification mechanism during high-speed casting and secondary processing variables affecting the final microstructure of austenitic grains

  10. Texture and magnetic properties improvement of a 3% Si non-oriented electrical steel by Sb addition

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Marcio Ferreira, E-mail: marciof.rodrigues@aperam.com [Aperam South America, Timóteo, MG (Brazil); Cunha, Marco Antonio da; Costa Paolinelli, Sebastião da [Aperam South America, Timóteo, MG (Brazil); Cota, André Barros [Physics Department—Universidade Federal de Ouro Preto, Redemat, Ouro Preto, MG (Brazil)

    2013-04-15

    The influence of small antimony addition and thermomechanical processing on the magnetic properties of a 3% Si steel was investigated. The samples were processed in the laboratory with 930 °C hot rolling finishing temperature, three different hot band thicknesses, hot band annealing at 1030 °C, cold rolling with three different reductions to 0.35 mm thickness and final annealing at 1030 °C. The results have shown that the best combination of core loss and magnetic induction can be obtained by Sb content of 0.045% and 76% cold rolling reduction, and that Eta/Gamma ratio is higher and grain size larger at this Sb content. -- Highlights: ► The Sb addition on the magnetic properties of a 3% Si steel was investigated. ► The 0.045% Sb and cold rolling reduction of 76% results in the best magnetic properties. ► Sb and cold rolling reduction results in a optimum final grain size and texture. ► The work was performed in a 3% Si non-oriented electrical steel.

  11. Evolution of microstructure, macrotexture and microtexture during hot rolling of Ti-6Al-4V

    International Nuclear Information System (INIS)

    Ari-Gur, P.; Semiatin, S.L.

    1998-01-01

    The evolution of microstructure, macrotexture and microtexture during subtransus hot working of Ti-6Al-4V with two different types of transformed β starting microstructures (lamellar colony, acicular martensitic α) was investigated. Globularization of the transformed microstructures required heavy rolling reductions or moderate reductions coupled with near transus post-rolling heat treatment. Despite the sluggish dynamic globularization kinetics, noticeable macrotexture changes were noted after low reductions, an effect ascribed to the rotations associated with kinking and bending of the lamellar acicular plates. Noticeable microtextures, noted in samples with an initial lamellar colony microstructure, persisted through hot rolling suggesting that dynamic globularization does not involve recrystallization. In contrast, hot rolled material with a starting acicular α microstructure exhibited weak microtextures and strong macrotextures. The absence of microtexture in these latter cases was explained on the basis of multiple transformation variants within each colony/prior β grain following the β-annealing-and-water-quenching process used to obtain the microstructure. (orig.)

  12. Rolling Contact Fatigue Performances of Carburized and High-C Nanostructured Bainitic Steels

    OpenAIRE

    Wang, Yanhui; Zhang, Fucheng; Yang, Zhinan; Lv, Bo; Zheng, Chunlei

    2016-01-01

    In the present work, the nanostructured bainitic microstructures were obtained at the surfaces of a carburized steel and a high-C steel. The rolling contact fatigue (RCF) performances of the two alloy steels with the same volume fraction of undissolved carbide were studied under lubrication. Results show that the RCF life of the carburized nanostructured bainitic steel is superior to that of the high-C nanostructured bainitic steel in spite of the chemical composition, phase constituent, plat...

  13. Effect of rolling deformation and solution treatment on microstructure ...

    Indian Academy of Sciences (India)

    Department of Metallurgy and Materials Engineering, Bengal Engineering and Science ... lume percent of elongated band of δ-ferrite (∼40%) and austenite phase which ... Duplex stainless steel; hot rolling; cold deformation; microstructure; tensile properties. 1. ... ssure vessels, storage tanks, rotors, impellers and shafts,.

  14. Strain hardening of cold-rolled lean-alloyed metastable ferritic-austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Papula, Suvi [Aalto University School of Engineering, Department of Mechanical Engineering, P.O. Box 14200, FI-00076 Aalto (Finland); Anttila, Severi [Centre for Advanced Steels Research, University of Oulu, P.O. Box 4200, 90014 Oulu (Finland); Talonen, Juho [Outokumpu Oyj, P.O. Box 245, FI-00181 Helsinki (Finland); Sarikka, Teemu; Virkkunen, Iikka; Hänninen, Hannu [Aalto University School of Engineering, Department of Mechanical Engineering, P.O. Box 14200, FI-00076 Aalto (Finland)

    2016-11-20

    Mechanical properties and strain hardening of two pilot-scale lean-alloyed ferritic-austenitic stainless steels having metastable austenite phase, present at 0.50 and 0.30 volume fractions, have been studied by means of tensile testing and nanoindentation. These ferritic-austenitic stainless steels have high strain-hardening capacity, due to the metastable austenite phase, which leads to an improved uniform elongation and higher tensile strength in comparison with most commercial lean duplex stainless steels. According to the results, even as low as 0.30 volume fraction of austenite seems efficient for achieving nearly 40% elongation. The austenite phase is initially the harder phase, and exhibits more strain hardening than the ferrite phase. The rate of strain hardening and the evolution of the martensite phase were found to depend on the loading direction: both are higher when strained in the rolling direction as compared to the transverse direction. Based on the mechanical testing, characterization of the microstructure by optical/electron microscopy, magnetic balance measurements and EBSD texture analysis, this anisotropy in mechanical properties of the cold-rolled metastable ferritic-austenitic stainless steels can be explained by the elongated dual-phase microstructure, fiber reinforcement effect of the harder austenite phase and the presence and interplay of rolling textures in the two phases.

  15. Investigation of hot ductility in Al-killed boron steels

    International Nuclear Information System (INIS)

    Chown, L.H.; Cornish, L.A.

    2008-01-01

    The influence of boron to nitrogen ratio, strain rate and cooling rate on hot ductility of aluminium-killed, low carbon, boron microalloyed steel was investigated. Hot tensile testing was performed on steel samples reheated in argon to 1300 deg. C, cooled at rates of 0.3, 1.2 and 3.0 deg. C s -1 to temperatures in the range 750-1050 deg. C, and then strained to failure at initial strain rates of 1 x 10 -4 or 1 x 10 -3 s -1 . It was found that the steel with a B:N ratio of 0.19 showed deep hot ductility troughs for all tested conditions; the steel with a B:N ratio of 0.47 showed a deep ductility trough for a high cooling rate of 3.0 deg. C s -1 and the steel with a near-stoichiometric B:N ratio of 0.75 showed no ductility troughs for the tested conditions. The ductility troughs extended from ∼900 deg. C (near the Ae 3 temperature) to ∼1000 or 1050 deg. C in the single-phase austenite region. The proposed mechanism of hot ductility improvement with increase in B:N ratio in these steels is that the B removes N from solution, thus reducing the strain-induced precipitation of AlN. Additionally, BN co-precipitates with sulphides, preventing precipitation of fine MnS, CuS and FeS, and forming large, complex precipitates that have no effect on hot ductility

  16. Hot Roll Bonding of Aluminum to Twin-Roll Cast (TRC) Magnesium and Its Subsequent Deformation Behavior

    Science.gov (United States)

    Saleh, H.; Schmidtchen, M.; Kawalla, R.

    2018-02-01

    In an experiment in which twin-roll cast AZ31 magnesium alloy and commercial purity aluminum (AA 1050) sheets were bonded by hot rolling as Al/Mg/Al laminate composites, it was found that increasing the preheating temperatures up to 400 °C enhances the bonding strength of composites. Further increases in the preheating temperatures accelerate the magnesium oxide growth and thus reduce the bonding strength. The influence of the reduction ratio on the bonding properties was also studied, whereby it was observed that increasing the rolling reduction led to an increase in the bonding strength. The experimental results show that the optimum bonding strength can be obtained at rolling temperatures of 375-400 °C with a 50-60% reduction in thickness. On the other hand, the subsequent deformation behavior of composite was assessed using plane strain compression and deep drawing tests. We demonstrate that the composites produced using the optimum roll bonding conditions exhibited sufficient bonding during subsequent deformation and did not reveal any debonding at the bonding interface.

  17. 75 FR 62104 - Certain Stainless Steel Sheet and Strip in Coils From Germany, Japan, the Republic of Korea, and...

    Science.gov (United States)

    2010-10-07

    ... trademark of Imphy, S.A. Certain martensitic precipitation-hardenable stainless steel is also excluded from...-831] Certain Stainless Steel Sheet and Strip in Coils From Germany, Japan, the Republic of Korea, and... duty orders on certain stainless steel sheet and strip in coils from Germany, Italy, Japan, the...

  18. Structure changes of Co-Ni-Al ferromagnetic shape memory alloys after vacuum annealing and hot rolling

    International Nuclear Information System (INIS)

    Maziarz, Wojciech

    2008-01-01

    The structure changes of vacuum annealed and hot rolled Co 35+x -Ni 40-x -Al 25 (x = 0, 2.5, 5.0) ferromagnetic shape memory alloys were examined by optical microscopy and X-ray diffraction measurements. Almost the same content of γ phase was observed in alloys after vacuum annealing. The change of grains morphology from dendrite in to equiaxed ones appeared after vacuum annealing. The hot rolling process was applied after annealing at 900 deg. C with thickness reduction up to about 90%. The structure of hot rolled samples revealed elongated grains of different phases. The hardness changes after heat treatment and plastic deformation processes have reflected the solution hardening and work hardening, respectively

  19. Using CCT Diagrams to Optimize the Composition of an As-Rolled Dual-Phase Steel

    Science.gov (United States)

    Coldren, A. Phillip; Eldis, George T.

    1980-03-01

    A continuous-cooling transformation (CCT) diagram study was conducted for the purpose of optimizing the composition of a Mn-Si-Cr-Mo as-rolled dual-phase (ARDP) steel. The individual effects of chromium, molybdenum, and silicon on the allowable cooling rates were determined. On the basis of the CCT diagram study and other available information, an optimum composition was selected. Data from recent mill trials at three steel companies, involving steels with compositions in or near the newly recommended range, are presented and compared with earlier mill trial data. The comparison shows that the optimized composition is highly effective in making the steel's properties more uniform and reproducible in the as-rolled condition.

  20. Hot super-Earths stripped by their host stars

    OpenAIRE

    Lundkvist, M. S.; Kjeldsen, H.; Albrecht, S.; Davies, G. R.; Basu, S.; Huber, D.; Justesen, A. B.; Karoff, C.; Aguirre, V. Silva; Van Eylen, V.; Vang, C.; Arentoft, T.; Barclay, T.; Bedding, T. R.; Campante, T. L.

    2016-01-01

    Simulations predict that hot super-Earth sized exoplanets can have their envelopes stripped by photoevaporation, which would present itself as a lack of these exoplanets. However, this absence in the exoplanet population has escaped a firm detection. Here we demonstrate, using asteroseismology on a sample of exoplanets and exoplanet candidates observed during the Kepler mission that, while there is an abundance of super-Earth sized exoplanets with low incident fluxes, none are found with high...

  1. Semi-solid twin-roll casting process of magnesium alloy sheets

    International Nuclear Information System (INIS)

    Watari, H.; Davey, K.; Rasgado, M.T. Alonso; Haga, T.; Koga, N.

    2004-01-01

    An experimental approach has been performed to ascertain the effectiveness of semi-solid strip casting using a horizontal twin roll caster. The demand for light-weight products with high strength has grown recently due to the rapid development of automobile and aircraft technology. One key to such development has been utilization of magnesium alloys, which can potentially reduce the total product weight. However, the problems of utilizing magnesium alloys are still mainly related to high manufacturing cost. One of the solutions to this problem is to develop magnesium casting-rolling technology in order to produce magnesium sheet products at competitive cost for commercial applications. In this experiment, magnesium alloy AZ31B was used to ascertain the effectiveness of semi-solid roll strip casting for producing magnesium alloy sheets. The temperature of the molten magnesium, and the roll speeds of the upper and lower rolls, (which could be changed independently), were varied to find an appropriate manufacturing condition. Rolling and heat treatment conditions were changed to examine which condition would be appropriate for producing wrought magnesium alloys with good formability. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled

  2. Use of moisture induced stress testing to evaluate stripping potential of hot mix asphalt (HMA).

    Science.gov (United States)

    2012-07-01

    Stripping of hot mix asphalt (HMA) in the field is an ongoing issue for many Departments of Transportation : (DOTs). A leading cause of stripping is hydraulic scouring. The Moisture Induced Stress Tester (MIST) is a recently : developed technology th...

  3. Presentation of the 'Atlas hot workability in steels'

    International Nuclear Information System (INIS)

    Merlone, G.F.; Nunez Pettinari, S.I.; Ruzzante, J.E.

    1993-01-01

    The Atlas summarizes the experience of almost two decades of applied research in the siderurgical industry (IAS-CNEA joint agreements), by means of hot torsion test to evaluate the hot workability in steels through ductility properties and the formation strength. It has a technical prologue, from the abundant specific bibliography, and diagrams of about 40 steels of domestic manufacturing. The information is of industrial application as well as metallurgical research. (Author)

  4. Development of Rolling Schedules for AZ31 Magnesium Alloy Sheets

    Science.gov (United States)

    2015-06-01

    Materials 2 2.2 Hot Rolling 3 2.2 Sample Characterization: Microstructure and Tensile Properties 3 3. Rolling Experiments 5 3.1 High-Temperature...material systems for protective and structural applications, especially in ground vehicles. Magnesium (Mg), due to its low density (~25% that of steel ...applications, wrought Mg is difficult to produce in thin sheets because of its inherently low ductility . As a result, Mg sheet is often produced at

  5. Research on Forming Mechanisms and Controlling Measurements for Surface Light Spot Defects of Galvanizing Steel Coils for Automobile Use

    Science.gov (United States)

    Guangmin, Wei; Haiyan, Sun; Jianqiang, Shi; Lianxuan, Wang; Haihong, Wu

    When producing high surface quality galvanizing steel coils for automobile use, there are always many light spots on the surface since Hansteel CGL No.1 has been put into operation. The defect samples were analyzed by SEM and EDS. The result shows that cause for light spot is not only one. There are more Mn and P in high strength auto sheet, which can result in difficulty to be cleaned off the oxide on the hot rolled coils, so the defects coming. This is why the defects come with high strength auto sheet. When coils galvanized, the defects can't be covered up. To the contrary, the defects will be more obvious when zinc growing on the surface. And sometimes zinc or residue can adhere to work rolls when strips passing through SPM. The deposits then press normal coating. So the light spots come more. When the defect comes from pressing, there is no defect on steel base. The causation is found and measures were taken including high pressure cleaning equipments adopted. Result shows that the defects disappeared.

  6. 76 FR 49726 - Continuation of Antidumping and Countervailing Duty Orders: Stainless Steel Sheet and Strip in...

    Science.gov (United States)

    2011-08-11

    ... martensitic precipitation-hardenable stainless steel, and (12) three specialty stainless steels typically used...\\ ``Gilphy 36'' is a trademark of Imphy, S.A. Certain martensitic precipitation-hardenable stainless steel is...-831] Continuation of Antidumping and Countervailing Duty Orders: Stainless Steel Sheet and Strip in...

  7. Contact conditions in skin-pass rolling

    DEFF Research Database (Denmark)

    Kijima, Hideo; Bay, Niels

    2007-01-01

    The special contact conditions in skin-pass rolling of steel strip is analysed by studying plane strain upsetting of thin sheet with low reduction applying long narrow tools and dry friction conditions. An extended sticking region is estimated by an elasto-plastic FEM analysis of the plane strain...... upsetting. This sticking region causes a highly inhomogeneous elasto-plastic deformation with large influence of work-hardening and friction. A numerical analysis of skin-pass rolling shows the same contact conditions, i.e. an extended sticking region around the center of the contact zone. The calculated...... size of the sticking region with varying contact length and pressure/reduction is experimentally verified by plane strain upsetting tests measuring the local surface deformation of the work pieces after unloading....

  8. Mechanical properties of CO2/MIG welded structural rolled steel and stainless steel

    International Nuclear Information System (INIS)

    Lim, Jong Young; Yoon, Myong Jin; Kim, Sang Youn; Kim, Tae Gyu; Shin, Hyeon Seung

    2015-01-01

    To accomplish long-term use of specific parts of steel, welding technology is widely applied. In this study, to compare the efficiency in improving mechanical properties, rolled steel (SS400) was welded with stainless steel (STS304) by both CO 2 welding method and MIG (metal inert gas) welding method, respectively. Multi-tests were conducted on the welded specimen, such as X-ray irradiation, Vickers' Hardness, tensile test, fatigue test and fatigue crack growth test. Based on the fatigue crack growth test performed by two different methods, the relationship of da/dN was analyzed. Although the hardness by the two methods was similar, tensile test and fatigue properties of MIG welded specimen are superior to CO 2 welded one.

  9. Effect of an Intermediate Heat-treatment on a Change of the Corrosion Resistance and Hardness of a HANA-4 Outer Strip

    International Nuclear Information System (INIS)

    Lee, Myung Ho; Jung, Yang Il; Park, Sang Yoon; Choi, Byoung Kwon; Park, Jeong Yong; Jeong, Yong Hwan; Eom, Kyong Bo; Park, Nam Gyu; Lim, Yoon Soo

    2008-01-01

    KAERI (Korea Atomic Energy Research Institute) in collaboration with KNF (Korea Nuclear Fuel) undertook some researches on the applicability of HANA-4 and HANA-6 alloys for the spacer grid for a PWR (Pressurized Water Reactor) nuclear fuel. As a part of the research, KAERI studied the effect of the final heat-treatment on the mechanical and corrosion properties of a HANA-4 inner strip. The strip was manufactured with a sheet which had been intermediately heat-treated at about 580 .deg. C for 2.5-4 hours after each cold rolling before being processed into the final strip product. It was mentioned that the process with the intermediate heat treatment needed reviewing to establish an improved manufacturing process for the cold rolling. So, this work tried to check the effect of an intermediate heat-treatment on the properties of a HANA-4 strip using a specimen that was taken from a second hot rolled material before a cold-rolling. The manufacturing processes, with three different kinds of annealings, were introduced to investigate the applicable intermediate heat-treatment process. After all the cold-rolling processes, the Vickers hardness was measured for the final annealed specimens and 60 days of corrosion tests were carried out to check on the effect of the intermediate heat-treatment. Finally, an appropriate intermediate heat-treatment was proposed to improve the manufacturability of the HANA-4 strip

  10. Influence of different kinds of rolling on the crystallographic texture and magnetic induction of a NOG 3 wt% Si steel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.M.; Baêta Júnior, E.S.; Moraes, N.R.D.C.; Botelho, R.A. [Department of Mechanical and Materials Engineering, Military Institute of Engineering (IME), Praça General Tibúrcio, 80,Urca, Rio de Janeiro/RJ (Brazil); Felix, R.A.C. [Scientific Instrumentation and Mechanical Technology Laboratory, Brazilian Center for Physics Research (CBPF), Rua Dr. Xavier Sigaud, 150-Urca, Rio de Janeiro-RJ (Brazil); Brandao, L., E-mail: brandao@ime.eb.br [Department of Mechanical and Materials Engineering, Military Institute of Engineering (IME), Praça General Tibúrcio, 80,Urca, Rio de Janeiro/RJ (Brazil)

    2017-01-01

    The purpose of this work was to study the influence of different kinds of rolling on the magnetic properties of NOG steel, an electric steel widely used in electrical motors. These properties are highly correlated with the crystallographic texture of the material, which can be changed by rolling. Three kinds of rolling were examined: conventional rolling, cross-rolling and asymmetrical rolling. The crystallographic texture was determined by X-ray diffraction and the magnetic properties were calculated from a theoretical model that related the magnetic induction to crystallographic texture through the anisotropy energy. The results show that cross-rolling yields higher values of magnetic induction than the other processes. - Highlights: • The B{sub 50} of NOG steels was evaluated via texture for different rolling processes. • On comparison to all processes used, the cross-rolling led to highest average B{sub 50}. • Cross-rolling enhances Goss and γ-fiber after annealing. • The better B{sub 50} values were obtained for symmetrical and cross-rolling processes. • For asymmetric rolling process, cylinder diameter ratio changed slightly the texture.

  11. Effect of hot rolling on the microstructure and mechanical properties of Ti3Al based dual phase alloys

    International Nuclear Information System (INIS)

    Wu, J.; Zhang, L.; Hua, W.; Qiu, G.

    1999-01-01

    Development of α 2 -Ti 3 Al based dual phase alloys have shown some promising potentials in property improvement by introducing Ti 5 Si 3 silicide phase into the matrix via Si alloying. However, the presence of coarse network of Ti 5 Si 3 phase formed by eutectic reaction in the as-cast state also embrittles the alloy. Both hot rolling and powder metallurgy are considered to be the possible ways to refine the Ti 5 Si 3 phase in the matrix. Two Ti-Al-Si-Nb alloys whose Si contents are 2 and 5 at.% respectively were arc melted into ingots and then hot rolled to sheets in this investigation. Optical metallographic examination correlates the microstructures of the as-cast and as-rolled alloys with the different rolling amounts, showing that the coarse silicide network is broken into small particles after hot rolling. Mechanical property testing from room temperature to 800 C indicates that the strength and plastic elongation of the hot-rolled alloys are much higher than those of the as-cast ones. The data obtained in this investigation are comparable with those obtained in the P/M processed specimens. Fracture surfaces of the alloys are also examined

  12. Model for texture evolution in cold rolling of 2.4 wt.-% Si non-oriented electrical steel

    Science.gov (United States)

    Wei, X.; Hojda, S.; Dierdorf, J.; Lohmar, J.; Hirt, G.

    2017-10-01

    Iron loss and limited magnetic flux density are constraints for NGO electrical steel used in highly efficient electrical machinery cores. The most important factors that affect these properties are the final microstructure and the texture of the NGO steel. Reviewing the whole process chain, cold rolling plays an important role because the recrystallization and grain growth during the final heat treatment can be strongly affected by the stored energy and microstructure of cold rolling, and some texture characteristics can be inherited as well. Therefore, texture evolution during cold rolling of NGO steel is worth a detailed investigation. In this paper, texture evolution in cold rolling of non-oriented (NGO) electrical steel is simulated with a crystal plasticity finite element method (CPFEM) model. In previous work, a CPFEM model has been implemented for simulating the texture evolution with periodic boundary conditions and a phenomenological constitutive law. In a first step the microstructure in the core of the workpiece was investigated and mapped to a representative volume element to predict the texture evolution. In this work an improved version of the CPFEM model is described that better reflects the texture evolution in cold rolling of NGO electrical steel containing 2.4 wt.-% Si. This is achieved by applying the deformation gradient and calibrating the flow curve within the CPFEM model. Moreover, the evolution of dislocation density is calculated and visualized in this model. An in depth comparison of the numerical and experimental results reveals, that the improved CPFEM model is able to represent the important characteristics of texture evolution in the core of the workpiece during cold rolling with high precision.

  13. A review of hot cracking in austenitic stainless steel weldments

    International Nuclear Information System (INIS)

    Shankar, V.; Gill, T.P.S.; Mannan, S.L.; Rodriguez, P.

    1991-01-01

    The occurrence of hot cracking in austenitic stainless steel weldments is discussed with respect to its origin and metallurgical contributory factors. Of the three types of hot cracking, namely solidification cracking, liquation and ductility dip cracking, solidification cracking occurs in the interdendritic regions in weld metal while liquation and ductility dip cracking occur intergranularly in the heat-affected zone (HAZ). Segregation of impurity and minor elements such as sulphur, phosphorous, silicon, niobium, boron etc to form low melting eutectic phases has been found to be the major cause of hot cracking. Control of HAZ cracking requires minimisation of impurity elements in the base metal. In stabilized stainless steels containing niobium, higher amounts of delta-ferrite have been found necessary to prevent cracking than in unstabilized compositions. Titanium compounds have been found to cause liquation cracking in maraging steels and titanium containing stainless steels and superalloys. In nitrogen added stainless steels, cracking resistance decreases when the solidification mode changes to primary austenitic due to nitrogen addition. A review of the test methods to evaluate hot cracking behaviour showed that several external restraint and semi-self-restraint tests are available. The finger Test, WRC Fissure Bend Test, the PVR test and the Varestraint Test are described along with typical test results. Hot ductility testing to reveal HAZ cracking tendency during welding is described, which is of particular importance to stabilized stainless steels. Based on the literature, recommendations are made for welding stabilized and nitrogen added steels, indicating areas of further work. (author). 81 refs., 30 figs., 1 tab

  14. 75 FR 81308 - Stainless Steel Sheet And Strip From Germany, Italy, Japan, Korea, Mexico, And Taiwan

    Science.gov (United States)

    2010-12-27

    ...)] Stainless Steel Sheet And Strip From Germany, Italy, Japan, Korea, Mexico, And Taiwan AGENCY: United States... and strip from Germany, Italy, Japan, Korea, Mexico, and Taiwan. SUMMARY: The Commission hereby gives... strip from Germany, Italy, Japan, Korea, Mexico, and Taiwan would be likely to lead to continuation or...

  15. Travel to Steel Warehouse Inc., Southbend, Indiana. Trip report, May 4, 1995

    International Nuclear Information System (INIS)

    Hill, N.F.

    1995-01-01

    On May 4, 1995 the author visited a steel plate and coil, cold reduction facility at Steel Warehouse Inc. located in South Bend, Indiana about 150 miles from Argonne. Some very interesting facts were learned about cold reduction of hot rolled steel during this visit. The company selected is only a cold reduction mill and buys steel from a number of steel producers. The author spent a total of about three hours with these people, and this included a tour of their pickling line, the small cold reduction mill which at present is limited to 15.5 in width maximum, and their large cold reduction mill which produces sheet and coil up to 72 in. wide. Some of the things that were learned, that will have an impact on the production of the Atlas steel plates are given here. (1) Hot rolled coils have some inherent, interesting, characteristics that must be taken into consideration when being cold reduced. (2) The monitoring of the coil thickness is only done along the center line of the coil, this has a serious impact on QC of plates cut from this coil for a number of reasons. (3) Hot rolled coils of steel in this particular instance may come from a number of different sources. This could cause problems if magnetic permeability is a serious issue. It was the author's impression that this facility is fairly typical of what one might expect from any similar facility

  16. Evolution of the texture, mechanical properties, and microstructure of Cu-2.7Be alloys during hot cross-rolling

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Daibo; Liu, Chuming; Liu, Yadi; Gao, Yonghao; Jiang, Shunong [Central South University, School of Materials Science and Engineering, Changsha (China); Han, Tan [Suzhou Kinkou Copper Industry Limited Liability Company, Taicang (China)

    2015-09-15

    The evolution of the microstructure and texture of Cu-2.7Be alloys during hot rolling was investigated and related to the mechanical properties of the resulting sheets. Hot cross-rolling is shown to be an effective way to refine the hard and brittle secondary-phase particles in Cu-2.7Be alloys. The Cu- and brass-type textures increase and decrease in prevalence, respectively, during the rolling process. The yield strengths along the first and second rolling directions, and 45 to the former, are all enhanced because the corresponding Schmid factors decrease as the sheets are rolled thinner. The ductility anisotropy of the as-rolled sheets is related to the distribution and shape of the secondary-phase particles therein. (orig.)

  17. Rolled-up transformer structure for a radiofrequency integrated circuit (RFIC)

    Science.gov (United States)

    Li, Xiuling; Huang, Wen

    2015-01-27

    A rolled-up transformer structure comprises a multilayer sheet having a rolled configuration comprising multiple turns about a longitudinal axis. The multilayer sheet comprises more than one conductive pattern layer on a strain-relieved layer, including a first conductive film and a second conductive film separated from the first conductive film in a thickness direction. The first conductive film comprises an even number of primary conductive strips, where each primary conductive strip has a length extending in the rolling direction, and the second conductive film comprises an even number of secondary conductive strips, where each secondary conductive strip has a length extending in the rolling direction. In the rolled configuration, turns of the primary conductive strips and turns of the secondary conductive strips wrap around the longitudinal axis. The primary conductive strips serve as a primary winding and the secondary conductive strips serve as a secondary winding of the rolled-up transformer structure.

  18. Rolled-up transformer structure for a radiofrequency integrated circuit (RFIC)

    Science.gov (United States)

    Li, Xiuling; Huang, Wen

    2016-05-03

    A rolled-up transformer structure comprises a multilayer sheet having a rolled configuration comprising multiple turns about a longitudinal axis. The multilayer sheet comprises more than one conductive pattern layer on a strain-relieved layer, including a first conductive film and a second conductive film separated from the first conductive film in a thickness direction. The first conductive film comprises an even number of primary conductive strips, where each primary conductive strip has a length extending in the rolling direction, and the second conductive film comprises an even number of secondary conductive strips, where each secondary conductive strip has a length extending in the rolling direction. In the rolled configuration, turns of the primary conductive strips and turns of the secondary conductive strips wrap around the longitudinal axis. The primary conductive strips serve as a primary winding and the secondary conductive strips serve as a secondary winding of the rolled-up transformer structure.

  19. Effect of current frequency on the mechanical properties, microstructure and texture evolution in AZ31 magnesium alloy strips during electroplastic rolling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaopei [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Beijing National Center for Electron Microscopy, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084 (China); Tang, Guoyi; Kuang, Jie; Li, Xiaohui [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Zhu, Jing, E-mail: jzhu@tsinghua.edu.cn [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Beijing National Center for Electron Microscopy, School of Materials Science and Engineering, The State Key Laboratory of New Ceramics and Fine Processing, Laboratory of Advanced Materials (MOE), Tsinghua University, Beijing 100084 (China)

    2014-08-26

    The effect of electroplastic rolling (ER) on the mechanical properties, microstructure and texture in the AZ31 magnesium alloy strips has been investigated by tensile testing and electron back scattered diffraction (EBSD) methods. It is shown that the mechanical properties, microstructure, and texture are highly current frequency-dependent. Best mechanical properties are obtained from the 500 Hz ER specimen by carrying out tensile tests for all the rolled strips. Besides, the frequencies of twin boundaries, which are reduced to the minimum at 500 Hz, vary with the current frequency. Moreover, it can be seen from the calculated (0001) and (101{sup ¯}0) pole figures that texture evolved into an obvious off-basal texture, and non-basal slip systems are activated under 500 Hz. The mechanisms of twinning growth and texture evolution in AZ31 magnesium alloy strips during ER are considered to be responsible for the experimental results.

  20. Microstructural Evolution During Cold Rolling and Subsequent Annealing in Low-Carbon Steel with Different Initial Microstructures

    Science.gov (United States)

    Ogawa, Toshio; Dannoshita, Hiroyuki; Maruoka, Kuniaki; Ushioda, Kohsaku

    2017-08-01

    Microstructural evolution during cold rolling and subsequent annealing of low-carbon steel with different initial microstructures was investigated from the perspective of the competitive phenomenon between recrystallization of ferrite and reverse phase transformation from ferrite to austenite. Three kinds of hot-rolled sheet specimens were prepared. Specimen P consisted of ferrite and pearlite, specimen B consisted of bainite, and specimen M consisted of martensite. The progress of recovery and recrystallization of ferrite during annealing was more rapid in specimen M than that in specimens P and B. In particular, the recrystallized ferrite grains in specimen M were fine and equiaxed. The progress of ferrite-to-austenite phase transformation during intercritical annealing was more rapid in specimen M than in specimens P and B. In all specimens, the austenite nucleation sites were mainly at high-angle grain boundaries, such as those between recrystallized ferrite grains. The austenite distribution was the most uniform in specimen M. Thus, we concluded that fine equiaxed recrystallized ferrite grains were formed in specimen M, leading to a uniform distribution of austenite.

  1. Influence of deformation process on the improvement of non-oriented electrical steel

    International Nuclear Information System (INIS)

    Fischer, O.; Schneider, J.

    2003-01-01

    World-wide there is a trend to develop higher permeability grades of non-oriented electrical steels. The paper discusses the practical relevance of these developments and describes the progress in higher permeability materials utilizing optimized hot rolling and cold rolling processes

  2. Effect of nanoprecipitates and grain size on the mechanical properties of advanced structural steels

    International Nuclear Information System (INIS)

    Suarez, M.A.; Alvarez-Perez, M.A.; Alvarez-Fregoso, O.; Juarez-Islas, J.A.

    2011-01-01

    Highlights: → The composition of the steel responded positively to the thermomechanical processing. → Yield strength was increased due to micrometric grain size of 2.2 μm. → Mechanical properties were improved due to nanometric precipitates of 5 nm. → Yield strength values of the API steel were improved up to 877.9 MPa. - Abstract: The microstructure and nanometric precipitates present in advanced structured steel have been studied by high resolution transmission electron microscopy equipped with energy dispersion X-ray microanalysis, in order to relate the nanometric precipitates and grain size with the improvement of the yield strength value of the API steel. The microstructure and nanometric precipitates of the advanced steel were obtained by a combination of thermo-mechanical controlled hot rolling and accelerated cooling procedures. The API steel composition consisted of hot rolled Nb-Ti microalloyed with: 0.07C, 1.40Mn, 0.24Si, 0.020Al, 0.009P, 0.001S, 0.05Mo, 0.5Cr, 0.05Nb, 0.25Ni, 0.10Cu, 0.012Ti, 0.05N in wt%. As a result, this hot rolled steel tested at a strain rate of 5 x 10 -3 s -1 showed an improved yield strength from 798 MPa to 878 MPa due to the micrometric grain size of 2.2 μm and to the nanometric precipitates with a size of around 5 nm in the microstructure of the steel studied.

  3. design chart procedures for polygonal concrete-filled steel columns

    African Journals Online (AJOL)

    ADMIN

    hexagonal and octagonal steel-concrete composite columns subjected to ... This paper also outlines procedures that will enable preparation of ... buildings and in a variety of large-span building ... Likewise, hot-rolled steel tubes are used while ... small moderate large. Fig. 2. Possible arrangement of composite polygonal ...

  4. Electron backscatter diffraction study of deformation and recrystallization textures of individual phases in a cross-rolled duplex steel

    Energy Technology Data Exchange (ETDEWEB)

    Zaid, Md; Bhattacharjee, P.P., E-mail: pinakib@iith.ac.in

    2014-10-15

    The evolution of microstructure and texture during cross-rolling and annealing was investigated by electron backscatter diffraction in a ferritic–austenitic duplex stainless steel. For this purpose an alloy with nearly equal volume fraction of the two phases was deformed by multi-pass cross-rolling process up to 90% reduction in thickness. The rolling and transverse directions were mutually interchanged in each pass by rotating the sample by 90° around the normal direction. In order to avoid deformation induced phase transformation and dynamic strain aging, the rolling was carried out at an optimized temperature of 898 K (625 °C) at the warm-deformation range. The microstructure after cross warm-rolling revealed a lamellar structure with alternate arrangement of the bands of two phases. Strong brass and rotated brass components were observed in austenite in the steel after processing by cross warm-rolling. The ferrite in the cross warm-rolling processed steel showed remarkably strong RD-fiber (RD//< 011 >) component (001)< 011 >. The development of texture in the two phases after processing by cross warm-rolling could be explained by the stability of the texture components. During isothermal annealing of the 90% cross warm-rolling processed material the lamellar morphology was retained before collapse of the lamellar structure to the mutual interpenetration of the phase bands. Ferrite showed recovery resulting in annealing texture similar to the deformation texture. In contrast, the austenite showed primary recrystallization without preferential orientation selection leading to the retention of deformation texture. The evolution of deformation and annealing texture in the two phases of the steel was independent of one another. - Highlights: • Effect of cross warm-rolling on texture formation is studied in duplex steel. • Brass texture in austenite and (001)<110 > in ferrite are developed. • Ferrite shows recovery during annealing retaining the (001

  5. Soil Contamination with Heavy Metals around Jinja Steel Rolling Mills in Jinja Municipality, Uganda

    Directory of Open Access Journals (Sweden)

    Noel Namuhani

    2015-01-01

    Conclusions. The concentration levels of heavy metals around the steel rolling mills did not appear to be of serious concern, except for copper and cadmium, which showed moderate pollution and moderate to strong pollution, respectively. All heavy metals were within the limits of the United States Environmental Protection Agency (USEPA residential soil standards and the Dutch intervention soil standards. Overall, soils around the Jinja steel rolling mills were slightly polluted with heavy metals, and measures therefore need to be taken to prevent further soil contamination with heavy metals.

  6. Effect of niobium and titanium addition on the hot ductility of boron containing steel

    International Nuclear Information System (INIS)

    Cho, Kyung Chul; Mun, Dong Jun; Koo, Yang Mo; Lee, Jae Sang

    2011-01-01

    Research highlights: → Addition of only Nb without Ti has little influence in the hot ductility of B steel. → Hot ductility loss of B-Nb steel is due to grain boundary precipitation of BN. → Adding a small amount of Ti improve the hot ductility of B-Nb steel. → In B-Nb-Ti steel, hot ductility improvement is related to presence of TiN particle. → Presence of TiN particles makes the BN precipitates' distribution more homogeneous. - Abstract: Hot ductility of boron containing steel (B steel) with adding Nb (0.03 wt.%) (B-Nb steel) and B-Nb steel with adding Ti (0.0079 wt.%) (B-Nb-Ti steel) was quantified using hot tensile tests. The specimens were solution-treated at 1350 deg. C and cooled at 20 deg. C s -1 to tensile test temperature (T) in the range of 750 ≤ T ≤ 1050 deg. C. After that, they were strained to failure at a strain rate of 2.5 x 10 -3 s -1 . For the B-Nb steel, severe hot ductility loss was observed at 850 ≤ T ≤ 950 deg. C, which covered the low temperature in which austenite (γ) single-phase exists, and the high temperature at which γ and ferrite (α) coexist. Ductility loss in the B-Nb steel was caused by the presence of a network of BN precipitates, rather than by Nb(C, N) precipitates at the γ grain boundaries. In contrast, hot ductility of the B-Nb-Ti steel was remarkably improved at 850 ≤ T ≤ 950 deg. C. In the B-Nb-Ti steel, BN precipitates preferentially on TiN particles, resulting in increased BN precipitation in the γ grain interior and a decrease in the network of BN precipitates at the γ grain boundaries. These changes reduce strain localization at the γ grain boundaries and therefore increase the hot ductility of the steel.

  7. Effect of cold-rolling on pitting corrosion of 304 austenitic stainless steel

    International Nuclear Information System (INIS)

    Peguet, L.; Malki, B.; Baroux, B.

    2004-01-01

    Full text of publication follows: This paper deals with a not very often investigated topic on relation between cold-working and stainless steels localized corrosion resistance. It is devoted to the study of the cold-rolling effects on the pitting corrosion behavior of a 304 stainless steel grade in chloride containing aqueous electrolytes. It focus particularly on the analysis of metastable pitting transients observed at Open Circuit Potential using an experimental protocol including two identical working electrodes connected through a zero-impedance. As received the used specimens were heat-treated at 1100 C for 30 s and cold-rolled at 10%, 20%, 30% up to a final reduction pass of 70% inducing a large amount of α'-martensite. Then, current-potential fluctuations measurements were performed at OCP in NaCl 0.1 M + FeCl 3 2.10 -4 M containing aqueous solution during 24 h from the immersion time. As expected, a detrimental effect on corrosion behavior induced by cold rolling has been confirmed. Surprisingly, this is a nonlinear effect as a function of cold-rolling rate which controverts the hypothesis that strain induced martensite is the principal factor to explain this kind of sensibilizing. In particular, the results show a maximum of the metastable pits initiation frequency at 20% of cold-rolling rate. Moreover, the passive film/electrochemical double layer resistance and capacity deduced from the transients study show an analog nonlinear behavior. So, the transfer resistance show a minimum around 10-20% of cold-rolling rate where one can assume an increase of the electrons transfer kinetics through the interface. Conversely, the interfacial capacity is the highest at 20% of cold-rolling rate. Finally, It is expected a combined effect of the cold-rolled induced martensite and the dislocations arrangement via the mechano-chemical theory discussed by Gutman. (authors)

  8. Measurement of the thermal conductivity of thin insulating anisotropic material with a stationary hot strip method

    International Nuclear Information System (INIS)

    Jannot, Yves; Degiovanni, Alain; Félix, Vincent; Bal, Harouna

    2011-01-01

    This paper presents a method dedicated to the thermal conductivity measurement of thin insulating anisotropic materials. The method is based on three hot-strip-type experiments in which the stationary temperature is measured at the center of the hot strip. A 3D model of the heat transfer in the system is established and simulated to determine the validity of a 2D transfer hypothesis at the center of the hot strip. A simplified 2D model is then developed leading to the definition of a geometrical factor calculable from a polynomial expression. A very simple calculation method enabling the estimation of the directional thermal conductivities from the three stationary temperature measurements and from the geometrical factor is presented. The uncertainties on each conductivity are estimated. The method is then validated by measurements on polyethylene foam and Ayous (anistropic low-density tropical wood); the estimated values of the thermal conductivities are in good agreement with the values estimated using the hot plate and the flash method. The method is finally applied on a thin super-insulating fibrous material for which no other method is able to measure the in-plane conductivity

  9. Effects of interface roughness on the annealing behaviour of laminated Ti-Al composite deformed by hot rolling

    DEFF Research Database (Denmark)

    Du, Y.; Fan, G.H.; Yu, Tianbo

    2015-01-01

    A laminated Ti-Al composite has been fabricated by hot compaction and hot rolling of alternate layers of commercial purity Ti and Al sheets with a thickness of 200 μm. The hot compaction temperature was 500˚C and in a following step the composite has been reduced 50% in thickness by hot rolling....... The fully consolidated composite has been annealed at 300˚C and 500˚C for different length of time. As a result of the differences in crystal structure and mechanical properties between Ti and Al protrusions and retrusions formed at the interface. A heterogeneous interface has thereby been created...

  10. Roll-to-roll hot embossing system with shape preserving mechanism for the large-area fabrication of microstructures

    Science.gov (United States)

    Peng, Linfa; Wu, Hao; Shu, Yunyi; Yi, Peiyun; Deng, Yujun; Lai, Xinmin

    2016-10-01

    Roll-to-roll (R2R) hot embossing is a promising approach to fulfilling the demands of high throughput fabrication of large-area polymeric components with micro-structure arrays which have been widely employed in the domains of optics, optoelectronics, biology, chemistry, etc. Nevertheless, the characteristic of continuous and fast forming for the R2R hot embossing process limits material flow during filling stage and results in significant springback during demolding stage. As a result, forming defects usually appear and the process window is very narrow which hinders the industrialization of this technology. This study developed a R2R hot embossing machine and proposed a shape preserving mechanism to extend the material filling time and realized the cooling effect during the demolding process. Comparative experiments were conducted on the R2R hot embossing process for micro-pyramid arrays to understand the effect of shape preserving mechanism. The influence of tension force and encapsulation angle to the forming quality was systematically analyzed. Furthermore, the influence of processing parameters has been investigated by using the one-variable-at-a-time method. Afterwards, a series of experiments based on the central composite design approach have been conducted for the analysis of variance and the establishment of empirical models of the R2R hot embossing process. As a result, the process window was extended by the shape preserving mechanism. More importantly, the feeding speed was improved from 0.5 m min-1 to 2.5 m min-1 for the large-area fabrication of micro-pyramid arrays, which is very attractive to the industrialization of this technology.

  11. Patterned immobilization of antibodies within roll-to-roll hot embossed polymeric microfluidic channels.

    Directory of Open Access Journals (Sweden)

    Belachew Feyssa

    Full Text Available This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R hot embossing on poly (methyl methacrylate (PMMA. Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA to provide an amine-reactive aldehyde surface (PEI-GA. This step was followed by a second deposition of antibody by overprinting on the PEI-GA patterned PMMA foil. The PEI polymer ink was first formulated to ensure stable drop formation in inkjet printing and the printed films were characterized using atomic force microscopy (AFM and X-ray photoelectron spectroscopy (XPS. Anti-CRP antibody was patterned on PMMA foil by the developed method and bonded permanently with R2R hot embossed PMMA microchannels by solvent bonding lamination. The functionality of the immobilized antibody inside the microfluidic channel was evaluated by fluorescence-based sandwich immunoassay for detection of C-reactive protein (CRP. The antibody-antigen assay exhibited a good level of linearity over the range of 10 ng/ml to 500 ng/ml (R(2 = 0.991 with a calculated detection limit of 5.2 ng/ml. The developed patterning method is straightforward, rapid and provides a versatile approach for creating multiple protein patterns in a single microfluidic channel for multiplexed immunoassays.

  12. Phase evolution and mechanical behavior of 0.36 wt% C high strength TRIP-assisted steel

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Swarup Kumar; Chattopadhyay, Partha Protim [Department of Metallurgy and Materials Engineering, Bengal Engineering and Science University, Shibpur, Howrah 711 103 (India)

    2012-12-15

    Phase evolution in a 0.36 wt% C steel has been studied by thermodynamic calculation and dilatometric analysis with an aim to achieve high strength TRIP-assisted steel with bainitic microstructure. The equilibrium phase fraction calculated as the function of temperature indicated the formation of {delta}-ferrite ({approx}98%) at 1417 C. In contrast, similar calculation under para-equilibrium condition exhibited transformation of {delta}-ferrite to austenite at the temperature below 1300 C. During further cooling two-phase ({alpha}+{gamma}) microstructure has been found to be stable at the intercritical temperature range. The experimentally determined CCT diagram has revealed that adequate hardenability is achievable in the steel under continuous cooling condition at cooling rate >5 C s{sup -1}. In view of the aforesaid results, the steel has been hot rolled and subjected to different process schedule conducive to the evolution of bainitic microstructure. The hot rolled steel has exhibited reasonably good tensile properties. However, cold deformation of the hot rolled sample followed by intercritical annealing and subsequent isothermal bainitic transformation has resulted in high strength (>1000 MPa) with attractive elongation due to the favorable work hardening condition during plastic deformation offered by the multiphase microstructure. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Influence of different kinds of rolling on the crystallographic texture and magnetic induction of a NOG 3 wt% Si steel

    Science.gov (United States)

    Silva, J. M.; Baêta Júnior, E. S.; Moraes, N. R. D. C.; Botelho, R. A.; Felix, R. A. C.; Brandao, L.

    2017-01-01

    The purpose of this work was to study the influence of different kinds of rolling on the magnetic properties of NOG steel, an electric steel widely used in electrical motors. These properties are highly correlated with the crystallographic texture of the material, which can be changed by rolling. Three kinds of rolling were examined: conventional rolling, cross-rolling and asymmetrical rolling. The crystallographic texture was determined by X-ray diffraction and the magnetic properties were calculated from a theoretical model that related the magnetic induction to crystallographic texture through the anisotropy energy. The results show that cross-rolling yields higher values of magnetic induction than the other processes.

  14. Adhesiveness of cold rolled steels for car body parts

    Directory of Open Access Journals (Sweden)

    Kleiner Marques Marra

    2007-09-01

    Full Text Available The aim of this work was to evaluate the adhesiveness of uncoated and zinc-electrogalvanized steel sheets used in the automotive industry. Three types of adhesives, one acrylic and two epoxy resins, were employed to join low carbon cold rolled steels, one uncoated and another electrogalvanized, both previously degreased or chemically pickled. Mechanical strength of the joints was evaluated by the T-peel and tensile strength tests. Steel grade, surface condition and heating below the cure temperatures did not influence the joints' mechanical strength. However, their shear strength decreased drastically as the test temperature increased. The exposure of the joints to an atmosphere with 90% relative humidity at 40 °C caused reduction of their shear strength. Epoxy adhesives showed higher mechanical strength, but exhibited higher degradation by humidity.

  15. Deformability of Oxide Inclusions in Tire Cord Steels

    Science.gov (United States)

    Zhang, Lifeng; Guo, Changbo; Yang, Wen; Ren, Ying; Ling, Haitao

    2018-04-01

    The deformation of oxide inclusions in tire cord steels during hot rolling was analyzed, and the factors influencing their deformability at high and low temperatures were evaluated and discussed. The aspect ratio of oxide inclusions decreased with the increasing reduction ratio of the steel during hot rolling owing to the fracture of the inclusions. The aspect ratio obtained after the first hot-rolling process was used to characterize the high-temperature deformability of the inclusions. The deformation first increased and then decreased with the increasing (MgO + Al2O3)/(SiO2 + MnO) ratio of the inclusions. It also increased with the decreasing melting temperatures of the inclusions. Young's modulus was used to evaluate the low-temperature deformability of the inclusions. An empirical formula was fitted to calculate the Young's moduli of the oxides using the mean atomic volume. The moduli values of the inclusions causing wire fracture were significantly greater than the average. To reduce fracture in tire cord steel wires during cold drawing, it is proposed that inclusions be controlled to those with high SiO2 content and extremely low Al2O3 content. This proposal is based on the hypothesis that the deformabilities of oxides during cold drawing are inversely proportional to their Young's moduli. The future study thus proposed includes an experimental confirmation for the abovementioned predictions.

  16. Microstructural analysis of hot press formed 22MnB5 steel

    Science.gov (United States)

    Aziz, Nuraini; Aqida, Syarifah Nur; Ismail, Izwan

    2017-10-01

    This paper presents a microstructural study on hot press formed 22MnB5 steel for enhanced mechanical properties. Hot press forming process consists of simultaneous forming and quenching of heated blank. The 22MnB5 steel was processed at three different parameter settings: quenching time, water temperature and water flow rate. 22MnB5 was processed using 33 full factorial design of experiment (DOE). The full factorial DOE was designed using three factors of quenching time, water temperature and water flow rate at three levels. The factors level were quenching time range of 5 - 11 s, water temperature; 5 - 27°C and water flow rate; 20 - 40 L/min. The as-received and hot press forming processed steel was characterised for metallographic study and martensitic structure area percentage using JEOL Field Emission Scanning Electron Microscopic (FESEM). From the experimental finding, the hot press formed 22MnB5 steel consisted of 50 to 84% martensitic structure area. The minimum quenching time of 8 seconds was required to obtain formed sample with high percentage of martensite. These findings contribute to initial design of processing parameters in hot press forming of 22MnB5 steel blanks for automotive component.

  17. An advanced dissymmetric rolling model for online regulation

    Science.gov (United States)

    Cao, Trong-Son

    2017-10-01

    Roll-bite model is employed to predict the rolling force, torque as well as to estimate the forward slip for preset or online regulation at industrial rolling mills. The rolling process is often dissymmetric in terms of work-rolls rotation speeds and diameters as well as the friction conditions at upper and lower contact surfaces between work-rolls and the strip. The roll-bite model thus must be able to account for these dissymmetries and in the same time has to be accurate and fast enough for online applications. In the present study, a new method, namely Adapted Discretization Slab Method (ADSM) is proposed to obtain a robust roll-bite model, which can take into account the aforementioned dissymmetries and has a very short response time, lower than one millisecond. This model is based on the slab method, with an adaptive discretization and a global Newton-Raphson procedure to improve the convergence speed. The model was validated by comparing with other dissymmetric models proposed in the literature, as well as Finite Element simulations and industrial pilot trials. Furthermore, back-calculation tool was also constructed for friction management for both offline and online applications. With very short CPU time, the ADSM-based model is thus attractive for all online applications, both for cold and hot rolling.

  18. Determination of Proper Austenitization Temperatures for Hot Stamping of AISI 4140 Steel

    Science.gov (United States)

    Samadian, Pedram; Parsa, Mohammad Habibi; Shakeri, Amid

    2014-04-01

    High strength steels are desirable materials for use in automobile bodies in order to reduce vehicle weight and increase the safety of car passengers, but steel grades with high strength commonly show poor formability. Recently, steels with controlled microstructures and compositions are used to gain adequate strength after hot stamping while maintaining good formability during processing. In this study, microstructure evolutions and changes in mechanical properties of AISI 4140 steel sheets resulting from the hot stamping process at different austenitization temperatures were investigated. To determine the proper austenitization temperatures, the results were compared with those of the cold-worked and cold-worked plus quench-tempered specimens. Comparisons showed that the austenitization temperatures of 1000 and 1100 °C are proper for hot stamping of 3-mm-thick AISI 4140 steel sheets due to the resultant martensitic microstructure which led to the yield and ultimate tensile strength of 1.3 and 2.1 GPa, respectively. Such conditions resulted in more favorable simultaneous strength and elongation than those of hot-stamped conventional boron steels.

  19. Simulation-based prediction of hot-rolled coil forced cooling

    Energy Technology Data Exchange (ETDEWEB)

    Saboonchi, Ahmad [Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84154 (Iran); Hassanpour, Saeid [Rayan Tahlil Sepahan Co., Isfahan Science and Technology Town, Isfahan 84155 (Iran)

    2008-09-15

    Hot-rolled coils take a long time to cool under normal storehouse conditions due to their high mass. Hotter seasons will lead to even longer storage times and, thus, to shortage of space. Forced cooling methods such as water-immersion and water-spray can be employed to reduce hot-rolled coil cooling time. In this paper, a mathematical model of the thermal behavior of coils is developed to predict and to evaluate the results expected from employing these methods before any real changes can be made on the ground. The results obtained from the model were compared with those from various experiments to verify the model's accuracy. The cooling time was then computed based on changes effected in the boundary conditions appropriate to each of the forced cooling methods employed. Moreover, the savings in storage times were compared to identify the best cooling method. Predictions showed that water immersion at the beginning of cooling cycle was more effective and that the cycle should not exceed 1 h for cost efficiency considerations. When using nozzles to spray it was found that spraying water on end surfaces of coils would be the optimum option resulting in savings in time, water and energy, and with restricted temperature gradient. (author)

  20. Deformation in Micro Roll Forming of Bipolar Plate

    Science.gov (United States)

    Zhang, P.; Pereira, M.; Rolfe, B.; Daniel, W.; Weiss, M.

    2017-09-01

    Micro roll forming is a new processing technology to produce bipolar plates for Proton Exchange Membrane Fuel Cells (PEMFC) from thin stainless steel foil. To gain a better understanding of the deformation of the material in this process, numerical studies are necessary before experimental implementation. In general, solid elements with several layers through the material thickness are required to analyse material thinning in processes where the deformation mode is that of bending combined with tension, but this results in high computational costs. This pure solid element approach is especially time-consuming when analysing roll forming processes which generally involves feeding a long strip through a number of successive roll stands. In an attempt to develop a more efficient modelling approach without sacrificing accuracy, two solutions are numerically analysed with ABAQUS/Explicit in this paper. In the first, a small patch of solid elements over the strip width and in the centre of the “pre-cut” sheet is coupled with shell elements while in the second approach pure shell elements are used to discretize the full sheet. In the first approach, the shell element enables accounting for the effect of material being held in the roll stands on material flow while solid elements can be applied to analyse material thinning in a small discrete area of the sheet. Experimental micro roll forming trials are performed to prove that the coupling of solid and shell elements can give acceptable model accuracy while using shell elements alone is shown to result in major deviations between numerical and experimental results.

  1. Mechanical Behaviour of 304 Austenitic Stainless Steel Processed by Room Temperature Rolling

    Science.gov (United States)

    Singh, Rahul; Goel, Sunkulp; Verma, Raviraj; Jayaganthan, R.; Kumar, Abhishek

    2018-03-01

    To study the effect of room temperature rolling on mechanical properties of 304 Austenitic Stainless Steel, the as received 304 ASS was rolled at room temperature for different percentage of plastic deformation (i.e. 30, 50, 70 and 90 %). Microstructural study, tensile and hardness tests were performed in accordance with ASTM standards to study the effect of rolling. The ultimate tensile strength (UTS) and hardness of a rolled specimen have enhanced with rolling. The UTS has increased from 693 MPa (as received) to 1700 MPa (after 90% deformation). The improvement in UTS of processed samples is due to combined effect of grain refinement and stress induced martensitic phase transformation. The hardness values also increases from 206 VHN (as received) to 499 VHN (after 90% deformation). Magnetic measurements were also conducted to confirm the formation of martensitic phase.

  2. Hot flow behavior of boron microalloyed steels

    International Nuclear Information System (INIS)

    Lopez-Chipres, E.; Mejia, I.; Maldonado, C.; Bedolla-Jacuinde, A.; El-Wahabi, M.; Cabrera, J.M.

    2008-01-01

    This research work studies the effect of boron contents on the hot flow behavior of boron microalloyed steels. For this purpose, uniaxial hot-compression tests were carried out in a low carbon steel microalloyed with four different amounts of boron over a wide range of temperatures (950, 1000, 1050 and 1100 deg. C) and constant true strain rates (10 -3 , 10 -2 and 10 -1 s -1 ). Experimental results revealed that both peak stress and peak strain tend to decrease as boron content increases, which indicates that boron additions have a solid solution softening effect. Likewise, the flow curves show a delaying effect on the kinetics of dynamic recrystallization (DRX) when increasing boron content. Deformed microstructures show a finer austenitic grain size in the steel with higher boron content (grain refinement effect). Results are discussed in terms of boron segregation towards austenitic grain boundaries during plastic deformation, which increases the movement of dislocations, enhances the grain boundary cohesion and modificates the grain boundary structure

  3. Review on Cold-Formed Steel Connections

    Science.gov (United States)

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  4. Effects of Ultra-Fast Cooling After Hot Rolling and Intercritical Treatment on Microstructure and Cryogenic Toughness of 3.5%Ni Steel

    Science.gov (United States)

    Wang, Meng; Liu, Zhenyu

    2017-07-01

    A novel process comprised of ultra-fast cooling after control rolling, intercritical quenching and tempering (UFC-LT) was applied to 3.5%Ni steel. In addition, quenching and tempering (QT) treatment was conducted in comparison. The present study focuses on the relationship between the microstructure and cryogenic toughness of 3.5%Ni steel. Results show that the microstructure of steel treated by UFC-LT consisted of tempered martensite, intercritical ferrite and two types of reversed austenite (RA) (needle shape and blocky). Compared to the QT sample, the UFC-LT sample's ultimate tensile strength decreased slightly, while its elongation increased from 32.3 to 35.7%, and its Charpy absorption energy at -135 °C increased from 112 to 237 J. The ductile-brittle transition temperature of UFC-LT sample was lower than that of the QT sample by 18 °C. The superior cryogenic toughness after UFC-LT compared to QT treatment can be attributed to the dissolution of cementite, approximately 3.0% increase in RA and the decrease in effective grain size.

  5. Stripping in hot mix asphalt produced by aggregates from construction and demolition waste.

    Science.gov (United States)

    Pérez, I; Pasandín, A R; Gallego, J

    2012-01-01

    This paper analyses the effect of water on the durability of hot asphalt mixtures made with recycled aggregates from construction and demolition debris. Indirect tensile stress tests were carried out to evaluate stripping behaviour. The mixtures tested were fabricated with 0, 20, 40 and 60% recycled aggregates. Two types of natural aggregates were used: schist and calcite dolomite. An increase in the percentage of recycled aggregates was found to produce a decrease in the tensile stress ratio of the hot asphalt mixtures. To study this phenomenon, two and three factor analyses of variance (ANOVA) were performed with indirect tensile stress being used as the dependent variable. The factors studied were the percentage of recycled aggregates (0, 20, 40 and 60%), the moisture state (dry, wet) and the type of natural aggregate (schist, calcite). On the basis of the ANOVA results, it was found that the most important factor affecting resistance was the moisture state (dry, wet) of the specimens. The percentage of recycled aggregate also affected indirect tensile stress, especially in the dry state. The type of natural aggregate did not have a significant effect on indirect tensile stress. The hot asphalt mixture specimens made with different percentages of recycled aggregates from construction and demolition debris and of natural quarry aggregates showed poor stripping behaviour. This stripping behaviour can be related to both the poor adhesion of the recycled aggregates and the high absorption of the mortar of cement adhered to them.

  6. Effects of hot rolling and titanium content on the microstructure and mechanical properties of high boron Fe–B alloys

    International Nuclear Information System (INIS)

    He, Lin; Liu, Ying; Li, Jun; Li, Binghong

    2012-01-01

    Highlights: ► The content of B is 1.8 wt.% in the high boron Fe–B alloys. ► Hot-rolling improves the mechanical properties, especially the elongation. ► The Ti content affects the microstructure and mechanical properties. ► Eutectic boride can be eliminated when the atomic ratio of Ti/B is no less than 0.5. ► Alloy exhibits balanced mechanical properties when the atomic ratio of Ti/B is 0.5. -- Abstract: High boron Fe–B alloys (1.8 wt.% B) with different titanium contents are fabricated by Vacuum Induction Melting (VIM) technique. The integrated mechanical properties of the as-cast alloys are poor, especially the ductility. In this investigation, hot-rolling technology is used to improve the microstructure and mechanical properties. The microstructure analysis shows that hot rolling can reduce the size and improve the distribution of the reinforcements. The mechanical properties testing indicates that the yield strength is unchanged basically, but the tensile strength and elongation are improved greatly by hot rolling, especially the elongation. The content of titanium also has great effects on the microstructures and mechanical properties of the hot-rolled alloys. For the hot-rolled alloys, with the titanium content increasing, the ultimate tensile strength and yield strength first decrease slightly and then increase. The elongation and impact toughness are improved significantly. In particular, when the atomic ratio of Ti to B is 0.5, the reinforcements are almost entirely TiB 2 and uniformly distributed in the Fe-matrix. The ternary Fe–B–Ti alloy exhibits balanced mechanical properties: yield strength, ultimate tensile strength, elongation and impact toughness are 334 MPa, 602 MPa, 16.2% and 213 kJ/m 2 , respectively.

  7. 75 FR 76700 - Stainless Steel Sheet and Strip in Coils From Taiwan: Final Results of Antidumping Duty...

    Science.gov (United States)

    2010-12-09

    ... is a trademark of Imphy, S.A. Certain martensitic precipitation-hardenable stainless steel is also... DEPARTMENT OF COMMERCE International Trade Administration [A-583-831] Stainless Steel Sheet and... antidumping duty order on stainless steel sheet and strip in coils (SSSSC) from Taiwan. This review covers...

  8. Effect of thermo-mechanical treatments on the microstructure and mechanical properties of an ODS ferritic steel

    International Nuclear Information System (INIS)

    Oksiuta, Z.; Mueller, P.; Spaetig, P.; Baluc, N.

    2011-01-01

    The Fe-14Cr-2W-0.3Ti-0.3Y 2 O 3 oxide dispersion strengthened (ODS) reduced activation ferritic (RAF) steel was fabricated by mechanical alloying of a pre-alloyed, gas atomised powder with yttria nano-particles, followed by hot isostatic pressing and thermo-mechanical treatments (TMTs). Two kinds of TMT were applied: (i) hot pressing, or (ii) hot rolling, both followed by annealing in vacuum at 850 deg. C. The use of a thermo-mechanical treatment was found to yield strong improvement in the microstructure and mechanical properties of the ODS RAF steel. In particular, hot pressing leads to microstructure refinement, equiaxed grains without texture, and an improvement in Charpy impact properties, especially in terms of the upper shelf energy (about 4.5 J). Hot rolling leads to elongated grains in the rolling direction, with a grain size ratio of 6:1, higher tensile strength and reasonable ductility up to 750 deg. C, and better Charpy impact properties, especially in terms of the ductile-to-brittle transition temperature (about 55 deg. C).

  9. Effect of thermo-mechanical treatments on the microstructure and mechanical properties of an ODS ferritic steel

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Z., E-mail: oksiuta@pb.edu.pl [Bialystok Technical University, Mechanical Department, Wiejska 45c, 15-351 Bialystok (Poland); Mueller, P.; Spaetig, P.; Baluc, N. [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, 5232 Villigen PSI (Switzerland)

    2011-05-15

    The Fe-14Cr-2W-0.3Ti-0.3Y{sub 2}O{sub 3} oxide dispersion strengthened (ODS) reduced activation ferritic (RAF) steel was fabricated by mechanical alloying of a pre-alloyed, gas atomised powder with yttria nano-particles, followed by hot isostatic pressing and thermo-mechanical treatments (TMTs). Two kinds of TMT were applied: (i) hot pressing, or (ii) hot rolling, both followed by annealing in vacuum at 850 deg. C. The use of a thermo-mechanical treatment was found to yield strong improvement in the microstructure and mechanical properties of the ODS RAF steel. In particular, hot pressing leads to microstructure refinement, equiaxed grains without texture, and an improvement in Charpy impact properties, especially in terms of the upper shelf energy (about 4.5 J). Hot rolling leads to elongated grains in the rolling direction, with a grain size ratio of 6:1, higher tensile strength and reasonable ductility up to 750 deg. C, and better Charpy impact properties, especially in terms of the ductile-to-brittle transition temperature (about 55 deg. C).

  10. Preliminary Feasibility Study on the Construction of Steel Hot Cell Facility for Precise Manipulated Examinations

    International Nuclear Information System (INIS)

    Ahn, Sangbok; Kwon, Hyungmun; Kim, Heemoon; Kim, Dosik; Min, Duckkee; Hong, Kwonpyo

    2006-01-01

    Hot laboratory is essential facility to research and develop in the nuclear industries to examine radioactive materials. The post irradiation examinations for irradiated fuels and materials should be mainly conducted in the hot cell facility to protect radiations to operators. Hot cells are divided into a concrete hot cell and a steel hot cell according to the wall materials. Usually a concrete hot cell is applied to test for high level radioactive materials like as a fuel assembly, rods, and large structure specimens, and a steel hot cell for comparatively lower level activity materials in fuel fragments, and small structural materials. A steel hot cell has many benefits in a specimen manipulation, construction and maintenance costs. In recent the test for the irradiated materials is more frequently required a small and precise manipulating examination for higher degree tests of research and developments. Unfortunately hot laboratory facilities in domestics have mainly constituted of concrete hot cells, and not ready for techniques in steel hot cells. In this paper the construction feasibility of steel hot cell facility is preliminary reviewed in the points of the status of domestic facilities, the test demand prospect and detailed plans

  11. Rolled-up inductor structure for a radiofrequency integrated circuit (RFIC)

    Science.gov (United States)

    Li, Xiuling; Huang, Wen; Ferreira, Placid M.; Yu, Xin

    2015-12-29

    A rolled-up inductor structure for a radiofrequency integrated circuit (RFIC) comprises a multilayer sheet in a rolled configuration comprising multiple turns about a longitudinal axis. The multilayer sheet comprises a conductive pattern layer on a strain-relieved layer, and the conductive pattern layer comprises at least one conductive strip having a length extending in a rolling direction. The at least one conductive strip thereby wraps around the longitudinal axis in the rolled configuration. The conductive pattern layer may also comprise two conductive feed lines connected to the conductive strip for passage of electrical current therethrough. The conductive strip serves as an inductor cell of the rolled-up inductor structure.

  12. Powdering of Hot-dip Galvannealed steel using Finite Element Analysis

    International Nuclear Information System (INIS)

    Kim, D. W.; Jang, Y. C.; Lee, Y. S.; Kim, S. I.

    2007-01-01

    Demand for hot-dip galvannealed steel has been increased due to it high corrosion resistance, paintability, and formability in automotive industry. Coating of Hot-dip galvannealed steel consists of various Fe-Zn intermetallic compounds. Since the coating is hard and therefore it is very brittle, the surface of steel sheet is easy to be ruptured during second manufacturing processing. This is called as powdering. Hence, various research have been carried out to prohibit powdering for improving the quality of GA steel during second manufacturing processing. This paper performed finite element analysis to evaluate local powdering and compared FEA results with V-bending test. The effects of punch radius and coating strength on the powdering was examined

  13. Hot super-Earths stripped by their host stars.

    Science.gov (United States)

    Lundkvist, M S; Kjeldsen, H; Albrecht, S; Davies, G R; Basu, S; Huber, D; Justesen, A B; Karoff, C; Silva Aguirre, V; Van Eylen, V; Vang, C; Arentoft, T; Barclay, T; Bedding, T R; Campante, T L; Chaplin, W J; Christensen-Dalsgaard, J; Elsworth, Y P; Gilliland, R L; Handberg, R; Hekker, S; Kawaler, S D; Lund, M N; Metcalfe, T S; Miglio, A; Rowe, J F; Stello, D; Tingley, B; White, T R

    2016-04-11

    Simulations predict that hot super-Earth sized exoplanets can have their envelopes stripped by photoevaporation, which would present itself as a lack of these exoplanets. However, this absence in the exoplanet population has escaped a firm detection. Here we demonstrate, using asteroseismology on a sample of exoplanets and exoplanet candidates observed during the Kepler mission that, while there is an abundance of super-Earth sized exoplanets with low incident fluxes, none are found with high incident fluxes. We do not find any exoplanets with radii between 2.2 and 3.8 Earth radii with incident flux above 650 times the incident flux on Earth. This gap in the population of exoplanets is explained by evaporation of volatile elements and thus supports the predictions. The confirmation of a hot-super-Earth desert caused by evaporation will add an important constraint on simulations of planetary systems, since they must be able to reproduce the dearth of close-in super-Earths.

  14. The Corrosion Behavior of Cold-Rolled 304 Stainless Steel In Salt Spray Environments

    International Nuclear Information System (INIS)

    Chiang, M.F.; Young, M.C.; Huang, J.Y.

    2011-01-01

    Saline corrosion is one of the major degradation mechanisms for stainless steel type 304 (SS304) dry storage cask during the spent fuel interim storage period. Slow strain rate test (SSRT) and neutral salt spray test (NSS) were performed at 85 degrees Celsius and 200 degrees Celsius with 0.5 wt% sodium chloride mist sprayed on the cold-rolled SS304 specimens of different degrees of reduction in this study. The weight changes of the NSS specimens tested at 85 degrees Celsius for 2000 hours differed greatly from those at 200 degrees Celsius. The weight loss of NSS specimens was not significant at 85 degrees Celsius but the weight gain decreased gradually with increasing the cold-rolled reduction. The yield strength (YS) and ultimate tensile stress (UTS) values obtained from the SSRT tests for lightly cold-rolled specimens in the salt spray environment at 85 degrees Celsius and 200 degrees Celsius are slightly lower than in air. But for those with 20% reductions, the specimen strengths were no longer changed by the saline corrosion. The preliminary results demonstrated that the quality and performance of cold-rolled SS304 is acceptable for fabrication of dry storage casks. However, more work on the corrosion behavior of cold-rolled stainless steel in the saline atmosphere is needed to better understand its long-term performance.

  15. Dual-phase ULCB steels thermomechanically processed

    International Nuclear Information System (INIS)

    Lis, A.K.; Lis, J.

    2001-01-01

    The design philosophy of the processing of dual-phase (D-P) ultra low carbon steels (ULCB) by thermomechanical treatment has been briefly discussed. Modelling of the structure evolution during thermomechanical rolling of ULCB steel was based upon the established empirical equations for yield flow at different conditions of: deformation temperatures, strain rates and stresses for applied amount of deformation during hot deformation compression tests. The critical amount of deformation needed for the occurrence of dynamic or static recrystallization was determined. The dependence of grain refinement of the acicular bainitic and polygonal ferrite of the accelerated cooling and amount of stored energy of deformation in steel has been evaluated. Effect of the decreasing of the finishing temperature of thermomechanical processing on the increase of the impact toughness of dual-phase microstructure consisted of the bainitie-martensite islands in the ferrite matrix has been shown. The effect of ageing process after thermomechanical rolling of heavy plates on fracture toughness values of J 0.2 for ULCB-Ni steels has been established from cod tests measurements. New low cost technology of rolling of ULCB steels dual-phase is proposed. (author)

  16. 75 FR 6631 - Stainless Steel Sheet and Strip in Coils from Japan: Final Results of Antidumping Duty...

    Science.gov (United States)

    2010-02-10

    ...\\``Gilphy 36'' is a trademark of Imphy, S.A. Certain martensitic precipitation-hardenable stainless steel is... DEPARTMENT OF COMMERCE International Trade Administration [A-588-845] Stainless Steel Sheet and... antidumping duty order on stainless steel sheet and strip in coils (SSSSC) from Japan. This review covers two...

  17. Steel slag in hot mix asphalt concrete : final report

    Science.gov (United States)

    2000-04-01

    In September 1994, steel slag test and control sections were constructed in Oregon to evaluate the use of steel slag in hot mix asphalt concrete (HMAC). This report covers the construction and five-year performance of a pavement constructed with 30% ...

  18. Investigation of the effect of heat treatment on the structure of the cold-rolled ferrite stainless steels

    Directory of Open Access Journals (Sweden)

    В. Л. Грешта

    2015-03-01

    Full Text Available The work presents the estimation of a factor, namely, the solid solution super saturation by carbon and nitrogen on crystalline nature of high-chromium ferrite (HCF in defining the inhibition mechanism of recrystallization processes in ferritic stainless steel. The essence of the study was to conduct an additional heat treatment of hot (h/r tackle for the following modes: annealing 800 ° C - 4 hours, tempering with temperatures of 900, 1000, 1100 ° C after exposure to 1 min/mm. It is established that the determining factor that influences the amount of the carbide phase in c/r sheet is prior treatment of h/r tackle. A definite connection between the volume fraction of the secondary phase and the degree of cold deformation was observed. In the structure of cold-rolled sheet the same pattern with respect to the degree of implementation processes allocation of excess phases is maintained as in hot-rolled, after appropriate heat treatment. The smallest amount of the secondary phase structure was observed in the letter after hardening from 1100 °C - 1 min/mm. The reason is the thermodynamic state of HCF, to which at 1100 °C all the excess carbon and nitrogen must exist in solid solution. Thus, it is found that according to the present analysis of structural changes it should be noted that the best option of thermal prior treatment of h/r tackle is the annealing at 800 °C – 4 hours

  19. Hot-Dip Coating of Lead-free Aluminum on Steel Substrates with Ultrasonic Vibration

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Hot-dip coating has been practically employed in manufacturing zinc alloy coated steel sheets. However, it is difficult to coat aluminum alloy on a bulky steel substrate without sufficient preheating, because a rapidly solidified layer containing gas babbles is formed on a substrate surface. A variety of iron-aluminides are also formed at the interface of a steel and aluminum hot-dip coating system, which is the main difficulty in joining of steel with aluminum. Ultrasonic vibration was applied to a steel substrate during hot-dip coating of aluminum alloy to control a rapidly solidified layer and a brittle reaction layer. Hot dipping of columnar steel substrates into molten aluminum alloy (Al-2.7 mass fraction Si-4.6 mass fraction Sn) was carried out through the use of a Langevin oscillator with resonant frequency of 19.5 kHz. The application of ultrasonic vibration is quite effective to control a rapidly solidified layer and a surface oxide layer from a substrate surface by the sonocapillary effect based on a cavitation phenomenon, so that the intimate contact is achieved at the beginning of hot-dip coating. The application of ultrasonic vibration to hot-dipping is effective to control a reaction layer with less than 5μm in thickness. An impact test exhibits that the good adhesive strength is approved in hot-dipped aluminum coatings with a thin reaction layer of approximately 5μm.

  20. 75 FR 6627 - Stainless Steel Sheet and Strip in Coils From Mexico; Final Results of Antidumping Duty...

    Science.gov (United States)

    2010-02-10

    ... martensitic precipitation-hardenable stainless steel is also excluded from the scope of the order. This high... DEPARTMENT OF COMMERCE International Trade Administration [A-201-822] Stainless Steel Sheet and... review of the antidumping duty order on stainless steel sheet and strip (S4) in coils from Mexico. See...

  1. Fracture of ledeburitic steel during hot plastic deformation

    International Nuclear Information System (INIS)

    Nikitin, V.P.; Borisov, Yu.A.; Bulat, S.I.; Zajtsev, V.V.

    1977-01-01

    The mechanisms of the high-temperature failure of high-carbon chromium Kh6F1, Kh6T2 and Kh6VF steels and a possibility to avoid their overheating have been investigated. At 1190 deg C and over the failure occurs along boundaries of grains at points of formation of the initial portions of the liquid phase as carbides are dissolved. If after a holding at 1190-1210 deg C the steels are cooled to 1120-1150 deg C and held for a sufficiently long time, secondary carbides are formed in the eutectic areas and, if the steels are deformed, the discontinuities present a rounded shape. Holding of an overheated steel at 1120-1150 deg C ensures its satisfactory workability in rolling. By choosing adequate overheating and subsequent slight cooling conditions, it is possible not only to retain, but even to improve the plasticity of carbide high-carbon steels. The results of laboratory tests have been confirmed under industrial conditions

  2. 75 FR 75455 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Final Results of Full...

    Science.gov (United States)

    2010-12-03

    ... Steel Inc., Steel Dynamics, Weirton Steel Corporation, Independent Steelworkers Union, and United... quality and chemistry restrictions as follows: 0.012 percent maximum phosphorus, 0.015 percent maximum...

  3. daptive Filter Used as a Dynamic Compensator in Automatic Gauge Control of Strip Rolling Processes

    Directory of Open Access Journals (Sweden)

    N. ROMAN

    2010-12-01

    Full Text Available The paper deals with a control structure of the strip thickness in a rolling mill of quarto type (AGC – Automatic Gauge Control. It performs two functions: the compensation of errors induced by unideal dynamics of the tracking systems lead by AGC system and the control adaptation to the change of dynamic properties of the tracking systems. The compensation of dynamical errors is achieved through inverse models of the tracking system, implemented as adaptive filters.

  4. Ultrahigh Charpy impact toughness (~450J) achieved in high strength ferrite/martensite laminated steels

    Science.gov (United States)

    Cao, Wenquan; Zhang, Mingda; Huang, Chongxiang; Xiao, Shuyang; Dong, Han; Weng, Yuqing

    2017-02-01

    Strength and toughness are a couple of paradox as similar as strength-ductility trade-off in homogenous materials, body-centered-cubic steels in particular. Here we report a simple way to get ultrahigh toughness without sacrificing strength. By simple alloying design and hot rolling the 5Mn3Al steels in ferrite/austenite dual phase temperature region, we obtain a series of ferrite/martensite laminated steels that show up-to 400-450J Charpy V-notch impact energy combined with a tensile strength as high as 1.0-1.2 GPa at room temperature, which is nearly 3-5 times higher than that of conventional low alloy steels at similar strength level. This remarkably enhanced toughness is mainly attributed to the delamination between ferrite and martensite lamellae. The current finding gives us a promising way to produce high strength steel with ultrahigh impact toughness by simple alloying design and hot rolling in industry.

  5. Boron effect on stainless steel plasticity under hot deformation

    International Nuclear Information System (INIS)

    Bulat, S.I.; Kardonov, B.A.; Sorokina, N.A.

    1978-01-01

    The effect of boron on plasticity of stainless steels at temperatures of hot deformation has been studied at three levels of alloying, i.e. 0-0.01% (micro-alloying or modifying), 0.01-0.02% (low alloying) and 0.02-2.0% (high alloying). Introduction of 0.001-0.005% of boron increases hot plasticity of both low and high carbon stainless steels due to decrease in grain size and strengthening of grain boundaries. Microalloying by boron has a positive effect at temperatures below 1200-1220 deg C. At higher temperatures, particularly when its content exceeds 0.008%, boron deteriorates plasticity by increasing the size of grains and weakening their boundaries. 0.1-2% boron strengthen the stainless steel and dectease its plasticity

  6. Properties of 40N3M powder structural steel

    International Nuclear Information System (INIS)

    Moskvina, T.P.; Gulyaev, A.P.; Gulyaev, I.A.; Byakov, S.V.; Melent'ev, I.V.; Morgun, G.N.

    1984-01-01

    Effect of the fabrication technique of compact slabs made of the 40N3M powder structural steel on mechanical properties with determination of a cold brittleness threshold was studied. It is established that after a thermal treatment at a density close to 100% a powder steel is sufficiently close to steel, rolled of an ingot, but is second in reference to steel in its ductility and impact strength. Properties of powder steel obtained by the method of dynamic hot forming (DHF) and hot extrusion are practically equal, but the first method has definite advantages as it allows to obtain details with a definitive form. The above investigation permits to recommend an application of the 40N3M powder steel fabricated by the DHF methods. The optimum thermal treatment course is: quenching+high annealing

  7. Layer texture of hot-rolled BCC metals and its significance for stress-corrosion cracking of main gas pipelines

    Science.gov (United States)

    Perlovich, Yu. A.; Isaenkova, M. G.; Krymskaya, O. A.; Morozov, N. S.

    2016-10-01

    Based on data of X-ray texture analysis of hot-rolled BCC materials it was shown that the layerwise texture inhomogeneity of products is formed during their manufacturing. The effect can be explained by saturation with interstitial impurities of the surface layer, resulting in dynamical deformation aging (DDA). DDA prevents the dislocation slip under rolling and leads to an increase of lattice parameters in the external layer. The degree of arising inhomogeneity correlates with the tendency of hot-rolled sheets and obtained therefrom tubes to stress-corrosion cracking under exploitation, since internal layers have a compressive effect on external layers, and prevents opening of corrosion cracks at the tube surface.

  8. Hot ductility and fracture mechanisms of a structural steel

    International Nuclear Information System (INIS)

    Calvo, J.; Cabrera, J. M.; Prado, J. M.

    2006-01-01

    The hot ductility of a structural steel produced from scrap recycling has been studied to determine the origin of the transverse cracks in the corners that appeared in some billets. Samples extracted both from a billet with transverse cracks and from a billet with no external damage were tested. To evaluate the influence of residual elements and inclusions, the steel was compared to another one impurity free. Reduction in area of the samples tensile tested to the fracture was taken as a measure of the hot ductility. The tests were carried out at temperatures ranging from 1000 degree centigree to 650 degree centigree and at a strain rate of 1.10-3 s-1. The fracture surfaces of the tested samples were observed by scanning electron microscopy in order to determine the embrittling mechanisms that could be acting. The steel with residuals and impurities exhibited lower ductility values for a wider temperature range than the clean steel. The embrittling mechanisms also changed as compared to the impurity free steel. (Author)

  9. Hot Ductility Behavior of an 8 Pct Cr Roller Steel

    Science.gov (United States)

    Wang, Zhenhua; Sun, Shuhua; Shi, Zhongping; Wang, Bo; Fu, Wantang

    2015-04-01

    The hot ductility of an 8 pct Cr roller steel was determined between 1173 K and 1473 K (900 °C and 1200 °C) at strain rates of 0.01 to 10 s-1 through tensile testing. The fracture morphology was observed using scanning electron microscopy, and the microstructure was examined through optical microscopy and transmission electron microscopy. The dependence of the hot ductility behavior on the deformation conditions, grain size, and precipitation was analyzed. The relationship between the reduction in area and the natural logarithm of the Zener-Hollomon parameter (ln Z) was found to be a second-order polynomial. When ln Z was greater than 40 s-1, the hot ductility was poor and fracture was mainly caused by incompatible deformation between the grains. When ln Z was between 32 and 40 s-1, the hot ductility was excellent and the main fracture mechanism was void linking. When ln Z was below 32 s-1, the hot ductility was poor and fracture was mainly caused by grain boundary sliding. A fine grain structure is beneficial for homogenous deformation and dynamic recrystallization, which induces better hot ductility. The effect of M7C3 carbide particles dispersed in the matrix on the hot ductility was small. The grain growth kinetics in the 8 pct Cr steel were obtained between 1373 K and 1473 K (1100 °C and 1200 °C). Finally, optimized preheating and forging procedures for 8 pct Cr steel rollers are provided.

  10. 75 FR 47263 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Final...

    Science.gov (United States)

    2010-08-05

    ..., Gallatin Steel, SSAB North America Division, ArcelorMittal USA, Inc., and Steel Dynamics, Inc... and chemistry restrictions as follows: 0.012 percent maximum phosphorus, 0.015 percent maximum sulfur...

  11. Investigation of the hot ductility of a high-strength boron steel

    International Nuclear Information System (INIS)

    Güler, Hande; Ertan, Rukiye; Özcan, Reşat

    2014-01-01

    In this study, the high-temperature ductility behaviour of an Al–Si-coated 22MnB5 sheet was investigated. The mechanical properties of Al–Si-coated 22MnB5 boron steel were examined via hot tensile tests performed at temperatures ranging from 400 to 900 °C at a strain rate of 0.083 s −1 . The deformation and fracture mechanisms under hot tensile testing were considered in relation to the testing data and to the fracture-surface observations performed via SEM. The hot ductility of the tested boron steel was observed as a function of increasing temperature and the Al–Si-coated 22MnB5 boron steel exhibited a ductility loss at 700 °C

  12. 75 FR 81221 - Stainless Steel Sheet and Strip in Coils From Mexico; Preliminary Results of the Five-Year...

    Science.gov (United States)

    2010-12-27

    ... trademark of Imphy, S.A. Certain martensitic precipitation-hardenable stainless steel is also excluded from... DEPARTMENT OF COMMERCE International Trade Administration [A-201-822 ] Stainless Steel Sheet and... of the antidumping duty order on stainless steel sheet and strip (``SSSS'') in coils from Mexico...

  13. 75 FR 43931 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil: Preliminary Results of...

    Science.gov (United States)

    2010-07-27

    ... Steel, SSAB N.A.D., Steel Dynamics, Inc., ArcelorMittal USA Inc. (collectively ``domestic interested... quality and chemistry restrictions as follows: 0.012 percent maximum phosphorus, 0.015 percent maximum...

  14. The effect of additional elements on the magnetic properties of hot-rolled Nd-Fe-B alloys

    International Nuclear Information System (INIS)

    Chang, W.C.; Nakamura, H.; Paik, C.R.; Sugimoto, S.; Okada, M.; Homma, M.

    1992-01-01

    The magnetic properties of hot-rolled Nd 16 Fe bal. B 6 M 1.5 (M = Cu, Ga and Al) and Nd 16 Fe 76 B 5.5 Ga 1.5 Al 1 alloys were investigated, in order to study the role of additive elements in improving the magnetic properties in the Nd-Fe-B system. It is found that the original grain size of Cu, Ga or Ga-Al added alloys is much finer than that of the ternary and Al added alloys. But the grain size is almost identical for all the alloys after hot-rolling at 1000degC with 90% reduction in thickness. The coercivity of hot-rolled alloys with Cu, Ga or Ga-Al addition is not improved as was expected, because Nd-rich liquid phase in these alloys is very easily squeezed out during high-reduction-ratio rolling. Less quantity and nonuniform distribution of Nd-rich phase between distributed grains are believed to be the main reasons to depress the effect on the grain boundary smoothing. This effect is not the same as those observed in the Pr-Fe-B system. The highest magnetic properties achieved in this study are B r = 10 kG, i H c = 8.2 kOe, (BH) max = 18.5 MGOe for the Nd 16 Fe 76.5 B 6 Al 1.5 alloy. (orig.)

  15. Application of rapid solidification powder metallurgy processing to prepare Cu–Al–Ni high temperature shape memory alloy strips with high strength and high ductility

    Energy Technology Data Exchange (ETDEWEB)

    Vajpai, S.K., E-mail: vajpaisk@gmail.com [Department of Materials Science and Engineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh (India); Dube, R.K., E-mail: rkd@iitk.ac.in [Department of Materials Science and Engineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh (India); Sangal, S., E-mail: sangals@iitk.ac.in [Department of Materials Science and Engineering, Indian Institute of Technology, Kanpur 208016, Uttar Pradesh (India)

    2013-05-15

    Cu–Al–Ni high temperature shape memory alloy (HTSMA) strips were successfully prepared from rapid solidified water atomized Cu–Al–Ni pre-alloyed powders via hot densification rolling of unsheathed sintered powder preforms. Finished heat-treated Cu–Al–Ni alloy strips had fine-grained structure, average grain size approximately 16 μm, and exhibited a combination of high strength and high ductility. It has been demonstrated that the redistribution of nano-sized alumina particles, present on the surface as well as inside the starting water atomized Cu–Al–Ni pre-alloyed powder particles, due to plastic deformation of starting powder particles during hot densification rolling resulted in the fine grained microstructure in the finished SMA strips. The finished SMA strips were almost fully martensitic in nature, consisting of a mixture of β{sub 1}{sup ′} and γ{sub 1}{sup ′} martensite. The average fracture strength and fracture strain of the finished SMA strips were 810 MPa and 12%, respectively, and the fractured specimens exhibited primarily micro-void coalescence type ductile nature of fracture. Finished Cu–Al–Ni SMA strips exhibited high characteristic transformation temperatures and an almost 100% one-way shape recovery was obtained in the specimens up to 4% applied deformation pre-strain. The retained two-way shape memory recovery increased with increasing applied training pre-strain, achieving a maximum value of 16.25% at 5% applied training pre-strain.

  16. Hot rolling effect on the characters of Zr-0.6Nb-0.5Fe-0.5Cr alloy

    International Nuclear Information System (INIS)

    Sungkono; Siti Aidah

    2015-01-01

    Characters of Zr-0.6Nb-0.5Fe-0.5Cr alloy after hot rolling have been studied. The objective of this research was to obtain of hot rolling effect on the characteristics of microstructures, hardness and phases formed in Zr-0.6Nb-0.5Fe-0.5Cr alloy. The hot rolling process of alloy carried out at temperature of 800 °C with retention time of 1.5 and 2 hours and a thickness reduction between 5 to 25 %. The results of this experiment showed that the Zr-0.6Nb-0.5Fe-0.5Cr alloy has Widmanstaetten structure with microstructure evolving into deformed columnar grains and deformed elongated grains with increasing thickness reduction. Besides, the longer the retention time at temperature of 800 °C is the larger are the grain structures and formation of α-Zr and Zr_3Fe phase. The hardness of Zr-0.6Nb-0.5Fe-0.5Cr alloy has same trends i.e the larger thickness reduction gives higher hardness. The Zr-0.6Nb-0.5Fe-0.5Cr alloy can under go hot rolling deformation at a thickness reduction of 25 % and the formation of α-Zr and Zr_3Fe can increased of hardness and strength of Zr-0.6 Nb-0.5 Fe-0.5 Cr alloy. (author)

  17. Properties of Reinforced Concrete Steel Rebars Exposed to High Temperatures

    OpenAIRE

    Topçu, İlker Bekir; Karakurt, Cenk

    2008-01-01

    The deterioration of the mechanical properties of yield strength and modulus of elasticity is considered as the primary element affecting the performance of steel structures under fire. In this study, hot-rolled S220 and S420 reinforcement steel rebars were subjected to high temperatures to investigate the fire performance of these materials. It is aimed to determine the remaining mechanical properties of steel rebars after elevated temperatures. Steels were subjected to 20, 100, 200, 300, 5...

  18. Studies of the AA2519 Alloy Hot Rolling Process and Cladding with EN AW-1050A Alloy

    Directory of Open Access Journals (Sweden)

    Płonka B.

    2016-03-01

    Full Text Available The objective of the study was to determine the feasibility of plastic forming by hot rolling of the AA2519 aluminium alloy sheets and cladding these sheets with a layer of the EN AW-1050A alloy. Numerous hot-rolling tests were carried out on the slab ingots to define the parameters of the AA2519 alloy rolling process. It has been established that rolling of the AA2519 alloy should be carried out in the temperature range of 400-440°C. Depending on the required final thickness of the sheet metal, appropriate thickness of the EN AW-1050A alloy sheet, used as a cladding layer, was selected. As a next step, structure and mechanical properties of the resulting AA2519 alloy sheets clad with EN AW-1050A alloy was examined. The thickness of the coating layer was established at 0,3÷0,5mm. Studies covered alloy grain size and the core alloy-cladding material bond strength.

  19. Evaluation and Control of Mechanical Degradation of Austenitic Stainless 310S Steel Substrate During Coated Superconductor Processing

    Science.gov (United States)

    Kim, Seung-Gyu; Kim, Najung; Shim, Hyung-Seok; Kwon, Oh Min; Kwon, Dongil

    2018-05-01

    The superconductor industry considers cold-rolled austenitic stainless 310S steel a less expensive substitute for Hastelloy X as a substrate for coated superconductor. However, the mechanical properties of cold-rolled 310S substrate degrade significantly in the superconductor deposition process. To overcome this, we applied hot rolling at 900 °C (or 1000 °C) to the 310S substrate. To check the property changes, a simulated annealing condition equivalent to that used in manufacturing was determined and applied. The effects of the hot rolling on the substrate were evaluated by analyzing its physical properties and texture.

  20. Annealing treatments for producing cold-rolled low-silicon multi-phase steels for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Vrieze, J.; Vortrefflich, W.; Winter, L. de [Applied Physical Metallurgy, Hoogovens Research and Development, Ijmuiden (Netherlands)

    2000-07-01

    Laboratory simulations of a hot-dip galvanizing line have been carried out on a 0.16%C-1.5%Mn-0.4%Si steel. It has been demonstrated that based on this steel composition materials with typical multi-phase properties can be produced on hot-dip galvanizing lines. By varying the process conditions a tensile strength between 570 and 650 MPa has been obtained. In addition, tensile tests at high strain rates have been carried out and the results have been compared with those of other non-multi-phase steel grades. (orig.)

  1. Hot embossing holographic images in BOPP shrink films through large-area roll-to-roll nanoimprint lithography

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Menglin; Lin, Shiwei, E-mail: linsw@hainu.edu.cn; Jiang, Wenkai; Pan, Nengqian

    2014-08-30

    Highlights: • High-quality holographic images were replicated in large-area shrink film. • Surface morphology evolution was analyzed in films embossed at different temperatures. • Optical, mechanical, and thermal characteristics were systematically analyzed. - Abstract: Diffraction grating-based holographic images have been successfully replicated in biaxially oriented polypropylene (BOPP) shrink films through large-area roll-to-roll nanoimprint technique. Such hot embossing of holographic images on BOPP films represents a promising means of creating novel security features in packaging applications. The major limitation of the high-quality replication is the relatively large thermal shrinkage of BOPP shrink film. However, although an appropriate shrinkage is demanded after embossing, over-shrinking not only causes distortion in embossed images, but also reduces the various properties of BOPP shrink films mainly due to the disappearance of orientation. The effects of embossing temperature on the mechanical, thermal and optical properties as well as polymer surface morphologies were systematically analyzed. The results show that the optimal process parameters are listed as follows: the embossing temperature at 104–110 °C, embossing force 6 kg/cm{sup 2} and film speed 32 m/min. The variation in flow behavior of polymer surface during hot embossing process is highly dependent on the temperature. In addition, the adhesion from the direct contact between the rubber press roller and polymer surfaces is suggested to cause the serious optical properties failure.

  2. New technology for the production of magnesium strips and sheets

    Directory of Open Access Journals (Sweden)

    R. Kawalla

    2008-07-01

    Full Text Available A new production technology for magnesium strip, based on twin-roll-casting and strip rolling was developed in Freiberg Germany. By means of this economic method it is possible to produce strips in deep drawing quality with good forming properties in order to satisfy the request for low cost Mg sheets in the automotive and electronic industry. Both, coils as single sheets, were manufactured and rolled to a thickness of 1mm(0,5 mm. The technology of the new process and the properties of the twin-roll-casted material and the final sheets are presented.

  3. Rolling Contact Fatigue Performances of Carburized and High-C Nanostructured Bainitic Steels

    Directory of Open Access Journals (Sweden)

    Yanhui Wang

    2016-11-01

    Full Text Available In the present work, the nanostructured bainitic microstructures were obtained at the surfaces of a carburized steel and a high-C steel. The rolling contact fatigue (RCF performances of the two alloy steels with the same volume fraction of undissolved carbide were studied under lubrication. Results show that the RCF life of the carburized nanostructured bainitic steel is superior to that of the high-C nanostructured bainitic steel in spite of the chemical composition, phase constituent, plate thickness of bainitic ferrite, hardness, and residual compressive stress value of the contact surfaces of the two steels under roughly similar conditions. The excellent RCF performance of the carburized nanostructured bainitic steel is mainly attributed to the following reasons: finer carbide dispersion distribution in the top surface, the higher residual compressive stress values in the carburized layer, the deeper residual compressive stress layer, the higher work hardening ability, the larger amount of retained austenite transforming into martensite at the surface and the more stable untransformed retained austenite left in the top surface of the steel.

  4. Rolling Contact Fatigue Performances of Carburized and High-C Nanostructured Bainitic Steels.

    Science.gov (United States)

    Wang, Yanhui; Zhang, Fucheng; Yang, Zhinan; Lv, Bo; Zheng, Chunlei

    2016-11-25

    In the present work, the nanostructured bainitic microstructures were obtained at the surfaces of a carburized steel and a high-C steel. The rolling contact fatigue (RCF) performances of the two alloy steels with the same volume fraction of undissolved carbide were studied under lubrication. Results show that the RCF life of the carburized nanostructured bainitic steel is superior to that of the high-C nanostructured bainitic steel in spite of the chemical composition, phase constituent, plate thickness of bainitic ferrite, hardness, and residual compressive stress value of the contact surfaces of the two steels under roughly similar conditions. The excellent RCF performance of the carburized nanostructured bainitic steel is mainly attributed to the following reasons: finer carbide dispersion distribution in the top surface, the higher residual compressive stress values in the carburized layer, the deeper residual compressive stress layer, the higher work hardening ability, the larger amount of retained austenite transforming into martensite at the surface and the more stable untransformed retained austenite left in the top surface of the steel.

  5. Enhanced hot ductility of a Cr–Mo low alloy steel by rare earth cerium

    International Nuclear Information System (INIS)

    Jiang, X.; Song, S.-H.

    2014-01-01

    The hot ductility of a 1Cr–0.5Mo low alloy steel is investigated over a temperature range of 700–1050 °C using a Gleeble thermomechanical simulator in conjunction with various characterization techniques. The steel samples undoped and doped with cerium are heated at 1300 °C for 3 min and then cooled with a rate of 5 K s −1 down to different test temperatures, followed by tensile deformation until fracture. The results show that the hot ductility of the steel, evaluated by the reduction in area, can be substantially enhanced by a minor addition of cerium, especially in the range 800–1000 °C. In the austenite–ferrite dual-phase region, cerium may delay the formation of proeutectoid ferrite layers along austenite grain boundaries, thereby increasing the hot ductility of the steel. In the single austenite region, grain boundary segregation of cerium may increase the grain boundary cohesion, toughening the steel and thus raising the resistance to grain boundary sliding as well as promoting dynamic recrystallization. Consequently, the hot ductility of the steel is enhanced

  6. Lubrication in cold rolling : Numerical simulation using multigrid techniques

    NARCIS (Netherlands)

    Lugt, Pieter Martin

    1992-01-01

    In the cold rolling process a lubricant is applied on the rolls and/or the strip mate­rial. Due to the velocities of the rolls and the strip, part of the lubricant is sheared into the contact causing, amongst others, a reduction of the friction. In this thesis a physical-mathematical model is

  7. Microstructure and mechanical properties of Mg-Al-Mn-Ca alloy sheet produced by twin roll casting and sequential warm rolling

    International Nuclear Information System (INIS)

    Wang Yinong; Kang, Suk Bong; Cho, Jaehyung

    2011-01-01

    Research highlights: → This work, taking AM30 + 0.2Ca alloy as experimental material, will provide some new information as follows: one is microstructural difference between twin roll cast and ingot cast AM31-0.2Ca alloy. The other is the comparison of tensile properties after warm rolling and annealing. Suggesting the possibility of the development of wrought magnesium alloy sheets by strip casting. - Abstract: Microstructural evolution and mechanical properties of twin roll cast (TRC) Mg-3.3 wt.%Al-0.8 wt.%Mn-0.2 wt.%Ca (AM31 + 0.2Ca) alloy strip during warm rolling and subsequent annealing were investigated in this paper. The as-TRC alloy strip shows columnar dendrites in surface and equiaxed dendrites in center regions, as well as finely dispersed primary Al 8 Mn 5 particles on interdendritic boundaries which result in the beneficial effect on microstructural refinement of strip casting. The warm rolled sheets show intensively deformed band or shear band structures, as well as finely and homogeneously dispersed Al-Mn particles. No evident dynamic recrystallization (DRX) takes place during warm rolling process, which is more likely attributed to the finely dispersed particle and high solid solution of Al and Mn atoms in α-Mg matrix. After annealing at 350 deg. C for 1 h, the warm rolled TRC sheets show fine equiaxed grains around 7.8 μm in average size. It has been shown that the present TRC alloy sheet has superior tensile strength and comparative elongation compared to commercial ingot cast (IC) one, suggesting the possibility of the development of wrought magnesium alloy sheets by twin roll strip casting processing. The microstructural evolution during warm rolling and subsequent annealing as well as the resulting tensile properties were analyzed and discussed.

  8. Effect of roll hot press temperature on crystallite size of PVDF film

    Energy Technology Data Exchange (ETDEWEB)

    Hartono, Ambran, E-mail: ambranhartono@yahoo.com; Sanjaya, Edi [Departement of Physics Faculty of Science and Technology, Islamic State University Syarif Hidayatullah , Jl. Juanda 95 Ciputat Jakarta (Indonesia); Djamal, Mitra; Satira, Suparno; Bahar, Herman [Theoretical High Energy Physics and Instrumentation Group Research, Faculty Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesa 10 Bandung (Indonesia); Ramli [Departement of Physics, Faculty of Mathematics and Natural Sciences, Universitas Negeri Padang, Jl.Prof. Hamka, Padang 25131 (Indonesia)

    2014-03-24

    Fabrication PVDF films have been made using Hot Roll Press. Preparation of samples carried out for nine different temperatures. This condition is carried out to see the effect of Roll Hot Press temperature on the size of the crystallite of PVDF films. To obtain the diffraction pattern of sample characterization is performed using X-Ray Diffraction. Furthermore, from the diffraction pattern is obtained, the calculation to determine the crystallite size of the sample by using the Scherrer equation. From the experimental results and the calculation of crystallite sizes obtained for the samples with temperature 130 °C up to 170 °C respectively increased from 7.2 nm up to 20.54 nm. These results show that increasing temperatures will also increase the size of the crystallite of the sample. This happens because with the increasing temperature causes the higher the degree of crystallization of PVDF film sample is formed, so that the crystallite size also increases. This condition indicates that the specific volume or size of the crystals depends on the magnitude of the temperature as it has been studied by Nakagawa.

  9. Study of Microstructure of the Al-Fe Alloys After Hot Rolling Deformation

    Science.gov (United States)

    Jabłońska, Magdalena Barbara; Rodak, Kinga; Bednarczyk, Iwona

    The aim of the paper is a microstructure analysis of alloys from the Al-Fe system after hot rolling tests, conducted by using a scanning transmission electron microscopy STEM and scanning electron microscope equipped with EBSD detector. Hot rolling was carried out at Technical University of Ostrava, Faculty of Metallurgy and Material Engineering, Institute of Modelling and Control of Forming Processes. The samples were heated to a temperature of 1200°C. The EBSD and STEM techniques have been applied in order to determine the influence of chemical composition and deformation parameters on structural changes. The microstructure analysis has included parameters such us: grain/sub-grain size, area fraction of grains/subgrains, misorientation angles, grains/subgrains shape aspect ratio and dislocations structure. The research structure techniques in scanning-transmission electron microscopy revealed numerous FeAl28 alloy phase separations of secondary nucleating sites favoured energetically, which are the boundary of grains/subgrains and dislocations. These changes in the structure of the test results have been confirmed by EBSD, which revealed the presence of grains/subgrains misorientation angle boundaries above 15°.

  10. Mathematical modelling and TMCP simulation for optimisation of steel behaviour

    International Nuclear Information System (INIS)

    Siwecki, T.

    2001-01-01

    Physically based mathematical models for prediction of steel behaviour and microstructure evolution in connection with thermal and thermomechanical controlled processing (TMCP) development in Swedish Institute for Metals Research are discussed. The models can be used for computer predictions of recrystallization and grain growth of austenite after deformation, precipitation or dissolution of microalloying carbonitride in austenite, flow stress during hot working, phase transformation behaviour during accelerated cooling as well as the final microstructure and mechanical properties. The database, which contains information about steel behaviour for a large number of HSLA steels, is also presented. Optimization of TMCP parameters for improving the properties of the steel are discussed in relation to the microstructure and mechanical properties. The effect of TMCP parameters (reheating temperature, rolling schedules and finish rolling temperature as well as accelerated control cooling) on steel properties was studied in laboratory scale. (author)

  11. Analytical solution for shear bands in cold-rolled 1018 steel

    Science.gov (United States)

    Voyiadjis, George Z.; Almasri, Amin H.; Faghihi, Danial; Palazotto, Anthony N.

    2012-06-01

    Cold-rolled 1018 (CR-1018) carbon steel has been well known for its susceptibility to adiabatic shear banding under dynamic loadings. Analysis of these localizations highly depends on the selection of the constitutive model. To deal with this issue, a constitutive model that takes temperature and strain rate effect into account is proposed. The model is motivated by two physical-based models: the Zerilli and Armstrong and the Voyiadjis and Abed models. This material model, however, incorporates a simple softening term that is capable of simulating the softening behavior of CR-1018 steel. Instability, localization, and evolution of adiabatic shear bands are discussed and presented graphically. In addition, the effect of hydrostatic pressure is illustrated.

  12. 75 FR 62101 - Stainless Steel Sheet and Strip in Coils From the Republic of Korea: Final Results of Expedited...

    Science.gov (United States)

    2010-10-07

    ...\\ ``Gilphy 36'' is a trademark of Imphy, S.A. Certain martensitic precipitation-hardenable stainless steel is... DEPARTMENT OF COMMERCE International Trade Administration [C-580-835] Stainless Steel Sheet and... countervailing duty order (``CVD'') on stainless steel sheet and strip in coils from the Republic of Korea...

  13. 75 FR 81214 - Stainless Steel Sheet and Strip in Coils From Italy: Preliminary Results of the Full Second Five...

    Science.gov (United States)

    2010-12-27

    ... martensitic precipitation-hardenable stainless steel is also excluded from the scope of the order. This high... DEPARTMENT OF COMMERCE International Trade Administration [A-475-824] Stainless Steel Sheet and... sunset review of the antidumping duty order on stainless steel sheet and strip in coils from Italy...

  14. Hot Deformation Behavior and a Two-Stage Constitutive Model of 20Mn5 Solid Steel Ingot during Hot Compression

    Directory of Open Access Journals (Sweden)

    Min Liu

    2018-03-01

    Full Text Available 20Mn5 steel is widely used in the manufacture of heavy hydro-generator shaft forging due to its strength, toughness, and wear resistance. However, the hot deformation and recrystallization behaviors of 20Mn5 steel compressed under a high temperature were not studied. For this article, hot compression experiments under temperatures of 850–1200 °C and strain rates of 0.01 s−1–1 s−1 were conducted using a Gleeble-1500D thermo-mechanical simulator. Flow stress-strain curves and microstructure after hot compression were obtained. Effects of temperature and strain rate on microstructure are analyzed. Based on the classical stress-dislocation relationship and the kinetics of dynamic recrystallization, a two-stage constitutive model is developed to predict the flow stress of 20Mn5 steel. Comparisons between experimental flow stress and predicted flow stress show that the predicted flow stress values are in good agreement with the experimental flow stress values, which indicates that the proposed constitutive model is reliable and can be used for numerical simulation of hot forging of 20Mn5 solid steel ingot.

  15. Processing of low carbon steel plate and hot strip—an overview

    Indian Academy of Sciences (India)

    Unknown

    hybrid computer modelling is used for production of strip products with tailor made properties. Although there ..... Thanks are due to the management of SAIL for support and to ... Houdremont E 1956 Handbook of special steels (Berlin: Springer ...

  16. Numerical Analysis of Edge Over Coating and Baffle Effect on Hot-Dip Galvanizing

    Science.gov (United States)

    Bao, Chengren; Kang, Yonglin; Li, Yan

    2017-06-01

    In hot-dip galvanizing process, air jet wiping control is so crucial to determine the coating thickness and uniformity of the zinc layer on the steel strip. A numerical simulation of gas-jet wiping in hot-dip galvanizing was conducted to minimize the occurrence of edge over coating (EOC). The causes of EOC were identified by contrasting and analyzing the airflow fields on the strip edge with and without a baffle. The factors influencing the airflow field on the strip edge during the change in the gap between the baffle and the strip edge were also analyzed. The effect of the distance between the air knife and the strip was evaluated. Technological parameters with on-site guidance role were obtained by combining them with the actual production to elucidate the role of the baffle in restraining the occurrence of EOC. The uniform distribution of pressure and coating thickness on the strip is achieved when the distance of the baffle from the strip edge is about 0.3 times of the jetting distance.

  17. 77 FR 19192 - Circular Welded Carbon-Quality Steel Pipe From India: Preliminary Affirmative Countervailing Duty...

    Science.gov (United States)

    2012-03-30

    .... See Memorandum to Susan H. Kuhbach, Director, Office 1 from David Layton, International Trade Analyst... Provision of Hot-Rolled Steel by the Steel Authority of India (``SAIL'') for Less Than Adequate Remuneration... the questions regarding land received at less than adequate remuneration, Zenith prevented us from...

  18. Modelling and simulations in hot deformation of steels

    International Nuclear Information System (INIS)

    Cabrera, J.M.

    2002-01-01

    Traditionally, hot forming has been employed to provide shape to metals. Nowadays, however, hot working not only produces the desired geometry, but also the mechanical characteristics required. An understanding of the thermomechanical behaviour of metals, and particularly steels, is essential in the simulation and control of the hot forming operations. Moreover, a right prediction of the final properties needs from accurate descriptions of the microstructural features occurring during the shaping step. For this purpose, the determination of constitutive equations describing the stress σ - strain ε relationships at a given strain rate ε, temperature T and initial microstructure, is a useful task. In this sense, computer simulations of hot working processes proportionate a benchmark to engineers and researchers and allow decreasing the cost of developing products and processes. With regard to the prediction of the final microstructure, the simulation of the hot plastic deformation usually gives unsatisfactory results. This is due to the inadequate constitutive equations employed by the conventional and commercial software available to describe the hot flow behaviour. There are scarce models which couple the typical hot working variables (temperature, strain and strain rate) with microstructural characteristics such as grain size. In this review work is presented how the latter limitation can be overcome by using physical-based constitutive equations, some of which have been partially developed by the present authors, where account of the interaction between microstructure and processing variables is taken. Moreover, a practical derivation of the latter expressions on an AISI-304 steel is presented. To conclude, some examples of industrial applications of the latter approach are also presented. Copyright (2002) AD-TECH - International Foundation for the Advancement of Technology Ltd

  19. NON-CENTRAL ROLLING OF FLAT WORKS WITH TAPERED THICKNESS

    Directory of Open Access Journals (Sweden)

    I. A. Isaevich

    2010-01-01

    Full Text Available The way of forming of variable shape strips with rolling in non-drive waves with rounding by the movable arbor strip is analyzed. The way of rolling with derivation of speeds of deforming instruments is offered.

  20. Influence of Copper on the Hot Ductility of 20CrMnTi Steel

    Science.gov (United States)

    Peng, Hong-bing; Chen, Wei-qing; Chen, Lie; Guo, Dong

    2015-02-01

    The hot ductility of 20CrMnTi steel with x% copper (x = 0, 0.34) was investigated. Results show that copper can reduce its hot ductility, but there is no significant copper-segregation at the boundary tested by EPMA. The average copper content at grain boundaries and substrate is 0.352% and 0.318% respectively in steel containing 0.34% copper tensile-tested at 950 °C. The fracture morphology was examined with SEM and many small and shallow dimples were found on the fracture of steel with copper, and fine copper sulfide was found from carbon extraction replicas using TEM. Additionally, adding 0.34% copper caused an increase in the dynamic recrystallization temperature from 950 °C to 1000 °C, which indicates that copper can retard the dynamic recrystallization (DRX) of austenite. The detrimental influence of copper on hot ductility of 20CrMnTi steel is due mainly to the fine copper sulfide in the steel and its retarding the DRX.

  1. Effects of surface coating on weld growth of resistance spot-welded hot-stamped boron steels

    International Nuclear Information System (INIS)

    Ji, Chang Wook; Lee, Hyun Ju; Kim, Yang Do; Jo, Il Guk; Choi, Il Dong; Park, Yeong Do

    2014-01-01

    Aluminum-silicon-based and zinc-based metallic coatings have been widely used for hot-stamped boron steel in automotive applications. In this study, resistance spot weldability was explored by investigating the effects of the properties of metallic coating layers on heat development and nugget growth during resistance spot welding. In the case of the aluminum-silicon-coated hot-stamped boron steel, the intermetallic coating transformed into a liquid film that covered the faying interface. A wide, weldable current range was obtained with slow heat development because of low contact resistance and large current passage. In the case of the zinc-coated hot-stamped boron steel, a buildup of liquid and vapor formation under large vapor pressure was observed at the faying interface because of the high contact resistance and low vaporization temperature of the intermetallic layers. With rapid heat development, the current passage was narrow because of the limited continuous layer at the faying interface. A more significant change in nugget growth was observed in the zinc coated hot-stamped boron steel than in the aluminum-silicon-coated hot-stamped boron steel.

  2. Damage Analysis and Evaluation of Light Steel Structures Exposed to Wind Hazards

    OpenAIRE

    Na Yang; Fan Bai

    2017-01-01

    Compared to hot-rolled steel structures, cold-formed steel structures are susceptible to extreme winds because of the light weight of the building and its components. Many modern cold-formed steel structures have sustained significant structural damage ranging from loss of cladding to complete collapse in recent cyclones. This article first provides some real damage cases for light steel structures induced by the high winds. After that, the paper reviews research on the damage analysis and e...

  3. Influence of severe plastic deformation obtained by warm rolling on microstructure and mechanical properties of the ferritic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Luana Alves; Campos, Wagner Reis Costa; Vilela, Jefferson José, E-mail: luana_alves_barbosa@hotmail.com, E-mail: wrrc@cdtn.br, E-mail: jjv@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Miqueletti, Estevesson Ferreira; Mazzer, Eric Marchezini; Santos, Dagoberto B., E-mail: estevess@demet.ufmg.br, E-mail: marchezini@demet.ufmg.br, E-mail: dsantos@demet.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2017-07-01

    Generation IV reactors require research on new materials. For example, materials that will be used in the reactor vessel must be resistant to creep and have high toughness. Grain refining is a technique used to improve toughness. This grain refinement can be achieved by severe plastic deformation. In this work, the stainless steel 409 was used to simulate the EUROFER one type of ODS steel. The rolling process was applied to make the severe plastic deformation. The rolling was performed at 600°C which corresponds to the warm working condition in the absence of dynamic recrystallization. The rolling schedule studied allowed a logarithmic strain accumulation of 3.16. The rolled sheet had a yield stress of 822 MPa and a hardness of 302 HV. The grains became quite elongated characteristic of a severe plastic deformation. The recrystallization temperature of the rolled sheet was approximately 500°C. It was obtained by heat treatment and hardness measurement. (author)

  4. Influence of severe plastic deformation obtained by warm rolling on microstructure and mechanical properties of the ferritic stainless steel

    International Nuclear Information System (INIS)

    Barbosa, Luana Alves; Campos, Wagner Reis Costa; Vilela, Jefferson José; Miqueletti, Estevesson Ferreira; Mazzer, Eric Marchezini; Santos, Dagoberto B.

    2017-01-01

    Generation IV reactors require research on new materials. For example, materials that will be used in the reactor vessel must be resistant to creep and have high toughness. Grain refining is a technique used to improve toughness. This grain refinement can be achieved by severe plastic deformation. In this work, the stainless steel 409 was used to simulate the EUROFER one type of ODS steel. The rolling process was applied to make the severe plastic deformation. The rolling was performed at 600°C which corresponds to the warm working condition in the absence of dynamic recrystallization. The rolling schedule studied allowed a logarithmic strain accumulation of 3.16. The rolled sheet had a yield stress of 822 MPa and a hardness of 302 HV. The grains became quite elongated characteristic of a severe plastic deformation. The recrystallization temperature of the rolled sheet was approximately 500°C. It was obtained by heat treatment and hardness measurement. (author)

  5. Hot drawn Fe–6.5 wt.%Si wires with good ductility

    International Nuclear Information System (INIS)

    Yang, W.; Li, H.; Yang, K.; Liang, Y.F.; Yang, J.; Ye, F.

    2014-01-01

    Highlights: • Fe–6.5wt%Si steel wire with diameter of 1.6 mm can be successfully obtained by hot drawing process. • The ductility of Fe–6.5wt%Si alloy can be improved significantly when it is fabricated in the form of wire. • The Dc magnetic property of Fe–6.5wt%Si steel wire 1.6 mm in diameter is excellent, which is close to that of 0.3 mm thick cold-rolling sheet. - Abstract: Fe–6.5 wt.%Si high silicon steel wires with a diameter of 1.6 mm are fabricated successfully by hot drawing. The high silicon steel wires show much better ductility than sheets. The tensile strength and elongation of the wires at the room temperature can reach 1.31 GPa and 1.4%, respectively. The tensile strength and elongation of the rolling sheet at the room temperature are 0.8 GPa and 0, respectively. The microstructure analyses show that the elongated grains after drawing and reduced ordering phases by deformation in the wires might contribute to its good ductility. Bs value of 1.437 T and Hc value of 16.96 A/m are obtained for the wire after proper heat treatment for the wires

  6. Analysis of microstructure and microtexture in grain-oriented electrical steel (GOES during manufacturing process

    Directory of Open Access Journals (Sweden)

    A. Volodarskaja

    2015-10-01

    Full Text Available The final Goss texture in grain-oriented electrical steels (GOES is affected by microstructure evolution and inheritance during the whole production process. This paper presents the results of detailed microtexture and microstructure investigations on GOES after the basic steps of the industrial AlN + Cu manufacturing process: hot rolling, first cold rolling + decarburization annealing, second cold rolling and final high temperature annealing. Microstructure studies showed that a copper addition to GOES affected solubility of sulphides. Copper rich sulphides dissolved during hot rolling and re-precipitated during decarburization annealing. An intensive precipitation of AlN and Si3N4 took place during decarburization annealing. No ε - Cu precipitation was detected. After high temperature annealing the misorientation of individual grains reached up to 8°.

  7. On the estimation of the magnetic easy axis in pipeline steels using magnetic Barkhausen noise

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Ortiz, P. [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Instituto Politécnico Nacional, UPALM Edif. Z-4 3 Piso, Zacatenco, Mexico D.F. 07738 (Mexico); Pérez-Benitez, J.A., E-mail: benitez_edl@yahoo.es [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Instituto Politécnico Nacional, UPALM Edif. Z-4 3 Piso, Zacatenco, Mexico D.F. 07738 (Mexico); Espina-Hernández, J.H. [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Instituto Politécnico Nacional, UPALM Edif. Z-4 3 Piso, Zacatenco, Mexico D.F. 07738 (Mexico); Caleyo, F.; Hallen, J.M. [Departamento de Ingeniería Metalúrgica, ESIQIE, UPALM Edif. 7, Instituto Politécnico Nacional, Zacatenco, C.P. 07738 México D.F. (Mexico)

    2015-01-15

    A method for determination of the magnetic easy axis of the Roll Magnetic Anisotropy in API-5L steels is proposed. The method is based on the fact that the angular dependence of the energy corresponding to the main peak of the Magnetic Barkhausen signal presents uniaxial anisotropy with its easy axis parallel to the rolling direction, independently of the angular dependence of the magnetocrystalline energy in the materials. The proposal is also justified based on the analysis of the influence of microstructural changes, produced by hot-rolling on the domain wall dynamics. - Highlights: • Propose a method for finding the easy axis of roll magnetic anisotropy. • Study of the causes of multi-axial anisotropy of MBN energy in API-5L steels. • Analyze the causes of the roll magnetic anisotropy.

  8. On the estimation of the magnetic easy axis in pipeline steels using magnetic Barkhausen noise

    International Nuclear Information System (INIS)

    Martínez-Ortiz, P.; Pérez-Benitez, J.A.; Espina-Hernández, J.H.; Caleyo, F.; Hallen, J.M.

    2015-01-01

    A method for determination of the magnetic easy axis of the Roll Magnetic Anisotropy in API-5L steels is proposed. The method is based on the fact that the angular dependence of the energy corresponding to the main peak of the Magnetic Barkhausen signal presents uniaxial anisotropy with its easy axis parallel to the rolling direction, independently of the angular dependence of the magnetocrystalline energy in the materials. The proposal is also justified based on the analysis of the influence of microstructural changes, produced by hot-rolling on the domain wall dynamics. - Highlights: • Propose a method for finding the easy axis of roll magnetic anisotropy. • Study of the causes of multi-axial anisotropy of MBN energy in API-5L steels. • Analyze the causes of the roll magnetic anisotropy

  9. Modification of the Structure of Low-Carbon Pipe Steel by Helical Rolling, and the Increase in Its Strength and Cold Resistance

    Science.gov (United States)

    Derevyagina, L. S.; Gordienko, A. I.; Pochivalov, Yu. I.; Smirnova, A. S.

    2018-01-01

    The paper reports the investigation results on the microstructure and mechanical properties of low-carbon pipe steel after helical rolling. The processing of the steel leads to the refinement of ferritic grains from 12 (for the coarse-grained state) to 5 μm, to the strengthening of ferrite by carbide particles, a decrease in the total fraction of perlite grains, a more uniform alternation of ferrite and perlite, and the formation of regions with bainitic structure. The mechanical properties of the steel have been determined in the conditions of static and dynamic loading in the range of test temperatures from +20 to-70°C. As a result of processing, the ultimate tensile strength increases (from 650 to 770 MPa at a rolling temperature from 920°C) and the viscoplastic properties at negative temperatures are improved significantly. The ductile-brittle transition temperature of the rolled steel decreases from-32 to-55°C and the impact toughness at the test temperature-40°C increases eight times compared to the initial state of the steel.

  10. Numerical Analysis of Carbon Fiber Reinforced Plastic (CFRP Shear Walls and Steel Strips under Cyclic Loads Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    N. Askarizadeh

    2017-12-01

    Full Text Available Reinforced concrete shear walls are the main elements of resistance against lateral loads in reinforced concrete structures. These walls should not only provide sufficient resistance but also provide sufficient ductility in order to avoid brittle fracture, particularly under strong seismic loads. However, many reinforced concrete shear walls need to be stabilized and reinforced due to various reasons such as changes in requirements of seismic regulations, weaknesses in design and execution, passage of time, damaging environmental factors, patch of rebar in plastic hinges and in some cases failures and weaknesses caused by previous earthquakes or explosion loads. Recently, Fiber Reinforced Polymer (FRP components have been extensively and successfully used in seismic improvement. This study reinforces FRP reinforced concrete shear walls and steel strips. CFRP and steel strips are evaluated by different yield and ultimate strength. Numerical and experimental studies are done on walls with scale 1/2. These walls are exposed to cyclic loading. Hysteresis curves of force, drift and strain of FRP strips are reviewed in order to compare results of numerical work and laboratory results. Both numerical and laboratory results show that CFRP and steel strips increase resistance, capacity and ductility of the structure.

  11. A temperature dependent cyclic plasticity model for hot work tool steel including particle coarsening

    Science.gov (United States)

    Jilg, Andreas; Seifert, Thomas

    2018-05-01

    Hot work tools are subjected to complex thermal and mechanical loads during hot forming processes. Locally, the stresses can exceed the material's yield strength in highly loaded areas as e.g. in small radii in die cavities. To sustain the high loads, the hot forming tools are typically made of martensitic hot work steels. While temperatures for annealing of the tool steels usually lie in the range between 400 and 600 °C, the steels may experience even higher temperatures during hot forming, resulting in softening of the material due to coarsening of strengthening particles. In this paper, a temperature dependent cyclic plasticity model for the martensitic hot work tool steel 1.2367 (X38CrMoV5-3) is presented that includes softening due to particle coarsening and that can be applied in finite-element calculations to assess the effect of softening on the thermomechanical fatigue life of hot work tools. To this end, a kinetic model for the evolution of the mean size of secondary carbides based on Ostwald ripening is coupled with a cyclic plasticity model with kinematic hardening. Mechanism-based relations are developed to describe the dependency of the mechanical properties on carbide size and temperature. The material properties of the mechanical and kinetic model are determined on the basis of tempering hardness curves as well as monotonic and cyclic tests.

  12. Orthogonal decomposition of core loss along rolling and transverse directions of non-grain oriented silicon steels

    Directory of Open Access Journals (Sweden)

    Xuezhi Wan

    2017-05-01

    Full Text Available Rotational core loss of the silicon steel laminations are measured under elliptical rotating excitation. The core loss decomposition model is very important in magnetic core design, in which the decomposition coefficients are calculated through the measurement data. By using the transformation of trigonometric function, the elliptical rotational magnetic flux can be decomposed into two parts along two directions. It is assumed that the rotating core loss is the sum of alternating core losses along rolling and transverse directions. The magnetic strength vector H of non-grain oriented (NGO silicon steel 35WW270 along rolling and transverse directions is measured by a novel designed 3-D magnetic properties tester. Alternating core loss along the rolling, transverse directions and rotating core loss in the xoy-plane of this specimen in different frequencies such as 50 Hz, 100 Hz, and 200 Hz. Experimental results show that the core loss model is more accurate and useful to predict the total core loss.

  13. Effect of Asymmetric Rolling on Plastic Anisotropy of Low Carbon Steels during Simple Shear Tests

    International Nuclear Information System (INIS)

    Gracio, J. J.; Vincze, G.; Panigrahi, B. B.; Kim, H. J.; Barlat, F.; Rauch, E. F.; Yoon, J. W.

    2010-01-01

    Simple shear tests are performed on low carbon steel pre-deformed in conventional, asymmetric and orthogonal-asymmetric rolling. The simple-shear tests were carried out at 0 deg. , 45 deg. and 135 deg. with respect to the previous rolling direction. For a reduction ratio of 15%, a transient stagnation in the hardening rate is observed at reloading for all changes in strain path. The shear stress level, the hardening rate and extent of the plateau appear to be insensitive to the preliminary applied rolling conditions. After a reduction ratio of 50%, plastic instability was detected at reloading for all the changes of strain path and rolling conditions studied. A specific heat treatment was then designed allowing the material to become ductile after rolling while retaining the fine microstructure and therefore the high strength. Promising results were obtained essentially for 45 deg. shear tests.

  14. Effects of Changing Hot Rolling Direction on Microstructure, Texture and Mechanical Properties of Cu-2.7Be Sheets

    Science.gov (United States)

    Zhu, Daibo; Liu, Chuming; Yu, Haijun; Han, Tan

    2018-03-01

    A hot rolling scheme (cross-rolling and unidirectional rolling) was adopted to process Cu-2.7Be sheets used as multiplier dynodes in photomultiplier. The effects of changing rolling direction on microstructure, texture and mechanical properties were studied by a combination of XRD, EBSD and TEM. It was found that higher copper-type texture and lower brass texture intensity were obtained in the ultimately cross-rolling (CR) sheet compared with the unidirectional rolling (UR) sheet.The EBSD results indicated that the grain orientation from mainly for UR sample turns to random for CR sample. Great enhancements in YS and UTS after unidirectional rolling were attributed to the massive and polygonal γ precipitates. The CR sample exhibited lower anisotropy, because of the increase of S and γ precipitates with spherical and tiny shape.

  15. Investigation of using steel slag in hot mix asphalt for the surface course of flexible pavements

    Science.gov (United States)

    Nguyen, Hien Q.; Lu, Dai X.; Le, Son D.

    2018-04-01

    The rapid development of heavy industry in Vietnam leads to the establishments of steel industry. Steel slag, a by-product of steelwork industry, under Vietnamese’s law, was considered as a deleterious solid waste which needed to be processed and landfilled. However, this has changed recently, and steel slag is now seen as a normal or non-deleterious solid waste, and has been studied for reuse in the construction industry. In this study, steel slag was used, as a replacement for mineral aggregate, in hot mix asphalt. Two hot mix asphalt mixtures with an equivalent nominal aggregate size of 12.5 (C12.5) and 19 mm (C19) were produced using steel slag. In addition, one conventional hot mix asphalt mixture of C19 was produced using mineral aggregate for comparison purpose. Investigation in laboratory condition and trial sections was carried out on Marshall tests, surface roughness, skid resistance, and modulus of the pavement before and after applying a new surface course of hot mix asphalt. The study showed that all steel slag asphalt mixtures passed the Marshall stability and flow test requirements. The skid resistance of steel slag hot mix asphalt mixtures for the surface course satisfied the Vietnamese specification for asphalt. Moreover, the pavement sections with the surface course of steel slag hot mix asphalt showed a considerable higher modulus than that of the conventional one. Only the roughness of the surface course paved with C19 did not pass the requirement of the specification.

  16. Practical measurement of silicon in low alloy steels by differential pulse stripping voltammetry

    International Nuclear Information System (INIS)

    Rahier, A.; Lunardi, S.; Triki, C.

    2005-01-01

    A sensitive differential pulse anodic stripping voltammetry has been adapted to allow the determination of Si in low-alloy steels using a hanging mercury drop electrode. The method has been qualified using certified ASTM standards and is now running in routine. The present report describes the experimental details, thereby allowing the reader to carry out the measurements precisely. (author)

  17. Prediction of hot-ductility of steels during continuous casting using artificial neural networks

    International Nuclear Information System (INIS)

    Liu, W.J.; Emadi, D.; Essadiqi, E.

    2000-01-01

    During continuous casting, transversal cracks can be developed due to tensile stress in temperature regions where the steel exhibits a low ductility. The cracking tendency during continuous casting depends on the steel chemistry and the casting parameters such as lubrication, mold type, secondary cooling and bending/unbending temperatures. To prevent cracking one needs to predict the hot-ductility of a material under continuous-casting conditions. However, hot-ductility is one of the poorly understood material behaviors and cannot be readily modeled using conventional techniques. In the present study, we used an alternative method, namely Artificial Neural Networks (ANN), to model the ductility of a steel under continuous casting conditions. A hot-ductility database was established based on published literature. Several standard three-layer ANN models were then trained using data randomly selected from the database. The outputs of the ANN models were subsequently compared with the remaining data in the database. The results indicate that ANN is a suitable modelling technique for hot-ductility prediction. (author)

  18. Study on the Hot Extrusion Process of Advanced Radiation Resistant Oxide Dispersion Strengthened Steel Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Byoungkwon; Noh, Sanghoon; Kim, Kibaik; Kang, Suk Hoon; Chun, Youngbum; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Ferritic/martensitic steel has a better thermal conductivity and swelling resistance than austenitic stainless steel. Unfortunately, the available temperature range of ferritic/martensitic steel is limited at up to 650 .deg. C. Oxide dispersion strengthened (ODS) steels have been developed as the most prospective core structural materials for next generation nuclear systems because of their excellent high strength and irradiation resistance. The material performances of this new alloy are attributed to the existence of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperature in a ferritic/martensitic matrix. This microstructure can be very attractive in achieving superior mechanical properties at high temperatures, and thus, these favorable microstructures should be obtained through the controls of the fabrication process parameters during the mechanical alloying and hot consolidation procedures. In this study, a hot extrusion process for advanced radiation resistant ODS steel tube was investigated. ODS martensitic steel was designed to have high homogeneity, productivity, and reproducibility. Mechanical alloying and hot consolidation processes were employed to fabricate the ODS steels. A microstructure observation and creep rupture test were examined to investigate the effects of the optimized fabrication conditions. Advanced radiation resistant ODS steel has been designed to have homogeneity, productivity, and reproducibility. For these characteristics, modified mechanical alloying and hot consolidation processes were developed. Microstructure observation revealed that the ODS steel has uniformly distributed fine-grain nano-oxide particles. The fabrication process for the tubing is also being propelled in earnest.

  19. Study on the Hot Extrusion Process of Advanced Radiation Resistant Oxide Dispersion Strengthened Steel Tubes

    International Nuclear Information System (INIS)

    Choi, Byoungkwon; Noh, Sanghoon; Kim, Kibaik; Kang, Suk Hoon; Chun, Youngbum; Kim, Tae Kyu

    2014-01-01

    Ferritic/martensitic steel has a better thermal conductivity and swelling resistance than austenitic stainless steel. Unfortunately, the available temperature range of ferritic/martensitic steel is limited at up to 650 .deg. C. Oxide dispersion strengthened (ODS) steels have been developed as the most prospective core structural materials for next generation nuclear systems because of their excellent high strength and irradiation resistance. The material performances of this new alloy are attributed to the existence of uniformly distributed nano-oxide particles with a high density, which is extremely stable at high temperature in a ferritic/martensitic matrix. This microstructure can be very attractive in achieving superior mechanical properties at high temperatures, and thus, these favorable microstructures should be obtained through the controls of the fabrication process parameters during the mechanical alloying and hot consolidation procedures. In this study, a hot extrusion process for advanced radiation resistant ODS steel tube was investigated. ODS martensitic steel was designed to have high homogeneity, productivity, and reproducibility. Mechanical alloying and hot consolidation processes were employed to fabricate the ODS steels. A microstructure observation and creep rupture test were examined to investigate the effects of the optimized fabrication conditions. Advanced radiation resistant ODS steel has been designed to have homogeneity, productivity, and reproducibility. For these characteristics, modified mechanical alloying and hot consolidation processes were developed. Microstructure observation revealed that the ODS steel has uniformly distributed fine-grain nano-oxide particles. The fabrication process for the tubing is also being propelled in earnest

  20. Hot Ductility Behavior of a Peritectic Steel during Continuous Casting

    OpenAIRE

    Arıkan, Mustafa

    2015-01-01

    Hot ductility properties of a peritectic steel for welded gas cylinders during continuous casting were studied by performing hot tensile tests at certain temperatures ranging from 1200 to 700 °C for some cooling rates by using Gleeble-3500 thermo-mechanical test and simulation machine in this study. The effects of cooling rate and strain rate on hot ductility were investigated and continuous casting process map (time-temperature-ductility) were plotted for this material. Reduction of area ...

  1. Hot ductility behavior of a low carbon advanced high strength steel (AHSS) microalloyed with boron

    International Nuclear Information System (INIS)

    Mejia, I.; Bedolla-Jacuinde, A.; Maldonado, C.; Cabrera, J.M.

    2011-01-01

    Research highlights: → Effect of boron on the hot ductility behavior of a low carbon NiCrVCu AHSS. → Boron addition of 117 ppm improves hot ductility over 100% in terms of RA. → Hot ductility improvement is associated with segregation/precipitation of boron. → Typical hot ductility recovery at lower temperatures does not appear in this steel. → Hot ductility loss is associated with precipitates/inclusions coupled with voids. - Abstract: The current study analyses the influence of boron addition on the hot ductility of a low carbon advanced high strength NiCrVCu steel. For this purpose hot tensile tests were carried out at different temperatures (650, 750, 800, 900 and 1000 deg. C) at a constant true strain rate of 0.001 s -1 . Experimental results showed a substantial improvement in hot ductility for the low carbon advanced high strength steel when microalloyed with boron compared with that without boron addition. Nevertheless, both steels showed poor ductility when tested at the lowest temperatures (650, 750 and 800 deg. C), and such behavior is associated to the precipitation of vanadium carbides/nitrides and inclusions, particularly MnS and CuS particles. The fracture mode of the low carbon advanced high strength steel microalloyed with boron seems to be more ductile than the steel without boron addition. Furthermore, the fracture surfaces of specimens tested at temperatures showing the highest ductility (900 and 1000 deg. C) indicate that the fracture mode is a result of ductile failure, while in the region of poor ductility the fracture mode is of the ductile-brittle type failure. It was shown that precipitates and/or inclusions coupled with voids play a meaningful role on the crack nucleation mechanism which in turn causes a hot ductility loss. Likewise, dynamic recrystallization (DRX) which always results in restoration of ductility only occurs in the range from 900 to 1000 deg. C. Results are discussed in terms of boron segregation towards

  2. Hot ductility behavior of a low carbon advanced high strength steel (AHSS) microalloyed with boron

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, I., E-mail: imejia@umich.mx [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio ' U' , Ciudad Universitaria, 58066 Morelia, Michoacan (Mexico); Bedolla-Jacuinde, A.; Maldonado, C. [Instituto de Investigaciones Metalurgicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio ' U' , Ciudad Universitaria, 58066 Morelia, Michoacan (Mexico); Cabrera, J.M. [Departament de Ciencia dels Materials i Enginyeria Metal.lurgica, ETSEIB - Universitat Politecnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundacio CTM Centre Tecnologic, Av. de las Bases de Manresa 1, 08240 Manresa (Spain)

    2011-05-25

    Research highlights: {yields} Effect of boron on the hot ductility behavior of a low carbon NiCrVCu AHSS. {yields} Boron addition of 117 ppm improves hot ductility over 100% in terms of RA. {yields} Hot ductility improvement is associated with segregation/precipitation of boron. {yields} Typical hot ductility recovery at lower temperatures does not appear in this steel. {yields} Hot ductility loss is associated with precipitates/inclusions coupled with voids. - Abstract: The current study analyses the influence of boron addition on the hot ductility of a low carbon advanced high strength NiCrVCu steel. For this purpose hot tensile tests were carried out at different temperatures (650, 750, 800, 900 and 1000 deg. C) at a constant true strain rate of 0.001 s{sup -1}. Experimental results showed a substantial improvement in hot ductility for the low carbon advanced high strength steel when microalloyed with boron compared with that without boron addition. Nevertheless, both steels showed poor ductility when tested at the lowest temperatures (650, 750 and 800 deg. C), and such behavior is associated to the precipitation of vanadium carbides/nitrides and inclusions, particularly MnS and CuS particles. The fracture mode of the low carbon advanced high strength steel microalloyed with boron seems to be more ductile than the steel without boron addition. Furthermore, the fracture surfaces of specimens tested at temperatures showing the highest ductility (900 and 1000 deg. C) indicate that the fracture mode is a result of ductile failure, while in the region of poor ductility the fracture mode is of the ductile-brittle type failure. It was shown that precipitates and/or inclusions coupled with voids play a meaningful role on the crack nucleation mechanism which in turn causes a hot ductility loss. Likewise, dynamic recrystallization (DRX) which always results in restoration of ductility only occurs in the range from 900 to 1000 deg. C. Results are discussed in terms of

  3. Characterization of a cold-rolled 2101 lean duplex stainless steel.

    Science.gov (United States)

    Bassani, Paola; Breda, Marco; Brunelli, Katya; Mészáros, Istvan; Passaretti, Francesca; Zanellato, Michela; Calliari, Irene

    2013-08-01

    Duplex stainless steels (DSS) may be defined as a category of steels with a two-phase ferritic-austenitic microstructure, which combines good mechanical and corrosion properties. However, these steels can undergo significant microstructural modification as a consequence of either thermo-mechanical treatments (ferrite decomposition, which causes σ- and χ-phase formation and nitride precipitation) or plastic deformation at room temperature [austenite transformation into strain-induced martensite (SIM)]. These secondary phases noticeably affect the properties of DSS, and therefore are of huge industrial interest. In the present work, SIM formation was investigated in a 2101 lean DSS. The material was subjected to cold rolling at various degrees of deformation (from 10 to 80% thickness reduction) and the microstructure developed after plastic deformation was investigated by electron backscattered diffraction, X-ray diffraction measurements, and hardness and magnetic tests. It was observed that SIM formed as a consequence of deformations higher than ~20% and residual austenite was still observed at 80% of thickness reduction. Furthermore, a direct relationship was found between microstructure and magnetic properties.

  4. Effect of boron on the hot ductility of 2.25Cr1Mo steel

    International Nuclear Information System (INIS)

    Song, S.-H.; Guo, A.-M.; Shen, D.-D.; Yuan, Z.-X.; Liu, J.; Xu, T.-D.

    2003-01-01

    The effect of boron on the hot ductility of 2.25Cr1Mo steel is investigated by means of a Gleeble 2000 thermomechanical simulator. There is a trough in the hot ductility-temperature curve, which is located between 1000 and 700 deg. C. The ductility trough shifts to lower temperatures with increasing boron content and the hot brittle range becomes shallow and narrow. In general, boron may improve the steel hot ductility in that it may retard the formation of pro-eutectoid ferrite and increase grain boundary cohesion. These effects may be related to the segregation of boron to austenite grain boundaries

  5. Hot working effect on austenite transformations in structural steel in continuous cooling

    International Nuclear Information System (INIS)

    Zajmovskij, V.A.; Kisteh, N.V.; Samedov, O.V.

    1979-01-01

    Austenite transformations in 40, 40Kh, 40KhN and 40KhNMA steels under hot working at 900 deg C with 20% reduction degree and continuous cooling with 1,7-16 0 /s are investigated. Changing of cooling rate in various ways affects the temperature range of austenite transformation in pearlite and bainite regions. Regulating the cooling rate after hot working one can essentially change the impact strength and steel ductility as a result of high temperature thermomechanical treatment effect

  6. Study of the influence between the strength of antibending of working rolls on the widening during hot rolling of thin sheet metal

    Directory of Open Access Journals (Sweden)

    U. Muhin

    2016-07-01

    Full Text Available Based on the variation principle of Jourdan was developed a mathematical model of the process of widening freely in hot rolling of thin sheet metal. The principle applies to rigid-plastic materials and for the cinematically admissible area of speeds. The developed model allows to study the distribution of the widening on the length of the deformation zone depending on the parameters of the rolling process and sheet metal. Results are obtained, characterizing the size of the widening and effectiveness of the process control on tension at the entrance and exit from the stand. The widening is dependent on the strength of anti bending.

  7. Tribo-chemical behavior of eutectoid steel during rolling contact friction

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Y.; Cai, Z.B. [Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031 (China); Peng, J.F. [Tribology Research Institute, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); Cao, B.B. [Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031 (China); Jin, X.S. [Tribology Research Institute, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); Zhu, M.H., E-mail: zhuminhao@swjtu.cn [Key Laboratory of Advanced Technologies of Materials, Ministry of Education, Southwest Jiaotong University, Chengdu 610031 (China); Tribology Research Institute, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China)

    2016-12-01

    Highlights: • Tribo-chemical behavior was investigated during rolling contact friction. • Tribo-film may weaken the absorptive ability of O/C atoms on the surface. • Tribo-film is related to a low friction coefficient at rolling friction condition. - Abstract: The tribo-chemical behavior of the eutectoid steel during rolling contact friction is investigated via scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and electron probe X-ray microanalysis. The worn surface is divided into three zones: matrix zone (without friction), tribo-film zone (formed during friction) and delamination zone (tribo-film spalling). The different chemical states of atoms between those three zones and the air were investigated using the XPS analysis. The results showed that the matrix zone is composed of Fe{sub 2}O{sub 3}, FeO and metallic Fe, while the tribo-film and delamination zones only contain Fe{sub 2}O{sub 3} and FeO. Where the tribo-film is formed, the absorptive ability of O and C atoms on the top 2–3 atomic layers is probably weakened, while the exposed fresh metal in the delamination zone tends to be continuously oxidized and form tribo-film. The tribo-chemical reaction in the delamination zone is more activated than that in the other two zones. The protective nature of the tribo-film probably maintains a low friction coefficient under rolling contact friction condition.

  8. 76 FR 25670 - Stainless Steel Sheet and Strip in Coils From Italy: Final Results of the Full Five-Year (“Sunset...

    Science.gov (United States)

    2011-05-05

    ... martensitic precipitation-hardenable stainless steel is also excluded from the scope of the order. This high... DEPARTMENT OF COMMERCE International Trade Administration [A-475-824] Stainless Steel Sheet and... duty order on stainless steel sheet and strip (``SSSS'') in coils from Italy would be likely to lead to...

  9. Electrochemical corrosion response of a low carbon heat treated steel in a NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, W.R.; Peixoto, L.C.; Garcia, L.R.; Garcia, A. [Department of Materials Engineering, State University of Campinas, SP (Brazil)

    2009-10-15

    Dual-phase (DP) steels are produced from a specific heat treatment procedure and have recently emerged as a potential class of engineering materials for a number of structural and automobile applications. Such steels have high strength-to-weight ratio and reasonable formability. The present study aims to investigate the effects of four different and conventional heat treatments (i.e., hot rolling, normalizing, annealing, and intercritical annealing) on the resulting microstructural patterns and on the electrochemical corrosion behavior. Electrochemical impedance spectroscopy (EIS) and Tafel plots were carried out on heat treated steel samples in a 0.5 M NaCl solution at 25 C with neutral pH. An equivalent circuit analysis was also used to provide quantitative support for the discussions. The normalizing and the annealing heat treatments have provided the highest and the lowest corrosion resistances, respectively. The intercritical annealing and as-received (hot rolled) low carbon steel samples have shown similar corrosion behavior. Although a deleterious effect on the corrosion resistance has been verified for DP steel due to the residual stress from the martensite formation, it combines good mechanical properties with intermediate electrochemical corrosion resistance. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  10. Hot ductility of medium carbon steel with vanadium

    International Nuclear Information System (INIS)

    Lee, Chang-Hoon; Park, Jun-Young; Chung, JunHo; Park, Dae-Bum; Jang, Jin-Young; Huh, Sungyul; Ju Kim, Sung; Kang, Jun-Yun; Moon, Joonoh; Lee, Tae-Ho

    2016-01-01

    Hot ductility of medium carbon steel containing 0.52 wt% of carbon and 0.11 wt% of vanadium was investigated using a hot tensile test performed up to fracture. The hot ductility was evaluated by measuring the reduction of area of the fractured specimens, which were strained at a variety of test temperatures in a range of 600–1100 °C at a strain rate of 2×10"−"3/s. The hot ductility was excellent in a temperature range of 950–1100 °C, followed by a decrease of the hot ductility below 950 °C. The hot ductility continued to drop as the temperature was lowered to 600 °C. The loss of hot ductility in a temperature range of 800–950 °C, which is above the Ae_3 temperature, was due to V(C,N) precipitation at austenite grain boundaries. The further decline of hot ductility between 700 °C and 750 °C resulted from the transformation of ferrite films decorating austenite grain boundaries. The hot ductility continued to decrease at 650 °C or less, owing to ferrite films and the pearlite matrix, which is harder than ferrite. The pearlite was transformed from austenite due to relatively high carbon content.

  11. Hot Ductility of the 17-4 PH Stainless Steels

    Science.gov (United States)

    Herrera Lara, V.; Guerra Fuentes, L.; Covarrubias Alvarado, O.; Salinas Rodriguez, A.; Garcia Sanchez, E.

    2016-03-01

    The mechanisms of loss of hot ductility and the mechanical behavior of 17-4 PH alloys were investigated using hot tensile testing at temperatures between 700 and 1100 °C and strain rates of 10-4, 10-2, and 10-1 s-1. Scanning electron microscopy was used in conjunction with the results of the tensile tests to find the temperature region of loss of ductility and correlate it with cracking observed during processing by hot upsetting prior to ring rolling. It is reported that 17-4 PH alloys lose ductility in a temperature range around 900 °C near to the duplex austenite + ferrite phase field. Furthermore, it is found that niobium carbides precipitated at austenite/ferrite interfaces and grain boundaries have a pronounced effect on the mechanical behavior of the alloy during high-temperature deformation.

  12. Characterization of gas metal arc welded hot rolled DP600 steel

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, K.; Ramazani, A.; Yang, L.; Prahl, U.; Bleck, W. [RWTH Aachen University, Institute for Ferrous Metallurgy (IEHK) (Germany); Reisgen, U.; Schleser, M.; Abdurakhmanov, A. [RWTH Aachen University, Welding and Joining Institute (ISF) (Germany)

    2011-12-15

    Dual-phase (DP) steels are suitable candidates for automotive applications due to their high strength and ductility. These advanced mechanical properties result from the special microstructure of the DP steel with 5{proportional_to}20% martensite phase in a soft ferrite matrix. However, during welding, which is an important process in automotive industry, this special microstructure is destroyed. In this research the characterization of Gas Metal Arc (GMA) welded joining zones was performed by optical microscopy and hardness mapping. Tensile tests were also performed keeping the welded portion in the gauge length. Scanning Electron Microscopy (SEM) was used for the fracture investigation. From the characterization and tensile tests, the soften zones were found, which are caused by the tempered martensite and larger ferrite grain size than that in base metal. Furthermore, GMA welding make a large Heat Affected Zone (HAZ). (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. High Strength-High Ductility Combination Ultrafine-Grained Dual-Phase Steels Through Introduction of High Degree of Strain at Room Temperature Followed by Ultrarapid Heating During Continuous Annealing of a Nb-Microalloyed Steel

    Science.gov (United States)

    Deng, Yonggang; Di, Hongshuang; Hu, Meiyuan; Zhang, Jiecen; Misra, R. D. K.

    2017-07-01

    Ultrafine-grained dual-phase (UFG-DP) steel consisting of ferrite (1.2 μm) and martensite (1 μm) was uniquely processed via combination of hot rolling, cold rolling and continuous annealing of a low-carbon Nb-microalloyed steel. Room temperature tensile properties were evaluated and fracture mechanisms studied and compared to the coarse-grained (CG) counterpart. In contrast to the CG-DP steel, UFG-DP had 12.7% higher ultimate tensile strength and 10.7% greater uniform elongation. This is partly attributed to the increase in the initial strain-hardening rate, decrease in nanohardness ratio of martensite and ferrite. Moreover, a decreasing number of ferrite grains with {001} orientation increased the cleavage fracture stress and increased the crack initiation threshold stress with consequent improvement in ductility UFG-DP steel.

  14. Introducing radioactivity monitoring systems in the production of steel

    International Nuclear Information System (INIS)

    Sofilic, T.; Marjanovic, T.; Rastovcan-Mioc, A.

    2005-01-01

    Over the last twenty years, a significant number of cases of radioactive pollution has been recorded in metallurgical processes. However, it is not certain whether the pollution was caused by increased uncontrolled disposal of waste containing radionuclides or whether it was the result of increased radioactivity monitoring and control of metallic scrap. Many metal producers in the world have therefore implemented systematic monitoring of radioactivity in their production processes. Special attention was given to monitoring radioactivity in steel making processes, which is still the most applied construction material with an annual output of over billion tonnes all over the world. Drawing on the experience of the best known steel producers in Europe and world, Croatian steel mills find it necessary and justified to introduce radioactivity monitoring and control systems of radioactive elements in steel scrap, semi-finished and finished products. The aim of this paper is to point out the need to introduce the radioactivity monitoring and control in steel and steel-casting production, and to inform experts in Croatian steel mills and foundries about potential solutions and current systems. At the same time, we wanted to demonstrate how implementation of monitoring equipment can improve quality management and environmental management systems. This would render Croatian products competitive on the European market both in terms of physical and chemical properties and in terms of product quality certificates and radioactivity information. Since we lack our own standards and regulations to control both domestic and imported steel scrap, semi-finished products (crude steel, hot and cold rolled strip) and finished products, we need apply current international recommendations and guidelines, until we design our own monitoring system and adopt relevant legislation on the national level. This paper describes basic types of radioactivity monitoring and control systems, the most

  15. Study of hot cracking potential in a 6-ton steel ingot casting

    Science.gov (United States)

    Yang, Jing'an; Liu, Baicheng; Shen, Houfa

    2018-04-01

    A new hot cracking potential (HCP) criterion, for the appearance of hot tearing in steel ingot castings, is proposed. The maximum value of the first principal stress, divided by the dynamic yield strength in the brittle temperature range (BTR), was used to identify the HCP. Experiments were carried out on a 6-ton P91 steel ingot in which severe hot tearing was detected in the upper centerline. Another ingot, with a better heat preservation riser, and without hot tearing, was used for comparison. Samples were obtained from the area of the ingot body with hot tearing, and their morphologies were inspected by a X-ray high energy industrial computed tomography. The carbon and sulfur distributions around the hot tearing were characterized by an infrared spectrometry carbon and sulfur analyzer. High temperature mechanical properties were obtained by a Gleeble thermal simulation machine, under different strain rates. Then, thermo-mechanical simulations using an elasto-viscoplastic finite-element model were conducted to analyze the stress and strain evolution during ingot solidification. The results showed that the hot tearing area, which was rich in both carbon and sulfur, was under excessive tensile stress in the BTR, bearing the highest HCP.

  16. PERSPECTIVES OF MODERNIZATION OF WIRE MILL OF HOT ROLLING 150 AT RUP “BMZ”

    Directory of Open Access Journals (Sweden)

    A. V. Gontarj

    2004-01-01

    Full Text Available The offered modernization of the mill presumes the increase of capacity of the small-sort wire mill of hot milling 150 approximately till 40% at reduction of cost of the produced on it rolled wire by 15%, that will allow in future as well to grow the volumes of hardware production.

  17. Cold rolling texture development of α/γ duplex stainless steels

    International Nuclear Information System (INIS)

    Akdut, N.; Foct, J.; Gottstein, G.

    1996-01-01

    The cold rolling texture development of two α/γ duplex stainless steels (DSS) with similar volume fractions of both phases but with totally different microstructures were investigated. Due to the limited number of available pole figures using X-rays, for the calculation of the ODFs both a direct method and a recent iterative series expansion method were used. The results were checked by neutron diffraction measurements. The austenitic phases of both DSS behave similarly to single phase materials with a low stacking fault energy which develop a brass-type rolling texture. In contrast, the texture development of the ferritic phases strongly differs from those of single phase ferrites. Instead of a fibre type texture the α-phase in both DSS exhibits a peak dominated texture regardless of whether it is the matrix phase or not. These differences, as well as the sharpness of both phases, are explained by the presence of the second phase. (orig.)

  18. A quantitative atom probe study of the Nb excess at prior austenite grain boundaries in a Nb microalloyed strip-cast steel

    International Nuclear Information System (INIS)

    Felfer, Peter J.; Killmore, Chris R.; Williams, Jim G.; Carpenter, Kristin R.; Ringer, Simon P.; Cairney, Julie M.

    2012-01-01

    Most modern HSLA steels rely on the effect of Nb in steels to achieve the properties desired for a specific application. While the role of Nb in forming precipitates has been well characterized, its role in a solid solution is less well understood due to the difficulty of obtaining quantitative experimental data. In the current work, site-specific atom probe tomography was used to quantify the amount of Nb present at prior austenite grain boundaries in a commercial strip-cast steel, produced via the Castrip ® process. This was compared to the amount of Nb found at ferrite–ferrite grain boundaries that had formed during the transformation from austenite to ferrite. With the interfacial excess Nb measured, thermodynamic calculations were carried out and compared to the change in transformation temperature obtained by dilatometry, with reference to a comparable Nb free, strip-cast steel.

  19. Cold rolled texture and microstructure in types 304 and 316L austenitic stainless steels

    International Nuclear Information System (INIS)

    Wasnik, D.N.; Samajdar, I.; Gopalakrishnan, I.K.; Yakhmi, J.V.; Kain, V.

    2003-01-01

    Two grades of austenitic stainless steel (ASS), types 304 (UNS S 30400) and 316L (UNS S 31603), were cold rolled to different reductions by unidirectional and by cross-rolling. The steels had reasonable difference in stacking fault energy (estimated respectively as 15 and 61 mJ/m 2 in types 304 and 316L) and also in starting (or pre-deformation) crystallographic texture-being relatively weak and reasonably strong in types 304 and 316L respectively. The cold rolling increased texturing in type 304, but not in type 316L ASS. The more significant effect of cold rolled texture development was in the relative increase of Brass ({011} ) against Copper ({112} ) and S ({231} ) orientations. In type 304 the increase in Brass was significant, while in type 316L the increase in Copper and S was stronger. This effect could be captured by Taylor type deformation texture simulations considering stronger twinning contributions in type 304 - for example the respective 'best-fits' (in terms of matching the changes in the volume fractions of Brass against Copper and S) were obtained by full constraint Taylor model with 1:100 and 1:10 slip:twin activities in types 304 and 316L ASS respectively. Microstructural developments during cold rolling were generalized as strain induced martensite formation and developments of dislocation substructure. The former, as estimated by vibrating sample magnetometer (VSM), increased with cold reduction, being significantly more in type 304 and was also noticeably stronger in both grades under cross-rolling. The most significant aspect of substructural developments was the formation of strain localizations. These were observed as dense dislocation walls (DDWs), micro-bands (MBs) and twin lamellar structures (TLS). The TLS contribution gained significance at higher reductions and during cross-rolling, especially in type 304. Large misorientation development and the accompanying grain splittings were always associated with such strain localizations

  20. Microstructure examination of Fe–14Cr ODS ferritic steels produced through different processing routes

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Z., E-mail: z.oksiuta@pb.edu.pl [Bialystok University of Technology, Mechanical Department (Poland); Hosemann, P. [University of California Berkeley, Nuclear Engineering, 4169 Etcheverry Hall, Berkeley, CA 94720 (United States); Vogel, S.C. [Los Alamos Neutron Science Center, Los Alamos National Laboratory, PO Box 1663, NM (United States); Baluc, N. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, Villigen PSI 5232 (Switzerland)

    2014-08-01

    Various thermo-mechanical treatments were applied to refine and homogenise grain size and improve mechanical properties of hot-isostatically pressed (HIP) 14%Cr ODS ferritic steel. The grain size was reduced, improving mechanical properties, tensile strength and Charpy impact, however bimodal-like distribution was also observed. As a result, larger, frequently elongated grains with size above 1 μm and refined, equiaxed grains with a diameter ranging from 250 to 500 nm. Neutron diffraction measurements revealed that for HIP followed by hydrostatic extrusion material the strongest fiber texture was observed oriented parallel to the extrusion direction. In comparison with hot rolling and hot pressing methods, this material exhibited promising mechanical properties: the ultimate tensile strength of 1350 MPa, yield strength of 1280 MPa, total elongation of 21.7% and Charpy impact energy of 5.8 J. Inferior Charpy impact energy of ∼3.0 J was measured for HIP and hot rolled material, emphasising that parameters of this manufacturing process still have to be optimised. As an alternative manufacturing route, due to the uniform microstructure and simplicity of the process, hot pressing might be a promising method for production of smaller parts of ODS ferritic steels. Besides, the ductile-to-brittle transition temperature of all thermo-mechanically treated materials, in comparison with as-HIPped ODS steel, was improved by more than 50%, the transition temperature ranging from 50 to 70 °C (323 and 343 K) remains still unsatisfactory.

  1. Friction and wear in hot forging of steels

    International Nuclear Information System (INIS)

    Daouben, E.; Dubar, L.; Dubar, M.; Deltombe, R.; Dubois, A.; Truong-Dinh, N.; Lazzarotto, L.

    2007-01-01

    In the field of hot forging of steels, the mastering of wear phenomena enables to save cost production, especially concerning tools. Surfaces of tools are protected thanks to graphite. The existing lubrication processes are not very well known: amount and quality of lubricant, lubrication techniques have to be strongly optimized to delay wear phenomena occurrence. This optimization is linked with hot forging processes, the lubricant layers must be tested according to representative friction conditions. This paper presents the first part of a global study focused on wear phenomena encountered in hot forging of steels. The goal is the identification of reliable parameters, in order to bring knowledge and models of wear. A prototype testing stand developed in the authors' laboratory is involved in this experimental analysis. This test is called Warm and Hot Upsetting Sliding Test (WHUST). The stand is composed of a heating induction system and a servo-hydraulic system. Workpieces taken from production can be heated until 1200 deg. C. A nitrided contactor representing the tool is heated at 200 deg. C. The contactor is then coated with graphite and rubs against the workpiece, leaving a residual track on it. Friction coefficient and surface parameters on the contactor and the workpiece are the most representative test results. The surface parameters are mainly the sliding length before defects occurrence, and the amplitude of surface profile of the contactor. The developed methodology will be first presented followed by the different parts of the experimental prototype. The results of experiment show clearly different levels of performance according to different lubricants

  2. Structure and microstructure evolution of a ternary Fe–Cr–Ni alloy akin to super martensitic stainless steel

    International Nuclear Information System (INIS)

    Ravi Kumar, B.; Sharma, Sailaja; Munda, Parikshit; Minz, R.K.

    2013-01-01

    Highlights: • Reaustenisation by recrystallisation rather by a diffusion controlled process. • Ultrafine grained austenite formation in martensite matrix by recrystallisation. • In situ high temperature austenite transformation studies by X-ray diffraction. • Microstructure tailoring to achieve tensile strength (∼1 GPa) with good ductility. - Abstract: A ternary Fe–Cr–Ni alloy, akin to super martensitic stainless steels was prepared in vacuum induction furnace. The as cast ingot was solution treated at 1200 °C for 25 h and then hot forged and rolled to reduce into plate form. The hot rolled plate of martensitic microstructure was then cold rolled to 80% of thickness reduction. The phase transformation studies by X-ray diffraction analysis of hot and cold rolled specimens showed presence of retained austenite in air cooled as well as in water quenched state after annealing/austenising temperature of 1060 °C. The reaustenisation behaviour of the cold rolled alloy in water quenched state was studied by high temperature X-ray diffraction analysis. It showed very stable martensitic phase and the completion of reaustenisation process were observed to occur at about 950 °C. The recrystallisation behaviour of cold rolled material under isothermal and repeated annealing treatment was studied in detail by electron microscope. The tensile properties of the material were evaluated after various annealing treatments. The study revealed that by a suitable sequence of repetitive annealing process microstructure could be tailored to achieve tensile strength above 1 GPa with good ductility in a super martensitic stainless steel

  3. Evolution of Non-metallic Inclusions and Precipitates in Oriented Silicon Steel

    Science.gov (United States)

    Luo, Yan; Yang, Wen; Ren, Qiang; Hu, Zhiyuan; Li, Ming; Zhang, Lifeng

    2018-06-01

    The evolution of inclusions in oriented silicon steel during the manufacturing process was carried out by chemical composition analysis, non-aqueous electrolytic corrosion, and thermodynamic calculation. The morphology, composition, and size of inclusions were analyzed introducing field emission scanning electron microscope. The oxides were mainly formed during the secondary refining, and the nitrides, sulfides, and compounds were formed during the solidification and cooling of steel in the processes of continuous casting and hot rolling.

  4. The influence of delta ferrite in the AISI 416 stainless steel hot workability

    International Nuclear Information System (INIS)

    Cardoso, P.H.S.; Kwietniewski, C.; Porto, J.P.; Reguly, A.; Strohaecker, T.R.

    2003-01-01

    Delta ferrite in martensitic stainless steels may have an adverse effect on the mechanical properties of these materials at high temperature. The occurrence of such phase is determined by the material chemical composition (mainly Cr and C), as-received microstructure condition and hot working temperature. The aim of this investigation is to assess the influence of delta ferrite on the hot workability of the martensitic AISI 416 stainless steel. Hence, different heats of this material (differing in chemical composition and as-received microstructure) were submitted to heating tests in order to observe the microstructural transformations that take place at high temperature and then examine the influence of these transformations on the mechanical behaviour. Phase characterisation and quantification were carried out using scanning electron microscopy/energy-dispersive X-ray microanalysis and image analysis. The heating tests were performed in the temperature range of 1100-1350 deg. C and hot workability in two heats with different delta ferrite content was assessed by hot torsion tests in the temperature range of 1000-1250 deg. C. The results have indicated that chemical composition and as-received microstructure strongly affect delta ferrite formation, which in turn deteriorates hot workability of the martensitic AISI 416 stainless steel

  5. Hot tensile behaviour in silicon-killed boron microalloyed steels

    Science.gov (United States)

    Chown, Lesley H.; Cornish, Lesley A.

    2017-10-01

    Low carbon steel for drawing and cold heading applications should have low strength, high ductility and low strain ageing rates. To achieve this, nitrogen must be removed from solid solution, which can be done by low additions of boron. A wire producer had been experiencing occasional problems with severe cracking on silicon-killed, boron steel billets during continuous casting, but the solution was not obvious. Samples from four billets, each from different casts, were removed for analysis and testing. The tested steel compositions were within the specification limits, with boron to nitrogen ratios of 0.40-1.19. Hot ductility testing was performed on a Gleeble 1500 using parameters approximating the capabilities of this particular billet caster. The steel specimens were subjected to in situ melting, then cooled at a rate of 2 C.s-1 to temperatures in the range 750-1250°C, where they were then pulled to failure at a strain rate of 8x10-4 s-1. In this work, it was found that both the boron to nitrogen ratio and the manganese to sulphur ratio influenced the hot ductility and hence the crack susceptibility. Excellent hot ductility was found for B:N ratios above 1.0, which confirmed that the B:N ratio should be above a stoichiometric value of 0.8 to remove all nitrogen from solid solution. TEM analysis showed that coarse BN precipitates nucleated on other precipitates, such as (Fe,Mn)S, which have relatively low melting points, and are detrimental to hot ductility. Low Mn:S ratios of 10 - 12 were shown to promote precipitation of FeS, so a Mn:S > 14 was recommended. A narrower billet surface temperature range for straightening was recommended to prevent transverse surface cracking. Additionally, analysis of industrial casting data showed that the scrap percentage due to transverse cracking increased significantly for Mn:S < 14. An exponential decay relationship between the manganese to sulphur ratio and the average scrap percentage due to transverse cracking was

  6. Behaviors of Deformation, Recrystallization and Textures Evolution of Columnar Grains in 3%Si Electrical Steel Slabs

    Directory of Open Access Journals (Sweden)

    SHAO Yuan-yuan

    2017-11-01

    Full Text Available The behaviors of deformation and recrystallization and textures evolution of 3% (mass fraction Si columnar-grained electrical steel slabs were investigated by electron backscatter diffractometer technique and X-ray diffraction. The results indicate that the three columnar-grained samples have different initial textures with the long axes arranged along rolling, transverse and normal directions. Three shear orientations can be obtained in surface layer after hot rolling, of which Goss orientation is formed easily. The α and γ fibre rolling orientations are obtained in RD sample, while strong γ fibre orientations in TD sample and sharp {100} orientations in ND sample are developed respectively. In addition, cube orientation can be found in all the three samples. The characteristics of hot rolled orientations in center region reveal distinct dependence on initial columnar-grained orientations. Strong {111}〈112〉 orientation in RD and TD samples separately comes from Goss orientation of hot rolled sheets, and sharp rotated cube orientation in ND sample originates from the initial {100} orientation of hot rolled sheets after cold rolling. Influenced by initial deviated orientations and coarse grain size, large orientation gradient of rotated cube oriented grain can be observed in ND sample. The coarse {100} orientated grains of center region in the annealed sheets show the heredity of the initial columnar-grained orientations.

  7. Mixed structures in continuously cooled low-carbon automotive steels

    International Nuclear Information System (INIS)

    Khalid, F.A.; Edmonds, D.V.

    1993-01-01

    Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.)

  8. Investigation of hot cracking resistance of 2205 duplex steel

    Energy Technology Data Exchange (ETDEWEB)

    Adamiec, J; Scibisz, B, E-mail: janusz.adamiec@polsl.pl [Silesian University of Technology, Faculty of Materials Science and Metallurgy, ul. Krasinskiego 8, PL-40019 Katowice (Poland)

    2010-02-15

    Austenitic duplex steel of the brand 2205 according to Avesta Sheffield is used for welded constructions (pipelines, tanks) in the petrol industry, chemical industry and food industry. It is important to know the range of high-temperature brittleness in designing welding technology for constructions made of this steel type. There is no data in literature concerning this issue. High-temperature brittleness tests using the simulator of heat flow device Gleeble 3800 were performed. The tests results allowed the evaluation of the characteristic temperatures in the brittleness temperature range during the joining of duplex steels, specifically the nil-strength temperature (NST) and nil-ductility temperatures (NDT) during heating, the strength and ductility recovery temperatures (DRT) during cooling, the R{sub f}parameter (R{sub f} = (T{sub liquidus} - NDT)/NDT) describing the duplex steel inclination for hot cracking, and the brittleness temperature range (BTR). It has been stated that, for the examined steel, this range is wide and amounts to ca. 90 deg. C. The joining of duplex steels with the help of welding techniques creates a significant risk of hot cracks. After analysis of the DTA curves a liquidus temperature of T{sub L} = 1465 deg. C and a solidus temperature of T{sub S} = 1454 deg. C were observed. For NST a mean value was assumed, in which the cracks appeared for six samples; the temperature was 1381 deg. C. As the value of the NDT temperature 1367 deg. C was applied while for DRT the assumed temperature was 1375 deg. C. The microstructure of the fractures was observed using a Hitachi S-3400N scanning electron microscope (SEM). The analyses of the chemical composition were performed using an energy-dispersive X-ray spectrometer (EDS), Noran System Six of Thermo Fisher Scientific. Essential differences of fracture morphology type over the brittle temperature range were observed and described.

  9. Investigation of hot cracking resistance of 2205 duplex steel

    Science.gov (United States)

    Adamiec, J.; Ścibisz, B.

    2010-02-01

    Austenitic duplex steel of the brand 2205 according to Avesta Sheffield is used for welded constructions (pipelines, tanks) in the petrol industry, chemical industry and food industry. It is important to know the range of high-temperature brittleness in designing welding technology for constructions made of this steel type. There is no data in literature concerning this issue. High-temperature brittleness tests using the simulator of heat flow device Gleeble 3800 were performed. The tests results allowed the evaluation of the characteristic temperatures in the brittleness temperature range during the joining of duplex steels, specifically the nil-strength temperature (NST) and nil-ductility temperatures (NDT) during heating, the strength and ductility recovery temperatures (DRT) during cooling, the Rfparameter (Rf = (Tliquidus - NDT)/NDT) describing the duplex steel inclination for hot cracking, and the brittleness temperature range (BTR). It has been stated that, for the examined steel, this range is wide and amounts to ca. 90 °C. The joining of duplex steels with the help of welding techniques creates a significant risk of hot cracks. After analysis of the DTA curves a liquidus temperature of TL = 1465 °C and a solidus temperature of TS = 1454 °C were observed. For NST a mean value was assumed, in which the cracks appeared for six samples; the temperature was 1381 °C. As the value of the NDT temperature 1367 °C was applied while for DRT the assumed temperature was 1375 °C. The microstructure of the fractures was observed using a Hitachi S-3400N scanning electron microscope (SEM). The analyses of the chemical composition were performed using an energy-dispersive X-ray spectrometer (EDS), Noran System Six of Thermo Fisher Scientific. Essential differences of fracture morphology type over the brittle temperature range were observed and described.

  10. Investigation of hot cracking resistance of 2205 duplex steel

    International Nuclear Information System (INIS)

    Adamiec, J; Scibisz, B

    2010-01-01

    Austenitic duplex steel of the brand 2205 according to Avesta Sheffield is used for welded constructions (pipelines, tanks) in the petrol industry, chemical industry and food industry. It is important to know the range of high-temperature brittleness in designing welding technology for constructions made of this steel type. There is no data in literature concerning this issue. High-temperature brittleness tests using the simulator of heat flow device Gleeble 3800 were performed. The tests results allowed the evaluation of the characteristic temperatures in the brittleness temperature range during the joining of duplex steels, specifically the nil-strength temperature (NST) and nil-ductility temperatures (NDT) during heating, the strength and ductility recovery temperatures (DRT) during cooling, the R f parameter (R f = (T liquidus - NDT)/NDT) describing the duplex steel inclination for hot cracking, and the brittleness temperature range (BTR). It has been stated that, for the examined steel, this range is wide and amounts to ca. 90 deg. C. The joining of duplex steels with the help of welding techniques creates a significant risk of hot cracks. After analysis of the DTA curves a liquidus temperature of T L = 1465 deg. C and a solidus temperature of T S = 1454 deg. C were observed. For NST a mean value was assumed, in which the cracks appeared for six samples; the temperature was 1381 deg. C. As the value of the NDT temperature 1367 deg. C was applied while for DRT the assumed temperature was 1375 deg. C. The microstructure of the fractures was observed using a Hitachi S-3400N scanning electron microscope (SEM). The analyses of the chemical composition were performed using an energy-dispersive X-ray spectrometer (EDS), Noran System Six of Thermo Fisher Scientific. Essential differences of fracture morphology type over the brittle temperature range were observed and described.

  11. Hot ductility behavior of a low carbon advanced high strength steel (AHSS) microalloyed with boron

    OpenAIRE

    Mejía, Ignacio; Bedolla Jacuinde, Arnoldo; Maldonado, Cuauhtémoc; Cabrera Marrero, José M.

    2011-01-01

    The current study analyses the influence of boron addition on the hot ductility of a low carbon advanced high strength NiCrVCu steel. For this purpose hot tensile tests were carried out at different temperatures (650, 750, 800, 900 and 1000 ◦C) at a constant true strain rate of 0.001 s−1. Experimental results showed a substantial improvement in hot ductility for the low carbon advanced high strength steel when microalloyed with boron compared with that without boron addition. Nevertheless,...

  12. Multifrequency eddy current examination for surface defects detection of hot steel products

    International Nuclear Information System (INIS)

    Hiroshima, Tatsuo; Sakamoto, Takahide; Takahashi, Akio; Miyata, Kenichi.

    1985-01-01

    Multifrequency eddy current testing method using probe coils has been studied for surface defects detection in hot steel products at high temperature over the magnetic Curie point. The conventional signal processing method is not available for suppression of an undesirable signal caused by lift-off variation or unevenness in inspected surfaces, because the undesirable signal pattern is similar to a defect signal pattern. In order to suppress the undesirable signal a new dual frequency signal processing method using three phase rotators has been developed, and was applied to several hot steel inspections. The results are as follows. 1. In the rotating eddy current machine for hot steel rods, the lift-off variation signal caused by a wobble of rods or the difference between rotating center and pass center of rods can be suppressed. A long seam or crack whose depth is more than 0.5mm can be detected. 2. In the hot inspection for continuously cast slabs, the signal caused by oscillation mark whose depth is under 1 mm can be suppressed. A fine transversal crack whose depth is 2 mm can be detected. 3. In the hot inspection for round billets, the lift-off variation signal caused by oval shape can be eliminated, and a crack which is deeper than 1.5 mm can be clearly detected. The detectability of defects can be improved by the analysis of dual frequency signal pattern. (author)

  13. High temperature creep strength of Advanced Radiation Resistant Oxide Dispersion Strengthened Steels

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, high temperature strength of advanced radiation resistance ODS steel was investigated for the core structural material of next generation nuclear systems. ODS martensitic steel was designed to have high homogeneity, productivity and reproducibility. Mechanical alloying, hot isostactic pressing and hot rolling processes were employed to fabricate the ODS steels, and creep rupture test as well as tensile test were examined to investigate the behavior at high temperatures. ODS steels were fabricated by a mechanical alloying and hot consolidation processes. Mechanical properties at high temperatures were investigated. The creep resistance of advanced radiation resistant ODS steels was more superior than those of ferritic/ martensitic steel, austenitic stainless steel and even a conventional ODS steel.

  14. Influence of boron on strain hardening behaviour and ductility of low carbon hot rolled steel

    International Nuclear Information System (INIS)

    Deva, Anjana; Jha, B.K.; Mishra, N.S.

    2011-01-01

    Highlights: → Unique feature of low strain hardening exponent (n) with high total elongation has been discussed in industrially produced low carbon boron containing steel. → n has been correlated with the micro structural changes occurring during deformation of steel. → This feature of low n and high % elongation has potential for higher cold reducibility. → The work is being reported for the first time on industrially produced low carbon boron containing steel. - Abstract: The beneficial effect of boron on mechanical properties of low carbon Al-killed steel has been reported in recent past. However, the effect of boron on strain hardening exponent (n) and ductility has not been fully understood. This aspect has been discussed in present work. The results of mill trials with reference to n and ductility with boron added steel are compared to those for commercial grade. The lowering of 'n' with increased total elongation in boron bearing steel has been related to the microstructural evolution as a result of boron addition.

  15. The morphology of coating/substrate interface in hot-dip-aluminized steels

    International Nuclear Information System (INIS)

    Awan, Gul Hameed; Hasan, Faiz ul

    2008-01-01

    In hot-dip-aluminized (HAD) steels, the morphology and the profile of the interface between the aluminum coating and the substrate steel, are affected both by the composition of the molten aluminum as well as by the composition, and even the microstructure, of the substrate steel. This effect has been investigated using optical and scanning electron microscopy, and X-ray diffraction. The reaction between the steel and the molten aluminum leads to the formation of Fe-Al inter-metallic compounds on the steel surface. The thickness of the inter-metallic compound layer as well as the morphology of the interface between the steel and the interlayer varies with the silicon content of the molten aluminum. In hot-dip-aluminizing with pure aluminum, the interlayer is 'thick' and exhibits a finger-like growth into the steel. With a gradually increasing addition of silicon into the aluminum melt, the thickness of the interlayer decreases while the interface between the interlayer and the substrate gradually becomes 'smoother'. With an increase in the carbon content of the substrate steel the growth of the interlayer into the steel is impeded by the pearlite phase, whereas the ferrite phase appears to dissolve more readily. X-ray diffraction and electron microscopic studies showed that the interlayer formed in samples aluminized in pure aluminum, essentially consisted of orthorhombic Fe 2 Al 5 . It was further observed that the finger-like grains of Fe 2 Al 5 phase exhibited a preferred lattice orientation. With a gradual addition of silicon into the aluminum melt, a cubic phase based on Fe 3 Al also started to form in the interlayer and replaced most of the Fe 2 Al 5

  16. Mechanical and microstructural behavior of oxide dispersion strengthened 8Cr-2W and 8Cr-1W steels during creep deformation

    Energy Technology Data Exchange (ETDEWEB)

    Shinozuka, K.; Tamura, M.; Esaka, H. [National Defense Academy, Dept. MS and E, Kanagawa (Japan); Shiba, K.; Nakamura, K. [Japan Atomic Energy Agency, Tokai-mura, Naga-gun, Ibaraki-ken (Japan)

    2007-07-01

    Full text of publication follows: Oxide dispersion strengthened (ODS) steel is a promising candidate for fusion reactor material because of excellent mechanical properties. However, the ODS steel exhibits some defects, such as mechanical anisotropy and little elongation . To reveal details of these defects, we investigated correlations between mechanical and microstructural behavior of ODS ferritic steels during creep deformation at high temperature. The materials used in this study are two kinds of hot rolled ODS steels: Fe-8Cr-2W-0.2V-0.1Ta-0.2Ti-0.4Y{sub 2}O{sub 3} (J1) and Fe-8Cr-1W-0.2Ti-0.4Y{sub 2}O{sub 3} (J2). Creep tests was carried out on specimens sampling along both the rolling direction and the cross direction at 670, 700 and 730 deg. C. Microstructural analyses were made on the normalized and tempered condition by using OM, SEM, TEM and XRD. Creep ruptured and interrupted specimens were also investigated. Both J1 and J2 existed two phases, namely martensite and {delta}-ferrite which was elongated in the rolling direction. Y-Ti complex oxide particles were finely dispersed in martensite and {delta}- ferrite phases. Results of creep tests indicated that the time-to-rupture of specimens of J1 were much longer than J2, and the time-to-rupture of specimens sampling along the rolling direction were longer than cross direction. Accordingly, J1 sampling along hot rolling direction was the strongest, for instance, the time-to-rupture was 11400 h at 700 deg. C and 162 MPa. All specimens indicated that elongation was less than 1.3 % and the rupture occurred at steady state creep region from creep curves. Internal cracks were propagated in martensite phase along elongated {delta}-ferrite phase in the direction of hot rolling. On the other hand, {delta}-ferrite phases seemed to prevent combining cracks. These results suggest that elongated {delta}-ferrite and internal clacks in martensite strongly affect on the anisotropy and little elongation of creep. (authors)

  17. Effect of Aluminum Alloying on the Hot Deformation Behavior of Nano-bainite Bearing Steel

    Science.gov (United States)

    Yang, Z. N.; Dai, L. Q.; Chu, C. H.; Zhang, F. C.; Wang, L. W.; Xiao, A. P.

    2017-12-01

    Interest in using aluminum in nano-bainite steel, especially for high-carbon bearing steel, is gradually growing. In this study, GCr15SiMo and GCr15SiMoAl steels are introduced to investigate the effect of Al alloying on the hot deformation behavior of bearing steel. Results show that the addition of Al not only notably increases the flow stress of steel due to the strong strengthening effect of Al on austenite phase, but also accelerates the strain-softening rates for its increasing effect on stacking fault energy. Al alloying also increases the activation energy of deformation. Two constitutive equations with an accuracy of higher than 0.99 are proposed. The constructed processing maps show the expanded instability regions for GCr15SiMoAl steel as compared with GCr15SiMo steel. This finding is consistent with the occurrence of cracking on the GCr15SiMoAl specimens, revealing that Al alloying reduces the high-temperature plasticity of the bearing steel. On the contrary, GCr15SiMoAl steel possesses smaller grain size than GCr15SiMo steel, manifesting the positive effect of Al on bearing steel. Attention should be focused on the hot working process of bearing steel with Al.

  18. Hot compression deformation behavior of AISI 321 austenitic stainless steel

    Science.gov (United States)

    Haj, Mehdi; Mansouri, Hojjatollah; Vafaei, Reza; Ebrahimi, Golam Reza; Kanani, Ali

    2013-06-01

    The hot compression behavior of AISI 321 austenitic stainless steel was studied at the temperatures of 950-1100°C and the strain rates of 0.01-1 s-1 using a Baehr DIL-805 deformation dilatometer. The hot deformation equations and the relationship between hot deformation parameters were obtained. It is found that strain rate and deformation temperature significantly influence the flow stress behavior of the steel. The work hardening rate and the peak value of flow stress increase with the decrease of deformation temperature and the increase of strain rate. In addition, the activation energy of deformation ( Q) is calculated as 433.343 kJ/mol. The microstructural evolution during deformation indicates that, at the temperature of 950°C and the strain rate of 0.01 s-1, small circle-like precipitates form along grain boundaries; but at the temperatures above 950°C, the dissolution of such precipitates occurs. Energy-dispersive X-ray analyses indicate that the precipitates are complex carbides of Cr, Fe, Mn, Ni, and Ti.

  19. Hot Ductility Behavior of a Peritectic Steel during Continuous Casting

    Directory of Open Access Journals (Sweden)

    Mustafa Merih Arıkan

    2015-06-01

    Full Text Available Hot ductility properties of a peritectic steel for welded gas cylinders during continuous casting were studied by performing hot tensile tests at certain temperatures ranging from 1200 to 700 °C for some cooling rates by using Gleeble-3500 thermo-mechanical test and simulation machine in this study. The effects of cooling rate and strain rate on hot ductility were investigated and continuous casting process map (time-temperature-ductility were plotted for this material. Reduction of area (RA decreases and cracking susceptibility increases during cooling from solidification between certain temperatures depending on the cooling rate. Although the temperatures which fracture behavior change upon cooling during continuous casting may vary for different materials, it was found that the type of fracture was ductile at 1100 and 1050 °C; semi-ductile at 1000 °C, and brittle at 800 °C for the steel P245NB. There is a ductility trough between 1000 and 725 °C. The ductility trough gets slightly narrower as the cooling rate decreases.

  20. Corrosion behaviour of Fe-Mn-Si based shape memory steels trained by cold rolling

    International Nuclear Information System (INIS)

    Soederberg, O.; Liu, X.W.; Ullakko, K.; Lindroos, V.K.

    1999-01-01

    Fe-Mn-Si based high nitrogen steels have been studied in recent years for potential industrial applications. These steels show good shape memory properties, high strength and excellent ductility. In the present study, the effects of training history on the corrosion properties of Fe-Mn-Si-Cr-Ni based high nitrogen steels were investigated. The corrosion behaviour of shape memory alloys was analyzed by implementing anodic polarisation measurements and immersion tests. The shape memory steels in annealed, deformed and recovered conditions were studied to examine the training effect on their corrosion behaviour. The features of the anodic polarisation curves indicated a general corrosion type of these steels. The experimental results showed that Cr and Mn had a marked influence on the corrosion behaviour of the steels, followed by Ni, N and V. It was also apparent that the deformation during the shape memory training by cold rolling decreased the corrosion stability, and the recovery heating reduced further their corrosion resistance. However, further studies are needed in order to better understand the corrosion behaviour of the investigated alloys. (orig.)

  1. Effect of Boron and Titanium Addition on the Hot Ductility of Low-Carbon Nb-Containing Steel

    Science.gov (United States)

    Liu, Wei-Jian; Li, Jing; Shi, Cheng-Bin; Huo, Xiang-Dong

    2015-12-01

    The effect of boron and titanium addition on the hot ductility of Nb-containing steel was investigated using hot tensile tests. The fracture surface and the quenched longitudinal microstructure were examined by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that both steel samples had the similar change from 1,100°C to 700°C. The hot ductility of Nb-containing steel with boron and titanium addition was higher than the steel without boron and titanium in the temperature range of 900-750°C. Because the formation of intergranular ferrite was inhibited by solute boron segregating on the grain boundary, the formation of TiN changed the distribution of Nb- and boron-containing precipitates and improved the amount of intragranular ferrite.

  2. 78 FR 69371 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan: Preliminary...

    Science.gov (United States)

    2013-11-19

    ... this investigation are flat-rolled, cold-reduced steel products, regardless of chemistry; whether or... 7210.70.6090, 7212.40.1000, 7212.40.5000, 7219.90.0020, 7219.90.0025, 7219.90.0060, 7219.90.0080, 7220.... Results of the DP Analysis f. Export Price g. Normal Value h. Level of Trade i. Affiliated Party...

  3. Phase transformation kinetics in rolled U-10 wt. % Mo foil: Effect of post-rolling heat treatment and prior γ-UMo grain size

    Energy Technology Data Exchange (ETDEWEB)

    Jana, Saumyadeep; Overman, Nicole; Varga, Tamas; Lavender, Curt; Joshi, Vineet V.

    2017-12-01

    The effect of sub-eutectoid heat treatment on the phase transformation behavior in rolled U-10 wt.percent Mo (U10Mo) foils was systematically investigated. The as-cast 5 mm thick foils were initially homogenized at 900 degrees C for 48 hours and were hot rolled to 2 mm and later cold rolled down to 0.2 mm. Three starting microstructures were evaluated: (i) hot- + cold-rolled to 0.2 mm (as-rolled condition), (ii) hot- + cold-rolled to 0.2 mm + annealed at 700 deg. C for 1 hour, and (iii) hot- + cold-rolled to 0.2 mm + annealed at 1000 deg. C for 60 hours. U10Mo rolled foils went through various degrees of decomposition when subjected to the sub-eutectoid heat-treatment step and formed a lamellar microstructure through a cellular reaction mostly along the previous γ-UMo grain boundaries.

  4. Numerical and experimental study on multi-pass laser bending of AH36 steel strips

    Science.gov (United States)

    Fetene, Besufekad N.; Kumar, Vikash; Dixit, Uday S.; Echempati, Raghu

    2018-02-01

    Laser bending is a process of bending of plates, small sized sheets, strips and tubes, in which a moving or stationary laser beam heats the workpiece to achieve the desired curvature due to thermal stresses. Researchers studied the effects of different process parameters related to the laser source, material and workpiece geometry on laser bending of metal sheets. The studies are focused on large sized sheets. The workpiece geometry parameters like sheet thickness, length and width also affect the bend angle considerably. In this work, the effects of width and thickness on multi-pass laser bending of AH36 steel strips were studied experimentally and numerically. Finite element model using ABAQUS® was developed to investigate the size effect on the prediction of the bend angle. Microhardness and flexure tests showed an increase in the flexural strength as well as microhardness in the scanned zone. The microstructures of the bent strips also supported the physical observations.

  5. Calculation and experimental technique of determination of rolling procedure for cold-rolling tube mills

    International Nuclear Information System (INIS)

    Igoshin, V.F.; Aleshin, V.A.; Khoroshikh, Yu.G.; Bogatov, A.A.; Mizhiritskij, O.I.

    1983-01-01

    Calculation and experimental technique of determination of tube cold rolling procedure has been developed. Rolling procedure based on the usage of regression equation epsilon=1.24 psi, where psi is the relative reduction of area, delta-permissible reduction during rolling, has been tested on 08Kh18N10T steel. The effect of tube geometry, tool calibration parameters, lubrication conditions etc. on metal deformability in taking into account experimentally. The use of the technique proposed has allowed to shorten the time of mastering of the production of tubes from different steels

  6. Hot Ductility Behavior of Boron Containing Microalloyed Steels with Varying Manganese Contents

    Science.gov (United States)

    Brune, Tobias; Senk, Dieter; Walpot, Raphael; Steenken, Bernhard

    2015-02-01

    The hot ductility is measured for six different steel grades with different microalloying elements and with varying manganese contents using the hot tensile test machine with melting/solidification unit at the Department of Ferrous Metallurgy RWTH Aachen University. To identify the influence of manganese on hot ductility, tests are performed with varying the manganese content from 0.7 to 18.2 wt pct, a high manganese steel. Additionally, the effect of different cooling and strain rates is analyzed by changing the particular rate for selected samples in the minima. To investigate and detect the cause of cracking during testing, the fracture surfaces in the ductility minima are considered with scanning electron microscope-energy dispersive X-ray spectroscopy. Thermodynamic modeling is conducted on basis of the commercial software ThermoCalc©. A sharp decrease of the hot ductility is recognizable at 1398 K (1125 °C), at only 0.7 wt pct manganese because of the low manganese to sulfur ratio. The grades with a Mn content up to 1.9 wt pct show a good ductility with minimal ductility loss. In comparison, the steel grade with 18.2 wt pct has a poor hot ductility. Because of the formation of complex precipitates, where several alloying elements are involved, the influence of boron on hot ductility is not fully clarified. By increasing the cooling rate, the reduction of area values are shifted to smaller values. For high test temperatures, these measured values are decreased for lower strain rates. Thereby, an early drop of the ductility is noticeable for the high temperatures around 1373 K (1100 °C).

  7. Mechanical properties of Fe -10Ni -7Mn martensitic steel subjected to severe plastic deformation via cold rolling and wire drawing

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemi-Nanesa, H; Shirazi, H [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, P.O. Box 14395-731 (Iran, Islamic Republic of); Nili-Ahmadabadi, M, E-mail: sut.caster.81710018@gmail.co, E-mail: nili@ut.ac.i [School of Metallurgy and Materials Engineering, Faculty of Engineering, University of Tehran, P.O. Box 14395-731 (Iran, Islamic Republic of) and Center of Excellence for High Performance Materials, University of Tehran, P.O. Box 14395-731, Tehran (Iran, Islamic Republic of)

    2010-07-01

    Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was {epsilon} {approx}7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

  8. Mechanical properties of Fe -10Ni -7Mn martensitic steel subjected to severe plastic deformation via cold rolling and wire drawing

    Science.gov (United States)

    Ghasemi-Nanesa, H.; Nili-Ahmadabadi, M.; Shirazi, H.

    2010-07-01

    Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was epsilon ~7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

  9. Causes of the fissure formation with shrinkage of metal on low carbon steel slabs

    International Nuclear Information System (INIS)

    Ksenzuk, F.A.; Khudas, A.L.; Zelenskaya, D.P.

    1977-01-01

    The causes have been investigated underlying the formation of fissures with spread of metal on low-carbon steel slabs during hot rolling. Metallographic investigations of templates from various sections of work pieces from 15-ton ingots of 08 ps (kp) steels have indicated that the fissures on the slabs are formed after the metal spreads along the small plane and the work piece thins out in the course of rolling because of the opening of large thin-walled honeycomb bubbles. The phenomenon was confirmed schematically on a model in the form of a slab-shaped lead specimen with longitudinal hole of a variable diameter close to one of the edges

  10. EBSD characterization of an IF steel processed by Accumulative Roll Bonding

    International Nuclear Information System (INIS)

    Cruz-Gandarilla, F; Salcedo-Garrido, A M; Avalos, M; Bolmaro, R; Baudin, T; Cabañas-Moreno, J G; Dorantes-Rosales, H J

    2015-01-01

    The objective of this work is to study the texture and microstructure evolution of an IF steel deformed by Accumulative Roll Bonding (ARB) using Electron Backscatter Diffraction. Texture changes occur with increasing number of ARB cycles. For the early cycles, the main components are the α and γ fiber components characteristic of steels. With increasing the number of ARB cycles a tendency towards a random texture is obtained. In the initial state, the mean grain size is 30 μm and after 5 cycles it decreases to 1.2 μm. For the first ARB cycles, the fraction of high angle grain boundary is low but it increases with the number of cycles to about 80% for 5 cycles. The Kernel Average Misorientation (KAM) has no appreciable changes with the number of ARB cycles for all the texture components. (paper)

  11. Numerical Analysis of Effectiveness of Strengthening Concrete Slab in Tension of the Steel-Concrete Composite Beam Using Pretensioned CFRP Strips

    Directory of Open Access Journals (Sweden)

    Jankowiak Iwona

    2017-12-01

    Full Text Available One of the methods to increase the load carrying capacity of the reinforced concrete (RC structure is its strengthening by using carbon fiber (CFRP strips. There are two methods of strengthening using CFRP strips - passive method and active method. In the passive method a strip is applied to the concrete surface without initial strains, unlike in the active method a strip is initially pretensioned before its application. In the case of a steel-concrete composite beam, strips may be used to strengthen the concrete slab located in the tension zone (in the parts of beams with negative bending moments. The finite element model has been developed and validated by experimental tests to evaluate the strengthening efficiency of the composite girder with pretensioned CFRP strips applied to concrete slab in its tension zone.

  12. Numerical Analysis of Effectiveness of Strengthening Concrete Slab in Tension of the Steel-Concrete Composite Beam Using Pretensioned CFRP Strips

    Science.gov (United States)

    Jankowiak, Iwona; Madaj, Arkadiusz

    2017-12-01

    One of the methods to increase the load carrying capacity of the reinforced concrete (RC) structure is its strengthening by using carbon fiber (CFRP) strips. There are two methods of strengthening using CFRP strips - passive method and active method. In the passive method a strip is applied to the concrete surface without initial strains, unlike in the active method a strip is initially pretensioned before its application. In the case of a steel-concrete composite beam, strips may be used to strengthen the concrete slab located in the tension zone (in the parts of beams with negative bending moments). The finite element model has been developed and validated by experimental tests to evaluate the strengthening efficiency of the composite girder with pretensioned CFRP strips applied to concrete slab in its tension zone.

  13. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    NARCIS (Netherlands)

    Carvalho, N.J.M.; Huis in 't Veld, A.J.; Hosson, J.T. de

    1998-01-01

    Titanium-nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test

  14. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    NARCIS (Netherlands)

    Carvalho, N.J.M.; Huis in ’t Veld, A.J.; Hosson, J.Th. De

    1998-01-01

    Titanium–nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test

  15. Design rules for out-of-plane stability of roller bent steel arches with FEM

    NARCIS (Netherlands)

    Spoorenberg, R.C.; Snijder, H.H.; Hoenderkamp, J.C.D.; Beg, D.

    2012-01-01

    This paper describes a numerical investigation into the out-of-plane buckling behavior of freestanding roller bent steel arches. As roller bent arches have structural imperfections which differ considerably from those of hot-rolled or welded sections, specific attention is paid to their inclusion in

  16. A LOW TEMPERATURE ALUMINIZING TREATMENT OF HOT WORK TOOL STEEL

    OpenAIRE

    Matijević, Božidar

    2013-01-01

    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to the X40CrMoV5-1 hot tool steel. The aluminizing temperature was from 550 °C to 620 °C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the alumini...

  17. Online Surface Defect Identification of Cold Rolled Strips Based on Local Binary Pattern and Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2018-03-01

    Full Text Available In the production of cold-rolled strip, the strip surface may suffer from various defects which need to be detected and identified using an online inspection system. The system is equipped with high-speed and high-resolution cameras to acquire images from the moving strip surface. Features are then extracted from the images and are used as inputs of a pre-trained classifier to identify the type of defect. New types of defect often appear in production. At this point the pre-trained classifier needs to be quickly retrained and deployed in seconds to meet the requirement of the online identification of all defects in the environment of a continuous production line. Therefore, the method for extracting the image features and the training for the classification model should be automated and fast enough, normally within seconds. This paper presents our findings in investigating the computational and classification performance of various feature extraction methods and classification models for the strip surface defect identification. The methods include Scale Invariant Feature Transform (SIFT, Speeded Up Robust Features (SURF and Local Binary Patterns (LBP. The classifiers we have assessed include Back Propagation (BP neural network, Support Vector Machine (SVM and Extreme Learning Machine (ELM. By comparing various combinations of different feature extraction and classification methods, our experiments show that the hybrid method of LBP for feature extraction and ELM for defect classification results in less training and identification time with higher classification accuracy, which satisfied online real-time identification.

  18. Influence of stainless steel Internals on Corrosion of tower wall materials

    Science.gov (United States)

    Chen, Bing; Ren, Ke

    2017-12-01

    In view of the galvanic corrosion of the tower wall material in the tower of a refinery atmospheric vacuum distillation unit, the electrochemical behavior of Q345R steel, stainless steel (201, 304 cold-rolled plate, 304 hot rolled plate and 316L) in 3.5%NaCl solution was studied by electrochemical method. The results show that the corrosion potential of Q345R is much lower than that of stainless steel, and the corrosion rate of Q345R is higher than that of stainless steel. As the anode is etched as the anode corrosion, the anode polarizability of stainless steel shows strong polarization ability, which is anodic polarization control, and Q345R is anode Active polarization control; Q345R / 201 galvanic pair may be the most serious corrosion, and Q345R/316L galvanic couple may be relatively slight. Therefore, in the actual production of tower equipment, material design or tower to upgrade the replacement, it are recommended to use the preferred anode and cathode potential difference with the use of materials.

  19. Study of the structure of intermetalics from Fe - Al system after the hot rolling

    Directory of Open Access Journals (Sweden)

    M. Jabłońska

    2015-10-01

    Full Text Available This paper presents the results of structure analysis of Fe - Al alloys after hot rolling deformation. Microstructure analysis were performed before and after deformation using a scanning transmission electron microscopy (STEM technique. The detailed quantities research of the structures was conducted using scanning electron microscopy (SEM equipped with the gun with cold field emission and the detector of electron back scattering diffraction (EBSD.

  20. Axial Force Analysis and Roll Contour Configuration of Four-High CVC Mill

    Directory of Open Access Journals (Sweden)

    Guang-ming Liu

    2018-01-01

    Full Text Available In order to analyze the influence of technical parameters on work roll axial force of four-high continuous variable crown (CVC mill, the deformation analyzing model with top roll system and strip was established based on influence function method. Then a CVC work roll curve designing scheme was proposed and it was carried out on some cold rolling mill considering the requirement of comprehensive work roll axial force minimization. The status of comprehensive work roll axial force is improved considering the rolling schedule that is beneficial to the roller bearing. Corresponding to the newly designed work roll contour, the backup roll end chamfer was designed considering comprehensive performance of interroll stress concentration, comprehensive work roll axial force, and strip shape control ability. The distribution of roll wear with newly designed backup roll contour is more even according to the field application data. The newly established roll configuration scheme is beneficial to four-high CVC mill.

  1. Experimental and numerical study of steel pipe with part-wall defect reinforced with fibre glass sleeve

    International Nuclear Information System (INIS)

    Mazurkiewicz, Lukasz; Tomaszewski, Michal; Malachowski, Jerzy; Sybilski, Kamil; Chebakov, Mikhail; Witek, Maciej; Yukhymets, Peter; Dmitrienko, Roman

    2017-01-01

    The paper presents numerical and experimental burst pressure evaluation of the gas seamless hot-rolled steel pipe. The main goal was to estimate mechanical toughness of pipe wrapped with composite sleeve and verify selected sleeve thickness. The authors used a nonlinear explicit FE code with constitutive models which allows for steel and composite structure failure modelling. Thanks to the achieved numerical and analytical results it was possible to perform the comparison with data received from a capacity test and good correlation between the results were obtained. Additionally, the conducted analyses revealed that local reduction of pipe wall thickness from 6 mm to 2.4 mm due to corrosion defect can reduce high pressure resistance by about 40%. Finally, pipe repaired by a fibre glass sleeve with epoxy resin with 6 mm thickness turned out more resistant than an original steel pipe considering burst pressure. - Highlights: • Numerical and experimental burst pressure evaluation of steel pipe was performed. • Seamless hot-rolled steel pipe with and without corrosion defect were considered. • Local reduction of pipe wall thickness from 6 to 2.4 mm reduces resistance by 40%. • Pipe repaired by a 6 mm fibre glass sleeve was more resistant than an original pipe.

  2. γ→α′ Martensitic transformation and magnetic property of cold rolled Fe–20Mn–4Al–0.3C steel

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Biao; Li, Changsheng, E-mail: lics@ral.neu.edu.cn; Han, Yahui; Wang, Jikai

    2016-12-01

    Direct γ→α′ martensitic transformation during cold rolling deformation was investigated for a high-Mn non-magnetic steel. Its influence on magnetic property was also analyzed. The magnetization under rolling reduction less than 50% almost presents a linear increase with the applied magnetic field. With deformation up to 73% and 93% thickness reductions, strain induced α′-martensite transformation starts to occur, causing the steel to be slightly magnetized. The α′-martensite prefers to nucleate directly at either microband–microband or microband-twin intersections without participation of intermediate ε-martensite. The volume fraction of α′-martensite is estimated as 0.070% and 0.17%, respectively, based on the magnetic hysteresis loops. Such a small fraction of ferromagnetic α′-martensite shows little influence on the magnetic induction intensity and low relative permeability. - Highlights: • Magnetic property of high-Mn austenitic steel was examined after cold rolling. • Nucleation mode for direct γ→α′ martensitic transformation was observed and discussed. • Volume fraction of strain induced α′-martensite was estimated by magnetic measurement.

  3. Independency of Elasticity on Residual Stress of Room Temperature Rolled Stainless Steel 304 Plates for Structure Materials

    Directory of Open Access Journals (Sweden)

    Parikin Parikin

    2015-12-01

    Full Text Available Mechanical strengths of materials are widely expected in general constructions of any building. These properties depend on its formation (cold/hot forming during fabrication. This research was carried out on cold-rolled stainless steel (SS 304 plates, which were deformed to 0, 34, 84, and 152% reduction in thickness. The tests were conducted using Vickers method. Ultra micro indentation system (UMIS 2000 was used to determine the mechanical properties of the material, i.e.: hardness, modulus elasticity, and residual stresses. The microstructures showed lengthening outcropping due to stress corrosion cracking for all specimens. It was found that the tensile residual stress in a specimen was maximum, reaching 442 MPa, for a sample reducing 34% in thickness and minimum; and about 10 MPa for a 196% sample. The quantities showed that the biggest residual stress caused lowering of the proportional limit of material in stress-strain curves. The proportional modulus elasticity varied between 187 GPa and of about 215 GPa and was free from residual stresses.

  4. 77 FR 72820 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; 2010-2011...

    Science.gov (United States)

    2012-12-06

    ... governing ``Other Provisions,'' the English and Russian language versions of this revision shall be... Carbon-Quality Steel Products From the Russian Federation; 2010-2011; Final Results of Administrative... from the Russian Federation (``the Agreement'') for the period July 1, 2010 through June 30, 2011. See...

  5. Bench-Scale Development of a Hot Carbonate Absorption Process with Crystallization-Enabled High-Pressure Stripping for Post-Combustion CO{sub 2} Capture

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Yongqi; DeVries, Nicholas; Ruhter, David; Manoranjan, Sahu; Ye, Qing; Ye, Xinhuai; Zhang, Shihan; Chen, Scott; Li, Zhiwei; O' Brien, Kevin

    2014-03-31

    A novel Hot Carbonate Absorption Process with Crystallization-Enabled High-Pressure Stripping (Hot-CAP) has been developed by the University of Illinois at Urbana-Champaign and Carbon Capture Scientific, LLC in this three-year, bench-scale project. The Hot-CAP features a concentrated carbonate solution (e.g., K{sub 2}CO{sub 3}) for CO{sub 2} absorption and a bicarbonate slurry (e.g., KHCO{sub 3}) for high-pressure CO{sub 2} stripping to overcome the energy use and other disadvantages associated with the benchmark monoethanolamine (MEA) process. The project was aimed at performing laboratory- and bench-scale experiments to prove its technical feasibility and generate process engineering and scale-up data, and conducting a techno-economic analysis (TEA) to demonstrate its energy use and cost competitiveness over MEA. To meet project goals and objectives, a combination of experimental, modeling, process simulation, and economic analysis studies were applied. Carefully designed and intensive experiments were conducted to measure thermodynamic and reaction engineering data relevant to four major unit operations in the Hot-CAP (i.e., CO{sub 2} absorption, CO{sub 2} stripping, bicarbonate crystallization, and sulfate reclamation). The rate promoters that could accelerate the CO{sub 2} absorption rate into the potassium carbonate/bicarbonate (PCB) solution to a level greater than that into the 5 M MEA solution were identified, and the superior performance of CO{sub 2} absorption into PCB was demonstrated in a bench-scale packed-bed column. Kinetic data on bicarbonate crystallization were developed and applied for crystallizer design and sizing. Parametric testing of high-pressure CO{sub 2} stripping with concentrated bicarbonate-dominant slurries at high temperatures ({>=}140{degrees}C) in a bench-scale stripping column demonstrated lower heat use than with MEA. The feasibility of a modified process for combining SO{sub 2} removal with CO{sub 2} capture was preliminarily

  6. A quality approach to maintain the properties of S235 JR structural carbon steel in Lebanon

    International Nuclear Information System (INIS)

    Sidawi, J.A.; Al Khatib, H.

    2004-01-01

    Full text.S235JR carbon steel is one of the most popular steels used in Lebanon. It is imported by steel dealers and is widely used by all fabricators and manufacturers of steels for many structural purposes and applications. This kind of steel has good ductile properties as well as excellent weldability. It is still known by its previous designation St 37-2 or E 24-2. S235JR is produced in many shapes and thicknesses such as steel plates, sheets, angles and different other geometric shapes. Standard chemical and mechanical tests were conducted and reported on S235JR hot-rolled structural low-carbon mild steel specimens collected from Lebanese steel market. The main objective of this work is to assure the compliance of these properties with those set by the steel manufacturer. The above mentioned tests were performed at the laboratories of the Industrial Research Institute (IR) in Lebanon to assure the quality and credibility of the results. related European and American standards were presented as references and compared with the achieved results. Discussion was presented to show the similarities and differences between S235JR steel samples and standard requirements. Some of the reasons for such differences were discussed. Sufficient data was furnished through this work for the public and mainly for the Lebanese Standard Organization LIBNOR to easily adopt and implement the EN 10025:1993 European standard that can be applied in Lebanon concerning the most commonly used hot rolled low carbon structural steel. A follow up concerning adopting and implementing EN 10025:1993 will be briefed

  7. Design of Experiment as a powerful tool when applying Finite Element Method: a case study on prediction of hot rolling process parameters

    Directory of Open Access Journals (Sweden)

    Giancarlo G. Bordonaro

    2018-04-01

    Full Text Available The ultimate goal in hot roll pass design is to manufacture a rolled product with the required dimensional accuracy, defect free surface, and mechanical properties. The proper selection of process parameters is crucial to meet increasing requirements for desired quality and geometrical properties of rolled products. Due to the complex behavior of the metal flow at high temperatures and the severe plastic deformations in shape rolling, most efforts that have been made so far only rely upon the practical experience gained by operators. The large number of variables involved and the difficulty in investigating the process characteristics, make the use of finite element (FE tools an effective and attractive opportunity towards a thorough understanding of the rolling process. In this work, Design of Experiment (DOE is proposed as a powerful and viable method for the prediction of rolling process parameters while reducing the computational effort. Nonlinear 3D FE models of the hot rolling process are developed for a large set of complex cross-section shapes and validated against experimental evidences provided by real plant products at each stage of the deformation sequence. Based on the accuracy of the validated FE models, DOE is applied to investigate the flat rolling process under a series of many parameters and scenarios. Effects of main roll forming variables are analyzed on material flow behavior and geometrical features of a rolled product. The selected DOE factors are the workpiece temperature, diameter size, diameter reduction (draught, and rolls angular velocity. The selected DOE responses are workpiece spread, effective stresses, contact stresses, and rolls reaction loads. Eventually, the application of Pareto optimality (a Multi-Criteria Decision Making method allows to detect an optimal combination of design factors which respect desired target requirements for the responses.

  8. Texture evolution during the recrystallization of a warm-rolled low-carbon steel

    International Nuclear Information System (INIS)

    Sanchez-Araiza, M.; Godet, S.; Jacques, P.J.; Jonas, J.J.

    2006-01-01

    The texture changes taking place during the recrystallization of a warm-rolled low-carbon steel were examined using electron backscattered diffraction. The deformation textures of the warm-rolled material are similar in shape to those of cold-rolled materials, but are somewhat more intense. The recrystallization textures resemble the deformation textures but with a more extended α fibre that includes the {1 1 3} orientation; the γ fibre extends to the {5 5 4} orientation. These two orientations are related to the {1 1 2} deformed grains by near 26 deg, rotations about selected axes. Nevertheless, both orientations appear in the early stages of recrystallization, an observation that does not support the oriented growth theory. The {1 1 1} orientations are the first to recrystallize while the α fibre is present until the end of recrystallization. It is finally consumed by all types of grains as well as by subgrain coalescence. The similarities in the growth rates for the {1 1 1} and random orientations and the late disappearance of the α fibre suggest that recrystallization takes place according to the high stored energy oriented nucleation concept

  9. Microstructure, Tensile and Fatigue Properties of Al-5 wt.%Mg Alloy Manufactured by Twin Roll Strip Casting

    Science.gov (United States)

    Heo, Joon-Young; Baek, Min-Seok; Euh, Kwang-Jun; Lee, Kee-Ahn

    2018-04-01

    This study investigated the microstructure, tensile and fatigue properties of Al-5 wt.%Mg alloy manufactured by twin roll strip casting. Strips cast as a fabricated (F) specimen and a specimen heat treated (O) at 400 °C/5 h were produced and compared. In the F specimen, microstructural observation discovered clustered precipitates in the center area, while in the O specimen precipitates were relatively more evenly distributed. Al, Al6(Mn, Fe), Mg2Al3 and Mg2Si phases were observed. However, most of the Mg2Al3 phase in the heat-treated O specimen was dissolved. A room temperature tensile test measured yield strength of 177.7 MPa, ultimate tensile strength of 286.1 MPa and elongation of 11.1% in the F specimen and 167.7 MPa (YS), 301.5 MPa (UTS) and 24.6% (EL) in the O specimen. A high cycle fatigue test measured a fatigue limit of 145 MPa in the F specimen and 165 MPa in the O specimen, and the O specimen achieved greater fatigue properties in all fatigue stress conditions. The tensile and fatigue fracture surfaces of the above-mentioned specimens were observed, and this study attempted to investigate the tensile and fatigue deformation behavior of strip cast Al-5 wt.%Mg based on the findings.

  10. Measurements of Residual Stresses In Cold-Rolled 304 Stainless Steel Plates Using X-Ray Diffraction with Rietveld Refinement Method

    International Nuclear Information System (INIS)

    Parikin; Killen, P; Rafterry, A.

    2009-01-01

    The determination of the residual stresses using X-ray powder diffraction in a series of cold-rolled 304 stainless steel plates, deforming 0, 34, 84, 152, 158, 175 and 196 % reduction in thickness has been carried out. The diffraction data were analyzed using the Rietveld structure refinement method. The analysis shows that for all specimens, the martensite particles are closely in compression and the austenite matrix is in tension. Both the martensite and austenite, for a sample reducing 34% in thickness (containing of about 1% martensite phase) the average lattice strains are anisotropic and decrease approximately exponential with an increase in the corresponding percent reduction (essentially phase content). It is shown that this feature can be qualitatively understood by taking into consideration the thermal expansion mismatch between the martensite and austenite grains. Also, for all cold-rolled stainless steel specimens, the diffraction peaks are broader than the unrolled one (instrumental resolution), indicating that the strains in these specimens are inhomogeneous. From an analysis of the refined peak shape parameters, the average root-mean square strain, which describes the distribution of the inhomogeneous strain field, was predicted. The average residual stresses in cold-rolled 304 stainless steel plates showed a combination effect of hydrostatic stresses of the martensite particles and the austenite matrix. (author)

  11. Heat Treatment Optimization and Properties Correlation for H11-Type Hot-Work Tool Steel

    Science.gov (United States)

    Podgornik, B.; Puš, G.; Žužek, B.; Leskovšek, V.; Godec, M.

    2018-02-01

    The aim of this research was to determine the effect of vacuum-heat-treatment process parameters on the material properties and their correlations for low-Si-content AISI H11-type hot-work tool steel using a single Circumferentially Notched and fatigue Pre-cracked Tensile Bar (CNPTB) test specimen. The work was also focused on the potential of the proposed approach for designing advanced tempering diagrams and optimizing the vacuum heat treatment and design of forming tools. The results show that the CNPTB specimen allows a simultaneous determination and correlation of multiple properties for hot-work tool steels, with the compression and bending strength both increasing with hardness, and the strain-hardening exponent and bending strain increasing with the fracture toughness. On the other hand, the best machinability and surface quality of the hardened hot-work tool steel are obtained for hardness values between 46 and 50 HRC and a fracture toughness below 60 MPa√m.

  12. Structure and hot-rolled reinforcement rods properties evolution in the process of long service life

    International Nuclear Information System (INIS)

    Mikryukov, V.R.; Syomin, A.P.; Konovalov, S.V.; Ivanov, Yu.F.; Gromov, V.E.

    2006-01-01

    The physical nature of mechanical properties of hot-rolled reinforcement rods degradation during long-life operation is established by methods of transmission diffraction electron microscopy. It is shown that strength and plasticity properties decrease is due to cementite plates cutting and dissolution, microcracks formation process as a result of interstitial phase inclusions creation in the near-surface layer of material

  13. Structure and hot-rolled reinforcement rods properties evolution in the process of long service life

    Energy Technology Data Exchange (ETDEWEB)

    Mikryukov, V R [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Syomin, A P [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Konovalov, S V [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Ivanov, Yu F [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Gromov, V E [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation)

    2006-08-25

    The physical nature of mechanical properties of hot-rolled reinforcement rods degradation during long-life operation is established by methods of transmission diffraction electron microscopy. It is shown that strength and plasticity properties decrease is due to cementite plates cutting and dissolution, microcracks formation process as a result of interstitial phase inclusions creation in the near-surface layer of material.

  14. Screening the performance of lubricants for ironing of stainless steel with a strip reduction test

    DEFF Research Database (Denmark)

    Andreasen, Jan Lasson; Bay, Niels; Andersen, Mette Merete

    1997-01-01

    A laboratory strip reduction test simulating the tribological conditions of an ironing process is proposed. The test is capable of simulating varying process conditions such as reduction, drawing speed, tool temperature and sliding length. The test makes it possible to quantify the onset of break...... of breakdown of the lubricant film and subsequent galling. Experimental investigations of stainless steel show the influence of varying process conditions and the performance of different lubricants.......A laboratory strip reduction test simulating the tribological conditions of an ironing process is proposed. The test is capable of simulating varying process conditions such as reduction, drawing speed, tool temperature and sliding length. The test makes it possible to quantify the onset...

  15. Effects of Mn addition on microstructures and mechanical properties of 10Cr ODS ferritic/martensitic steels

    International Nuclear Information System (INIS)

    Jin, Hyun Ju; Kim, Tae Kyu

    2014-01-01

    Ferritic/martensitic (FM) steels are very attractive for the structural materials of fast fission reactors such as a sodium cooled fast reactor (SFR) owing to their excellent irradiation resistance to a void swelling, but are known to reveal an abrupt loss of their creep and tensile strengths at temperatures above 600 .deg. C. Accordingly, high temperature strength should be considerably improved for an application of the FM steel to the structural materials of SFR. Oxide dispersion strengthened (ODS) FM steels are considered to be promising candidate materials for high- temperature components operating in severe environments such as nuclear fusion and fission systems due to their excellent high temperature strength and radiation resistance stemming from the addition of extremely thermally stable oxide particles dispersed in the ferritic/martensitic matrix.. To develop an advanced ODS steel for core structural materials for next generation nuclear reactor system applications, it is important to optimize its compositions to improve the high temperature strength and radiation resistance. This study investigates effects of Mn addition on microstructures and mechanical properties of 10Cr ODS FM steel. For this, two 10 Cr ODS FM steels were prepared by mechanical alloying (MA), hot isostatic pressing (HIP), and hot rolling process. Tensile tests were carried out at room temperature and 700 .deg. C to evaluate the influences of the Mn element on the mechanical properties. The microstructures were observed using SEM, electron back-scatter diffraction (EBSD) and transmission electron microscopy (TEM) with energy dispersive spectroscopy (EDS). In the present study, the effects of Mn addition on the microstructure and mechanical properties of ODS FM steels were investigated. The ODS FM steels were manufactured by the MA, HIP and hot-rolling processes

  16. Cross Coating Weight Control by Electromagnetic Strip Stabilization at the Continuous Galvanizing Line of ArcelorMittal Florange

    Science.gov (United States)

    Guelton, Nicolas; Lopès, Catherine; Sordini, Henri

    2016-08-01

    In hot dip galvanizing lines, strip bending around the sink roll generates a flatness defect called crossbow. This defect affects the cross coating weight distribution by changing the knife-to-strip distance along the strip width and requires a significant increase in coating target to prevent any risk of undercoating. The already-existing coating weight control system succeeds in eliminating both average and skew coating errors but cannot do anything against crossbow coating errors. It has therefore been upgraded with a flatness correction function which takes advantage of the possibility of controlling the electromagnetic stabilizer. The basic principle is to split, for every gage scan, the coating weight cross profile of the top and bottom sides into two, respectively, linear and non-linear components. The linear component is used to correct the skew error by realigning the knives with the strip, while the non-linear component is used to distort the strip in the stabilizer in such a way that the strip is kept flat between the knives. Industrial evaluation is currently in progress but the first results have already shown that the strip can be significantly flattened between the knives and the production tolerances subsequently tightened without compromising quality.

  17. Theoretical Investigation of the Interfacial Reactions during Hot-Dip Galvanizing of Steel

    Science.gov (United States)

    Mandal, G. K.; Balasubramaniam, R.; Mehrotra, S. P.

    2009-03-01

    In the modern galvanizing line, as soon as the steel strip enters the aluminum-containing zinc bath, two reactions occur at the strip and the liquid-zinc alloy interface: (1) iron rapidly dissolves from the strip surface, raising the iron concentration in the liquid phase at the strip-liquid interface; and (2) aluminum forms a stable aluminum-iron intermetallic compound layer at the strip-coating interface due to its greater affinity toward iron. The main objective of this study is to develop a simple and realistic mathematical model for better understanding of the kinetics of galvanizing reactions at the strip and the liquid-zinc alloy interface. In the present study, a model is proposed to simulate the effect of various process parameters on iron dissolution in the bath, as well as, aluminum-rich inhibition layer formation at the substrate-coating interface. The transient-temperature profile of the immersed strip is predicted based on conductive and convective heat-transfer mechanisms. The inhibition-layer thickness at the substrate-coating interface is predicted by assuming the cooling path of the immersed strip consists of a series of isothermal holds of infinitesimal time-step. The influence of galvanizing reaction is assessed by considering nucleation and growth mechanisms at each hold time, which is used to estimate the total effect of the immersion time on the formation mechanism of the inhibition layer. The iron- dissolution model is developed based on well established principles of diffusion taking into consideration the area fraction covered by the intermetallic on the strip surface during formation of the inhibition layer. The model can be effectively used to monitor the dross formation in the bath by optimizing the process parameters. Theoretical predictions are compared with the findings of other researchers. Simulated results are in good agreement with the theoretical and experimental observation carried out by other investigators.

  18. Hydrogen effect on mechanical properties and flake formation in the 10KhSND steel rolled plates

    Energy Technology Data Exchange (ETDEWEB)

    Muradova, R G; Zakharov, V A; Kuzin, A P; Gol' tsov, V A; Podgajskij, M S [Donetskij Politekhnicheskij Inst. (Ukrainian SSR); Donetskij Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii (Ukrainian SSR))

    1982-01-01

    The effect of hydrogen on mechanical properties of the 10KhSND steel rolled plates during natural aging is studied. Optimum period of metal acceptance tests, which are advisable to conduct after 5-7 day natural aging of finished products, are found out. The technique is worked out and a safe hydrogen content to prevent flake formation in the 10KhSND steel is determined. It is shown that a safe hydrogen content is dependent on the experiment conditions (sample dimensions, conditions of cooling, and prehistory).

  19. Hydrogen effect on mechanical properties and flake formation in the 10KhSND steel rolled plates

    International Nuclear Information System (INIS)

    Muradova, R.G.; Zakharov, V.A.; Kuzin, A.P.; Gol'tsov, V.A.; Podgajskij, M.S.

    1982-01-01

    The effect of hydrogen on mechanical properties of the 10KhSND steel rolled plates during natural aging is studied. Optimum period of metal acceptance tests, which are advisable to conduct after 5-7 day natural aging of finished products, are found out. The technique is worked out and a safe hydrogen content to prevent flake formation in the 10KhSND steel is determined. It is shown that a safe hydrogen content is dependent on the experiment conditions (sample dimensions, conditions of cooling, and prehistory)

  20. Transient thermal stresses of work roll by coupled thermoelasticity

    Science.gov (United States)

    Lai, W. B.; Chen, T. C.; Weng, C. I.

    1991-01-01

    A numerical method, based on a two-dimensional plane strain model, is developed to predict the transient responses (that include distributions of temperature, thermal deformation, and thermal stress) of work roll during strip rolling by coupled thermoelasticity. The method consists of discretizing the space domain of the problem by finite element method first, and then treating the time domain by implicit time integration techniques. In order to avoid the difficulty in analysis due to relative movement between work roll and its thermal boundary, the energy equation is formulated with respect to a fixed Eulerian reference frame. The effect of thermoelastic coupling term, that is generally disregarded in strip rolling, can be considered and assessed. The influences of some important process parameters, such as rotational speed of the roll and intensity of heat flux, on transient solutions are also included and discussed. Furthermore, since the stress history at any point of the roll in both transient and steady state could be accurately evaluated, it is available to perform the analysis of thermal fatigue for the roll by means of previous data.