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Sample records for hot rolled high

  1. 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.

  2. 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.

  3. High thermal shock resistance of the hot rolled and swaged bulk W–ZrC alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Z.M.; Liu, R.; Miao, S.; Yang, X.D. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Zhang, T., E-mail: zhangtao@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Fang, Q.F.; Wang, X.P. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Liu, C.S., E-mail: csliu@issp.ac.cn [Key Laboratory of Materials Physics, Institute of Solid State Physics, Hefei Science Center, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Lian, Y.Y. [Southwestern Institute of Physics, Chengdu (China); Liu, X., E-mail: xliu@swip.ac.cn [Southwestern Institute of Physics, Chengdu (China); Luo, G.N. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-02-15

    The thermal shock (single shot) resistance and mechanical properties of the W–0.5wt% ZrC (WZC) alloys manufactured by ordinary sintering followed by swaging or rolling process were investigated. No cracks or surface melting were detected on the surface of the rolled WZC alloy plates after thermal shock at a power density of 0.66 GW/m{sup 2} for 5 ms, while primary intergranular cracks appear on the surface of the swaged WZC samples after thermal shock at a power density of 0.44 GW/m{sup 2} for 5 ms. Three point bending tests indicate that the rolled WZC alloy has a flexural strength of ∼2.4 GPa and a total strain of 1.8% at room temperature, which are 100% and 260% higher than those of the swaged WZC, respectively. The fracture energy density of the rolled WZC alloy is 3.23 × 10{sup 7} J/m{sup 3}, about 10 times higher than that of the swaged WZC (2.9 × 10{sup 6} J/m{sup 3}). The high thermal shock resistance of the rolled WZC alloys can be ascribed to their extraordinary ductility and plasticity. - Graphical abstract: (Left panel) surface morphology observed by optical microscope after a single pulse for 5 ms with various absorbed power densities at RT on the rolled WZC. (Right panel) curves of flexural stress versus strain at RT (a) and the calculated fracture energy (b) for the swaged WZC and rolled WZC alloys. - Highlights: • No cracks or surface melting were detected on the rolled WZC alloy samples after thermal shock at 0.66 GW/m{sup 2} for 5 ms. • Hot rolled WZC alloy plates exhibit a flexural strength of 2.4 GPa and a strain of 1.8% at RT. • The fracture energy of the rolled WZC alloy is 3.23 × 10{sup 7} J/m{sup 3} at RT, about 10 times higher than that of the swaged WZC. • A detailed analysis of the relationships between the mechanical properties and the thermal shock resistance is given.

  4. 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.

  5. 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.

  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. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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)

  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. 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

  19. 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)

  20. 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...

  1. 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...

  2. 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)

  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. 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)

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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)

  11. 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%.

  12. 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

  13. 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...

  14. 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

  15. 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

  16. 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)

  17. 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)

  18. 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.)

  19. 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...

  20. 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.

  1. 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.

  2. 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.

  3. 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%

  4. 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)

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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...

  12. 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...

  13. 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.

  14. 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..

  15. 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.)

  16. Precision ring rolling technique and application in high-performance bearing manufacturing

    Directory of Open Access Journals (Sweden)

    Hua Lin

    2015-01-01

    Full Text Available High-performance bearing has significant application in many important industry fields, like automobile, precision machine tool, wind power, etc. Precision ring rolling is an advanced rotary forming technique to manufacture high-performance seamless bearing ring thus can improve the working life of bearing. In this paper, three kinds of precision ring rolling techniques adapt to different dimensional ranges of bearings are introduced, which are cold ring rolling for small-scale bearing, hot radial ring rolling for medium-scale bearing and hot radial-axial ring rolling for large-scale bearing. The forming principles, technological features and forming equipments for three kinds of precision ring rolling techniques are summarized, the technological development and industrial application in China are introduced, and the main technological development trend is described.

  17. 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.

  18. 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)

  19. 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.

  20. 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...

  1. 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.)

  2. 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.)

  3. 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.

  4. 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.

  5. 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.

  6. Microstructure Evolution and Mechanical Behavior of a Hot-Rolled High-Manganese Dual-Phase Transformation-Induced Plasticity/Twinning-Induced Plasticity Steel

    Science.gov (United States)

    Fu, Liming; Shan, Mokun; Zhang, Daoda; Wang, Huanrong; Wang, Wei; Shan, Aidang

    2017-05-01

    The microstructures and deformation behavior were studied in a high-temperature annealed high-manganese dual-phase (28 vol pct δ-ferrite and 72 vol pct γ-austenite) transformation-induced plasticity/twinning-induced plasticity (TRIP/TWIP) steel. The results showed that the steel exhibits a special Lüders-like yielding phenomenon at room temperature (RT) and 348 K (75 °C), while it shows continuous yielding at 423 K, 573 K and 673 K (150 °C, 300 °C and 400 °C) deformation. A significant TRIP effect takes place during Lüders-like deformation at RT and 348 K (75 °C) temperatures. Semiquantitative analysis of the TRIP effect on the Lüders-like yield phenomenon proves that a softening effect of the strain energy consumption of strain-induced transformation is mainly responsible for this Lüders-like phenomenon. The TWIP mechanism dominates the 423 K (150 °C) deformation process, while the dislocation glide controls the plasticity at 573 K (300 °C) deformation. The delta-ferrite, as a hard phase in annealed dual-phase steel, greatly affects the mechanical stability of austenite due to the heterogeneous strain distribution between the two phases during deformation. A delta-ferrite-aided TRIP effect, i.e., martensite transformation induced by localized strain concentration of the hard delta-ferrite, is proposed to explain this kind of Lüders-like phenomenon. Moreover, the tensile curve at RT exhibits an upward curved behavior in the middle deformation stage, which is principally attributed to the deformation twinning of austenite retained after Lüders-like deformation. The combination of the TRIP effect during Lüders-like deformation and the subsequent TWIP effect greatly enhances the ductility in this annealed high-manganese dual-phase TRIP/TWIP steel.

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. Rolling of molybdenum and niobium tubes on cold-rolling mill with high stiff stand

    Energy Technology Data Exchange (ETDEWEB)

    Potapov, I N; Shejkh-Ali, A D; Filimonov, G V; Lunev, A G

    1984-03-01

    To develop the technique of tube production the process of rolling is studied and comparative evaluation of the structure formed is carried out. It is shown that billets of rods deformed by screw rolling have the improved plastic properties and are deformed on cold-rolling mill (CRM) with a high degree of reduction without defect formation. High stiff stand of the CRM permits to produce high-quality molybdenum tubes.

  15. 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)

  16. 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)

  17. Plasmonic color metasurfaces fabricated by a high speed roll-to-roll method

    DEFF Research Database (Denmark)

    Murthy, Swathi; Pranov, Henrik; Feidenhans'l, Nikolaj Agentoft

    2017-01-01

    Lab-scale plasmonic color printing using nano-structured and subsequently metallized surfaces have been demonstrated to provide vivid colors. However, upscaling these structures for large area manufacturing is extremely challenging due to the requirement of nanometer precision of metal thickness....... In this study, we have investigated a plasmonic color meta-surface design that can be easily upscaled. We have demonstrated the feasibility of fabrication of these plasmonic color surfaces by a high-speed roll-to-roll method, comprising roll-to-roll extrusion coating at 10 m min-1 creating a polymer foil having...... 100 nm deep pits of varying sub-wavelength diameter and pitch length. Subsequently this polymer foil was metallized and coated also by high-speed roll-to-roll methods. The perceived colors have high tolerance towards the thickness of the metal layer, when this thickness exceeds the depths of the pits...

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.)

  4. 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...

  5. 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...

  6. Interdiffusion studies on hot rolled U-10Mo/AA1050

    Energy Technology Data Exchange (ETDEWEB)

    Saliba-Silva, A.M.; Martins, I.C.; Carvalho, E.U.; Durazzo, M.; Riella, H.G. [Instituto de Pesquisas Energeticas e Nucleares (CCN/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Combustivel Nuclear], e-mail: saliba@ipen.br

    2010-07-01

    The U-Mo alloys are investigated with the goal of becoming nuclear material to fabricate high-density fuel elements for high performance research reactors. This enrichment level suggests that the U-Mo alloys should be between 6 to 10wt%, which can give up to 9gU/cm{sup 3} as fuel density. Nevertheless, the U-Mo alloys are very reactive with Al. Interdiffusion reaction products are formed since nuclear fission promotes chemical interaction layer during operation, leading to potential structural failure. Present studies were made with treated hot rolled diffusion couples of U-10Mo inserted in Al (AA1050). The U-10Mo/AA1050 pairs were treated in two temperature (150 degree C and 550 degree C) with three soaking times (5h, 40h and 80h). From microstructure analyses, rapid diffusion of Al happened inside U-10Mo in the first heating at 540 degree C during 15 min, reaching 8 at%Al in a range of 200 {mu}m towards U-10Mo. Longer time (5, 40, 80h) at 550 degree C maintain this level of Al-content up to 1000 {mu}m inside U-10Mo. A minor depth ({approx}1 {mu}m) near the interdiffusion contact had higher Al-content, but not sufficient to form identifiable (U,Mo)Al{sub x} structures. Probably, residual elements reduced drastically the interdiffusion phenomena between U-10Mo and AA1050, maybe due to silicon presence. (author)

  7. 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.

  8. 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

  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. 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...

  11. 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

  12. 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.

  13. Use of Hot Rolling for Generating Low Deviation Twins and a Disconnected Random Boundary Network in Inconel 600 Alloy

    Science.gov (United States)

    Sahu, Sandeep; Yadav, Prabhat Chand; Shekhar, Shashank

    2018-02-01

    In this investigation, Inconel 600 alloy was thermomechanically processed to different strains via hot rolling followed by a short-time annealing treatment to determine an appropriate thermomechanical process to achieve a high fraction of low-Σ CSL boundaries. Experimental results demonstrate that a certain level of deformation is necessary to obtain effective "grain boundary engineering"; i.e., the deformation must be sufficiently high to provide the required driving force for postdeformation static recrystallization, yet it should be low enough to retain a large fraction of original twin boundaries. Samples processed in such a fashion exhibited 77 pct length fraction of low-Σ CSL boundaries, a dominant fraction of which was from Σ3 ( 64 pct), the latter with very low deviation from its theoretical misorientation. The application of hot rolling also resulted in a very low fraction of Σ1 ( 1 pct) boundaries, as desired. The process also leads to so-called "triple junction engineering" with the generation of special triple junctions, which are very effective in disrupting the connectivity of the random grain boundary network.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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°.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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 %.

  7. 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.

  8. 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.

  9. 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.

  10. On the Effects of Hot Forging and Hot Rolling on the Microstructural Development and Mechanical Response of a Biocompatible Ti Alloy

    Science.gov (United States)

    Okazaki, Yoshimitsu

    2012-01-01

    Zr, Nb, and Ta as alloying elements for Ti alloys are important for attaining superior corrosion resistance and biocompatibility in the long term. However, note that the addition of excess Nb and Ta to Ti alloys leads to higher manufacturing cost. To develop low-cost manufacturing processes, the effects of hot-forging and continuous-hot-rolling conditions on the microstructure, mechanical properties, hot forgeability, and fatigue strength of Ti-15Zr-4Nb-4Ta alloy were investigated. The temperature dependences with a temperature difference (ΔT) from β-transus temperature (Tβ) for the volume fraction of the α- and β-phases were almost the same for both Ti-15Zr-4Nb-4Ta and Ti-6Al-4V alloys. In the α-β-forged Ti-15Zr-4Nb-4Ta alloy, a fine granular α-phase structure containing a fine granular β-phase at grain boundaries of an equiaxed α-phase was observed. The Ti-15Zr-4Nb-4Ta alloy billet forged at Tβ-(30 to 50) °C exhibited high strength and excellent ductility. The effects of forging ratio on mechanical strength and ductility were small at a forging ratio of more than 3. The maximum strength (σmax) markedly increased with decreasing testing temperature below Tβ. The reduction in area (R.A.) value slowly decreased with decreasing testing temperature below Tβ. The temperature dependences of σmax for the Ti-15Zr-4Nb-4Ta and Ti-6Al-4V alloys show the same tendency and might be caused by the temperature difference (ΔT) from Tβ. It was clarified that Ti-15Zr-4Nb-4Ta alloy could be manufactured using the same manufacturing process as for previously approved Ti-6Al-4V alloy, taking into account the difference (ΔT) between Tβ and heat treatment temperature. Also, the manufacturing equivalency of Ti-15Zr-4Nb-4Ta alloy to obtain marketing approval of implants was established. Thus, it was concluded that continuous hot rolling is useful for manufacturing α-β-type Ti alloy.

  11. 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.

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. Interfacial layers evolution during annealing in Ti-Al multi-laminated composite processed using hot press and roll bonding

    Science.gov (United States)

    Assari, A. H.; Eghbali, B.

    2016-09-01

    Ti-Al multi-laminated composites have great potential in high strength and low weight structures. In the present study, tri-layer Ti-Al composite was synthesized by hot press bonding under 40 MPa at 570 °C for 1 h and subsequent hot roll bonding at about 450 °C. This process was conducted in two accumulative passes to 30% and to 67% thickness reduction in initial and final passes, respectively. Then, the final annealing treatments were done at 550, 600, 650, 700 and 750 °C for 2, 4 and 6 h. Investigations on microstructural evolution and thickening of interfacial layers were performed by scanning electron microscopes, energy dispersive spectrometer, X-ray diffraction and micro-hardness tests. The results showed that the thickening of diffusion layers corresponds to amount of deformation. In addition to thickening of the diffusion layers, the thickness of aluminum layers decreased and after annealing treatment at 750 °C for 6 h the aluminum layers were consumed entirely, which occurred because of the enhanced interdiffusion of Ti and Al elements. Scanning electron microscope equipped with energy dispersive spectrometer showed that the sequence of interfacial layers as Ti3Al-TiAl-TiAl2-TiAl3 which are believed to be the result of thermodynamic and kinetic of phase formation. Micro-hardness results presented the variation profile in accordance with the sequence of intermetallic phases and their different structures.

  19. 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

  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. 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...

  2. Prediction of microstructure and ductile damage of a high-speed railway axle steel during cross wedge rolling

    OpenAIRE

    Huo, Y; Lin, J; Bai, Q; Wang, B; Tang, X; Ji, H

    2016-01-01

    Microstructure and ductile damage have a significant influence on the deformation behavior of high-speed railway axles during hot cross wedge rolling (CWR) and its final performance. In this study, based on the continuum damage mechanics, a multiaxial constitutive model coupling microstructure and ductile damage was established to predict the evolution of microstructure and ductile damage of 25CrMo4 during hot CWR processes. Material constants within the multiaxial constitutive model were det...

  3. 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)

  4. 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)

  5. 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.

  6. Modelling of drawing and rolling of high carbon flat wires

    International Nuclear Information System (INIS)

    Bobadilla, C.; Persem, N.; Foissey, S.

    2007-01-01

    In order to meet customer requirements, it is necessary to develop new flat wires with a high tensile strength and a high width/thickness ratio. These products are manufactured from wire rod. The first step is to draw the wire until we have the required mechanical properties and required surface area of the section. After this, the wire is rolled from a round to a rectangular section. During the flat rolling process it can be reduced by more than 50%. Then the wire is exposed to a high level of stress during this process. Modelling allows us to predetermine this stress level, taking into account the final dimensions and the mechanical properties, thus optimising both rolling and drawing process. Forge2005 was used in order to simulate these processes. The aim of this study is to determine the value of residual stresses after drawing and so to optimise rolling. Indeed, the highest stress values are reached at this step of the process by changing the section of the wire from a round to a rectangular one. In order to evaluate the stress value accuracy for high strain levels, a behaviour law has been identified. This is a result of tensile tests carried out at each step of the drawing process. Finally, a multi-axial damage criterion was implemented using Forge2005. The optimisation of the rolling is directly linked to the minimisation of this criterion

  7. Flexible organic tandem solar modules with 6% efficiency: combining roll-to-roll compatible processing with high geometric fill factors

    DEFF Research Database (Denmark)

    Spyropoulos, G. D.; Kubis, P.; Li, Na

    2014-01-01

    Organic solar cell technology bears the potential for high photovoltaic performance combined with truly low-cost, high-volume processing. Here we demonstrate organic tandem solar modules on flexible substrates fabricated by fully roll-to-roll compatible processing at temperatures...

  8. 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...

  9. 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.

  10. 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%).

  11. 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.

  12. Influence of feed rate on damage development in hot ring rolling

    NARCIS (Netherlands)

    Wang, Chao; van den Boogaard, Antonius H.; Omerspahic, E.; Recina, V.; Geijselaers, Hubertus J.M.; Ishikawa, T.; Mori, K.-I.

    2014-01-01

    As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. Applications of ring rolling cover a wide range of products in aerospace, automotive and civil engineering industries. Under some process conditions, defects such as

  13. 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)

  14. High-Tc SQUID Application for Roll to Roll Metallic Contaminant Detector

    International Nuclear Information System (INIS)

    Tanaka, S.; Kitamura, Y.; Uchida, Y.; Hatsukade, Y.; Ohtani, T.; Suzuki, S.

    2012-01-01

    A sensitive eight-channel high-Tc Superconducting Interference Device (SQUID) detection system for magnetic contaminant in a lithium ion battery anode was developed. Finding ultra-small metallic foreign matter is an important issue for a manufacturer because metallic contaminants carry the risk of an internal short. When contamination occurs, the manufacturer of the product suffers a great loss from recalling the tainted product. Metallic particles with outer dimensions smaller than 100 microns cannot be detected using a conventional X-ray imaging system. Therefore, a highly sensitive detection system for small foreign matter is required. We have already developed a detection system based on a single-channel SQUID gradiometer and horizontal magnetization. For practical use, the detection width of the system should be increased to at least 65 mm by employing multiple sensors. In this paper, we present an 8-ch high-Tc SQUID roll-to-roll system for inspecting a lithium-ion battery anode with a width of 65 mm. A special microscopic type of a cryostat was developed upon which eight SQUID gradiometers were mounted. As a result, small iron particles of 35 microns on a real lithium-ion battery anode with a width of 70 mm were successfully detected. This system is practical for the detection of contaminants in a lithium ion battery anode sheet.

  15. 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

  16. Effects of Al content on structure and mechanical properties of hot-rolled ZrTiAlV alloys

    International Nuclear Information System (INIS)

    Liang, S.X.; Yin, L.X.; Che, H.W.; Jing, R.; Zhou, Y.K.; Ma, M.Z.; Liu, R.P.

    2013-01-01

    Highlights: • Phase structure is greatly dependent on the Al content. • Intermetallic compound will precipitates while Al content is over 6.9 wt%. • Equiaxed α-phase grains present in the hot-rolled alloy with 6.9 wt% Al. • Alloys with Al content from 3.3 wt% to 5.6 wt% have good mechanical properties. - Abstract: Zirconium alloys show attractive properties for astronautic applications where the most important factors are anti-irradiation, corrosion resistance, anti-oxidant, very good strength-to-weight ratio. The effects of Al content (2.2–6.9 wt%) on structure and mechanical properties of the hot-rolled ZrTiAlV alloy samples were investigated in this study. Each sample of the hot-rolled ZrTiAlV alloys with Al contents from 2.2 wt% to 5.6 wt% is composed of the α phase and β phase, meanwhile, the relative content of the α phase increased with the Al content. However, the (ZrTi) 3 Al intermetallic compound was observed as the Al content increased to 6.9 wt%. Changes of phase compositions and structure with Al content distinctly affected mechanical properties of ZrTiAlV alloys. Yield strength of the alloy with 2.2 wt% Al is below 200 MPa. As Al content increased to 5.6 wt%, the yield strength, tensile strength and elongation of the examined alloy are 1088 MPa, 1256 MPa and 8%, respectively. As Al content further increased to 6.9 wt%, a rapid decrease in ductility was observed as soon as the (ZrTi) 3 Al intermetallic compound precipitated. Results show that the ZrTiAlV alloys with Al contents between 3.3 wt% and 5.6 wt% have excellent mechanical properties

  17. Electron backscatter diffraction study of dislocation content of a macrozone in hot-rolled Ti-6Al-4V alloy

    International Nuclear Information System (INIS)

    Britton, T. Ben; Birosca, Soran; Preuss, Michael; Wilkinson, Angus J.

    2010-01-01

    We compare the dislocation substructure within macrozone and non-macrozone regions of hot-rolled Ti-6Al-4 V. Hough-based and cross-correlation-based analysis of electron backscatter diffraction (EBSD) patterns are used to establish the grain orientations and intra-granular misorientations, respectively. The set of geometrically necessary dislocations (GNDs) that support measured lattice curvatures and minimize the total GND line energy are calculated. The GND content in the macrozone is approximately twice that in the non-macrozone region, and GNDs are present at densities ∼10 times higher than GNDs.

  18. 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.).

  19. 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.)

  20. A Feeding Strategy in Inner L-Shape Ring Hot Rolling Process

    Directory of Open Access Journals (Sweden)

    Wen Meng

    2017-01-01

    Full Text Available In order to make the inner L-shape ring polling process with a closed die structure (ILRRCDS on the top and bottom of the driven roll stable, at first, this paper established the mathematical model for ILRRCDS. Then, the plastic penetration and biting-in conditions for ILRRCDS were deduced based on plain ring rolling theory. Moreover, a feeding strategy that can realize a constant growth of the ring’s outer radius was proposed and the reasonable value ranges of the feed rate of the mandrel were determined. The numerical simulation model for ILRRCDS is established based on ABAQUS software. Finally, the equivalent plastic strain (PEEQ and temperature distributions of rolled ring were obtained. The results indicated that the proposed feeding strategy can realize a stable ILRRCDS. At the end of ILRRCDS, the PEEQ at the inner radius surface of the ring is maximum, the PEEQ at the outer radius surface of the ring takes the second place, and the PEEQ at the middle part of ring is minimum. With the increase of rolling time, the higher temperature zone of the rolled ring gradually moves from the center part of the ring to the “inner corner zone” of the ring.

  1. Hot nuclei: high temperatures, high angular momenta

    International Nuclear Information System (INIS)

    Guerreau, D.

    1991-01-01

    A review is made of the present status concerning the production of hot nuclei above 5 MeV temperature, concentrating mainly on the possible experimental evidences for the attainment of a critical temperature, on the existence of dynamical limitations to the energy deposition and on the experimental signatures for the formation of hot spinning nuclei. The data strongly suggest a nuclear disassembly in collisions involving very heavy ions at moderate incident velocities. Furthermore, hot nuclei seem to be quite stable against rotation on a short time scale. (author) 26 refs.; 12 figs

  2. UTILIZATION OF TORAY FLY ASH AS FILLER SUBSTITUTION IN THE HOT ROLLED SHEET-WEARING COURSE (HRS-WC MIXTURE

    Directory of Open Access Journals (Sweden)

    F. Candra

    2012-02-01

    Full Text Available In road construction materials, the utilization of fly ash as additive materials is limited and also small in quantity, while the disposal of fly ash is quite high. An abundance of fly ash can be found at PT Toray Company in Jakarta and Surabaya. Toray fly ash is disposed coal ash resulting from coal-fired electricity generating power plants. Toray fly ash in this research is used as substitute mineral filler in asphalt paving mixtures. Research on utilization of Toray fly ash as filler is conducted in the Hot Rolled Sheet – Wearing Course Mixture.  Filler content in the HRS –WC mixture is 9%. Variations of Toray fly ash in the mixture tested are 0%, 25%, 50%, 75%, 100% and the variations of asphalt content are 6%, 6.5%, 7%, 7.5%, 8%. Marshall test is  performed to determine the Optimum Asphalt Content  and Marshall Stability, Indirect Tensile Strength (ITS test and Tensile Strength Ratio (TSR to select the optimum Toray fly ash utilization in the mixture based on the moisture susceptibility of specimens. The research results show that in variations of 0%, 25%, 50%, 75% and 100% Toray fly ash in the HRS-WC Mixture, the Optimum Asphalt Contents are at 6.8%, 7.0%, 7.0%, 7.1% and 7.6%  and Marshall Stability values of the variations are 1649 kg, 1541 kg, 1568 kg, 1678 kg, 1718 kg respectively. TSR values in variations of Toray fly ash are 98.32%, 90.28%, 89.38%, 87.62%, 64.71% respectively, with Minimum TSR value required is 80%. Based on the overall parameters, the optimum Toray fly ash utilization in the HRS-WC Mixture recommended is 75% of Toray fly ash at 7.1% Optimum Asphalt Content.

  3. Ionospheric hot spot at high latitudes

    International Nuclear Information System (INIS)

    Schunk, R.W.; Sojka, J.J.

    1982-01-01

    A hot spot (or spots) can occur in the high-latitude ionosphere depending on the plasma convection pattern. The hot spot corresponds to a small magnetic local time-magnetic latitude region of elevated ion temperatures located near the dusk and/or dawn meridians. For asymmetric convection electric field patterns, with enhanced flow in either the dusk or dawn sector of the polar cap, a single hot spot should occur in association with the strong convection cell. However, on geomagnetically disturbed days, two strong convection cells can occur, and hence, two hot spots should exist. The hot spot should be detectable when the electric field in the strong convection cell exceeds about 40 mV m -1 . For electric fields of the order of 100 mV m -1 in the convection cell, the ion temperature in the hot spot is greatest at low altitudes, reaching 4000 0 K at 160 km, and decreases with altitude in the F-region. An ionospheric hot spot (or spots) can be expected at all seasons and for a wide range of solar cycle conditions

  4. 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.

  5. 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

  6. Improvement of high-temperature thermomechanical treatment of the rolled section made of VT3-1 alloy

    International Nuclear Information System (INIS)

    Gavze, A.L.; Korostelev, Yu.P.

    2002-01-01

    Changes in mechanical properties and structure are investigated in alloy VT3-1 rods produced with the use of high temperature thermomechanical treatment (HTMT) on their heating and deformation during straightening as well as during preliminary hot deformation of the billets on a helical rolling mill (HRM). It is stated that the straightening at 550-700 deg C with elongation of ∼ 2% results in some decrease of ultimate strength and in essential enhancement of plasticity and impact strength. In a similar manner, preliminary rolling on HRM affects the properties of rods after final heat treatment. It is shown that rod production according to the experimental processing procedure increases the quality of the rods and can be realized when manufacturing rolled products of alloy VT3-1 with the use of HTMT [ru

  7. High Temperature Chemistry at NASA: Hot Topics

    Science.gov (United States)

    Jacobson, Nathan S.

    2014-01-01

    High Temperature issues in aircraft engines Hot section: Ni and Co based Superalloys Oxidation and Corrosion (Durability) at high temperatures. Thermal protection system (TPS) and RCC (Reinforced Carbon-Carbon) on the Space Shuttle Orbiter. High temperatures in other worlds: Planets close to their stars.

  8. 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.

  9. Roll-to-roll coated PBI membranes for high temperature PEM fuel cells

    DEFF Research Database (Denmark)

    Steenberg, Thomas; Hjuler, Hans Aage; Terkelsen, Carina

    2012-01-01

    We employed roll-to-roll coating in the preparation of 40 μm thick poly[2,2′(m-phenylene)-5,5′bibenzimidazole] (PBI) films for fuel cells using both knife-coating (KC) and slot-die (SD) coating. The films were coated directly from a 9% (w/w) solution of PBI in dimethylacetamide onto a sacrificial...

  10. Heat transfer modeling in asymmetrical sheet rolling of aluminium alloys with ultra high shear strain

    Directory of Open Access Journals (Sweden)

    Pesin Alexander

    2016-01-01

    Full Text Available Asymmetrical sheet rolling is a method of severe plastic deformation (SPD for production of aluminium alloys with UFG structure. Prediction of sheet temperature during SPD is important. The temperature of sheet is changed due to the conversion of mechanical work into heat through sliding on contact surfaces and high shear strain. Paper presents the results of FEM simulation of the effect of contact friction, rolling speed and rolls speed ratio on the heating of aluminium sheets during asymmetrical rolling.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Highly flexible indium zinc oxide electrode grown on PET substrate by cost efficient roll-to-roll sputtering process

    International Nuclear Information System (INIS)

    Park, Yong-Seok; Kim, Han-Ki; Jeong, Soon-Wook; Cho, Woon-Jo

    2010-01-01

    We have investigated the characteristics of flexible indium zinc oxide (IZO) electrode grown on polyethylene terephthalate (PET) substrates using a specially designed roll-to-roll (RTR) sputtering system for use in flexible optoelectronics. It was found that both electrical and optical properties of the flexible IZO electrode were critically dependent on the DC power and Ar/O 2 flow ratio during the roll-to-roll sputtering process. At optimized conditions (constant working pressure of 3 mTorr, Ar/O 2 flow ratio of Ar at only 30 sccm, DC power 800 W and rolling speed at 0.1 cm/s) the flexible IZO electrode exhibits a sheet resistance of 17.25 Ω/sq and an optical transmittance of 89.45% at 550 nm wavelength. Due to the low PET substrate temperature, which is effectively maintained by cooling drum system, all IZO electrodes showed an amorphous structure regardless of the DC power and Ar/O 2 flow ratio. Furthermore, the IZO electrodes grown at optimized condition exhibited superior flexibility than the conventional amorphous ITO electrodes due to its stable amorphous structure. This indicates that the RTR sputter grown IZO electrode is a promising flexible electrode that can substitute for the conventional ITO electrode, due to its low resistance, high transparency, superior flexibility and fast preparation by the RTR process.

  18. HOT STARS WITH HOT JUPITERS HAVE HIGH OBLIQUITIES

    International Nuclear Information System (INIS)

    Winn, Joshua N.; Albrecht, Simon; Fabrycky, Daniel; Johnson, John Asher

    2010-01-01

    We show that stars with transiting planets for which the stellar obliquity is large are preferentially hot (T eff > 6250 K). This could explain why small obliquities were observed in the earliest measurements, which focused on relatively cool stars drawn from Doppler surveys, as opposed to hotter stars that emerged more recently from transit surveys. The observed trend could be due to differences in planet formation and migration around stars of varying mass. Alternatively, we speculate that hot-Jupiter systems begin with a wide range of obliquities, but the photospheres of cool stars realign with the orbits due to tidal dissipation in their convective zones, while hot stars cannot realign because of their thinner convective zones. This in turn would suggest that hot Jupiters originate from few-body gravitational dynamics and that disk migration plays at most a supporting role.

  19. 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)

  20. High throughput in situ scattering of roll-to-roll coated functional polymer films

    DEFF Research Database (Denmark)

    Andreasen, Jens Wenzel

    2017-01-01

    The development of conjugated polymers for organic electronics and photovoltaics has relied heavily on advanced X-ray scattering techniques almost since the earliest studies in the field. Almost from the beginning, structural studies focused on how the polymers self-organize in thin films......, and the relation between chemical configuration of the polymer, structure and performance. This chapter presents the latest developments where structural analysis is applied as in situ characterization of structure formation during roll-to-roll coating of photoactive layers for solar cells....

  1. 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)

  2. 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.

  3. The feasibility of bonding aluminum alloy 6061 via hot isostatic pressing (HIP)/rolling

    International Nuclear Information System (INIS)

    Fenolietto, R.A.

    1991-01-01

    The advantage of developing a HIP bonding process for dispersion fuel plates is that applying a thin cladding in a more uniform manner could allow the upper limit for LEU U 3 Si-Al dispersion fuel plate densities to be overcome. Since much less mechanical deformation would be required, the existing process limitations on the density could be removed, theoretically allowing more fuel to be added. These increases are, of course, subject to irradiation behavior of the higher loadings which is not addressed in this paper. Initial results indicate that aluminum Alloy 6061 can be successfully bonded by seal welding via electron beam (EB), HIPping, and finishing with a limited amount of rolling. (orig.)

  4. High density high-TC ceramic superconductors by hot pressing

    International Nuclear Information System (INIS)

    Mak, S.; Chaklader, A.C.D.

    1989-01-01

    High density and high T C superconductor specimens, YBa 2 Cu 3 O x , have been produced by hot-pressing. The factors studied are the effect of hot pressing on the density, the oxygen stoichiometry, the crystal structure, and the critical temperature. Hot pressing followed by heat treatment increased the density of the specimen to 93%. The hot pressing itself did not significantly affect the oxygen content in the specimen, and although the crystal structure appeared to be orthorhombic, the specimens were not superconducting above liquid nitrogen temperature. The superconductivity was restored after head treatment in oxygen. The highest critical temperature (T C ) of the hot pressed pellets was 82K, which was slightly lower than the T C that could be obtained with the cold pressed/sintered pellets. (6 refs., 5 figs., tab.)

  5. 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)

  6. 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)

  7. 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.

  8. Disposable photonic integrated circuits for evanescent wave sensors by ultra-high volume roll-to-roll method.

    Science.gov (United States)

    Aikio, Sanna; Hiltunen, Jussi; Hiitola-Keinänen, Johanna; Hiltunen, Marianne; Kontturi, Ville; Siitonen, Samuli; Puustinen, Jarkko; Karioja, Pentti

    2016-02-08

    Flexible photonic integrated circuit technology is an emerging field expanding the usage possibilities of photonics, particularly in sensor applications, by enabling the realization of conformable devices and introduction of new alternative production methods. Here, we demonstrate that disposable polymeric photonic integrated circuit devices can be produced in lengths of hundreds of meters by ultra-high volume roll-to-roll methods on a flexible carrier. Attenuation properties of hundreds of individual devices were measured confirming that waveguides with good and repeatable performance were fabricated. We also demonstrate the applicability of the devices for the evanescent wave sensing of ambient refractive index. The production of integrated photonic devices using ultra-high volume fabrication, in a similar manner as paper is produced, may inherently expand methods of manufacturing low-cost disposable photonic integrated circuits for a wide range of sensor applications.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. High-strength high-conductivity Cu-Nb microcomposite sheet fabricated via multiple roll bonding

    International Nuclear Information System (INIS)

    Jha, S.C.; Delagi, R.G.; Forster, J.A.; Krotz, P.D.

    1993-01-01

    Copper-niobium microcomposites are a new class of high-strength high-conductivity materials that have attractive properties for room- and elevated-temperature applications. Since Nb has little solid solubility in Cu, addition of Nb to Cu does not affect its conductivity. Copper-niobium microcomposites are melted and cast so that the microstructure of cast Cu-Nb ingots consists of 1- to 10 μm Nb dendrites uniformly distributed within the copper matrix. Extensive wire drawing with a true processing strain (η> 12) of Cu-Nb alloy leads to refinement and elongation of Nb dendrites into 1- to 10 nm-thick filaments. The presence of such fine Nb filaments causes a significant increase in the strength of Cu-Nb wires. The tensile strength of heavily drawn Cu-Nb wires was determined to be significantly higher than the values predicted by the rule of mixtures. This article reports the fabrication of high-strength Cu-Nb microcomposite sheet by multiple roll bonding. It is difficult and impractical to attain high processing strains (η>3) by simple cold rolling. In most practical cold-rolling operation, the thickness reduction does not exceed 90 pct (η ≅2). Therefore, innovative processing is required to generate high strength in Cu-Nb microcomposite sheet. Multiple roll bonding of Cu-Nb has been utilized to store high processing strain ( η>10) in the material and refine the Nb particle size within the copper matrix. This article describes the microstructure, mechanical properties, and thermal stability of roll-bonded Cu-Nb microcomposite sheet

  16. 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.%.

  17. 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.

  18. 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)

  19. Influence of Low Speed Rolling Movement on High Electrical Breakdown for Water Dielectric with Microsecond Charging

    International Nuclear Information System (INIS)

    Zhang Zicheng; Zhang Jiande; Yang Jianhua

    2006-01-01

    By means of a coaxial apparatus, high electrical breakdown experiments are carried out in the rest state and the low speed rolling state with microsecond charging and the experimental results are analyzed. The conclusions are: (1) the breakdown stress of water dielectric in the rolling state is in good agreement with that in Martin formula, and so is that in the rest state; (2) the breakdown stress of water dielectric in the rolling state is about 5% higher than that in the rest state; (3) the results simulated with ANSYS demonstrate that the breakdown stress of water dielectric decreases when the bubbles appear near the surface of electrodes; (4) the primary mechanism to increase the breakdown stress of water dielectric in the rolling state is that the bubbles are driven away and the number of bubbles near the surface of electrodes is decreased by rolling movement

  20. 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.

  1. Texture evolution in Nd:YAG-laser welds of AZ31 magnesium alloy hot rolled sheets and its influence on mechanical properties

    International Nuclear Information System (INIS)

    Commin, Lorelei; Dumont, Myriam; Rotinat, Rene; Pierron, Fabrice; Masse, Jean-Eric; Barrallier, Laurent

    2011-01-01

    Research highlights: → AZ31 LBW fusion zone results in Mg 17 (Al-Zn) 12 precipitation, twins formation and {0 0 2} texture modification. → The mechanical properties were reduced after LBW but the fracture occurred in the base metal. → The mechanical properties were reduced after LBW but the fracture occurred in the base metal. → A recovery of elongation and UTS can be achieved by a 300 deg. C/1 h heat treatment. The texture evolution is mainly responsible for the yield strength reduction in the fusion zone. - Abstract: AZ31 hot rolled magnesium alloy presents a strong basal texture. Using laser beam welding (LBW) as a joining process induces high temperature gradients leading to major texture changes. Electron back scattered diffraction (EBSD) was used to study the texture evolution, and tensile tests coupled with speckle interferometry were performed to understand its influence on mechanical properties. The random texture obtained in the LBW fusion zone is mainly responsible for the yield strength reduction.

  2. 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.

  3. 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.

  4. Simplified High-Performance Roll Out Composite Magnetometer Boom, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to NASA's need for compact, low-cost deployable magnetometer booms for CubeSats, Roccor proposes to develop a Simple High-performance Roll-Out Composite...

  5. Novel technique of making thin target foil of high density material via rolling method

    Science.gov (United States)

    Gupta, C. K.; Rohilla, Aman; Singh, R. P.; Singh, Gurjot; Chamoli, S. K.

    2018-05-01

    The conventional rolling method fails to yield good quality thin foils of thicknesses less than 2 mg/cm2 for high density materials with Z ≥ 70 (e.g. gold, lead). A special and improved technique has been developed to obtain such low thickness good quality gold foils by rolling method. Using this technique thin gold foils of thickness in the range of 0.850-2.5 mg/cm2 were obtained in the present work. By making use of alcohol during rolling, foils of thickness 1 mg/cm2 can be obtained in shorter time with less effort.

  6. Hot Chips and Hot Interconnects for High End Computing Systems

    Science.gov (United States)

    Saini, Subhash

    2005-01-01

    I will discuss several processors: 1. The Cray proprietary processor used in the Cray X1; 2. The IBM Power 3 and Power 4 used in an IBM SP 3 and IBM SP 4 systems; 3. The Intel Itanium and Xeon, used in the SGI Altix systems and clusters respectively; 4. IBM System-on-a-Chip used in IBM BlueGene/L; 5. HP Alpha EV68 processor used in DOE ASCI Q cluster; 6. SPARC64 V processor, which is used in the Fujitsu PRIMEPOWER HPC2500; 7. An NEC proprietary processor, which is used in NEC SX-6/7; 8. Power 4+ processor, which is used in Hitachi SR11000; 9. NEC proprietary processor, which is used in Earth Simulator. The IBM POWER5 and Red Storm Computing Systems will also be discussed. The architectures of these processors will first be presented, followed by interconnection networks and a description of high-end computer systems based on these processors and networks. The performance of various hardware/programming model combinations will then be compared, based on latest NAS Parallel Benchmark results (MPI, OpenMP/HPF and hybrid (MPI + OpenMP). The tutorial will conclude with a discussion of general trends in the field of high performance computing, (quantum computing, DNA computing, cellular engineering, and neural networks).

  7. 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.

  8. HOT HIGH-MASS ACCRETION DISK CANDIDATES

    International Nuclear Information System (INIS)

    Beuther, H.; Walsh, A. J.; Longmore, S. N.

    2009-01-01

    To better understand the physical properties of accretion disks in high-mass star formation, we present a study of a dozen high-mass accretion disk candidates observed at high spatial resolution with the Australia Telescope Compact Array (ATCA) in the high-excitation (4,4) and (5,5) lines of NH 3 . All of our originally selected sources were detected in both NH 3 transitions, directly associated with CH 3 OH Class II maser emission and implying that high-excitation NH 3 lines are good tracers of the dense gas components in hot-core-type targets. Only the one source that did not satisfy the initial selection criteria remained undetected. From the 11 mapped sources, six show clear signatures of rotation and/or infall motions. These signatures vary from velocity gradients perpendicular to the outflows, to infall signatures in absorption against ultracompact H II regions, to more spherical infall signatures in emission. Although our spatial resolution is ∼1000 AU, we do not find clear Keplerian signatures in any of the sources. Furthermore, we also do not find flattened structures. In contrast to this, in several of the sources with rotational signatures, the spatial structure is approximately spherical with sizes exceeding 10 4 AU, showing considerable clumpy sub-structure at even smaller scales. This implies that on average typical Keplerian accretion disks-if they exist as expected-should be confined to regions usually smaller than 1000 AU. It is likely that these disks are fed by the larger-scale rotating envelope structure we observe here. Furthermore, we do detect 1.25 cm continuum emission in most fields of view. While in some cases weak cm continuum emission is associated with our targets, more typically larger-scale H II regions are seen offset more than 10'' from our sources. While these H II regions are unlikely to be directly related to the target regions, this spatial association nevertheless additionally stresses that high-mass star formation rarely

  9. High-Speed Rolling of AZ31 Magnesium Alloy Having Different Initial Textures

    Science.gov (United States)

    Onuki, Yusuke; Hara, Kenichiro; Utsunomiya, Hiroshi; Szpunar, Jerzy A.

    2015-02-01

    It is known that magnesium alloys can be rolled up to a large thickness reduction and develop a unique texture when the rolling speed is high (>1000 m/min). In order to understand the texture formation mechanism during high-strain-rate deformation, high-speed rolling of AZ31 magnesium alloy samples having different initial textures was conducted. The main components of the textures after the rolling were the RD-split basal, which consisted of 10°-20° inclining basal poles from the normal direction toward the rolling direction of the sheet, regardless of the different initial textures. With preheating at 473 K, all the samples were rolled without cracking while all were cracked when preheating was not applied. The optical micrographs and EBSD measurements showed a significant amount of twins and the cracks that developed along the shear bands consisted with laminated twins. Based on the texture simulation using the visco-plastic self-consistent model, it is concluded that the rapid development of the RD-split basal component from the initial basal alignment along the transverse direction was attributable to the tension twinning, The effect of the initial texture on the crack formation can be explained by the activation of the twinning system.

  10. Develop Roll-to-Roll Manufacturing Process of ZrO2 Nanocrystals/Acrylic Nanocomposites for High Refractive Index Applications

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Pooran C [ORNL; Compton, Brett G [ORNL; Li, Jianlin [ORNL; Jellison Jr, Gerald Earle [ORNL; Duty, Chad E [ORNL

    2015-04-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop and evaluate ZrO2/acrylic nanocomposite coatings for integrated optoelectronic applications. The formulations engineered to be compatible with roll-to-roll process were evaluated in terms of optical and dielectric properties. The uniform distribution of the ZrO2 nanocrystals in the polymer matrix resulted in highly tunable refractive index and dielectric response suitable for advanced photonic and electronic device applications.

  11. High-throughput roll-to-roll X-ray characterization of polymer solar cell active layers

    DEFF Research Database (Denmark)

    Böttiger, Arvid P.L.; Jørgensen, Mikkel; Menzel, Andreas

    2012-01-01

    Synchrotron-based X-rays were used to probe active materials for polymer solar cells on flexible polyester foil. The active material was coated onto a flexible 130 micron thick polyester foil using roll-to-roll differentially pumped slot-die coating and presented variation in composition, thickness...

  12. Roll-to-Roll Slot–Die Coated Organic Photovoltaic (OPV) Modules with High Geometrical Fill Factors

    NARCIS (Netherlands)

    Galagan, Y.; Fledderus, H.; Gorter, H.; Mannetje, H.H. 't; Shanmugam, S.; Mandamparambil, R.; Bosman, J.; Rubingh, J.M.; Teunissen, J.P.; Salem, A.; Vries, I.G. de; Andriessen, R.; Groen, W.A.

    2015-01-01

    Flexible semi-transparent organic photovoltaic (OPV) modules were manufactured by roll-to-roll slot–die coating of three functional layers [ZnO, photoactive layer, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)] and either the screen printing or inkjet printing of the top

  13. Ultrafine Structure and High Strength in Cold-Rolled Martensite

    DEFF Research Database (Denmark)

    Huang, Xiaoxu; Morito, S.; Hansen, Niels

    2012-01-01

    Structural refinement by cold rolling (10 to 80 pct reductions) of interstitial free (IF) steel containing Mn and B has been investigated from samples with different initial structures: (a) lath martensite, (b) coarse ferrite (grain size 150 mu m), and (c) fine ferrite (22 mu m). Unalloyed IF steel....... At low to medium strains, lath martensite transforms into a cell block structure composed of cell block boundaries and cell boundaries with only a negligible change in strength. At medium to large strains, cell block structures in all samples refine with increasing strain and the hardening rate...... is constant (stage IV). A strong effect of the initial structure is observed on both the structural refinement and the strength increase. This effect is largest in lath martensite and smallest in unalloyed ferrite. No saturation in structural refinement and strength is observed. The discussion covers...

  14. 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.

  15. 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).

  16. 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...

  17. 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).

  18. Fluid-structure interaction of a rolling restrained body of revolution at high angles of attack

    Science.gov (United States)

    Degani, D.; Ishay, M.; Gottlieb, O.

    2017-03-01

    The current work investigates numerically rolling instabilities of a free-to-roll slender rigid-body of revolution placed in a wind tunnel at a high angle of attack. The resistance to the roll moment is represented by a linear torsion spring and equivalent linear damping representing friction in the bearings of a simulated wind tunnel model. The body is subjected to a three-dimensional, compressible, laminar flow. The full Navier-Stokes equations are solved using the second-order implicit finite difference Beam-Warming scheme, adapted to a curvilinear coordinate system, whereas the coupled structural second order equation of motion for roll is solved by a fourth-order Runge-Kutta method. The body consists of a 3.5-diameter tangent ogive forebody with a 7.0-diameter long cylindrical afterbody extending aft of the nose-body junction to x/D = 10.5. We describe in detail the investigation of three angles of attack 20°, 40°, and 65°, at a Reynolds number of 30 000 (based on body diameter) and a Mach number of 0.2. Three distinct configurations are investigated as follows: a fixed body, a free-to-roll body with a weak torsion spring, and a free-to-roll body with a strong torsion spring. For each angle of attack the free-to-roll configuration portrays a distinct and different behavior pattern, including bi-stable limit-cycle oscillations. The bifurcation structure incorporates both large and small amplitude periodic roll oscillations where the latter lose their periodicity with increasing stiffness of the restraining spring culminating with distinct quasiperiodic oscillations. We note that removal of an applied upstream disturbance for a restrained body does not change the magnitude or complexity of the oscillations or of the flow patterns along the body. Depending on structure characteristics and flow conditions even a small rolling moment coefficient at the relatively low angle of attack of 20° may lead to large amplitude resonant roll oscillations.

  19. Pose Measurement Method and Experiments for High-Speed Rolling Targets in a Wind Tunnel

    Directory of Open Access Journals (Sweden)

    Zhenyuan Jia

    2014-12-01

    Full Text Available High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°.

  20. Pose measurement method and experiments for high-speed rolling targets in a wind tunnel.

    Science.gov (United States)

    Jia, Zhenyuan; Ma, Xin; Liu, Wei; Lu, Wenbo; Li, Xiao; Chen, Ling; Wang, Zhengqu; Cui, Xiaochun

    2014-12-12

    High-precision wind tunnel simulation tests play an important role in aircraft design and manufacture. In this study, a high-speed pose vision measurement method is proposed for high-speed and rolling targets in a supersonic wind tunnel. To obtain images with high signal-to-noise ratio and avoid impacts on the aerodynamic shape of the rolling targets, a high-speed image acquisition method based on ultrathin retro-reflection markers is presented. Since markers are small-sized and some of them may be lost when the target is rolling, a novel markers layout with which markers are distributed evenly on the surface is proposed based on a spatial coding method to achieve highly accurate pose information. Additionally, a pose acquisition is carried out according to the mentioned markers layout after removing mismatching points by Case Deletion Diagnostics. Finally, experiments on measuring the pose parameters of high-speed targets in the laboratory and in a supersonic wind tunnel are conducted to verify the feasibility and effectiveness of the proposed method. Experimental results indicate that the position measurement precision is less than 0.16 mm, the pitching and yaw angle precision less than 0.132° and the roll angle precision 0.712°.

  1. The high albedo of the hot Jupiter Kepler-7b

    DEFF Research Database (Denmark)

    Demory, B.-O.; Seager, S.; Madhusudhan, N.

    2011-01-01

    Hot Jupiters are expected to be dark from both observations (albedo upper limits) and theory (alkali metals and/or TiO and VO absorption). However, only a handful of hot Jupiters have been observed with high enough photometric precision at visible wavelengths to investigate these expectations....... The NASA Kepler mission provides a means to widen the sample and to assess the extent to which hot Jupiter albedos are low. We present a global analysis of Kepler-7 b based on Q0-Q4 data, published radial velocities, and asteroseismology constraints. We measure an occultation depth in the Kepler bandpass...

  2. 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.

  3. Making Ends Meet: Flow Synthesis as the Answer to Reproducible High-Performance Conjugated Polymers on the Scale that Roll-to-Roll Processing Demands

    DEFF Research Database (Denmark)

    Helgesen, Martin; Carlé, Jon Eggert; Benatto, Gisele Alves dos Reis

    2015-01-01

    reaction times down to 10 min afforded PBDTTTz-4 with high molecular weight and a constant quality. The flow method enables full control of the molecular weight via tuning of the flow speed, catalyst loading, and temperature and avoids variation in materials’ quality associated with conventional batch......Continuous flow methods are employed for the controlled polymerization of the roll-to-roll (R2R) compatible polymer PBDTTTz-4 including optimization and upscaling experiments. The polymerization rate and materials’ quality can be increased significantly with the continuous fl ow method where...

  4. 76 FR 7546 - Certain Hot-Rolled Carbon Steel Flat Products From Brazil: Rescission of Countervailing Duty...

    Science.gov (United States)

    2011-02-10

    ..., through December 31, 2009. Since Nucor Corporation (Nucor) was the only party that requested a review of... administrative review. This rescission is based on Nucor's timely withdrawal of its request for review. DATES... 19 CFR 351.213(b), the Department received a timely request from Nucor, a domestic producer of hot...

  5. Slot-die Coating of a High Performance Copolymer in a Readily Scalable Roll Process for Polymer Solar Cells

    DEFF Research Database (Denmark)

    Helgesen, Martin; Carlé, Jon Eggert; Krebs, Frederik C

    2013-01-01

    reported compact coating/printing machine, which enables the preparation of PSCs that are directly scalable with full roll-to-roll processing. The positioning of the side-chains on the thiophene units proves to be very significant in terms of solubility of the polymers and consequently has a major impact...... on the device yield and process control. The most successful processing is accomplished with the polymer, PDTSTTz-4, that has the side-chains situated in the 4-position on the thiophene units. Inverted PSCs based on PDTSTTz-4 demonstrate high fill factors, up to 59%, even with active layer thicknesses well...... above 200 nm. Power conversion efficiencies of up to 3.5% can be reached with the roll-coated PDTSTTz-4:PCBM solar cells that, together with good process control and high device yield, designate PDTSTTz-4 as a convincing candidate for high-throughput roll-to-roll production of PSCs....

  6. 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...

  7. High chromium nickel base alloys hot cracking susceptibility

    International Nuclear Information System (INIS)

    Tirand, G.; Primault, C.; Robin, V.

    2014-01-01

    High Chromium nickel based alloys (FM52) have a higher ductility dip cracking sensitivity. New filler material with higher niobium and molybdenum content are developed to decrease the hot crack formation. The behavior of these materials is studied by coupling microstructural analyses and hot cracking test, PVR test. The metallurgical analyses illustrate an Nb and Mo enrichment of the inter-dendritic spaces of the new materials. A niobium high content (FM52MSS) induces the formation of primary carbide at the end of solidification. The PVR test reveal a solidification crack sensitivity of the new materials, and a lowest ductility dip cracking sensitivity for the filler material 52MSS. (authors)

  8. 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

  9. Influence of Hot-Working Conditions on High-Temperature Properties of a Heat-Resistant Alloy

    Science.gov (United States)

    Ewing, John F; Freeman, J W

    1957-01-01

    The relationships between conditions of hot-working and properties at high temperatures and the influence of the hot-working on response to heat treatment were investigated for an alloy containing nominally 20 percent molybdenum, 2 percent tungsten, and 1 percent columbium. Commercially produced bar stock was solution-treated at 2,200 degrees F. to minimize prior-history effects and then rolled at temperatures of 2,200 degrees, 2,100 degrees, 2,000 degrees, 1,800 degrees, and 1,600 degrees F. Working was carried out at constant temperature and with incremental decreases in temperature simulating a falling temperature during hot-working. In addition, a few special repeated cyclic conditions involving a small reduction at high temperature followed by a small reduction at a low temperature were used to study the possibility of inducing very low strengths by the extensive precipitation accompanying such properties. Most of the rolling was done in open passes with a few check tests being made with closed passes. Heat treatments at both 2,050 degrees and 2,200 degrees F. subsequent to working were used to study the influence on response to heat treatment.

  10. NUMERICAL EVALUATION OF TEMPERATURE DISTRIBUTION IN THE ROLLING MILL ROLLS

    Directory of Open Access Journals (Sweden)

    José Claudino de Lira Júnior

    2013-06-01

    Full Text Available In hot rolling processes occur changes in the profile of the rolling mill rolls (expansion and contraction and constant wear due to mechanical stress and continuous thermal cycles of heating/cooling caused by contact rolled material- working roll and the cooling system by water jets in their surface, decreasing their lifetime. This paper presents a computational model to simulate the thermal performance of rolling mill rolls. The model was developed using the finite volume method for a transient two-dimensional system and allows calculating the temperature distribution of the rolling mill rolls under various conditions of service. Here it is investigated the influence of flow rate and temperature of the cooling water on the temperature distribution. The results show that the water temperature has greater influence than the water flow to control the surface temperature of the cylinders.

  11. 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.

  12. Rolling estimations of long range dependence volatility for high frequency S&P500 index

    Science.gov (United States)

    Cheong, Chin Wen; Pei, Tan Pei

    2015-10-01

    This study evaluates the time-varying long range dependence behaviors of the S&P500 volatility index using the modified rescaled adjusted range (R/S) statistic. For better computational result, a high frequency rolling bipower variation realized volatility estimates are used to avoid possible abrupt jump. The empirical analysis findings allow us to understand better the informationally market efficiency before and after the subprime mortgage crisis.

  13. High frequency conductivity of hot electrons in carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Amekpewu, M., E-mail: mamek219@gmail.com [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, S.Y. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Musah, R. [Department of Applied Physics, University for Development Studies, Navrongo (Ghana); Mensah, N.G. [Department of Mathematics, College of Agriculture and Natural Sciences, U.C.C. (Ghana); Abukari, S.S.; Dompreh, K.A. [Department of Physics, College of Agriculture and Natural Sciences, U.C.C. (Ghana)

    2016-05-01

    High frequency conductivity of hot electrons in undoped single walled achiral Carbon Nanotubes (CNTs) under the influence of ac–dc driven fields was considered. We investigated semi-classically Boltzmann's transport equation with and without the presence of the hot electrons’ source by deriving the current densities in CNTs. Plots of the normalized current density versus frequency of ac-field revealed an increase in both the minimum and maximum peaks of normalized current density at lower frequencies as a result of a strong injection of hot electrons. The applied ac-field plays a twofold role of suppressing the space-charge instability in CNTs and simultaneously pumping an energy for lower frequency generation and amplification of THz radiations. These have enormous promising applications in very different areas of science and technology.

  14. 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.

  15. Hot-rolled and cold-finished zirconium and zirconium alloy bars, rod, and wire for nuclear application

    International Nuclear Information System (INIS)

    Anon.

    1981-01-01

    The specification covers hot- and cold-finished zirconium alloy bars, rod, and wire, other than those required for reforging, including rounds, squares, and shapes. One unalloyed grade and three alloy grades for use in nuclear applications are described. The products covered include the following sections and sizes: bars, rounds in coils for subsequent reworking (6.4 to 19 mm) and flats (6.4 to 250 mm); rods, rounds in coils for subsequent reworking (6.4 to 19 mm); wire (9.5 mm). The specification covers ordering information, manufacture, condition, chemical requirements, mechanical properties, corrosion properties, permissible variations in dimensions, significance of numerical limits, lot size, special tests, workmanship, finish, inspection, certification, packaging and marking

  16. A jelly-roll process for high temperature superconducting tapes and wires

    International Nuclear Information System (INIS)

    Tsuei, C.C.; Chi, C.C.; Frey, T.; Mitzi, D.B.; Kazyaka, T.; Haugan, T.; Ye, J.; Patel, S.; Shaw, D.T.; Wu, M.K.

    1992-01-01

    As an alternative to the powder-in-tube method, a new technique called the jelly-roll process is proposed for making high-T c superconducting tapes and wires. A normal-metal sheet coated with high-T c cuprate is configured in a jelly-roll fashion and cold worked into tapes or wires made of alternating cuprate superconductor and normal metal layers. The feasibility of this new process is demonstrated for both the YBa 2 Cu 3 O 7 /Ag and Bi 2 Sr 2 CaCu 2 O 8 /Ag composite systems. The role of reduction in the cross-sectional area by cold-rolling, heat treatment and oxygenation in optimizing T c and J c has been studied. Preliminary results indicate that partialmelt texturing, in the Bi 2 Sr 2 CaCu 2 O 8 /Ag system, results in a relatively field independent J c (H c (H = 0) ∝5 X 10 4 A cm -2 at 4.2 K

  17. A jelly-roll process for high temperature superconducting tapes and wires

    Energy Technology Data Exchange (ETDEWEB)

    Tsuei, C C; Chi, C C; Frey, T; Mitzi, D B; Kazyaka, T [IBM Thomas J. Watson Research Center, Yorktown Heights, NY (United States); Haugan, T; Ye, J; Patel, S; Shaw, D T [New York State Inst. on Superconductivity, SUNY, Buffalo, Amherst, NY (United States); Wu, M K [Dept. of Physics, National Tsing Hua Univ., Hsinchu (Taiwan)

    1992-07-01

    As an alternative to the powder-in-tube method, a new technique called the jelly-roll process is proposed for making high-T[sub c] superconducting tapes and wires. A normal-metal sheet coated with high-T[sub c] cuprate is configured in a jelly-roll fashion and cold worked into tapes or wires made of alternating cuprate superconductor and normal metal layers. The feasibility of this new process is demonstrated for both the YBa[sub 2]Cu[sub 3]O[sub 7]/Ag and Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8]/Ag composite systems. The role of reduction in the cross-sectional area by cold-rolling, heat treatment and oxygenation in optimizing T[sub c] and J[sub c] has been studied. Preliminary results indicate that partialmelt texturing, in the Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8]/Ag system, results in a relatively field independent J[sub c] (H< or approx.7T) with J[sub c](H = 0) [proportional to]5 X 10[sup 4] A cm[sup -2] at 4.2 K.

  18. Roll-to-Roll Laser-Printed Graphene-Graphitic Carbon Electrodes for High-Performance Supercapacitors.

    Science.gov (United States)

    Kang, Sangmin; Lim, Kyungmi; Park, Hyeokjun; Park, Jong Bo; Park, Seong Chae; Cho, Sung-Pyo; Kang, Kisuk; Hong, Byung Hee

    2018-01-10

    Carbon electrodes including graphene and thin graphite films have been utilized for various energy and sensor applications, where the patterning of electrodes is essentially included. Laser scribing in a DVD writer and inkjet printing were used to pattern the graphene-like materials, but the size and speed of fabrication has been limited for practical applications. In this work, we devise a simple strategy to use conventional laser-printer toner materials as precursors for graphitic carbon electrodes. The toner was laser-printed on metal foils, followed by thermal annealing in hydrogen environment, finally resulting in the patterned thin graphitic carbon or graphene electrodes for supercapacitors. The electrochemical cells made of the graphene-graphitic carbon electrodes show remarkably higher energy and power performance compared to conventional supercapacitors. Furthermore, considering the simplicity and scalability of roll-to-roll (R2R) electrode patterning processes, the proposed method would enable cheaper and larger-scale synthesis and patterning of graphene-graphitic carbon electrodes for various energy applications in the future.

  19. OUTFLOW AND HOT DUST EMISSION IN HIGH-REDSHIFT QUASARS

    International Nuclear Information System (INIS)

    Wang, Huiyuan; Xing, Feijun; Wang, Tinggui; Zhou, Hongyan; Zhang, Kai; Zhang, Shaohua

    2013-01-01

    Correlations of hot dust emission with outflow properties are investigated, based on a large z ∼ 2 non-broad absorption line quasar sample built from the Wide-field Infrared Survey and the Sloan Digital Sky Survey data releases. We use the near-infrared slope and the infrared to UV luminosity ratio to indicate the hot dust emission relative to the emission from the accretion disk. In our luminous quasars, these hot dust emission indicators are almost independent of the fundamental parameters, such as luminosity, Eddington ratio and black hole mass, but moderately dependent on the blueshift and asymmetry index (BAI) and FWHM of C IV lines. Interestingly, the latter two correlations dramatically strengthen with increasing Eddington ratio. We suggest that, in high Eddington ratio quasars, C IV regions are dominated by outflows so the BAI and FWHM (C IV) can reliably reflect the general properties and velocity of outflows, respectively. In low Eddington ratio quasars, on the other hand, C IV lines are primarily emitted by virialized gas so the BAI and FWHM (C IV) become less sensitive to outflows. Therefore, the correlations for the highest Eddington ratio quasars are more likely to represent the true dependence of hot dust emission on outflows and the correlations for the entire sample are significantly diluted by the low Eddington ratio quasars. Our results show that an outflow with a large BAI or velocity can double the hot dust emission on average. We suggest that outflows either contain hot dust in themselves or interact with the dusty interstellar medium or torus

  20. 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.

  1. 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

  2. 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.

  3. Simulation and Analysis of Passive Rolling Compensation of High Sea Salvage System

    Directory of Open Access Journals (Sweden)

    Lin Liqun

    2017-01-01

    Full Text Available Method and device of a flexible interception and salvage system was introduced in this paper. In order to study the effect of wave motion on salvage operation, we proposed a passive wave compensation scheme that utilizes a combination of variable-pitch cylinders and accumulators, and established the mathematical vibration model of the rolling motion of the salvage compensation system. With the relationships between the stiffness coefficient and the accumulator parametric of passive compensated gas-liquid system, we determined the effective compensation stiffness range through Mathematica simulation analysis. The relationship between the roll displacement of the salvage arm and the initial volume Vo of the accumulator has been analysed. The results show that the accumulatorVo in a certain range has a great influence on the passive compensation. However, when the volume is greater than 20m3, the compensation effect is weakened, and tend to a certain value, irrespective of the passive system accumulator volume capacity, it does not achieve full compensation. The results have important guidance on the design and optimization of rolling passive compensation of the practical high sea salvage system.

  4. Deformation mechanism study of a hot rolled Zr-2.5Nb alloy by transmission electron microscopy. I. Dislocation microstructures in as-received state and at different plastic strains

    Energy Technology Data Exchange (ETDEWEB)

    Long, Fei; Daymond, Mark R., E-mail: mark.daymond@queensu.ca; Yao, Zhongwen [Department of Mechanical and Materials Engineering, Queen' s University Kingston, Ontario K7L 3N6 (Canada)

    2015-03-07

    Thin foil dog bone samples prepared from a hot rolled Zr-2.5Nb alloy have been deformed by tensile deformation to different plastic strains. The development of slip traces during loading was observed in situ through SEM, revealing that deformation starts preferentially in certain sets of grains during the elastic-plastic transition region. TEM characterization showed that sub-grain boundaries formed during hot rolling consisted of screw 〈a〉 dislocations or screw 〈c〉 and 〈a〉 dislocations. Prismatic 〈a〉 dislocations with large screw or edge components have been identified from the sample with 0.5% plastic strain. Basal 〈a〉 and pyramidal 〈c + a〉 dislocations were found in the sample that had been deformed with 1.5% plastic strain, implying that these dislocations require larger stresses to be activated.

  5. 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

  6. Hot nuclei with high spin states in collisions between heavy nuclei

    International Nuclear Information System (INIS)

    Galin, J.

    1991-01-01

    In the first part of this contribution we have shown that pretty hot nuclei could be obtained in peripheral collisions of Kr+Au. The collisions considered in the chosen example give rise to a nucleus of Z=28 with a kinetic energy of 1600 MeV (i.e. a velocity close to 27 MeV/u to be compared with the 32 MeV/u of the beam). The excitation energy deposited in the non-detected target like-nucleus, deduced from the neutron multiplicity measurements, amounts to 700 MeV (T= 6 MeV). In the second part of the contribution one used the well known properties of fission, and particularly its sensitivity to spin, to show in a qualitative way that pretty high spin values are into play. A more quantitative analysis together with additional measurements are still needed in order to infer precise figures of spin. It can be noted that for the 29 MeV/u Pb+Au reaction 1 max amounts to 1700 ℎ. If we assume that the sticking or rolling conditions can be fulfilled for initial angular momenta of about 2/3 1 max , then a projectile-like (and its target partner) could acquire an intrinsic spin of about 160 ℎ. The behavior of a Pb-like nucleus brought in such an exotic state (T=6 MeV and J=160ℎ)) is certainly worth to be studied in detail. It is also worth recalling that, when obtained in peripheral collisions, the hot nuclei thus formed do not suffer much initial compression at variance with what happens in more central collisions. There is thus an interesting field to be explored of hot, high spin but uncompressed nuclei

  7. Comparison of Rolling Moment Characteristics During Roll Oscillations for a Low and a High Aspect Ratio Configuration

    Science.gov (United States)

    Brandon, Jay M.; Foster, John V.; Shah, Gautam H.; Gato, William; Wilborn, James E.

    2004-01-01

    Improvements in testing and modeling of nonlinear and unsteady aerodynamic effects for flight dynamics predictions of vehicle performance is critical to enable the design and implementation of new, innovative vehicle concepts. Any configuration which exhibits significant flow separation, nonlinear aerodynamics, control interactions or attempts maneuvering through one or more conditions such as these is, at present, a challenge to test, model or predict flight dynamic responses prior to flight. Even in flight test experiments, adequate models are not available to study and characterize the complex nonlinear and time-dependent flow effects occurring during portions of the maneuvering envelope. Traditionally, airplane designs have been conducted to avoid these areas of the flight envelope. Better understanding and characterization of these flight regimes may not only reduce risk and cost of flight test development programs, but also may pave the way for exploitation of those characteristics that increase airplane capabilities. One of the hurdles is that the nonlinear/unsteady effects appear to be configuration dependent. This paper compares some of the dynamic aerodynamic stability characteristics of two very different configurations - representative of a fighter and a transport airplane - during dynamic body-axis roll wind tunnel tests. The fighter model shows significant effects of oscillation frequency which are not as apparent for the transport configuration.

  8. INFLUENCE OF CONFIGURATION OF EQUIPMENT OF A HIGH-SPEED ROD MILL ON QUALITATIVE CHARACTERISTICS OF HIGH-CARBON ROLLED WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available The quality of output production has increased in the result of new arrangement of finishing train of block construction of rod mill of RUP «BMZ». Additional using in rolled line of reducing-sizing block at production of high- carbon rolled wire enabled to reduce the dispersion of mechanical characteristics, to decrease the depth of decarburized layer.

  9. Epitaxial YBa2Cu3O7 films on rolled-textured metals for high temperature superconducting applications

    International Nuclear Information System (INIS)

    Norton, D.P.; Park, C.; Prouteau, C.

    1998-04-01

    The epitaxial growth of high temperature superconducting (HTS) films on rolled-textured metal represents a viable approach for long-length superconducting tapes. Epitaxial, 0.5 microm thick YBa 2 Cu 3 O 7 (YBCO) films with critical current densities, J c , greater than 1 MA/cm 2 have been realized on rolled-textured (001) Ni tapes with yttria-stabilized zirconia (YSZ)/CeO 2 oxide buffer layers. This paper describes the synthesis using pulsed-laser deposition (PLD) of epitaxial oxide buffer layers on biaxially-textured metal that comprise the so-called rolling-assisted biaxially-textured substrates (RABiTs trademark). The properties of the buffer and YBa 2 Cu 3 O 7 films on rolled-textured Ni are discussed, with emphasis given to the crystallographic and microstructural properties that determine the superconducting properties of these multilayer structures

  10. 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.

  11. 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.

  12. Microstructural and Material Quality Effects on Rolling Contact Fatigue of Highly Elastic Intermetallic Ball Bearings

    Science.gov (United States)

    DellaCorte, Christopher; Howard, S. Adam; Thomas, Fransua; Stanford, Malcolm K.

    2016-01-01

    Rolling element bearings made from highly-elastic intermetallic materials (HIM)s, such as 60NiTi, are under development for applications that require superior corrosion and shock resistance. Compared to steel, intermetallics have been shown to have much lower rolling contact fatigue (RCF) stress capability in simplified 3-ball on rod (ASTM STP 771) fatigue tests. In the 3-ball tests, poor material quality and microstructural flaws negatively affect fatigue life but such relationships have not been established for full-scale 60NiTi bearings. In this paper, 3-ball-on-rod fatigue behavior of two quality grades of 60NiTi are compared to the fatigue life of full-scale 50mm bore ball bearings made from the same materials. 60NiTi RCF rods with material or microstructural flaws suffered from infant mortality failures at all tested stress levels while high quality 60NiTi rods exhibited no failures at lower stress levels. Similarly, tests of full-scale bearings made from flawed materials exhibited early surface fatigue and through crack type failures while bearings made from high quality material did not fail even in long-term tests. Though the full-scale bearing test data is yet preliminary, the results suggest that the simplified RCF test is a good qualitative predictor of bearing performance. These results provide guidance for materials development and to establish minimum quality levels required for successful bearing operation and life.

  13. Modeling Single Occupant Vehicle Behavior in High-Occupancy Toll (HOT) Facilities

    Science.gov (United States)

    2009-12-14

    High-occupancy toll (HOT) lanes are in operation, under construction, and planned for in several major metropolitan areas. The premise behind HOT lanes is to allow single occupant vehicles (SOVs) to access high occupancy vehicle (HOV) lanes (and theo...

  14. USE OF HIGH SPEED STEEL WORK ROLLS (HSS ON APERAM STECKEL MILL

    Directory of Open Access Journals (Sweden)

    Arísio de Abreu Barbosa

    2013-12-01

    Full Text Available This paper outlines the main actions taken to reinforce the decision to use HSS work rolls on the Aperam Steckel Mill. These are: work roll cooling improvements, systematically analyzing Eddy Current and Ultrasonic non destructive tests, mechanical adjustment of work roll crown and critically examining the rolling process. These actions applied together have contributed to the success of HSS rolls state of the art application, and provide the Steckel Mill with a much improved performance. Significant results have been achieved, such as: increasing of work roll change intervals, increasing of the available production time, a yield gain, a product quality improvement, less working hours needed for the roll grinding operation, etc

  15. Confined recrystallization of high-purity aluminium during accumulative roll bonding of aluminium laminates

    International Nuclear Information System (INIS)

    Chekhonin, Paul; Beausir, Benoît; Scharnweber, Juliane; Oertel, Carl-Georg; Hausöl, Tina; Höppel, Heinz Werner; Brokmeier, Heinz-Günter; Skrotzki, Werner

    2012-01-01

    Aluminium laminates consisting of high-purity aluminium and commercially pure aluminium have been produced by accumulative roll bonding (ARB) at ambient temperature for up to 10 cycles. To study the microstructure and texture development of the high-purity aluminium layers with regard to the shrinking layer thickness during ARB, microstructure and texture investigations were carried out by electron backscatter diffraction and neutron and X-ray diffraction, respectively. While the commercially pure aluminium layers develop an ultrafine-grained microstructure, partial discontinuous recrystallization occurs in the high-purity layers. The texture of the high-purity layers mainly consists of Cube and “Tilted Cube” (tilted with respect to the transverse direction) components. The experimental results are discussed with respect to confined recrystallization in the ARB aluminium laminates.

  16. Influence of rolling direction and carbide precipitation on IGSCC susceptibility in hydrogenated high temperature water

    International Nuclear Information System (INIS)

    Arioka, Koji; Yamada, Takuyo; Terachi, Takumi; Chiba, Goro

    2005-01-01

    IGSCC growth behaviors of austenitic stainless steels in hydrogenated high temperature water were studied using compact type specimens (0.5T for cold worked materials). The effect of cold rolling direction, alloy composition and carbide precipitation on crack growth behaviors was studied in hydrogenated high temperature water. Then, to examine the effect of cold work and carbide precipitation on IGSCC behaviors, the role of grain boundary sliding studied in high temperature air using CT specimens. The similar dependences of carbide precipitation and cold work on IGSCC and creep behaviors suggest that grain boundary sliding might play an important role by itself or in conjunction with other reactions such as crack tip dissolution etc. (author)

  17. Effect of Si content on fatigue fracture behavior of hot-rolled high-silicon steels

    Science.gov (United States)

    Umezawa, Osamu; Kanda, Jyunichi; Yamazaki, Takao

    2017-05-01

    As the Si content was increased from 1.5 to 5 mass%, both the yield stress and ultimate tensile strength were increased, respectively. The work hardening rate was also increased as the increase of Si content. On the contrary, the elongation was decreased as the increase of Si content, and the fracture manner was shifted from ductile to brittle. The 107 cycles fatigue strength was higher as the increase of Si content. The small misorientation distribution as ladder-like was detected in the grains of 1.5 mass%Si steel. Around the grain boundary, the strain incompatibility was detected in the steels containing over 3 mass%Si. The lattice rotation was locally detected in the vicinity of grain boundaries.

  18. Drilling and testing hot, high-pressure wells

    Energy Technology Data Exchange (ETDEWEB)

    MacAndrew, R. (Ranger Oil Ltd, Aberdeen (United Kingdom)); Parry, N. (Phillips Petroleum Company United Kingdom Ltd, Aberdeen (United Kingdom)); Prieur, J.M. (Conoco UK Ltd, Aberdeen (United Kingdom)); Wiggelman, J. (Shell UK Exploration and Production, Aberdeen (United Kingdom)); Diggins, E. (Brunei Shell Petroleum (Brunei Darussalam)); Guicheney, P. (Sedco Forex, Montrouge (France)); Cameron, D.; Stewart, A. (Dowell Schlumberger, Aberdeen (United Kingdom))

    Meticulous planning and careful control of operations are needed to safely drill and test high-temperature, high-pressure (HTHP) wells. Techniques, employed in the Central Graben in the UK sector of the North Sea, where about 50 HTHP wells have been drilled, are examined. Three main areas of activity are covered in this comprehensive review: drilling safety, casing and cementation, and testing. The three issues at the heart of HTHP drilling safety are kick prevention, kick detection and well control. Kicks are influxes of reservoir fluid into the well. Test equipment and operations are divided into three sections: downhole, subsea and surface. Also details are given of how this North Sea experience has been used to help plan a jackup rig modification for hot, high-pressure drilling off Brunei. 16 figs., 32 refs.

  19. On the rolling of hard-to-work iron-cobalt alloys with application of electric current of high density

    International Nuclear Information System (INIS)

    Klimov, K.M.; Mordukhovich, A.M.; Glezer, A.M.; Molotilov, B.V.

    1981-01-01

    Results on experimental fabrication of thin sheets of commercial iron-cobalt 49KF alloy (Se-Co-2%V) without preliminary quenching and intermediate annealings by rolling with application of high-density electric current are considered. It is shown that rolling with application of high-density electric current in the deformation zone permits to obtain thin sheets of difficult-to-form magnetically soft materials without preliminary thermal treatments. Electric current effect on metal in the deformation zone results in the increase of dislocation mobility and facilitates the cross glide [ru

  20. Effect of defect length on rolling contact fatigue crack propagation in high strength steel

    Directory of Open Access Journals (Sweden)

    T. Makino

    2015-10-01

    Full Text Available The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF crack propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR micro CT imaging were conducted. In the case of the defect with the 15 m diameter, flaking life decreased with increasing defect length. In a comparison of the CT image and the SEM view, the shapes of defects and the locations of the horizontal cracks were almost the same respectively. The mechanism of RCF crack propagation was discussed by finite element (FE analysis. Defects led to higher tensile residual stress than that without defects in the region where the defect exists. The shear stress range at 0.1 mm in depth on the middle line of the defect and the range of mode II stress intensity factor at the bottom of a vertical crack increased with increasing defect length.

  1. Highly Efficient TADF Polymer Electroluminescence with Reduced Efficiency Roll-off via Interfacial Exciplex Host Strategy.

    Science.gov (United States)

    Lin, Xingdong; Zhu, Yunhui; Zhang, Baohua; Zhao, Xiaofei; Yao, Bing; Cheng, Yanxiang; Li, Zhanguo; Qu, Yi; Xie, Zhiyuan

    2018-01-10

    Solution-processed organic light-emitting diodes (s-OLED) consisting of TAPC/TmPyPB interfacial exciplex host and polymer PAPTC TADF emitter are prepared, simultaneously displaying ultralow voltages (2.50/2.91/3.51/4.91 V at luminance of 1/100/1000/1000 cd m -2 ), high efficiencies (14.9%, 50.1 lm W -1 ), and extremely low roll-off rates (J 50 of 63.16 mA cm -2 , L 50 of ca. 15000 cd m -2 ). Such performance is distinctly higher than that of pure-PAPTC s-OLED. Compared to pure-PAPTC, the advanced emissive layer structure of TAPC:PAPTC/TmPyPB is unique in much higher PL quantum yield (79.5 vs 36.3%) and nearly 4-fold enhancement in k RISC of the PAPTC emitter to 1.48 × 10 7 s -1 .

  2. Fabrication of a metallic roll stamp with low internal stress and high hardness for large area display applications by a pulse reverse current electroforming process

    International Nuclear Information System (INIS)

    Kim, Joongeok; Han, Jungjin; Kim, Taekyung; Kang, Shinill

    2014-01-01

    With the increasing demand for large scale micro/nano components in the fields of display, energy and electrical devices, etc, the establishment of a roll imprinting process has become a priority. The fabrication of a roll stamp with high dimensional accuracy and uniformity is one of the key issues in the roll imprinting process, because the roll stamp determines the properties of the replicated micro/nano structures. In this study, a method to fabricate a metallic roll stamp with low internal stress, high flatness, and high hardness was proposed by a pulse reverse current (PRC) electroforming process. The effects of PRC electroforming processes on the internal stress, hardness, and grain size of the electroformed stamp were examined, and the optimum process conditions were suggested. As a practical example of the proposed method, various micro-patterns for electronic circuits were fabricated via the roll imprinting process using a PRC electroformed stamp. (paper)

  3. Tension-controlled single-crystallization of copper foils for roll-to-roll synthesis of high-quality graphene films

    Science.gov (United States)

    Jo, Insu; Park, Subeom; Kim, Dongjin; San Moon, Jin; Park, Won Bae; Kim, Tae Hyeong; Hyoun Kang, Jin; Lee, Wonbae; Kim, Youngsoo; Lee, Dong Nyung; Cho, Sung-Pyo; Choi, Hyunchul; Kang, Inbyeong; Park, Jong Hyun; Lee, Jeong Soo; Hong, Byung Hee

    2018-04-01

    It has been known that the crystalline orientation of Cu substrates plays a crucial role in chemical vapor deposition (CVD) synthesis of high-quality graphene. In particular, Cu (1 1 1) surface showing the minimum lattice mismatch with graphene is expected to provide an ideal catalytic reactivity that can minimize the formation of defects, which also induces larger single-crystalline domain sizes of graphene. Usually, the Cu (1 1 1) substrates can be epitaxially grown on single-crystalline inorganic substrates or can be recrystallized by annealing for more than 12 h, which limits the cost and time-effective synthesis of graphene. Here, we demonstrate a new method to optimize the crystalline orientations of vertically suspended Cu foils by tension control during graphene growth, resulting in large-area recrystallization into Cu (1 1 1) surface as the applied tension activates the grain boundary energy of Cu and promotes its abnormal grain growth to single crystals. In addition, we found a clue that the formation of graphene cooperatively assists the recrystallization into Cu (1 1 1) by minimizing the surface energy of Cu. The domain sizes and charge carrier mobility of graphene grown on the single-crystalline Cu (1 1 1) are 5 times and ~50% increased, respectively, in comparison with those of graphene from Cu (1 0 0), indicating that the less lattice mismatch and the lower interaction energy between Cu (1 1 1) and graphene allows the growth of larger single-crystalline graphene with higher charge carrier mobility. Thus, we believe that our finding provides a crucial idea to design a roll-to-roll (R2R) graphene synthesis system where the tension control is inevitably involved, which would be of great importance for the continuous production of high-quality graphene in the future.

  4. Development and evolution of biaxial texture of rolled nickel tapes by ion beam bombardment for high Tc coated conductors

    International Nuclear Information System (INIS)

    Wang, S.S.; Wu, K.; Shi, K.; Liu, Q.; Han, Z.

    2004-01-01

    High quality YBa 2 Cu 3 O 7-x films on metallic substrates with high critical current densities well over 10 6 A/cm 2 can be prepared by the rolling assisted biaxially textured substrates (RABiTS) method. Nickel or its alloys have been used as biaxially textured substrates formed through a specific rolling and high temperature annealing procedures. In this paper, we report a newly developed process for developing biaxial texture in rolled Ni tape by argon ion beam bombardment. It is named the ion-beam structure modification (ISM) process. In the ISM processed Ni foils, X-ray diffraction ω scans showed the full width-half maximum (FWHM) value of the (2 0 0) peak was 5.7 deg. . And the electron back scattering diffraction (EBSP) analysis based on scanning electron microscopy showed good {1 0 0} cubic orientation and the mean grain size was determined as about 25 μm. The texture evolution of rolled Ni foils during ISM process is reported also. For ISM process, local temperature elevation and distribution arises from the ion bombardment, coupled with anisotropic incident ion penetration and propagation as a result of channeling effects in the metal lattice, are expected to play the major roles in the development of grain reorientation in the Ni foil. Due to the simplicity and efficiency of the ISM process, the technique shows a great promise for application in the industrial scale production of long-lengths of superconductor tapes

  5. Effect of Reduction in Thickness and Rolling Conditions on Mechanical Properties and Microstructure of Rolled Mg-8Al-1Zn-1Ca Alloy

    Directory of Open Access Journals (Sweden)

    Yuta Fukuda

    2017-01-01

    Full Text Available A cast Mg-8Al-1Zn-1Ca magnesium alloy was multipass hot rolled at different sample and roll temperatures. The effect of the rolling conditions and reduction in thickness on the microstructure and mechanical properties was investigated. The optimal combination of the ultimate tensile strength, 351 MPa, yield strength, 304 MPa, and ductility, 12.2%, was obtained with the 3 mm thick Mg-8Al-1Zn-1Ca rolled sheet, which was produced with a roll temperature of 80°C and sample temperature of 430°C. This rolling process resulted in the formation of a bimodal structure in the α-Mg matrix, which consequently led to good ductility and high strength, exclusively by the hot rolling process. The 3 mm thick rolled sheet exhibited fine (mean grain size of 2.7 μm and coarse grain regions (mean grain size of 13.6 μm with area fractions of 29% and 71%, respectively. In summary, the balance between the strength and ductility was enhanced by the grain refinement of the α-Mg matrix and by controlling the frequency and orientation of the grains.

  6. 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)

  7. High-Performance Elastically Self-Deployed Roll-Out Solar Array (ROSA), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Deployable Space Systems (DSS) has developed an ultra-lightweight elastically self-deployable roll-out solar array (ROSA) structural platform that when combined with...

  8. The Effect of Rolling As-Cast and Homogenized U-10Mo Samples on the Microstructure Development and Recovery Curves

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-30

    Over the past several years Pacific Northwest National Laboratory (PNNL) has been actively involved in supporting the U.S. Department of Energy National Nuclear Security Administration Office of Material Management and Minimization (formerly Global Threat Reduction Initiative). The U.S. High- Power Research Reactor (USHPRR) project is developing alternatives to existing highly enriched uranium alloy fuel to reduce the proliferation threat. One option for a high-density metal fuel is uranium alloyed with 10 wt% molybdenum (U-10Mo). Forming the U-10Mo fuel plates/foils via rolling is an effective technique and is actively being pursued as part of the baseline manufacturing process. The processing of these fuel plates requires systematic investigation/understanding of the pre- and post-rolling microstructure, end-state mechanical properties, residual stresses, and defects, their effect on the mill during processing, and eventually, their in-reactor performance. In the work documented herein, studies were conducted to determine the effect of cold and hot rolling the as-cast and homogenized U-10Mo on its microstructure and hardness. The samples were homogenized at 900°C for 48 h, then later annealed for several durations and temperatures to investigate the effect on the material’s microstructure and hardness. The rolling of the as-cast plate, both hot and cold, was observed to form a molybdenum-rich and -lean banded structure. The cold rolling was ineffective, and in some cases exacerbated the as-cast defects. The grains elongated along the rolling direction and formed a pancake shape, while the carbides fractured perpendicularly to the rolling direction and left porosity between fractured particles of UC. The subsequent annealing of these samples at sub-eutectoid temperatures led to rapid precipitation of the ' lamellar phase, mainly in the molybdenum-lean regions. Annealing the samples above the eutectoid temperature did not refine the grain size or the banded

  9. 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.

  10. 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.

  11. 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.

  12. High-throughput genotyping of single nucleotide polymorphisms with rolling circle amplification

    Directory of Open Access Journals (Sweden)

    Sun Zhenyu

    2001-08-01

    Full Text Available Abstract Background Single nucleotide polymorphisms (SNPs are the foundation of powerful complex trait and pharmacogenomic analyses. The availability of large SNP databases, however, has emphasized a need for inexpensive SNP genotyping methods of commensurate simplicity, robustness, and scalability. We describe a solution-based, microtiter plate method for SNP genotyping of human genomic DNA. The method is based upon allele discrimination by ligation of open circle probes followed by rolling circle amplification of the signal using fluorescent primers. Only the probe with a 3' base complementary to the SNP is circularized by ligation. Results SNP scoring by ligation was optimized to a 100,000 fold discrimination against probe mismatched to the SNP. The assay was used to genotype 10 SNPs from a set of 192 genomic DNA samples in a high-throughput format. Assay directly from genomic DNA eliminates the need to preamplify the target as done for many other genotyping methods. The sensitivity of the assay was demonstrated by genotyping from 1 ng of genomic DNA. We demonstrate that the assay can detect a single molecule of the circularized probe. Conclusions Compatibility with homogeneous formats and the ability to assay small amounts of genomic DNA meets the exacting requirements of automated, high-throughput SNP scoring.

  13. Modeling Hot-Spot Contributions in Shocked High Explosives at the Mesoscale

    Energy Technology Data Exchange (ETDEWEB)

    Harrier, Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-08-12

    When looking at performance of high explosives, the defects within the explosive become very important. Plastic bonded explosives, or PBXs, contain voids of air and bonder between the particles of explosive material that aid in the ignition of the explosive. These voids collapse in high pressure shock conditions, which leads to the formation of hot spots. Hot spots are localized high temperature and high pressure regions that cause significant changes in the way the explosive material detonates. Previously hot spots have been overlooked with modeling, but now scientists are realizing their importance and new modeling systems that can accurately model hot spots are underway.

  14. Estimation of residual stress in cold rolled iron-disks from strain measurements on the high resolution Fourier diffractometer

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Balagurov, A.M.; Taran, Yu.V.

    1995-01-01

    The results of estimating residual stresses in cold rolled iron disks by measurements with the high resolution Fourier diffractometer (HRFD) at the IBR-2 pulsed reactor are presented. These measurements were made for calibration of magnetic and ultrasonic measurements carried out at the Fraunhofer-Institute for Nondestructive Testing in Saarbrucken (Germany). The tested objects were cold rolled steel disks of 2.5 mm thickness and diameter of about 500 mm used for forming small, gas pressure tanks. Neutron diffraction experiments were carried out at the scattering angle 2θ=+152 d eg with resolution Δd/d=1.5·10 -3 . The gauge volume was chosen according to the magnetic measurements lateral resolution 20x20 mm 2 . In the nearest future the neutron diffraction measurements with cold rolled iron disks at the scattering angle 2θ=±90 0 are planned. Also the texture analysis will be included in the Rietveld refinement procedure for more correct calculation of residual stress fields in the cold rolled materials. 8 refs., 10 figs., 1 tab

  15. Slip-rolling resistance of novel Zr(C,N) thin film coatings under high Hertzian contact pressures

    Energy Technology Data Exchange (ETDEWEB)

    Manier, Charles-Alix

    2010-08-24

    Today, coatings are used in many applications ranging from the decoration purposes to the improvement of efficiency such as in machining tools, medical tools, computer devices (hard disks) and many more. Especially the automotive industry anticipates a benefit in using coatings for example in powertrains and gears where the mechanical components are stressed under slip-rolling motion. A cost effective option to increase efficiency is based on the increase of the load carrying capacity by thin film coatings. It would also represent a way towards downsizing. In the work presented here, a small review concerning rolling contact fatigue of coatings was performed. Experimentally it is then shown, that crystalline Zr(C,N) coatings can be slip-rolling resistant at 120 C in factory fill engine oil up to ten million cycles under average Hertzian contact pressures up to P{sub 0mean} = 1.94 GPa (P{sub 0max} = 2.91 GPa). Basically, it represents here the doubling of the normal force acting on the surface compared to uncoated steel traditionally lubricated with fully formulated oil. Typically, the coated substrates are made of the quenched and tempered bearing steel Cronidur 30. The Zr(C,N) coatings were fully characterized using different characterisation techniques in order to understand the difference in slip-rolling resistance under those high tribological demands. Effectively, the slip-rolling resistance of different batches of the Zr(C,N) coatings is evaluated using a defined and powerful testing procedure. Different results of lifetime were achieved without fundamental changes of the deposition procedure. The characterisation achieved permits the identification of microstructural disparities which should affect the load carrying capacity of the coating. Moreover, the efficiency of the high slip-rolling resistant Zr(C,N) coating was considered not only with respect to the improvement of the load carrying capacity of the substrate but also in terms of tribological

  16. High rate of destruction of molecular clouds by hot stars

    International Nuclear Information System (INIS)

    Heydari-Malayeri, M.; Lortet, M.C.; Deharveng, L.

    1980-01-01

    Tenorio-Tagle (1979) first proposed the idea of a third dynamical phase, the champagne phase, following the formation and expansion phases of an HII region. The champagne phase begins when the high pressure gas of an HII region formed inside a molecular cloud reaches the edge of the cloud and bursts into the lower pressure, low density, intercloud medium. One important implication of the model is the prediction of an enormous enhancement of the rate of erosion of the molecular cloud by the ionising radiation of hot stars, which begins as soon as the process of the decrease of the gas density between the star and the cloud is started. The proportion of hydrogen molecules eroded by ionising photons may reach about 10 -2 . The mass eroded may exceed the mass of the ionised gas in the case where the ionisation front reaching the edge of the cloud is of D-type. Additional mechanisms (for instance stellar winds), if at work, may even increase the efficiency of the mechanism. (Auth.)

  17. 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.

  18. 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.

  19. Hydrogen Permeation in Cold-Rolled High-Mn Twinning-Induced Plasticity Steels

    Science.gov (United States)

    Han, Do Kyeong; Hwang, A. In; Byeon, Woo Jun; Noh, Seung Jeong; Suh, Dong-Woo

    2017-11-01

    Hydrogen permeation is investigated in cold-rolled Fe-0.6C-18Mn-(1.5Al) alloys. The hydrogen mobility is lower in cold-rolled alloys compared with annealed alloys. Al-containing alloy shows less deceleration of hydrogen mobility compared with the Al-free alloy. This is attributed to the reduced formation of mechanical twins and dislocations. Mechanical twins trap hydrogen strongly but are vulnerable to crack initiation; suppression of these is thought to be a major favorable influence of Al on hydrogen-induced mechanical degradation.

  20. High Thermal Conductivity and High Wear Resistance Tool Steels for cost-effective Hot Stamping Tools

    Science.gov (United States)

    Valls, I.; Hamasaiid, A.; Padré, A.

    2017-09-01

    In hot stamping/press hardening, in addition to its shaping function, the tool controls the cycle time, the quality of the stamped components through determining the cooling rate of the stamped blank, the production costs and the feasibility frontier for stamping a given component. During the stamping, heat is extracted from the stamped blank and transported through the tool to the cooling medium in the cooling lines. Hence, the tools’ thermal properties determine the cooling rate of the blank, the heat transport mechanism, stamping times and temperature distribution. The tool’s surface resistance to adhesive and abrasive wear is also an important cost factor, as it determines the tool durability and maintenance costs. Wear is influenced by many tool material parameters, such as the microstructure, composition, hardness level and distribution of strengthening phases, as well as the tool’s working temperature. A decade ago, Rovalma developed a hot work tool steel for hot stamping that features a thermal conductivity of more than double that of any conventional hot work tool steel. Since that time, many complimentary grades have been developed in order to provide tailored material solutions as a function of the production volume, degree of blank cooling and wear resistance requirements, tool geometries, tool manufacturing method, type and thickness of the blank material, etc. Recently, Rovalma has developed a new generation of high thermal conductivity, high wear resistance tool steel grades that enable the manufacture of cost effective tools for hot stamping to increase process productivity and reduce tool manufacturing costs and lead times. Both of these novel grades feature high wear resistance and high thermal conductivity to enhance tool durability and cut cycle times in the production process of hot stamped components. Furthermore, one of these new grades reduces tool manufacturing costs through low tool material cost and hardening through readily

  1. 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.)

  2. Fundamentals of and experiences with forming by rolling of sintered rods of the high-melting metals molybdenum and tungsten

    International Nuclear Information System (INIS)

    Kohlstrung, G.; Marx, H.; Bresch, J.; Leich, M.; Kalning, I.

    1986-01-01

    An efficient and economical technique for rolling sintered rods of the high-melting metals molybdenum and tungsten which comprises only a minimum of processing steps and provides crucial advantages in comparison with the conventional hammering procedure has been developed for application in medium-sized powder-metallurgical plants. The advantages are, in particular, given with the favourable structure development and the elimination of pores from the sintered bar as a result of the higher degree of deformation, increased labour productivity, savings of electrical energy and consumables, as well as a reduction of the working inconveniencies. Experiences gained in test series as well as in industrial practice indicate that final wire diameters can be obtained with a high material economy, provided that the preceding and subsequent process stages are adapted in the optimum manner dependent on the physical and chemical parameters of the starting material and the strain-hardening behaviour in the process of forming by rolling. (orig.) [de

  3. THERMO-MECHANICALLY PROCESSED ROLLED WIRE FOR HIGH-STRENGTH ON-BOARD WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available It is shown that at twisting of wire of diameter 1,83 mm, produced by direct wire drawing of thermomechanically processed rolled wire of diameter 5,5 mm of steel 90, metal stratification is completely eliminated at decrease of carbon, manganese and an additional alloying of chrome.

  4. A study of energy-size relationship and wear rate in a lab-scale high pressure grinding rolls unit

    Science.gov (United States)

    Rashidi Dashtbayaz, Samira

    This study is focused on two independent topics of energy-size relationship and wear-rate measurements on a lab-scale high pressure grinding rolls (HPGR). The first part of this study has been aimed to investigate the influence of the operating parameters and the feed characteristics on the particle-bed breakage using four different ore samples in a 200 mm x 100 mm lab-scale HPGR. Additionally, multistage grinding, scale-up from a lab-scale HPGR, and prediction of the particle size distributions have been studied in detail. The results obtained from energy-size relationship studies help with better understanding of the factors contributing to more energy-efficient grinding. It will be shown that the energy efficiency of the two configurations of locked-cycle and open multipass is completely dependent on the ore properties. A test procedure to produce the scale-up data is presented. The comparison of the scale-up factors between the data obtained on the University of Utah lab-scale HPGR and the industrial machine at the Newmont Boddington plant confirmed the applicability of lab-scale machines for trade-off studies. The population balance model for the simulation of product size distributions has shown to work well with the breakage function estimated through tests performed on the HPGR at high rotational speed. Selection function has been estimated by back calculation of population balance model with the help of the experimental data. This is considered to be a major step towards advancing current research on the simulation of particle size distribution by using the HPGR machine for determining the breakage function. Developing a technique/setup to measure the wear rate of the HPGR rolls' surface is the objective of the second topic of this dissertation. A mockup was initially designed to assess the application of the linear displacement sensors for measuring the rolls' weight loss. Upon the analysis of that technique and considering the corresponding sources of

  5. High temperature cyclic oxidation and hot corrosion behaviours of ...

    Indian Academy of Sciences (India)

    Administrator

    eutectic reaction below 600°C. When the temperature ... blades, consequently corrosion rate rapidly increases due ... the corrosion run. ... Figure 1. Surface macrographs of superalloys subjected to hot corrosion and oxidation .... show the oxide scales of three different chemical compo- .... Li J and Wahi R P 1995 Acta Metall.

  6. PROTECCIÓN CONTRA LA CORROSIÓN EN SALES FUNDIDAS DE UN ACERO HOT ROLLED, EN EL RANGO DE TEMPERATURAS DE 400 ºC-600 ºC, RECUBIERTO POR ROCIADO TÉRMICO CON ACERO INOXIDABLE 312

    Directory of Open Access Journals (Sweden)

    JOSE LUDDEY MARULANDA

    2009-01-01

    Full Text Available Se evaluó la corrosión por sales fundidas mediante la técnica gravimétrica en un acero de bajo carbono tipo hot rolled, rociado térmicamente con una aleación de acero inoxidable tipo 312, con el equipo Rototec, en una mezcla de sal 20% Na2SO4 - 80% V2O5, entre 400ºC - 600ºC, durante tiempos de 1-7-22 horas. Los resultados mostraron una moderada protección de la capa rociada térmicamente y se presentó alta degradación en el recubrimiento a 600ºC. Se concluyó que la velocidad de corrosión aumenta con la temperatura y disminuye con el tiempo de exposición.

  7. 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.

  8. High Velocity Oxidation and Hot Corrosion Resistance of Some ODS Alloys

    Science.gov (United States)

    Lowell, C. E.; Deadmore, D. L.

    1977-01-01

    Several oxide dispersion strengthened (ODS) alloys were tested for cyclic, high velocity, oxidation, and hot corrosion resistance. These results were compared to the resistance of an advanced, NiCrAl coated superalloy. An ODS FeCrAl were identified as having sufficient oxidation and hot corrosion resistance to allow potential use in an aircraft gas turbine without coating.

  9. Influence of prior cold rolling reduction on microstructure and mechanical properties of a reversion annealed high-Mn austenitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Behjati, P., E-mail: p.behjatipournaki@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Kermanpur, A. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Karjalainen, L.P.; Järvenpää, A.; Jaskari, M. [Centre for Advanced Steels Research, University of Oulu, FIN-90014 Oulu (Finland); Samaei Baghbadorani, H. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Najafizadeh, A. [Foulad Institute of Technology, Fouladshahr, Isfahan 84916-63763 (Iran, Islamic Republic of); Hamada, A. [Metallurgical and Materials Engineering Department, Faculty of Petroleum and Mining Engineering, Suez University, Suez 43721 (Egypt)

    2016-01-05

    The martensitic reversion is known to be effective in refining the grain size of metastable austenitic stainless steels. However, severe cold rolling reductions are generally required for this process. In this study, the influence of the degree of prior cold rolling and subsequent annealing on the microstructure and mechanical properties of a metastable high-Mn austenitic steel was investigated. Three cold rolling reductions of 20%, 35% and 50% were applied at ambient temperature before the annealing at 700 °C for the durations of 10, 100 and 1000 s. Microstructures were examined by optical, scanning and transmission electron microscopes. Mechanical properties were measured by hardness and tensile tests. The microstructure changes were followed by magnetic measurements and X-ray diffraction. It was shown that a relatively small reduction of 35% and 100 s annealing could provide efficient grain refinement (the average size of 0.5 µm) and accordingly an outstanding combination of strength-ductility properties with the yield strength 890 MPa, tensile strength 1340 MPa and elongation 41% was achieved. The occurrence of martensite reversion and recrystallization processes with different contributions in dependence on degree of prior deformation before annealing was discussed.

  10. Phase Transformation of Hot Dipped Aluminium during High Temperature Oxidation

    International Nuclear Information System (INIS)

    Zaifol Samsu; Muhammad Daud; Hishamuddin Husain; Mohd Saari Ripin; Rusni Rejab; Zaiton Selamat; Mohd Shariff Sattar

    2014-01-01

    Low alloy carbon steel was coated by hot-dipping into a molten aluminum bath. Isothermal oxidations were carried out at 750 degree Celsius in static air to study the oxidation behaviour of the hot-dipped aluminide steel. The phase transformation in the aluminide layer during diffusion at 750 degree Celsius in static air was analyzed by SEM-EDX and XRD. After hot-dip treatment, the coating layers consisted of three phases, where Al, thinner layer of FeAl 3 , and thicker layer of Fe 2 Al 5 were detected from external topcoat to the aluminide/ steel substrate. After oxidation, the Fe 2 Al 5 formed during the immersion process completely transformed to Fe 2 Al 5 , FeAl 2 , FeAl and Al-Fe(Al) phases because of the composition gradient and the chemical diffusion by oxidation. After oxidation, there are some voids were found at the coating/ substrate interface due to the rapid inter-diffusion of iron and aluminium during oxidation. The FeAl phase kept growing with increasing exposure time at 750 degree Celsius, while the Fe 2 Al 5 was consumed during oxidation. After 168 hrs oxidation, the Fe 2 Al 5 phase was going disappeared as the aluminum layer was consumed. (author)

  11. 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.)

  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. High-frequency microinstabilities in hot-electron plasmas

    International Nuclear Information System (INIS)

    Chen, Y.J.; Nevins, W.M.; Smith, G.R.

    1981-01-01

    Instabilities with frequencies in the neighborhood of the electron cyclotron frequency are of interest in determining stable operating regimes of hot-electron plasmas in EBT devices and in tandem mirrors. Previous work used model distributions significantly different than those suggested by recent Fokker-Planck studies. We use much more realistic model distributions in a computer code that solves the full electromagnetic dispersion relation governing longitudinal and transverse waves in a uniform plasma. We allow for an arbitrary direction of wave propagation. Results for the whistler and upper-hybrid loss-cone instabilities are presented

  14. 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,...

  15. A self-adaptive toll rate algorithm for high occupancy toll (HOT) lane operations.

    Science.gov (United States)

    2009-12-01

    Dramatically increasing travel demands and insufficient traffic facility supplies have resulted in severe : traffic congestion. High Occupancy Toll (HOT) lane operations have been proposed as one of the most : applicable and cost-effective countermea...

  16. High temperature gasification and gas cleaning – phase II of the HotVegas project

    OpenAIRE

    Meysel, P.; Halama, S.; Botteghi, F.; Steibel, M.; Nakonz, M.; Rück, R.; Kurowski, P.; Buttler, A.; Spliethoff, H.

    2016-01-01

    The primary objective of the research project HotVeGas is to lay the necessary foundations for the long-term development of future, highly efficient high-temperature gasification processes. This includes integrated hot gas cleaning and optional CO2 capture and storage for next generation IGCC power plants and processes for the development of synthetic fuels. The joint research project is funded by the German Federal Ministry of Economics and Technology and five industry partners. It is coordi...

  17. Kulturens rolle

    DEFF Research Database (Denmark)

    Hasse, Cathrine

    2007-01-01

    Kulturens rolle. Herunder kulturens betydning for psykologisk teori og forskning set i lyset af den stigende globalisering og væksten i kulturmøder. Der gives eksempler fra hverdagssituationer, den pædagogiske praksis, fra indvandrerforskning, turister men også fra avisernes referater af kulturmø......Kulturens rolle. Herunder kulturens betydning for psykologisk teori og forskning set i lyset af den stigende globalisering og væksten i kulturmøder. Der gives eksempler fra hverdagssituationer, den pædagogiske praksis, fra indvandrerforskning, turister men også fra avisernes referater af...

  18. Deep-blue efficient OLED based on NPB with little efficiency roll-off under high current density

    Science.gov (United States)

    Liu, Jian

    2017-03-01

    NPB usually is used as a hole-transport layer in OLED. In fact, it is a standard pure blue-emission material. However, its light-emitting efficiency in OLED is low due to emissive nature of organic material. Herein, a deep-blue OLDE based on NPB was fabricated. The light-emitting efficiency of the device demonstrates a moderate value, and efficiency roll-off is little under high current density. The device demonstrates that the electroplex's emission decreases with increasing electric field intensity.

  19. 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.

  20. Hot-cell shielding system for high power transmission in DUPIC fuel fabrication

    International Nuclear Information System (INIS)

    Kim, K.; Lee, J.; Park, J.; Yang, M.; Park, H.

    2000-01-01

    This paper presents a newly designed hot-cell shielding system for use in the development of DUPIC (Direct Use of spent PWR fuel In CANDU reactors) fuel at KAERI (Korea Atomic Energy Research Institute). This hot-cell shielding system that was designed to transmit high power to sintering furnace in-cell from the out-of-cell through a thick cell wall has three subsystems - a steel shield plug with embedded spiral cooling line, stepped copper bus bars, and a shielding lead block. The dose-equivalent rates of the hot-cell shielding system and of the apertures between this system and the hot-cell wall were calculated. Calculated results were compared with the allowable dose limit of the existing hot-cell. Experiments for examining the temperature changes of the shielding system developed during normal furnace operation were also carried out. Finally, gamma-ray radiation survey experiments were conducted by Co-60 source. It is demonstrated that, from both calculated and experimental results, the newly designed hot-cell shielding system meets all the shielding requirements of the existing hot-cell facility, enabling high power transmission to the in-cell sintering furnace. (author)

  1. A High-Fidelity Haze Removal Method Based on HOT for Visible Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Hou Jiang

    2016-10-01

    Full Text Available Spatially varying haze is a common feature of most satellite images currently used for land cover classification and mapping and can significantly affect image quality. In this paper, we present a high-fidelity haze removal method based on Haze Optimized Transformation (HOT, comprising of three steps: semi-automatic HOT transform, HOT perfection and percentile based dark object subtraction (DOS. Since digital numbers (DNs of band red and blue are highly correlated in clear sky, the R-squared criterion is utilized to search the relative clearest regions of the whole scene automatically. After HOT transform, spurious HOT responses are first masked out and filled by means of four-direction scan and dynamic interpolation, and then homomorphic filter is performed to compensate for loss of HOT of masked-out regions with large areas. To avoid patches and halo artifacts, a procedure called percentile DOS is implemented to eliminate the influence of haze. Scenes including various land cover types are selected to validate the proposed method, and a comparison analysis with HOT and Background Suppressed Haze Thickness Index (BSHTI is performed. Three quality assessment indicators are selected to evaluate the haze removed effect on image quality from different perspective and band profiles are utilized to analyze the spectral consistency. Experiment results verify the effectiveness of the proposed method for haze removal and the superiority of it in preserving the natural color of object itself, enhancing local contrast, and maintaining structural information of original image.

  2. Highly reliable wind-rolling triboelectric nanogenerator operating in a wide wind speed range

    Science.gov (United States)

    Yong, Hyungseok; Chung, Jihoon; Choi, Dukhyun; Jung, Daewoong; Cho, Minhaeng; Lee, Sangmin

    2016-01-01

    Triboelectric nanogenerators are aspiring energy harvesting methods that generate electricity from the triboelectric effect and electrostatic induction. This study demonstrates the harvesting of wind energy by a wind-rolling triboelectric nanogenerator (WR-TENG). The WR-TENG generates electricity from wind as a lightweight dielectric sphere rotates along the vortex whistle substrate. Increasing the kinetic energy of a dielectric converted from the wind energy is a key factor in fabricating an efficient WR-TENG. Computation fluid dynamics (CFD) analysis is introduced to estimate the precise movements of wind flow and to create a vortex flow by adjusting the parameters of the vortex whistle shape to optimize the design parameters to increase the kinetic energy conversion rate. WR-TENG can be utilized as both a self-powered wind velocity sensor and a wind energy harvester. A single unit of WR-TENG produces open-circuit voltage of 11.2 V and closed-circuit current of 1.86 μA. Additionally, findings reveal that the electrical power is enhanced through multiple electrode patterns in a single device and by increasing the number of dielectric spheres inside WR-TENG. The wind-rolling TENG is a novel approach for a sustainable wind-driven TENG that is sensitive and reliable to wind flows to harvest wasted wind energy in the near future. PMID:27653976

  3. Roll-to-Roll production of carbon nanotubes based supercapacitors

    Science.gov (United States)

    Zhu, Jingyi; Childress, Anthony; Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Carbon nanomaterials provide an excellent platform for electrochemical double layer capacitors (EDLCs). However, current industrial methods for producing carbon nanotubes are expensive and thereby increase the costs of energy storage to more than 10 Wh/kg. In this regard, we developed a facile roll-to-roll production technology for scalable manufacturing of multi-walled carbon nanotubes (MWNTs) with variable density on run-of-the-mill kitchen Al foils. Our method produces MWNTs with diameter (heights) between 50-100 nm (10-100 μm), and a specific capacitance as high as ~ 100 F/g in non-aqueous electrolytes. In this talk, the fundamental challenges involved in EDLC-suitable MWNT growth, roll-to-roll production, and device manufacturing will be discussed along with electrochemical characteristics of roll-to-roll MWNTs. Research supported by NSF CMMI Grant1246800.

  4. Microstructural and Material Quality Effects on Rolling Contact Fatigue of Highly Elastic Intermetallic NiTi Ball Bearings

    Science.gov (United States)

    Dellacorte, Christopher; Howard, S. Adam; Thomas, Fransua; Stanford, Malcolm K.

    2017-01-01

    Rolling element bearings made from highly-elastic intermetallic materials (HIM)s, such as 60NiTi, are under development for applications that require superior corrosion and shock resistance. Compared to steel, intermetallics have been shown to have much lower rolling contact fatigue (RCF) stress capability in simplified 3-ball on rod (ASTM STP 771) fatigue tests. In the 3-ball tests, poor material quality and microstructural flaws negatively affect fatigue life but such relationships have not been established for full-scale 60NiTi bearings. In this paper, 3-ball-on-rod fatigue behavior of two quality grades of 60NiTi are compared to the fatigue life of full-scale 50mm bore ball bearings made from the same materials. 60NiTi RCF rods with material or microstructural flaws suffered from infant mortality failures at all tested stress levels while high quality 60NiTi rods exhibited no failures at lower stress levels. Similarly, tests of full-scale bearings made from flawed materials exhibited early surface fatigue and through crack type failures while bearings made from high quality material did not fail even in long-term tests. Though the full-scale bearing test data is yet preliminary, the results suggest that the simplified RCF test is a good qualitative predictor of bearing performance. These results provide guidance for materials development and to establish minimum quality levels required for successful bearing operation and life.

  5. Deformation induced dynamic recrystallization and precipitation strengthening in an Mg−Zn−Mn alloy processed by high strain rate rolling

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jimiao; Song, Min [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Yan, Hongge [School of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Yang, Chao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Ni, Song, E-mail: song.ni@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

    2016-11-15

    The microstructure of a high strain-rate rolled Mg−Zn−Mn alloy was investigated by transmission electron microscopy to understand the relationship between the microstructure and mechanical properties. The results indicate that: (1) a bimodal microstructure consisting of the fine dynamic recrystallized grains and the largely deformed grains was formed; (2) a large number of dynamic precipitates including plate-like MgZn{sub 2} phase, spherical MgZn{sub 2} phase and spherical Mn particles distribute uniformly in the grains; (3) the major facets of many plate-like MgZn{sub 2} precipitates deviated several to tens of degrees (3°–30°) from the matrix basal plane. It has been shown that the high strength of the alloy is attributed to the formation of the bimodal microstructure, dynamic precipitation, and the interaction between the dislocations and the dynamic precipitates. - Highlights: •A bimodal microstructure was formed in a high strain-rate rolled Mg−Zn−Mn alloy. •Plate-like MgZn{sub 2}, spherical MgZn{sub 2} and spherical Mn phases were observed. •The major facet of the plate-like MgZn{sub 2} deviated from the matrix basal plane.

  6. 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.

  7. Experimental optimization of temperature distribution in the hot-gas duct through the installation of internals in the hot-gas plenum of a high-temperature reactor

    International Nuclear Information System (INIS)

    Henssen, J.; Mauersberger, R.

    1990-01-01

    The flow conditions in the hot-gas plenum and in the adjacent hot-gas ducts and hot-gas pipes for the high-temperature reactor project PNP-1000 (nuclear process heat project for 1000 MW thermal output) have been examined experimentally. The experiments were performed in a closed loop in which the flow model to be analyzed, representing a 60deg sector of the core bottom of the PNP-1000 with connecting hot-gas piping and diverting arrangements, was installed. The model scale was approx. 1:5.6. The temperature and flow velocity distribution in the hot-gas duct was registered by means of 14 dual hot-wire flowmeters. Through structural changes and/or the installation of internals into the hot-gas plenum of the core bottom offering little flow resistance coolant gas temperature differentials produced in the core could be reduced to such an extent that a degree of mixture amounting to over 80% was achieved at the entrance of the connected heat exchanger systems. Thereby the desired goal of an adequate degree of mixture of the hot gas involving an acceptable pressure loss was reached. (orig.)

  8. 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.

  9. Preparation of high-strength Al-Mg-Si-Cu-Fe alloy via heat treatment and rolling

    Science.gov (United States)

    Liu, Chong-yu; Yu, Peng-fei; Wang, Xiao-ying; Ma, Ming-zhen; Liu, Ri-ping

    2014-07-01

    An Al-Mg-Si-Cu-Fe alloy was solid-solution treated at 560°C for 3 h and then cooled by water quenching or furnace cooling. The alloy samples which underwent cooling by these two methods were rolled at different temperatures. The microstructure and mechanical properties of the rolled alloys were investigated by optical microscopy, scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, and tensile testing. For the water-quenched alloys, the peak tensile strength and elongation occurred at a rolling temperature of 180°C. For the furnace-cooled alloys, the tensile strength decreased initially, until the rolling temperature of 420°C, and then increased; the elongation increased consistently with increasing rolling temperature. The effects of grain boundary hardening and dislocation hardening on the mechanical properties of these rolled alloys decreased with increases in rolling temperature. The mechanical properties of the 180°C rolling water-quenched alloy were also improved by the presence of β″ phase. Above 420°C, the effect of solid-solution hardening on the mechanical properties of the rolled alloys increased with increases in rolling temperature.

  10. Hot-working behavior of cast Pr-Fe-B magnets

    International Nuclear Information System (INIS)

    Shimoda, T.; Akioka, K.; Kobayashi, O.; Yamagami, T.; Ohki, T.; Miyagawa, M.; Yuri, T.

    1989-01-01

    The hot-working behavior of cast Pr-Fe-B magnets is investigated. The hot-working is done both at a low strain rate (hot-pressing) and a high strain rate (hot-rolling). Magnetic alignment induced by the hot-working is found to be closely related to the macrostructure of the cast ingots and the direction of principal stress. The appropriate structure is a columnar structure. The c-axis of the Pr2Fe14B phase is lying in the plane perpendicular to the growth direction of the dendrites. The principal stress during working should be given perpendicular to the growth direction

  11. A Bio-Realistic Analog CMOS Cochlea Filter With High Tunability and Ultra-Steep Roll-Off.

    Science.gov (United States)

    Wang, Shiwei; Koickal, Thomas Jacob; Hamilton, Alister; Cheung, Rebecca; Smith, Leslie S

    2015-06-01

    This paper presents the design and experimental results of a cochlea filter in analog very large scale integration (VLSI) which highly resembles physiologically measured response of the mammalian cochlea. The filter consists of three specialized sub-filter stages which respectively provide passive response in low frequencies, actively tunable response in mid-band frequencies and ultra-steep roll-off at transition frequencies from pass-band to stop-band. The sub-filters are implemented in balanced ladder topology using floating active inductors. Measured results from the fabricated chip show that wide range of mid-band tuning including gain tuning of over 20 dB, Q factor tuning from 2 to 19 as well as the bio-realistic center frequency shift are achieved by adjusting only one circuit parameter. Besides, the filter has an ultra-steep roll-off reaching over 300 dB/dec. By changing biasing currents, the filter can be configured to operate with center frequencies from 31 Hz to 8 kHz. The filter is 9th order, consumes 59.5 ∼ 90.0 μW power and occupies 0.9 mm2 chip area. A parallel bank of the proposed filter can be used as the front-end in hearing prosthesis devices, speech processors as well as other bio-inspired auditory systems owing to its bio-realistic behavior, low power consumption and small size.

  12. Effects of magnetic configuration on hot electrons in highly charged ECR plasma

    International Nuclear Information System (INIS)

    Zhao, H Y; Zhao, H W; Sun, L T; Wang, H; Ma, B H; Zhang, X Zh; Li, X X; Ma, X W; Zhu, Y H; Lu, W; Shang, Y; Xie, D Z

    2009-01-01

    To investigate the hot electrons in highly charged electron cyclotron resonance (ECR) plasma, Bremsstrahlung radiations were measured on two ECR ion sources at the Institute of Modern Physics. Used as a comparative index of the mean energy of the hot electrons, a spectral temperature, T spe , is derived through a linear fitting of the spectra in a semi-logarithmic representation. The influences of the external source parameters, especially the magnetic configuration, on the hot electrons are studied systematically. This study has experimentally demonstrated the importance of high microwave frequency and high magnetic field in the electron resonance heating to produce a high density of hot electrons, which is consistent with the empirical ECR scaling laws. The experimental results have again shown that a good compromise is needed between the ion extraction and the plasma confinement for an efficient production of highly charged ion beams. In addition, this investigation has shown that the correlation between the mean energy of the hot electrons and the magnetic field gradient at the ECR is well in agreement with the theoretical models.

  13. SOFIA/EXES High Spectral Resolution Observations of the Orion Hot Core

    Science.gov (United States)

    Rangwala, Naseem; Colgan, Sean; Le Gal, Romane; Acharya, Kinsuk; Huang, Xinchuan; Herbst, Eric; Lee, Timothy J.; Richter, Matthew J.; Boogert, Adwin

    2018-01-01

    The Orion hot core has one of the richest molecular chemistries observed in the ISM. In the MIR, the Orion hot core composition is best probed by the closest, compact, bright background continuum source in this region, IRc2. We present high-spectral resolution observations from 12.96 - 13.33 μm towards Orion IRc2 using the mid-infrared spectrograph, EXES, on SOFIA, to probe the physical and chemical conditions of the Orion hot core. All ten of the rovibrational C2H2 transitions expected in our spectral coverage, are detected with high S/N, yielding continuous coverage of the R-branch lines from J=9-8 to J=18-17, including both ortho and para species. Eight of these rovibrational transitions are newly reported detections. These data show distinct ortho and para ladders towards the Orion hot core for the first time, with an ortho to para ratio (OPR) of only 0.6 - much lower than the high temperature equilibrium value of 3. A non-equilibrium OPR is a further indication of the Orion hot core being heated externally by shocks likely resulting from a well-known explosive event which occurred 500 yrs ago. The OPR conversion timescales are much longer than the 500 yr shock timescale and thus a low OPR might be a remnant from an earlier colder pre-stellar phase before the density enhancement (now the hot core) was impacted by shocks.We will also present preliminary results from an on-going SOFIA Cycle-5 impact program to use EXES to conduct an unbiased, high-S/N, continuous, molecular line survey of the Orion hot core from 12.5 - 28.3 microns. This survey is expected to be 50 times better than ISO in detecting isolated, narrow lines to (a) resolve the ro-vibrational structure of the gas phase molecules and their kinematics, (b) detect new gas phase molecules missed by ISO, and (c) provide useful constraints on the hot core chemistry and the source of Orion hot core excitation. This survey will greatly enhance the inventory of resolved line features in the MIR for hot cores

  14. LEDs are on a roll

    NARCIS (Netherlands)

    Blom, P.W.M.; Mol, A.M.B. van

    2011-01-01

    Light-emitting diodes are more efficient than conventional lighting, but high production costs limit their uptake. Organic versions that can be produced using a cheap newspaper-style 'roll-to-roll' printing process are likely to revolutionize our lighting and signage, say Paul Blom and Ton van Mol.

  15. High strain rate superplasticity in an Al–Mg–Sc–Zr alloy processed via simple rolling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mengjia [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Pan, Qinglin, E-mail: csupql@163.com [Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Central South University, Changsha 410083 (China); Shi, Yunjia; Sun, Xue; Xiang, Hao [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2017-02-27

    The superplastic behavior of Al–Mg–Sc–Zr samples with standard gauge size (18 mm by 6 mm) were prepared using simple rolling and were tested in the temperature range from 450 °C to 525 °C at strain rates ranging from 1.67×10{sup –3} s{sup −1} to 1×10{sup –1} s{sup −1}. With proper deformation parameters, the Al–Mg–Sc–Zr alloy has an elongation to failure much higher than 300% and the maximum elongation is 740%. The Microstructure and dislocation substructure investigation using optical microscopy (OM) and transmission electron microscopy (TEM) revealed a dynamic recrystallization in it. The grain size and activation energy on the deformation mechanisms of superplastic is discussed. Results also show that these nano-scale Al{sub 3}(Sc{sub 1−x}Zr{sub x}) particles play an important role in the superplastic process. Al{sub 6}FeMn particles were found to induce the formation and growth of cavities, which can lead to the fracture of specimens.

  16. High-speed DNA-based rolling motors powered by RNase H

    Science.gov (United States)

    Yehl, Kevin; Mugler, Andrew; Vivek, Skanda; Liu, Yang; Zhang, Yun; Fan, Mengzhen; Weeks, Eric R.

    2016-01-01

    DNA-based machines that walk by converting chemical energy into controlled motion could be of use in applications such as next generation sensors, drug delivery platforms, and biological computing. Despite their exquisite programmability, DNA-based walkers are, however, challenging to work with due to their low fidelity and slow rates (~1 nm/min). Here, we report DNA-based machines that roll rather than walk, and consequently have a maximum speed and processivity that is three-orders of magnitude greater than conventional DNA motors. The motors are made from DNA-coated spherical particles that hybridise to a surface modified with complementary RNA; motion is achieved through the addition of RNase H, which selectively hydrolyses hybridised RNA. Spherical motors move in a self-avoiding manner, whereas anisotropic particles, such as dimerised particles or rod-shaped particles travel linearly without a track or external force. Finally, we demonstrate detection of single nucleotide polymorphism by measuring particle displacement using a smartphone camera. PMID:26619152

  17. Electrochemical aptasensor for highly sensitive determination of cocaine using a supramolecular aptamer and rolling circle amplification

    International Nuclear Information System (INIS)

    Shen, Bo; Yan, Yurong; Tang, Renkuan; Li, Yongguo; Li, Jianbo; Cheng, Wei; Ju, Huangxian; Ding, Shijia

    2015-01-01

    We report on a novel strategy for the electrochemical detection of cocaine. It is based on the use of a supramolecular aptamer, rolling circle amplification (RCA), and multiplex binding of a biotin-strepavidin system. The aptamer fragments were assembled to a supramolecular aptamer which, in the presence of cocaine, conjugates to streptavidin for anchoring of biotinylated circular DNA. This initiates RCA and enables sensitive electrochemical-enzymatic readout. A significant signal amplification was obtained by using streptavidin linked to alkaline phosphatase that binds to the remaining biotinylated detection probes and catalyzes the hydrolysis of the synthetic enzyme substrate α-naphthylphosphate. This dual amplification strategy tremendously increases the detection limit of the aptasensor. Under optimal conditions and using differential pulse voltammetry, cocaine can be detected in the concentration range between 2 and 500 nM with a detection limit as low as 1.3 nM (at S/N = 3). The method is specific and acceptably reproducible. It was successfully applied to the detection of cocaine in (spiked) urine samples. The data were in good agreement with those obtained by the GC-MS reference method. (author)

  18. Microstructure and Mechanical Properties Evolution of the Al, C-Containing CoCrFeNiMn-Type High-Entropy Alloy during Cold Rolling.

    Science.gov (United States)

    Klimova, Margarita; Stepanov, Nikita; Shaysultanov, Dmitry; Chernichenko, Ruslan; Yurchenko, Nikita; Sanin, Vladimir; Zherebtsov, Sergey

    2017-12-29

    The effect of cold rolling on the microstructure and mechanical properties of an Al- and C-containing CoCrFeNiMn-type high-entropy alloy was reported. The alloy with a chemical composition (at %) of (20-23) Co, Cr, Fe, and Ni; 8.82 Mn; 3.37 Al; and 0.69 C was produced by self-propagating high-temperature synthesis with subsequent induction. In the initial as-cast condition the alloy had an face centered cubic single-phase coarse-grained structure. Microstructure evolution was mostly associated with either planar dislocation glide at relatively low deformation during rolling (up to 20%) or deformation twinning and shear banding at higher strain. After 80% reduction, a heavily deformed twinned/subgrained structure was observed. A comparison with the equiatomic CoCrFeNiMn alloy revealed higher dislocation density at all stages of cold rolling and later onset of deformation twinning that was attributed to a stacking fault energy increase in the program alloy; this assumption was confirmed by calculations. In the initial as-cast condition the alloy had low yield strength of 210 MPa with yet very high uniform elongation of 74%. After 80% rolling, yield strength approached 1310 MPa while uniform elongation decreased to 1.3%. Substructure strengthening was found to be dominated at low rolling reductions (<40%), while grain (twin) boundary strengthening prevailed at higher strains.

  19. Hot working alkali halides for laser window applications

    International Nuclear Information System (INIS)

    Koepke, B.G.; Anderson, R.H.; Stokes, R.J.

    1975-01-01

    The techniques used to hot work alkali halide crystals into laser window blanks are reviewed. From the point of view of high power laser window applications one of the materials with a high figure of merit is KCl. Thus the materials examined are KCl and alloys of KCl-KBr containing 5 mole percent KBr. The fabrication techniques include conventional and constrained press forging, isostatic press forging and hot rolling. Optical properties are paramount to the ultimate usefulness of these materials. Results on the optical properties of the hot worked material are included together with mechanical properties and microstructural data

  20. Hot pressing of nanocrystalline tantalum using high frequency induction heating and pulse plasma sintering

    Science.gov (United States)

    Jakubowicz, J.; Adamek, G.; Sopata, M.; Koper, J. K.; Siwak, P.

    2017-12-01

    The paper presents the results of nanocrystalline powder tantalum consolidation using hot pressing. The authors used two different heating techniques during hot pressing: high-frequency induction heating (HFIH) and pulse plasma sintering (PPS). A comparison of the structure, microstructure, mechanical properties and corrosion resistance of the bulk nanocrystalline tantalum obtained in both techniques was performed. The nanocrystalline powder was made to start from the microcrystalline one using the high-energy ball milling process. The nanocrystalline powder was hot-pressed at 1000 °C, whereas, for comparison, the microcrystalline powder was hot pressed up to 1500 °C for proper consolidation. The authors found that during hot pressing, the powder partially reacts with the graphite die covered by boron nitride, which facilitated punches and powder displacement in the die during densification. Tantalum carbide and boride in the nanocrystalline material was found, which can improve the mechanical properties. The hardness of the HFIH and PPS nanocrystalline tantalum was as high as 625 and 615 HV, respectively. The microstructure was more uniform in the PPS nanomaterial. The corrosion resistance in both cases deteriorated, in comparison to the microcrystalline material, while the PPS material corrosion resistance was slightly better than that of the HFIH one.

  1. Solar heating and domestic hot water system installed at North Dallas High School

    Science.gov (United States)

    1980-01-01

    The solar energy system located at the North Dallas High School, Dallas, Texas is discussed. The system is designed as a retrofit in a three story with basement, concrete frame high school building. Extracts from the site files, specification references for solar modification to existing building heating and domestic hot water systems, drawings, installation, operation and maintenance instructions are included.

  2. 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.

  3. Improving hot-spot pressure for ignition in high-adiabat Inertial Confinement Fusion implosion

    OpenAIRE

    Kang, Dongguo; Zhu, Shaoping; Pei, Wenbing; Zou, Shiyang; Zheng, Wudi; Gu, Jianfa; Dai, Zhensheng

    2017-01-01

    A novel capsule target design to improve the hot-spot pressure in the high-adiabat implosion for inertial confinement fusion is proposed, where a layer of comparatively high-density material is used as a pusher between the fuel and the ablator. This design is based on our theoretical finding of the stagnation scaling laws, which indicates that the hot spot pressure can be improved by increasing the kinetic energy density $\\rho_d V_{imp}^2/2$ ($\\rho_d$ is the shell density when the maximum she...

  4. 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

  5. High Performance Walls in Hot-Dry Climates

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [National Renewable Energy Lab. (NREL), Golden, CO (United States); Springer, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dakin, Bill [National Renewable Energy Lab. (NREL), Golden, CO (United States); German, Alea [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-01-01

    High performance walls represent a high priority measure for moving the next generation of new homes to the Zero Net Energy performance level. The primary goal in improving wall thermal performance revolves around increasing the wall framing from 2x4 to 2x6, adding more cavity and exterior rigid insulation, achieving insulation installation criteria meeting ENERGY STAR's thermal bypass checklist, and reducing the amount of wood penetrating the wall cavity.

  6. Effect of phosphorus on hot ductility of high purity iron

    International Nuclear Information System (INIS)

    Abiko, K.; Liu, C.M.; Ichikawa, M..; Suenaga, H.; Tanino, M.

    1995-01-01

    Tensile tests on high purity Fe-P alloys with 0, 0.05 and 0.1 mass%P were carried out at temperatures between 300 K and 1073 K to clarify the intrinsic effect of phosphorus on the mechanical properties of iron at elevated temperatures. Microstructures of as-quenched, interrupted and ruptured specimens were observed. Experimental results show that the addition of phosphorus causes a remarkable increase in proof stress of high purity iron at 300 K, but the increase in proof stress by phosphorus decreases with increasing test temperature. The strengthening effect of phosphorus reduces to zero at 1073 K. High purity iron and Fe-P alloys rupture at almost 100% reduction in area at the whole test temperatures. However, Fe-P alloys show much larger elongation at test temperatures above 773 K than high purity iron. The increased elongation of high purity iron by addition of phosphorus was shown to be related to the effect of phosphorus on dynamic recovery and recrystallization of iron as its intrinsic effect. (orig.)

  7. Application research of ferrous matrix composites in roller ring used in high-speed wire/bar rolling mill

    International Nuclear Information System (INIS)

    Song Yanpei; Li Xiuqing; Bi Shuangxu

    2010-01-01

    Research highlights: → A composite structure roller rings was fabricated by centrifugal casting. → The roller rings consisted of outer WCP/Fe-C composites layer and inner Fe-C alloy matrix. → Hardness attained to HRA80-85 in the composites layer, and HRA73-76 in inner Fe-C alloy matrix where the toughness was over 8 J/cm 2 . → The wear resistance of the roller rings excelled that of high-speed steel, and approached to that of the WC hard alloy roll. → The production cost of the WCP/Fe-C composites roller ring decreased by 50%. - Abstract: Tungsten carbide particle (WC P ) reinforced ferrous matrix composites roller rings were fabricated by centrifugal casting. The microstructures, properties and application effect of the composites roller rings were investigated by SEM, TEM and various property testers. The experimental results show that the WC P were uniformly distributed in outer reinforced-layer (working-layer) of 20-50 mm in thickness and their volume fraction reached 60-80 vol.%; there was a good interface bonding between WC P and Fe-C alloy without any reaction products; hardness attained to HRA80-85 in working-layer, and HRA73-76 in inner ferrous matrix where the toughness was over 8 J/cm 2 ; the wear resistance of the composites roller rings excels that of high-speed steel; service life of the composites parts approached to that of the WC hard alloy roll when the same WC P -volume-fraction in working-layer were obtained for both of them, but the production cost of the WC P /Fe-C composites roller ring decreased by 50%.

  8. 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

  9. 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

  10. 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.

  11. High-speed photography application to pulsed hot plasma investigation

    International Nuclear Information System (INIS)

    Borov'etskij, M.; Koz'yarkevich, V.; Skrzhechanovskij, V.; Socha, R.

    1986-01-01

    Plasma focus is investigated using an electron-optical chamber for high-speed photography (KSK-1). Experimental devices for studying dynamics and structure of a plasma layer in the chosen interval, recording plasma spectra with time resolution as well as for studying the dynamics and structure of a plasma layer by Schlieren- and shadow methods are briefly described. Experimental results are presented

  12. High Performance Walls in Hot-Dry Climates

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Springer, David [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); Dakin, Bill [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States); German, Alea [Alliance for Residential Building Innovation (ARBI), Davis, CA (United States)

    2015-01-01

    High performance walls represent a high priority measure for moving the next generation of new homes to the Zero Net Energy performance level. The primary goal in improving wall thermal performance revolves around increasing the wall framing from 2x4 to 2x6, adding more cavity and exterior rigid insulation, achieving insulation installation criteria meeting ENERGY STAR's thermal bypass checklist. To support this activity, in 2013 the Pacific Gas & Electric Company initiated a project with Davis Energy Group (lead for the Building America team, Alliance for Residential Building Innovation) to solicit builder involvement in California to participate in field demonstrations of high performance wall systems. Builders were given incentives and design support in exchange for providing site access for construction observation, cost information, and builder survey feedback. Information from the project was designed to feed into the 2016 Title 24 process, but also to serve as an initial mechanism to engage builders in more high performance construction strategies. This Building America project utilized information collected in the California project.

  13. 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

  14. An overview of high thermal conductive hot press forming die material development

    Directory of Open Access Journals (Sweden)

    A.R. Zulhishamuddin

    2015-12-01

    Full Text Available Most of the automotive industries are using high strength steel components, which are produced via hot press forming process. This process requires die material with high thermal conductivity that increases cooling rate during simultaneous quenching and forming stage. Due to the benefit of high quenching rate, thermal conductive die materials were produced by adding carbide former elements. This paper presents an overview of the modification of alloying elements in tool steel for high thermal conductivity properties by transition metal elements addition. Different types of manufacturing processes involved in producing high thermal conductive materials were discussed. Methods reported were powder metallurgy hot press, direct metal deposition, selective laser melting, direct metal laser sintering and spray forming. Elements likes manganese, nickel, molybdenum, tungsten and chromium were proven to increase thermal conductivity properties. Thermal conductivity properties resulted from carbide network presence in the steel microstructure. To develop feasible and low cost hot press forming die material, casting of Fe-based alloy with carbide former composition can be an option. Current thermal conductivity properties of hot press forming die material range between 25 and 66 W/m.K. The wide range of thermal conductivity varies the mechanical properties of the resulting components and lifetime of HPF dies.

  15. Hot embossing and mechanical punching of biodegradable microcontainers for oral drug delivery

    DEFF Research Database (Denmark)

    Petersen, Ritika Singh; Mahshid, Rasoul; Andersen, Nis Korsgaard

    2015-01-01

    A process has been developed to fabricate discrete three-dimensional microcontainers for oral drug delivery application in Poly-L-Lactic Acid (PLLA) polymer. The method combines hot embossing for the definition of holes in a PLLA film and mechanical punching to penetrate the polymer layer around...... and shapes of microcontainers. Finally, the process is compatible with roll-to-roll processing that could lead to low cost high volume production. © 2014 Elsevier B.V. All rights reserved....

  16. Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

    International Nuclear Information System (INIS)

    Yuan, Y.; Greuner, H.; Böswirth, B.; Krieger, K.; Luo, G.-N.; Xu, H.Y.; Fu, B.Q.; Li, M.; Liu, W.

    2013-01-01

    Highlights: ► Recrystallization temperature of a rolled W was ∼2480 °C under applied HHF loads. ► Fine grains were obtained under HHF loads with appropriate short pulse length. ► With increasing pulse length, the recrystallized grains significantly grew larger. ► A linear relationship between ln d and 1/T max was found. ► Activation energy for grain growth in T evolution up to T max in 1.5 s was obtained. -- Abstract: Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m 2 were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/T max ) was found and accordingly the activation energy for grain growth in temperature evolution up to T max in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads

  17. High-Performance Ducts in Hot-Dry Climates

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschele, Marc [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Chitwood, Rick [National Renewable Energy Laboratory (NREL), Golden, CO (United States); German, Alea [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weitzel, Elizabeth [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-07-30

    Duct thermal losses and air leakage have long been recognized as prime culprits in the degradation of heating, ventilating, and air-conditioning (HVAC) system efficiency. Both the U.S. Department of Energy’s Zero Energy Ready Home program and California’s proposed 2016 Title 24 Residential Energy Efficiency Standards require that ducts be installed within conditioned space or that other measures be taken to provide similar improvements in delivery effectiveness (DE). Pacific Gas & Electric Company commissioned a study to evaluate ducts in conditioned space and high-performance attics (HPAs) in support of the proposed codes and standards enhancements included in California’s 2016 Title 24 Residential Energy Efficiency Standards. The goal was to work with a select group of builders to design and install high-performance duct (HPD) systems, such as ducts in conditioned space (DCS), in one or more of their homes and to obtain test data to verify the improvement in DE compared to standard practice. Davis Energy Group (DEG) helped select the builders and led a team that provided information about HPD strategies to them. DEG also observed the construction process, completed testing, and collected cost data.

  18. Optimisation of thermo mechanical treatments using cryogenic rolling and aging of the high strength aluminium alloy AlZn5.5MgCu (AA7075)

    Energy Technology Data Exchange (ETDEWEB)

    Hunger, S.; Scholze, M.; Hockauf, M.; Wagner, M.F.X. [Chemnitz University of Technology, Institute of Materials Science and Engineering, Chemnitz (Germany); Fritsch, S.

    2011-07-15

    In this study, we consider the optimisation of mechanical properties and the microstructure of the high strength and difficult-to-work aluminium alloy AA7075 by cryogenic rolling. In order to reduce the grain size into the (ultra)fine-grained regime, cryogenic rolling is used to introduce different amount of plastic strain. We discuss how rolling at lower temperatures allows the introduction of higher strains on the one hand, and suppresses dynamic recovery and aging effectively on the other hand. Our results demonstrate that, in combination with an appropriate post-processing aging treatment, an outstanding combination of strength and ductility can be achieved. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. A method to achieve comparable thermal states of car brakes during braking on the road and on a high-speed roll-stand

    Science.gov (United States)

    Wolff, Andrzej

    2010-01-01

    The temperature of a brake friction surface influences significantly the braking effectiveness. The paper describes a heat transfer process in car brakes. Using a developed program of finite element method, the temperature distributions in brake rotors (disc and drum brake) of a light truck have been calculated. As a preliminary consistency criterion of the brake thermal state in road and roll-stand braking conditions, a balance of the energy cumulated in the brake rotor has been taken into account. As the most reliable consistency criterion an equality of average temperatures of the friction surface has been assumed. The presented method allows to achieve on a roll-stand the analogical thermal states of automotive brakes, which are observed during braking in road conditions. Basing on this method, it is possible to calculate the braking time and force for a high-speed roll-stand. In contrast to the previous papers of the author, new calculation results have been presented.

  20. Detailed SEM-EPMA investigation of high specific radioactivity particles (hot particles)

    International Nuclear Information System (INIS)

    Burin, K.; Tsacheva, Ts.; Mandjoukov, I.; Mandjoukova, B.

    1993-01-01

    Scanning electron microscope (SEM) images and electron probe microanalysis (EPMA) spectra of a group of hot particles collected in Bulgaria after the Chernobyl accident have been obtained. A technique for hot particle localization is described. The object is irradiated for two days with a β source and the resulting autoradiographs show particles location precisely. High resolution x-ray spectrum of each particle has been obtained using EPMA. The distribution of chemical elements is visualized by colour dot maps representing the regions of interest of the spectrum. It is concluded that apart from reactor fuel the investigated hot particles come from either construction materials or materials used for the covering of the damaged reactor. 7 figs., 2 ref

  1. 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

  2. Coaxial Ag/ZnO/Ag nanowire for highly sensitive hot-electron photodetection

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, Yaohui; Li, Xiaofeng, E-mail: xfli@suda.edu.cn; Wu, Kai; Wu, Shaolong; Deng, Jiajia [College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province and Key Lab of Modern Optical Technologies of Education Ministry of China, Soochow University, Suzhou 215006 (China)

    2015-02-23

    Single-nanowire photodetectors (SNPDs) are mostly propelled by p-n junctions, where the detection wavelength is constrained by the band-gap width. Here, we present a simple doping-free metal/semiconductor/metal SNPD, which shows strong detection tunability without such a material constraint. The proposed hot-electron SNPD exhibits superior optical and electrical advantages, i.e., optically the coaxial design leads to a strong asymmetrical photoabsorption and results in a high unidirectional photocurrent, as desired by the hot-electron collection; electrically the hot-electrons are generated in the region very close to the barrier, facilitating the electrical transport. Rigorous calculations predict an unbiased photoresponsivity of ∼200 nA/mW.

  3. Analysis of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applications

    Science.gov (United States)

    Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

    1996-01-01

    The prospects of a YBa2Cu3O7(delta)(YBCO) hot-electron bolometer (HEB) mixer for a THz heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate.

  4. High-Current Gain Two-Dimensional MoS 2 -Base Hot-Electron Transistors

    KAUST Repository

    Torres, Carlos M.

    2015-12-09

    The vertical transport of nonequilibrium charge carriers through semiconductor heterostructures has led to milestones in electronics with the development of the hot-electron transistor. Recently, significant advances have been made with atomically sharp heterostructures implementing various two-dimensional materials. Although graphene-base hot-electron transistors show great promise for electronic switching at high frequencies, they are limited by their low current gain. Here we show that, by choosing MoS2 and HfO2 for the filter barrier interface and using a noncrystalline semiconductor such as ITO for the collector, we can achieve an unprecedentedly high-current gain (α ∼ 0.95) in our hot-electron transistors operating at room temperature. Furthermore, the current gain can be tuned over 2 orders of magnitude with the collector-base voltage albeit this feature currently presents a drawback in the transistor performance metrics such as poor output resistance and poor intrinsic voltage gain. We anticipate our transistors will pave the way toward the realization of novel flexible 2D material-based high-density, low-energy, and high-frequency hot-carrier electronic applications. © 2015 American Chemical Society.

  5. High-Current Gain Two-Dimensional MoS 2 -Base Hot-Electron Transistors

    KAUST Repository

    Torres, Carlos M.; Lan, Yann Wen; Zeng, Caifu; Chen, Jyun Hong; Kou, Xufeng; Navabi, Aryan; Tang, Jianshi; Montazeri, Mohammad; Adleman, James R.; Lerner, Mitchell B.; Zhong, Yuan Liang; Li, Lain-Jong; Chen, Chii Dong; Wang, Kang L.

    2015-01-01

    The vertical transport of nonequilibrium charge carriers through semiconductor heterostructures has led to milestones in electronics with the development of the hot-electron transistor. Recently, significant advances have been made with atomically sharp heterostructures implementing various two-dimensional materials. Although graphene-base hot-electron transistors show great promise for electronic switching at high frequencies, they are limited by their low current gain. Here we show that, by choosing MoS2 and HfO2 for the filter barrier interface and using a noncrystalline semiconductor such as ITO for the collector, we can achieve an unprecedentedly high-current gain (α ∼ 0.95) in our hot-electron transistors operating at room temperature. Furthermore, the current gain can be tuned over 2 orders of magnitude with the collector-base voltage albeit this feature currently presents a drawback in the transistor performance metrics such as poor output resistance and poor intrinsic voltage gain. We anticipate our transistors will pave the way toward the realization of novel flexible 2D material-based high-density, low-energy, and high-frequency hot-carrier electronic applications. © 2015 American Chemical Society.

  6. 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...

  7. 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...

  8. Low friction slip-rolling contacts. Influences of alternative steels, high performance thin film coatings and lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Scholz, Christian

    2013-02-01

    Due to the growing environmental awareness worldwide, containment provisions for CO{sub 2} emissions in mobility systems and increasing performance requirements the demands on mechanical systems and their materials continuously rise. These high demands require the implementation of new technical approaches, for example of light-weight strategies in automotive powertrains, and directly raise questions about the suitability of the most promising technical solution. Two basic parameters, the surface hardness of the tooth flanks and the core fatigue strength of the tooth root, illustrate exemplarily increasing demands on material grades used for gear wheels in automotive powertrains. In addition to light-weight strategies, a reduction in friction and an increase of the fatigue lifetime are two other major development directions to strive the mentioned targets. It is clear that any kind of solution must show an equal application profile, preferably an improvement, compared to the state-of-the-art solutions. For tribological systems, the following paths may offer lower friction and higher load carrying capabilities: 1. Alternative base oils and additives (such as esters, polyglycols), 2. Thin film coatings (e.g. DLC) and/or 3. Novel steel metallurgies. In previous investigations on the slip-rolling resistance of thin film coatings (a-C, ta-C, Zr(C,N)) the substrates were mainly made of the bearing steels 100Cr6H and Cronidur 30. Applying contact pressures of up to P{sub 0max} = 2.9 GPa (F{sub N} = 2,000 N), the samples were tested up to 10 million load cycles in endurance tests. The aim of the present work is to broaden the research by varying the input parameters. Newly developed engine oil mixtures, high performance thin film coatings and alternative steel solutions are intensively investigated in highly stressed slip-rolling contacts at lubricant temperatures of 120 C. Specifically, in using new steel metallurgies, i.e. the high toughness and high strength steels V300

  9. Manufacture and qualification of hot roll-clad composites with nickel base cladding material for use in flue gas desulphurization plants. Final report; Herstellung und Qualifizierung warmwalzplattierter Verbundwerkstoffe mit Nickelbasisauflagen fuer den Einsatz in Rauchgasentschwefelungsanlagen. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Kirchheiner, R.; Stenner, F.

    1992-03-16

    Flue gas desulphurization plants (FGD), which have been required by law since 1983, mainly apply wet scrubbing techniques. The chemical reactions taking place in those plants lead to extremely corrosive situations. Unprotected carbon steel surfaces or organic based anticorrosive systems are extremely affected after being in operation for only a few years. NiCrM alloys applied by the chemical industry in comparable situations have proved their efficiency for decades. When such massive components are newly built in FDGs, economic aspects require the use of those NiCrMo alloys in clad form. Within the frame of this project tests included the manufacture of hot roll-clad composites comprising cladding materials of the type NiMo16Cr15W (2.4819) and NiCr21Mo14W (2.4602) on the base steel RST 37-2. Large-sized sheets (10000 x 2000 x 10+2 mm) were made by means of an optimized cladding technique. The behaviour of the cladding material in case of uniform and local corrosion exposure was examined in standard laboratory tests. An increased susceptibility to intercrystalline corrosion was not detected, according to the excellent microstructure. Further laboratory tests under simulated FGD conditions and exposure tests in FGDs in operation permitted the transfer of those positive test results to practical work. The same applies without limitation to the joint-welded state with similar filler material of clad a comparable chemical composition. With respect to their technological behaviour the new hot roll-clad composites correspond to that of solid sheets of NiCrMo alloys; therefore they are qualified for use in flue gas desulphurization plants. (orig./BBR) With 32 refs., 13 tabs., 29 figs. [Deutsch] In den seit 1983 gesetzlich vorgeschriebenen Anlagen zur Rauchgasentschwefelung (REA) werden ueberwiegend nasse Waschverfahren eingesetzt. Die in diesen Anlagen ablaufenden chemischen Reaktionen fuehren zu extrem korrosiven Bedingungen. Ungeschuetzte C-Stahl-Oberflaechen bzw

  10. Hot nuclei studied with high efficiency neutron detectors

    International Nuclear Information System (INIS)

    Galin, J.

    1990-01-01

    We have shown the invaluable benefit that a high efficiency 4π neutron detector can bring to the study of reaction mechanisms following collisions of heavy nuclei at intermediate energy. Analysis requires Monte-Carlo simulations for comparison between experimental data and any emission model. In systematic measurements with projectiles of velocity corresponding to energies between 27 and 77 MeV/u, where both the influence of beam velocity and mass have been investigated separately, it has been shown that the projectile-target mass asymmetry, much more than velocity, has a decisive influence on energy dissipation. The closer the projectile mass to the target mass, the more energy is dissipated per unit mass of the considered projectile plus target system. The latter presents all the characteristics of a thermalized system, evaporating a copious number of light particles: up to about 40 neutrons (after efficiency correction) and 11 light charged particles in the most dissipative collisions between Kr+Au, and 90 neutrons for Pb+U with a yet unknown number of l.c.p. In the Kr experiment, these particles are isotropically emitted in the frame of a fused system, excited with 1.2 GeV. Moreover, l.c.p. exhibit Maxwellian energy distributions as in any standard evaporation process. We are now eager to better characterize the properties of the Pb+Au (U) systems for which about 1/3 of the neutrons are freed in a rather large fraction of all collisions. The thermalized energy should then approach very closely the total binding energy of the two interacting nuclei

  11. Effects of Hot Streak Shape on Rotor Heating in a High-Subsonic Single-Stage Turbine

    Science.gov (United States)

    Dorney, Daniel J.; Gundy-Burlet, Karen L.; Norvig, Peter (Technical Monitor)

    1999-01-01

    Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location (clocking) of the hot streak relative to the first-stage vane airfoils can be used to minimize the adverse effects of the hot streak. The effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have also been evaluated. In the present investigation, three-dimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine operating in high subsonic flow. In addition to a simulation of the baseline turbine, simulations have been performed for circular and elliptical hot streaks of varying sizes in an effort to represent different combustor designs. The predicted results for the baseline simulation show good agreement with the available experimental data. The results of the hot streak simulations indicate: that a) elliptical hot streaks mix more rapidly than circular hot streaks, b) for small hot streak surface area the average rotor temperature is not a strong function of hot streak temperature ratio or shape, and c) hot streaks with larger surface area interact with the secondary flows at the rotor hub endwall, generating an additional high temperature region.

  12. High Throughput, High Precision Hot Testing Tool for HBLED Wafer Level Testing

    Energy Technology Data Exchange (ETDEWEB)

    Solarz, Richard [KLA-Tencor Corporation, Milpitas, CA (United States); McCord, Mark [KLA-Tencor Corporation, Milpitas, CA (United States)

    2015-12-31

    The Socrates research effort developed an in depth understanding and demonstrated in a prototype tool new precise methods for teh characterization of color characteristics and flux from individual LEDs for the production of uniform quality lighting. This effort was focused on improving the color quality and consistency of solid state lighting and potentially reducing characterization costs for all LED product types. The patented laser hot testing method was demonstrated to be far more accurate than all current state of the art color and flux characterization methods in use by the solid state lighting industry today. A seperately patented LED grouping method (statistical binning) was demonstrated to be a useful approach to improving utilization of entire lots of large color and flux distributions of manufactured LEDs for high quality color solid-state lighting. At the conclusion of the research in late 2015 the solid-state lighting industry was however generally satisfied with its existing production methods for high quality color products for the small segment of customers that demand it, albeit with added costs.

  13. Specular Reflectivity and Hot-Electron Generation in High-Contrast Relativistic Laser-Plasma Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, Gregory Elijah [The Ohio State Univ., Columbus, OH (United States)

    2013-01-01

    Ultra-intense laser (> 1018 W/cm2) interactions with matter are capable of producing relativistic electrons which have a variety of applications in state-of-the-art scientific and medical research conducted at universities and national laboratories across the world. Control of various aspects of these hot-electron distributions is highly desired to optimize a particular outcome. Hot-electron generation in low-contrast interactions, where significant amounts of under-dense pre-plasma are present, can be plagued by highly non-linear relativistic laser-plasma instabilities and quasi-static magnetic field generation, often resulting in less than desirable and predictable electron source characteristics. High-contrast interactions offer more controlled interactions but often at the cost of overall lower coupling and increased sensitivity to initial target conditions. An experiment studying the differences in hot-electron generation between high and low-contrast pulse interactions with solid density targets was performed on the Titan laser platform at the Jupiter Laser Facility at Lawrence Livermore National Laboratory in Livermore, CA. To date, these hot-electrons generated in the laboratory are not directly observable at the source of the interaction. Instead, indirect studies are performed using state-of-the-art simulations, constrained by the various experimental measurements. These measurements, more-often-than-not, rely on secondary processes generated by the transport of these electrons through the solid density materials which can susceptible to a variety instabilities and target material/geometry effects. Although often neglected in these types of studies, the specularly reflected light can provide invaluable insight as it is directly influenced by the interaction. In this thesis, I address the use of (personally obtained) experimental specular reflectivity measurements to indirectly study hot-electron generation in the context of high-contrast, relativistic

  14. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... of the cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  15. Detection method based on Kalman filter for high speed rail defect AE signal on wheel-rail rolling rig

    Science.gov (United States)

    Hao, Qiushi; Shen, Yi; Wang, Yan; Zhang, Xin

    2018-01-01

    Nondestructive test (NDT) of rails has been carried out intermittently in traditional approaches, which highly restricts the detection efficiency under rapid development of high speed railway nowadays. It is necessary to put forward a dynamic rail defect detection method for rail health monitoring. Acoustic emission (AE) as a practical real-time detection technology takes advantage of dynamic AE signal emitted from plastic deformation of material. Detection capacities of AE on rail defects have been verified due to its sensitivity and dynamic merits. Whereas the application under normal train service circumstance has been impeded by synchronous background noises, which are directly linked to the wheel speed. In this paper, surveys on a wheel-rail rolling rig are performed to investigate defect AE signals with varying speed. A dynamic denoising method based on Kalman filter is proposed and its detection effectiveness and flexibility are demonstrated by theory and computational results. Moreover, after comparative analysis of modelling precision at different speeds, it is predicted that the method is also applicable for high speed condition beyond experiments.

  16. High Temperature Deformation of Twin-Roll Cast Al-Mn-Based Alloys after Equal Channel Angular Pressing.

    Science.gov (United States)

    Málek, Přemysl; Šlapáková Poková, Michaela; Cieslar, Miroslav

    2015-11-12

    Twin roll cast Al-Mn- and Al-Mn-Zr-based alloys were subjected to four passes of equal channel angular pressing. The resulting grain size of 400 nm contributes to a significant strengthening at room temperature. This microstructure is not fully stable at elevated temperatures and recrystallization and vast grain growth occur at temperatures between 350 and 450 °C. The onset of these microstructure changes depends on chemical and phase composition. Better stability is observed in the Al-Mn-Zr-based alloy. High temperature tensile tests reveal that equal channel angular pressing results in a softening of all studied materials at high temperatures. This can be explained by an active role of grain boundaries in the deformation process. The maximum values of ductility and strain rate sensitivity parameter m found in the Al-Mn-Zr-based alloy are below the bottom limit of superplasticity (155%, m = 0.25). However, some features typical for superplastic behavior were observed-the strain rate dependence of the parameter m , the strengthening with increasing grain size, and the fracture by diffuse necking. Grain boundary sliding is believed to contribute partially to the overall strain in specimens where the grain size remained in the microcrystalline range.

  17. Stress and accidental defect detection on rolling mill rolls

    International Nuclear Information System (INIS)

    Auzas, J.-D.

    1999-01-01

    During the rolling mill process, rolls are submitted to high pressures that can lead to local decohesion or metallurgical changes. Both these cracks or softened areas must be detected as soon as they appear because of the risk of spalling, marks on the product, and mill wreck. These defects can be detected using the eddy current method, and particularly sensors specially developed for micro-defects detection. These sensors must be adapted to the environment of a roll grinding machine on which they must be installed. Users' schedule of conditions also require them to be attached to a wide range of eddy current generator and automatic computerized interpretation. Mill requirements for new high tech roll grades and quality lead to continuous development and improvement of the tools that will provide immediate 'go - no go' information. This paper is an update of these developments. (author)

  18. Vibration of high-voltage electric machines with rotors on rolling bearings

    Science.gov (United States)

    Shekyan, H. G.; Gevorgyan, A. V.

    2018-04-01

    The paper presents an investigation of vibrational activity of electric machines due to high-harmonic vibrational loadings. It is shown that the vibrational loadings experienced by bearings may result in the interruption of their normal operation and even take them out of action. Therefore, the values of the vibrational speed-up leading to high harmonics are factors determining the admissible dynamic loading on the bearings. In the paper, an attempt is made to consider the factors which result in origination of high harmonics and to illustrate methods for their smoothing.

  19. Efficiency roll-off suppression in organic light-emitting diodes using size-tunable bimetallic bowtie nanoantennas at high current densities

    International Nuclear Information System (INIS)

    Zhao, Yukun; Yun, Feng; Li, Yufeng; Feng, Lungang; Ding, Wen; Huang, Yi; Wu, Zhaoxin; Jiao, Bo; Li, Sanfeng; Zhang, Ye

    2016-01-01

    Size-tunable bimetallic bowtie nanoantennas have been utilized to suppress the efficiency roll-off characteristics in organic light-emitting diodes (OLEDs) using both the numerical and experimental approaches. The resonant range can be widened by the strong dual-atomic couplings in bimetallic bowtie nanoantennas. Compared with the green OLED with conventional bowtie nanoantennas at a high current density of 800 mA/cm"2, the measured efficiency roll-off ratio of the OLED with size-modulated bowtie nanoantennas is decreased from 53.2% to 41.8%, and the measured current efficiency is enhanced by 29.9%. When the size-modulated bowtie nanoantennas are utilized in blue phosphorescent OLEDs, the experimental roll-off ratio is suppressed from 43.6% to 25.9% at 250 mA/cm"2, and the measured current efficiency is also enhanced significantly. It is proposed that the efficiency roll-off suppression is mainly related to the enhanced localized surface plasmon effect, which leads to a shorter radiative lifetime.

  20. Efficiency roll-off suppression in organic light-emitting diodes using size-tunable bimetallic bowtie nanoantennas at high current densities

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yukun [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics & Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ (United Kingdom); Yun, Feng, E-mail: fyun2010@mail.xjtu.edu.cn; Li, Yufeng; Feng, Lungang; Ding, Wen [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics & Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Huang, Yi [Department of Electrical Engineering and Electronics, University of Liverpool, Liverpool L69 3GJ (United Kingdom); Wu, Zhaoxin; Jiao, Bo; Li, Sanfeng [Key Laboratory of Physical Electronics and Devices of Ministry of Education and Shaanxi Provincial Key Laboratory of Photonics & Information Technology, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Zhang, Ye [Solid-State Lighting Engineering Research Center, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2016-07-04

    Size-tunable bimetallic bowtie nanoantennas have been utilized to suppress the efficiency roll-off characteristics in organic light-emitting diodes (OLEDs) using both the numerical and experimental approaches. The resonant range can be widened by the strong dual-atomic couplings in bimetallic bowtie nanoantennas. Compared with the green OLED with conventional bowtie nanoantennas at a high current density of 800 mA/cm{sup 2}, the measured efficiency roll-off ratio of the OLED with size-modulated bowtie nanoantennas is decreased from 53.2% to 41.8%, and the measured current efficiency is enhanced by 29.9%. When the size-modulated bowtie nanoantennas are utilized in blue phosphorescent OLEDs, the experimental roll-off ratio is suppressed from 43.6% to 25.9% at 250 mA/cm{sup 2}, and the measured current efficiency is also enhanced significantly. It is proposed that the efficiency roll-off suppression is mainly related to the enhanced localized surface plasmon effect, which leads to a shorter radiative lifetime.

  1. Fabrication of High Current YBa2Cu3O7-y Coated Conductors Using Rolling-Assisted Biaxially Textured Substrates

    International Nuclear Information System (INIS)

    Christen, D.K.; Feenstra, R.; Kroeger, D.M.; Lee, D.F.; List, F.A.; Martin, P.M.; Norton, D.P.; Paranthaman, M.; Park, C.; Royal, A.; Specht, E.D.; Verebelyi, D.T.

    1999-01-01

    High critical current YBa 2 Cu 3 O 7-y (referred to as YBCO) coated conductors were fabricated with a layer sequence of YBCO/YSZ/CeO 2 /Ni. The cube (100) texture in the starting Ni substrates was obtained by cold rolling followed by recrystallization. A thin CeO 2 (Cerium Oxide) layer with a thickness of 100-200 was grown epitaxially on the biaxially textured-Ni substrates using an e-beam evaporation technique. This was followed by the growth of a thick ( 2 film had a dense microstructure. The microstructure of the e-beam YSZ film was porous whereas the sputtered YSZ film was dense. The YBCO films were grown by pulsed laser deposition on both e-beam and sputtered YSZ layers. A transport critical current density of 1 x l0 6 A/cm 2 at 77 K was obtained for 0.8 m thick YBCO Rims on both YSZ surfaces in zero field. To demonstrate the quality and compatibility of the e-beam CeO 2 layers; YBCO films were also grown on CeO 2 -buffered YSZ (100) single crystal substrates using e-beam co-evaporated Y-BaF 2 -Cu precursors followed by a post-annealing process. A transport critical current density of over 1 x lO 6 A/cm 2 at 77 K was obtained on a 0.3 m thick YBCO film in zero field

  2. Recrystallization and grain growth behavior of rolled tungsten under VDE-like short pulse high heat flux loads

    Science.gov (United States)

    Yuan, Y.; Greuner, H.; Böswirth, B.; Krieger, K.; Luo, G.-N.; Xu, H. Y.; Fu, B. Q.; Li, M.; Liu, W.

    2013-02-01

    Short pulse heat loads expected for vertical displacement events (VDEs) in ITER were applied in the high heat flux (HHF) test facility GLADIS at IPP-Garching onto samples of rolled W. Pulsed neutral beams with the central heat flux of 23 MW/m2 were applied for 0.5, 1.0 and 1.5 s, respectively. Rapid recrystallization of the adiabatically loaded 3 mm thick samples was observed when the pulse duration was up to 1.0 s. Grains grew markedly following recrystallization with increasing pulse length. The recrystallization temperature and temperature dependence of the recrystallized grain size were also investigated. The results showed that the recrystallization temperature of the W grade was around 2480 °C under the applied heat loading condition, which was nearly 1150 °C higher than the conventional recrystallization temperature, and the grains were much finer. A linear relationship between the logarithm of average grain size (ln d) and the inverse of maximum surface temperature (1/Tmax) was found and accordingly the activation energy for grain growth in temperature evolution up to Tmax in 1.5 s of the short pulse HHF load was deduced to be 4.1 eV. This provided an effective clue to predict the structure evolution under short pulse HHF loads.

  3. Austenitic Reversion of Cryo-rolled Ti-Stabilized Austenitic Stainless Steel: High-Resolution EBSD Investigation

    Science.gov (United States)

    Tiamiyu, A. A.; Odeshi, A. G.; Szpunar, J. A.

    2018-02-01

    In this study, AISI 321 austenitic stainless steel (ASS) was cryo-rolled and subsequently annealed at 650 and 800 °C to reverse BCC α'-martensite to FCC γ-austenite. The texture evolution associated with the reversion at the selected temperatures was investigated using high-resolution EBSD. After the reversion, TiC precipitates were observed to be more stable in 650 °C-annealed specimens than those reversed at 800 °C. {110} texture was mainly developed in specimens subjected to both annealing temperatures. However, specimens reversed at 650 °C have stronger texture than those annealed at 800 °C, even at the higher annealing time. The strong intensity of {110} texture component is attributed to the ability of AISI 321 ASS to memorize the crystallographic orientation of the deformed austenite, a phenomenon termed texture memory. The development of weaker texture in 800 °C-annealed specimens is attributed to the residual strain relief in grains, dissolution of grain boundary precipitates, and an increase in atomic migration along the grain boundaries. Based on the observed features of the reversed austenite grains and estimation from an existing model, it is suspected that the austenite reversion at 650 and 800 °C undergone diffusional and martensitic shear reversion, respectively.

  4. Roll type conducting polymer legs for rigid-flexible thermoelectric generator

    Directory of Open Access Journals (Sweden)

    Teahoon Park

    2017-07-01

    Full Text Available A roll-type conducting polymer film was explored as a flexible organic p-type thermoelectric leg using poly(3,4-ethylenedioxythiophene (PEDOT doped with tosylate. The PEDOT films were prepared through solution casting polymerization and rolled up for a roll-type leg. Due to the high flexibility, the roll-type PEDOT leg enabled easy contact to both top and bottom electrodes. Simulation on the dynamic heat transfer and convective cooling for a vertically roosted rod- and roll-type PEDOT leg showed that the temperature difference (ΔT between the hot and cold sides of the leg was much higher in the roll than that of the rod. The PEDOT legs were integrated with n-type Bi2Te3 blocks, to give a 36-couple rigid-flexible thermoelectric generator (RF-TEG. The maximum output voltage from the 36-couple RF-TEG under a ΔT of 7.9 K was determined as 36.7 mV along with a high output power of 115 nW. A wearable RF-TEG was prepared upon the combination of the 36-couple RF-TEG with an arm warmer, to afford an output voltage of 10.6 mV, which was generated constantly and steadily from human wrist heat.

  5. Analysis of Metal Flow Behavior and Residual Stress Formation of Complex Functional Profiles under High-Speed Cold Roll-Beating

    Directory of Open Access Journals (Sweden)

    Fengkui Cui

    2018-01-01

    Full Text Available To obtain a good surface layer performance of the complex functional profile during the high-speed cold roll-beating forming process, this paper analyzed the metal plastic flow and residual stress-formed mechanism by using a theoretical model of the metal flow and residual stress generation. By using simulation software, the cold roll-beating forming process of a spline shaft was simulated and analyzed. The metal flow and residual stress formation law in the motion were researched. In a practical experiment, the changes in the grains in the spline tooth profile section and the residual stress distribution on the tooth profile were studied. A microcorrespondence relationship was established between the metal plastic flow and the residual stress generation. The conclusions indicate that the rate at which the metal flow decreases changes gradually at different metal layers. The residual stress value is directly related to the plastic flow difference. As the roll-beating speed increases, the uneven degree of plastic deformation at the workpiece surface increases, and the residual stress in the tooth profile is generally greater. At the same roll-beating speed, the rate change trend of the metal flow decreases gradually from the surface to the inner layer and from the dedendum to the addendum. The residual stress distribution on the surface of the tooth profile decreases from the dedendum to the addendum. These findings provide a basis and guidance for the controlled use of residual stress, obtaining better surface layer quality in the high-speed cold roll-beating process of the complex functional profile.

  6. Rheo-optical Raman study of microscopic deformation in high-density polyethylene under hot drawing

    OpenAIRE

    Kida, Takumitsu; Hiejima, Yusuke; Nitta, Koh-hei

    2015-01-01

    In situ observation of the microscopic structural changes in high-density polyethylene during hot drawing was performed by incorporating a temperature-controlled tensile machine into a Raman spectroscopy apparatus. It was found that the load sharing and molecular orientation during elongation drastically changed at 50°C. The microscopic stress of the crystalline chains decreased with increasing temperature and diminished around 50°C. Moreover, the orientation of the crystalline chains was gre...

  7. Target Surface Area Effects on Hot Electron Dynamics from High Intensity Laser-Plasma Interactions

    Science.gov (United States)

    2016-08-19

    Science, University ofMichigan, AnnArbor,MI 48109-2099, USA E-mail: czulick@umich.edu Keywords: laser- plasma ,mass-limited, fast electrons , sheath...New J. Phys. 18 (2016) 063020 doi:10.1088/1367-2630/18/6/063020 PAPER Target surface area effects on hot electron dynamics from high intensity laser... plasma interactions CZulick, ARaymond,AMcKelvey, VChvykov, AMaksimchuk, AGRThomas, LWillingale, VYanovsky andKKrushelnick Center forUltrafast Optical

  8. Hot-wall corrosion testing of simulated high level nuclear waste

    International Nuclear Information System (INIS)

    Chandler, G.T.; Zapp, P.E.; Mickalonis, J.I.

    1995-01-01

    Three materials of construction for steam tubes used in the evaporation of high level radioactive waste were tested under heat flux conditions, referred to as hot-wall tests. The materials were type 304L stainless steel alloy C276, and alloy G3. Non-radioactive acidic and alkaline salt solutions containing halides and mercury simulated different high level waste solutions stored or processed at the United States Department of Energy's Savannah River Site. Alloy C276 was also tested for corrosion susceptibility under steady-state conditions. The nickel-based alloys C276 and G3 exhibited excellent corrosion resistance under the conditions studied. Alloy C276 was not susceptible to localized corrosion and had a corrosion rate of 0.01 mpy (0.25 μm/y) when exposed to acidic waste sludge and precipitate slurry at a hot-wall temperature of 150 degrees C. Type 304L was susceptible to localized corrosion under the same conditions. Alloy G3 had a corrosion rate of 0.1 mpy (2.5 μm/y) when exposed to caustic high level waste evaporator solution at a hot-wall temperature of 220 degrees C compared to 1.1 mpy (28.0 μ/y) for type 304L. Under extreme caustic conditions (45 weight percent sodium hydroxide) G3 had a corrosion rate of 0.1 mpy (2.5 μm/y) at a hot-wall temperature of 180 degrees C while type 304L had a high corrosion rate of 69.4 mpy (1.8 mm/y)

  9. 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.

  10. Use of high frequency analysis of acoustic emission signals to determine rolling element bearing condition

    International Nuclear Information System (INIS)

    Cockerill, A; Holford, K M; Pullin, R; Clarke, A; Bradshaw, T; Cole, P

    2015-01-01

    Acoustic Emission (AE) sensors were used to detect signals arising from a cylindrical roller bearing with artificial defects seeded onto the outer raceway. An SKF N204ECP roller bearing was placed between two double row spherical roller bearings, type SKF 22202E, and loaded between 0.29 and 1.79kN. Speed was constant at 5780rpm. High frequency analysis allowed insight into the condition of the bearings through the determination of an increase in the structural resonances of the system as the size of an artificial defect was increased. As higher loads were applied, frequencies around 100kHz were excited, indicating the release of AE possibly attributed to friction and the plastic deformation as peaks, induced through engraving of the raceway, were flattened and worn down. Sensitivity of AE to this level in bearings indicates the potential of the technique to detect the early stages of bearing failure during life tests. (paper)

  11. High-Performance Flexible Thin-Film Transistors Based on Single-Crystal-like Silicon Epitaxially Grown on Metal Tape by Roll-to-Roll Continuous Deposition Process.

    Science.gov (United States)

    Gao, Ying; Asadirad, Mojtaba; Yao, Yao; Dutta, Pavel; Galstyan, Eduard; Shervin, Shahab; Lee, Keon-Hwa; Pouladi, Sara; Sun, Sicong; Li, Yongkuan; Rathi, Monika; Ryou, Jae-Hyun; Selvamanickam, Venkat

    2016-11-02

    Single-crystal-like silicon (Si) thin films on bendable and scalable substrates via direct deposition are a promising material platform for high-performance and cost-effective devices of flexible electronics. However, due to the thick and unintentionally highly doped semiconductor layer, the operation of transistors has been hampered. We report the first demonstration of high-performance flexible thin-film transistors (TFTs) using single-crystal-like Si thin films with a field-effect mobility of ∼200 cm 2 /V·s and saturation current, I/l W > 50 μA/μm, which are orders-of-magnitude higher than the device characteristics of conventional flexible TFTs. The Si thin films with a (001) plane grown on a metal tape by a "seed and epitaxy" technique show nearly single-crystalline properties characterized by X-ray diffraction, Raman spectroscopy, reflection high-energy electron diffraction, and transmission electron microscopy. The realization of flexible and high-performance Si TFTs can establish a new pathway for extended applications of flexible electronics such as amplification and digital circuits, more than currently dominant display switches.

  12. Development of maintenance equipment for nuclear material fabrication equipment in a highly active hot cell

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. J.; Yang, M. S.; Kim, K. H. and others

    2000-09-01

    This report presents the development of a maintenance system for a highly contaminated nuclear material handling equipment at a hot-cell. This maintenance system has mainly three subsystems - a gamma-radiation measurement module for detecting a gamma-radiation level and identifying its distribution in-situ, a dry-type decontamination device for cleaning up contaminated particles, and a maintenance chamber for isolating contaminated equipment. The mechanical design considerations, controller, capabilities and remote operation and manipulation of the maintenance system are described. Such subsystems developed were installed and tested in the IMEF (Irradiated Material Examination Facility) M6 hot-cell after mock-up tests and performed their specific tasks successfully.

  13. Development of maintenance equipment for nuclear material fabrication equipment in a highly active hot cell

    International Nuclear Information System (INIS)

    Park, J. J.; Yang, M. S.; Kim, K. H. and others

    2000-09-01

    This report presents the development of a maintenance system for a highly contaminated nuclear material handling equipment at a hot-cell. This maintenance system has mainly three subsystems - a gamma-radiation measurement module for detecting a gamma-radiation level and identifying its distribution in-situ, a dry-type decontamination device for cleaning up contaminated particles, and a maintenance chamber for isolating contaminated equipment. The mechanical design considerations, controller, capabilities and remote operation and manipulation of the maintenance system are described. Such subsystems developed were installed and tested in the IMEF (Irradiated Material Examination Facility) M6 hot-cell after mock-up tests and performed their specific tasks successfully

  14. High Density Radiation Shielding Concretes for Hot Cells of 99mTc Project

    International Nuclear Information System (INIS)

    Sakr, K.

    2006-01-01

    High density concrete [more than 3.6 ton/m 3 (3.6x10 3 kg/m 3 )] was prepared to be used as a radiation shielding concrete (RSC) for hot-cells in gel technetium project at inshas to attenuate gamma radiation emitted from radioactive sources. different types of concrete were prepared by mixing local mineral aggregates mainly gravel and ilmenite . iron shots were added to the concrete mixture proportion as partial replacement of heavy aggregates to increase its density. the physical properties of prepared concrete in both plastic and hardened phases were investigated. compressive strength and radiation attenuation of gamma rays were determined. Results showed that ilmenite concrete mixed with iron shots had the highest density suitable to be use as RSC according to the chinese hot cell design requirements. Recommendations to avoid some technical problems of manufacturing radiation shielding concrete were maintained

  15. The hot bench scale plant Ester for the vitrification of high level wastes

    International Nuclear Information System (INIS)

    Nannicini, R.; Strazzer, A.; Cantale, C; Donato, A.; Grossi, G.

    1985-01-01

    In this paper the hot bench-scale plant ESTER for the vitrification of the high-level radioactive wastes is described, and the main results of the first radioactive campaign are reported. The ESTER plant, which is placed in the ADECO-ESSOR hot cells of the C.C.R.-EURATOM-ISPRA, has been built and is operated by the ENEA, Departement of Fuel Cycle. It began operating with real radioactive wastes about 1 year ago, solidifying a total of 12 Ci of fission products into 2,02 Kg of borosilicate glass, corresponding to 757 ml of glass. During the vitrification many samples of liquid and gaseous streams have been taken and analyzed. A radioactivity balance in the plant has been calculated, as well as a mass balance of nitrates and of the 137 Cs and 106 Ru volatized in the process

  16. Instability and associated roll structure of Marangoni convection in high Prandtl number liquid bridge with large aspect ratio

    Science.gov (United States)

    Yano, T.; Nishino, K.; Kawamura, H.; Ueno, I.; Matsumoto, S.

    2015-02-01

    This paper reports the experimental results on the instability and associated roll structures (RSs) of Marangoni convection in liquid bridges formed under the microgravity environment on the International Space Station. The geometry of interest is high aspect ratio (AR = height/diameter ≥ 1.0) liquid bridges of high Prandtl number fluids (Pr = 67 and 207) suspended between coaxial disks heated differentially. The unsteady flow field and associated RSs were revealed with the three-dimensional particle tracking velocimetry. It is found that the flow field after the onset of instability exhibits oscillations with azimuthal mode number m = 1 and associated RSs traveling in the axial direction. The RSs travel in the same direction as the surface flow (co-flow direction) for 1.00 ≤ AR ≤ 1.25 while they travel in the opposite direction (counter-flow direction) for AR ≥ 1.50, thus showing the change of traveling directions with AR. This traveling direction for AR ≥ 1.50 is reversed to the co-flow direction when the temperature difference between the disks is increased to the condition far beyond the critical one. This change of traveling directions is accompanied by the increase of the oscillation frequency. The characteristics of the RSs for AR ≥ 1.50, such as the azimuthal mode of oscillation, the dimensionless oscillation frequency, and the traveling direction, are in reasonable agreement with those of the previous sounding rocket experiment for AR = 2.50 and those of the linear stability analysis of an infinite liquid bridge.

  17. Evidence for a Dayside Thermal Inversion and High Metallicity for the Hot Jupiter WASP-18b

    Science.gov (United States)

    Sheppard, Kyle; Mandell, Avi M.; Tamburo, Patrick; Gandhi, Siddarth; Pinhas, Arazi; Madhusudhan, Nikku; Deming, Drake

    2018-01-01

    Hot Jupiters have been vital in revealing the structural and atmospheric diversity of gas-rich planets. Since they are exposed to extreme conditions and relatively easy to observe through transit and eclipse spectroscopy, hot Jupiters provide a window into a unique part of parameter space, allowing us to better understand both atmospheric physics and planetary structure. Additionally, constraints on the structure and composition of exoplanetary atmospheres allow us to test and generalize planetary formation models. We find evidence for a strong thermal inversion in the dayside atmosphere of the highly irradiated hot Jupiter WASP-18b (Teq=2400K, M=10MJ) based on Hubble Space Telescope secondary eclipse observations and Spitzer eclipse photometry. We report a 4.7σ detection of CO, and a non-detection of water vapor as well as all other relevant species (e.g., TiO, VO). The most probable atmospheric retrieval solution indicates a C/O ratio of 1 and an extremely high metallicity (C/H=~283x solar). If confirmed with future observations, WASP-18b would be the first example of a planet with a non-oxide driven thermal inversion and an atmospheric metallicity inconsistent with that predicted for Jupiter-mass planets.

  18. Decommissioning of a hot cell with high levels of contamination. Experience during the Undressed of Workers

    International Nuclear Information System (INIS)

    Martinez, A.; Sancho, C.

    1998-01-01

    The object of this work is to show the radiological controls in decommissioning of the inner of the Base Cell of the Nuclear Facility of CIEMAT, IN-04 (Metallurgy Hot Cells) and the experience during the undressed of workers in decommissioning of this cell. The workers were equipped with one cotton overalls and one or two paper overalls of one-use. Also, when the radiation levels are high, the workers were equipped with leaded glasses and aprons. The protection equipment for internal contamination were autonomous and semi-autonomous respiratory equipment. Due to a high superficial contamination levels, two areas were established in order to proceed to the undressed of the workers when these concluded their work. The first area was a confined enclosure by joined to the hot cell, where an expert of the Radiation Protection Service (RPS), trained for it, take off the first paper overall and the first pair of gloves to the worker that come out the hot cells. The second area was at the exist of the Load Zone, where another expert of PRS, take off the second paper overall, the second pair of gloves and dislocated the pipe of air of the semi-autonomous respiratory equipment, to the worker that come out this zone. (Author)

  19. A MULTIWAVELENGTH STUDY OF THE HIGH SURFACE BRIGHTNESS HOT SPOT IN PKS 1421-490

    International Nuclear Information System (INIS)

    Godfrey, L. E. H.; Bicknell, G. V.; Lovell, J. E. J.; Jauncey, D. L.; Gelbord, J.; Schwartz, D. A.; Birkinshaw, M.; Worrall, D. M.; Marshall, H. L.; Georganopoulos, M.; Perlman, E. S.; Murphy, D. W.

    2009-01-01

    Long Baseline Array imaging of the z = 0.663 broadline radio galaxy PKS 1421-490 reveals a 400 pc diameter high surface brightness hot spot at a projected distance of ∼40 kpc from the active galactic nucleus. The isotropic X-ray luminosity of the hot spot, L 2-10keV = 3 x 10 44 ergs s -1 , is comparable to the isotropic X-ray luminosity of the entire X-ray jet of PKS 0637-752, and the peak radio surface brightness is hundreds of times greater than that of the brightest hot spot in Cygnus A. We model the radio to X-ray spectral energy distribution using a one-zone synchrotron self-Compton model with a near equipartition magnetic field strength of 3 mG. There is a strong brightness asymmetry between the approaching and receding hotspots and the hot spot spectrum remains flat (α ∼ 0.5) well beyond the predicted cooling break for a 3 mG magnetic field, indicating that the hotspot emission may be Doppler beamed. A high plasma velocity beyond the terminal jet shock could be the result of a dynamically important magnetic field in the jet. There is a change in the slope of the hotspot radio spectrum at GHz frequencies, which we model by incorporating a cutoff in the electron energy distribution at γ min ∼ 650, with higher values implied if the hotspot emission is Doppler beamed. We show that a sharp decrease in the electron number density below a Lorentz factor of 650 would arise from the dissipation of bulk kinetic energy in an electron/proton jet with a Lorentz factor Γ jet ∼> 5.

  20. 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

  1. Low roll-off and high efficiency orange OLEDs using green and red dopants in an exciplex forming co-host

    Science.gov (United States)

    Lee, Sunghun; Kim, Kwon-Hyeon; Yoo, Seung-Jun; Park, Young-Seo; Kim, Jang-Joo

    2013-09-01

    We present high efficiency orange emitting OLEDs with low driving voltage and low roll-off of efficiency using an exciplex forming co-host by (1) co-doping of green and red emitting phosphorescence dyes in the host and (2) red and green phosphorescent dyes doped in the host as separate red and green emitting layers. The orange OLEDs achieved a low turn-on voltage of 2.4 V and high external quantum efficiencies (EQE) of 25.0% and 22.8%, respectively. Moreover, the OLEDs showed low roll-off of efficiency with an EQE of over 21% and 19.6% at 10,000 cd/m2, respectively. The devices displayed good orange color with very little color shift with increasing luminance. The transient electroluminescence of the OLEDs indicated that both energy transfer and direct charge trapping took place in the devices.

  2. Evolution of Microstructure and Texture during Annealing of Aluminum AA1050 Cold Rolled to High and Ultrahigh Strains

    DEFF Research Database (Denmark)

    Mishin, Oleg; Juul Jensen, Dorte; Hansen, Niels

    2010-01-01

    The microstructure and texture of commercial purity aluminum (AA1050) have been investigated after cold rolling to von Mises strains of 3.6 to 6.4 followed by recovery and recrystallization during annealing. The evolution of structural parameters of the deformed microstructure, such as boundary...

  3. Elution behavior into the high pressured hot water and the organizational change of granite and andesite

    Energy Technology Data Exchange (ETDEWEB)

    Matsunaga, Isao; Miyazaki, Akira; Yamaguchi, Tsutomu; kuriyakawa, Michio

    1988-04-01

    In the development of a high temperature rock system, the interaction between the rock and hot water which occurs in a reservoir provides big effects. The decline of the strength and the increase of the permeability are caused by the elusion of the rock on the surface of the hydraulic fracture and the redeposition of the eluded material also causes to narrow or close the channel. However, studies concerning the organizational change of the rock by the hot water or the material change associated with the organizational change are small in number. In this research, Inaba granite and Honkomatsu andesite were treated in heat with an autoclave in order to investigate the organizational changes of the rocks and at the same time, the elusion behavior of the rocks into the hot water was investigated by examining chemical components which were eluded into the fluid and the components remaining on the rock surface. The decreased amount per specific surface area due to the autoclave treatment is the order of 10/sup -3/(gcm/sup -2/) for both rocks and changeable depending upon the heating temperature and the kind of rock. As a result of the analysis of the fluids in the autoclave after the heat treatment, the Si concentration of Honkomatsu andesite was higher in the same temperature and the heating time. (2 figs, 3 tabs, 6 refs)

  4. Prediction of hot deformation behavior of high phosphorus steel using artificial neural network

    Science.gov (United States)

    Singh, Kanchan; Rajput, S. K.; Soota, T.; Verma, Vijay; Singh, Dharmendra

    2018-03-01

    To predict the hot deformation behavior of high phosphorus steel, the hot compression experiments were performed with the help of thermo-mechanical simulator Gleeble® 3800 in the temperatures ranging from 750 °C to 1050 °C and strain rates of 0.001 s-1, 0.01 s-1, 0.1 s-1, 0.5 s-1, 1.0 s-1 and 10 s-1. The experimental stress-strain data are employed to develop artificial neural network (ANN) model and their predictability. Using different combination of temperature, strain and strain rate as a input parameter and obtained experimental stress as a target, a multi-layer ANN model based on feed-forward back-propagation algorithm is trained, to predict the flow stress for a given processing condition. The relative error between predicted and experimental stress are in the range of ±3.5%, whereas the correlation coefficient (R2) of training and testing data are 0.99986 and 0.99999 respectively. This shows that a well-trained ANN model has excellent capability to predict the hot deformation behavior of materials. Comparative study shows quite good agreement of predicted and experimental values.

  5. Highly stable and regenerable Mn-based/SBA-15 sorbents for desulfurization of hot coal gas

    International Nuclear Information System (INIS)

    Zhang, F.M.; Liu, B.S.; Zhang, Y.; Guo, Y.H.; Wan, Z.Y.; Subhan, Fazle

    2012-01-01

    Highlights: ► A series of mesoporous Cu x Mn y O z /SBA-15 sorbents were fabricated for hot coal gas desulfurization. ► 1Cu9Mn/SBA-15 sorbent with high breakthrough sulfur capacity is high stable and regenerable. ► Utilization of SBA-15 constrained the sintering and pulverization of sorbents. - Abstract: A series of mesoporous xCuyMn/SBA-15 sorbents with different Cu/Mn atomic ratios were prepared by wet impregnation method and their desulfurization performance in hot coal gas was investigated in a fixed-bed quartz reactor in the range of 700–850 °C. The successive nine desulfurization–regeneration cycles at 800 °C revealed that 1Cu9Mn/SBA-15 presented high performance with durable regeneration ability due to the high dispersion of Mn 2 O 3 particles incorporated with a certain amount of copper oxides. The breakthrough sulfur capacity of 1Cu9Mn/SBA-15 observed 800 °C is 13.8 g S/100 g sorbents, which is remarkably higher than these of 40 wt%LaFeO 3 /SBA-15 (4.8 g S/100 g sorbents) and 50 wt%LaFe 2 O x /MCM-41 (5.58 g S/100 g sorbents) used only at 500–550 °C. This suggested that the loading of Mn 2 O 3 active species with high thermal stability to SBA-15 support significantly increased sulfur capacity at relatively higher sulfidation temperature. The fresh and used xCuyMn/SBA-15 sorbents were characterized by means of BET, XRD, XPS, XAES, TG/DSC and HRTEM techniques, confirmed that the structure of the sorbents remained intact before and after hot coal gas desulfurization.

  6. Basic design and construction of a mobile hot cell for the conditioning of spent high activity radioactive sources

    International Nuclear Information System (INIS)

    An Hongxiang; Fan Zhiwen; Al-Mughrabi, M.

    2011-01-01

    The conditioning of spent high activity radioactive sources is one important step in sealed radioactive sources management strategies. Based on the practice on the designing of the immobilized hot cell, the handling of the sealed radioactive sources, and the reference of the mobile hot cell constructed in South Africa, SHARS conditioning process and the basic design of a mobile hot cell is developed. The mobile hot cell has been constructed and the tests including the cold test of the SRS conditioning, the hot cell assemble and disassemble and SRS recovery were done. The shielding capacity were tested by 3.8 x 10 13 Bq cobalt-60 sources and the dose rate of the equipment surface, below 2 m, is less than 0.016 mSv/h. It is proved that the designing requirement is meet and the function of the equipment is good. (authors)

  7. Handling of Highly Radioactive Radiation Sources in a Hot Cell Using a Mechanically Driven Cell Crane - 13452

    Energy Technology Data Exchange (ETDEWEB)

    Klute, Stefan; Huber, Wolfgang-Bruno [Siempelkamp Nukleartechnik GmbH, Am Taubenfeld 25/1, 69123 Heidelberg (Germany); Meyer, Franz [Nuclear Engineering Seibersdorf GmbH, 2444 Seibersdorf (Austria)

    2013-07-01

    In 2010, Siempelkamp Nukleartechnik GmbH was awarded the contract for design and erection of a Hot Cell for handling and storage of highly radioactive radiation sources. This Hot Cell is part of a new hot cell laboratory, constructed for the NHZ (Neues Handhabungszentrum = New Handling Center) of the Nuclear Engineering Seibersdorf GmbH (NES). All incurring radioactive materials from Austria are collected in the NHZ, where they are safely conditioned and stored temporarily until their final storage. The main tasks of the NES include, apart from the collection, conditioning and storage of radioactive waste, also the reprocessing and the decontamination of facilities and laboratories originating from 45 years of research and development at the Seibersdorf site as well as the operation of the Hot Cell Laboratory [1]. The new Hot Cell Laboratory inside the NHZ consists of the following room areas: - One hot cell, placed in the center, for remote controlled, radiation protected handling of radioactive materials, including an integrated floor storage for the long-term temporary storage of highly radioactive radiation sources; - An anteroom for the loading and unloading of the hot cell; - One control room for the remote controlling of the hot cell equipment; - One floor storage, placed laterally to the hot cell, for burial, interim storage and removal of fissionable radioactive material in leak-proof packed units in 100 l drums. The specific design activity of the hot cell of 1.85 Pbq relating to 1-Me-Radiator including the integrated floor storage influences realization and design of the components used in the cell significantly. (authors)

  8. Rolling induced size effects in elastic–viscoplastic sheet metals

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2015-01-01

    sheet rolling, where a non-homogeneous material deformation takes place between the rollers. Large strain gradients develop where the rollers first come in contact with the sheet, and a higher order plasticity model is employed to illustrate their influence at small scales. The study reveals...... presented revolves around the rolling induced effect of visco-plasticity (ranging hot and cold rolling) in combination with strain gradient hardening – including both dissipative and energetic contributions. To bring out first order effects on rolling at small scale, the modeling efforts are limited to flat...

  9. Influence of Ti on the Hot Ductility of High-manganese Austenitic Steels

    Science.gov (United States)

    Liu, Hongbo; Liu, Jianhua; Wu, Bowei; Su, Xiaofeng; Li, Shiqi; Ding, Hao

    2017-07-01

    The influence of Ti addition ( 0.10 wt%) on hot ductility of as-cast high-manganese austenitic steels has been examined over the temperature range 650-1,250 °C under a constant strain rate of 10-3 s-1 using Gleeble3500 thermal simulation testing machine. The fracture surfaces and particles precipitated at different tensile temperatures were characterized by means of scanning electron microscope and X-ray energy dispersive spectrometry (SEM-EDS). Hot ductility as a function of reduction curves shows that adding 0.10 wt% Ti made the ductility worse in the almost entire range of testing temperatures. The phases' equilibrium diagrams of precipitates in Ti-bearing high-Mn austenitic steel were calculated by the Thermo-Calc software. The calculation result shows that 0.1 wt% Ti addition would cause Ti(C,N) precipitated at 1,499 °C, which is higher than the liquidus temperature of high-Mn austenitic steel. It indicated that Ti(C,N) particles start forming in the liquid high-Mn austenitic steel. The SEM-EDS results show that Ti(C,N) and TiC particles could be found along the austenite grain boundaries or at triple junction, and they would accelerate the extension of the cracks along the grain boundaries.

  10. Growth of highly oriented carbon nanotubes by plasma-enhanced hot filament chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Z.P.; Xu, J.W.; Ren, Z.F.; Wang, J.H. [Materials Synthesis Laboratory, Departments of Physics and Chemistry, and Center for Advanced Photonic and Electronic Materials (CAPEM), State University of New York at Buffalo, Buffalo, New York 14260 (United States); Siegal, M.P.; Provencio, P.N. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States)

    1998-12-01

    Highly oriented, multiwalled carbon nanotubes were grown on polished polycrystalline and single crystal nickel substrates by plasma enhanced hot filament chemical vapor deposition at temperatures below 666 {degree}C. The carbon nanotubes range from 10 to 500 nm in diameter and 0.1 to 50 {mu}m in length depending on growth conditions. Acetylene is used as the carbon source for the growth of the carbon nanotubes and ammonia is used for dilution gas and catalysis. The plasma intensity, acetylene to ammonia gas ratio, and their flow rates, etc. affect the diameters and uniformity of the carbon nanotubes. {copyright} {ital 1998 American Institute of Physics.}

  11. Ductile failure analysis of high strength steel in hot forming based on micromechanical damage model

    Directory of Open Access Journals (Sweden)

    Ying Liang

    2016-01-01

    Full Text Available The damage evolution of high strength steel at elevated temperature is investigated by using the Gurson-Tvergaard-Needleman (GTN model. A hybrid method integrated thermal tensile test and numerical technique is employed to identify the damage parameters. The analysis results show that the damage parameters are different at different temperature as the variation of tested material microstructure. Furthermore, the calibrated damage parameters are implemented to simulate a bugling forming at elevated temperature. The experimental results show the availability of GTN damage model in analyzing sheet formability in hot forming.

  12. Evidence of high-field radio-frequency hot spots due to trapped vortices in niobium cavities

    Directory of Open Access Journals (Sweden)

    G. Ciovati

    2008-12-01

    Full Text Available Superconducting radio-frequency (rf cavities made of high-purity niobium exhibit strong anomalous rf losses starting at peak surface magnetic fields of about 90–100 mT in the gigahertz range. This phenomenon is referred to as “Q drop.” Temperature maps of the cavity surface have revealed the presence of “hot spots” in the high magnetic field region of the cavities. Several models have been proposed over the years to explain this phenomenon but there is still no experimental evidence on the mechanisms behind such hot spots. In this work we show that at least some of the hot spots are due to trapped vortices responsible for the anomalous losses. Here we report experiments in which a local thermal gradient was applied to the hot spot regions of a cavity in order to displace the vortices. Temperature maps measured before and after applying the thermal gradient unambiguously show that the hot spots do move and change their intensities, allowing us to determine changes in the hot spot positions and strengths and their effect on the cavity performance. Results on a large-grain niobium cavity clearly show a different distribution and in some cases a weakening of the intensity of the “hot spots,” suggesting new ways of improving the cavity performance without additional material treatments.

  13. Multi-Fault Diagnosis of Rolling Bearings via Adaptive Projection Intrinsically Transformed Multivariate Empirical Mode Decomposition and High Order Singular Value Decomposition.

    Science.gov (United States)

    Yuan, Rui; Lv, Yong; Song, Gangbing

    2018-04-16

    Rolling bearings are important components in rotary machinery systems. In the field of multi-fault diagnosis of rolling bearings, the vibration signal collected from single channels tends to miss some fault characteristic information. Using multiple sensors to collect signals at different locations on the machine to obtain multivariate signal can remedy this problem. The adverse effect of a power imbalance between the various channels is inevitable, and unfavorable for multivariate signal processing. As a useful, multivariate signal processing method, Adaptive-projection has intrinsically transformed multivariate empirical mode decomposition (APIT-MEMD), and exhibits better performance than MEMD by adopting adaptive projection strategy in order to alleviate power imbalances. The filter bank properties of APIT-MEMD are also adopted to enable more accurate and stable intrinsic mode functions (IMFs), and to ease mode mixing problems in multi-fault frequency extractions. By aligning IMF sets into a third order tensor, high order singular value decomposition (HOSVD) can be employed to estimate the fault number. The fault correlation factor (FCF) analysis is used to conduct correlation analysis, in order to determine effective IMFs; the characteristic frequencies of multi-faults can then be extracted. Numerical simulations and the application of multi-fault situation can demonstrate that the proposed method is promising in multi-fault diagnoses of multivariate rolling bearing signal.

  14. Methodology for the investigation of ignition near hot surfaces in a high-pressure shock tube

    Science.gov (United States)

    Niegemann, P.; Fikri, M.; Wlokas, I.; Röder, M.; Schulz, C.

    2018-05-01

    Autoignition of fuel/air mixtures is a determining process in internal combustion engines. Ignition can start either homogeneously in the gas phase after compression or in the vicinity of hot surfaces. While ignition properties of commercial fuels are conventionally described by a single quantity (octane number), it is known that some fuels have a varying propensity to the two processes. We present a new experimental concept that generates well-controlled temperature inhomogeneities in the shock-heated gases of a high-pressure shock tube. A shock-heated reactive mixture is brought into contact with a heated silicon nitride ceramic glow plug. The glow-plug temperature can be set up to 1200 K, higher than the post-reflected-shock gas temperatures (650-1050 K). High-repetition-rate chemiluminescence imaging is used to localize the onset of ignition in the vicinity of the hot surface. In experiments with ethanol, the results show that in most cases under shock-heated conditions, the ignition begins inhomogeneously in the vicinity of the glow plug and is favored because of the high wall temperature. Additionally, the interaction of geometry, external heating, and gas-dynamic effects was investigated by numerical simulations of the shock wave in a non-reactive flow.

  15. The Process of Thinking among Junior High School Students in Solving HOTS Question

    Science.gov (United States)

    Bakry, Md Nor Bin Bakar

    2015-01-01

    Higher order thinking skills (HOTS) is one of the important aspect of teaching and learning mathematics. By using HOTS, student will be able to acquire a deep understand of mathematical concepts and can be applied in real life. Students ability to develop the capacity of the HOTS is closely related with thinking processes while solving mathematics…

  16. High Prevalence, Genetic Diversity and Intracellular Growth Ability of Legionella in Hot Spring Environments

    Science.gov (United States)

    Zhou, Haijian; Wang, Huanxin; Xu, Ying; Zhao, Mingqiang; Guan, Hong; Li, Machao; Shao, Zhujun

    2013-01-01

    Background Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. Methods Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE) and sequence-based typing (SBT) were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. Results Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (pLegionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (pLegionella pneumophila was the most frequently isolated species (98.9%), and the isolated serogroups included serogroups 3 (25.3%), 6 (23.4%), 5 (19.2%), 1 (18.5%), 2 (10.2%), 8 (0.4%), 10 (0.8%), 9 (1.9%) and 12 (0.4%). Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. Conclusions Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control and prevention strategies are

  17. High prevalence, genetic diversity and intracellular growth ability of Legionella in hot spring environments.

    Directory of Open Access Journals (Sweden)

    Tian Qin

    Full Text Available BACKGROUND: Legionella is the causative agent of Legionnaires' disease, and hot springs are a major source of outbreaks of this disease. It is important from a public health perspective to survey hot spring environments for the presence of Legionella. METHODS: Prospective surveillance of the extent of Legionella pollution was conducted at three hot spring recreational areas in Beijing, China in 2011. Pulsed-field gel electrophoresis (PFGE and sequence-based typing (SBT were used to describe the genetic polymorphism of isolates. The intracellular growth ability of the isolates was determined by interacting with J774 cells and plating the dilutions onto BCYE agar plates. RESULTS: Overall, 51.9% of spring water samples showed Legionella-positive, and their concentrations ranged from 1 CFU/liter to 2,218 CFU/liter. The positive rates of Legionella were significantly associated with a free chlorine concentration of ≥0.2 mg/L, urea concentration of ≥0.05 mg/L, total microbial counts of ≥400 CFU/ml and total coliform of ≥3 MPN/L (p<0.01. The Legionella concentrations were significantly associated with sample temperature, pH, total microbial counts and total coliform (p<0.01. Legionella pneumophila was the most frequently isolated species (98.9%, and the isolated serogroups included serogroups 3 (25.3%, 6 (23.4%, 5 (19.2%, 1 (18.5%, 2 (10.2%, 8 (0.4%, 10 (0.8%, 9 (1.9% and 12 (0.4%. Two hundred and twenty-eight isolates were analyzed by PFGE and 62 different patterns were obtained. Fifty-seven L. pneumophila isolates were selected for SBT analysis and divided into 35 different sequence types with 5 main clonal groups. All the 57 isolates had high intracellular growth ability. CONCLUSIONS: Our results demonstrated high prevalence and genetic polymorphism of Legionella in springs in Beijing, China, and the SBT and intracellular growth assay results suggested that the Legionella isolates of hot spring environments were pathogenic. Improved control

  18. Structure and properties of highly oriented polyoxymethylene produced by hot stretching

    International Nuclear Information System (INIS)

    Zhao Xiaowen; Ye Lin

    2011-01-01

    Research highlights: → Highly oriented POM was fabricated through solid hot stretching technology → Tensile strength and modulus of POM increased remarkably with draw ratio. → The crystal structure of POM changed from spherulite to mat texture by drawing. → Crystallinity and orientation factor of POM increased remarkably by drawing. → The mechanical structure model of microfibril of POM was established. - Abstract: Highly oriented self-reinforced polyoxymethylene (POM) was successfully fabricated through solid phase hot stretching technology. The tensile strength and modulus increased with draw ratio, which reached 900 MPa and 12 GPa, respectively at a high draw ratio of 900% without remarkable drop of the elongation at break. The structure and morphology of the drawn products were studied and the mechanical structure model of microfibril of POM was established. Raman spectral exhibited a low-frequency shift, which indicated two types of molecular chains with different response to the stress. During drawing, the spherulitic structure of POM was broken up and the mat texture crystals were formed. With the increase of draw ratio, the melting peak moved to high temperature and an additional shoulder peak ascribed to melting of highly chain-extended and oriented crystalline blocks was observed. X-ray diffraction showed that the crystallinity and orientation factor increased, while the grain size perpendicular to (1 0 0) crystal plane of POM decreased by drawing. The α relaxation peak corresponding to the glass transition temperature of POM (T g ) moved to high temperature with draw ratio. The section morphology of drawn POM exhibited a fibrillar structure which contributed to the significantly high tensile strength and modulus of the product.

  19. The use of electromagnetic field in designing the high quality Al alloys for hot forging process

    Directory of Open Access Journals (Sweden)

    Zvonko Gulišija

    2014-12-01

    Full Text Available This work presents a way to obtain the better quality of EN AW 7075 aluminum high-strength alloy by application of electromagnetic field (EMF during the casting process. In this way, the uniform fine-grained microstructure, and hence the better mechanical properties of the alloy can be achieved. The microstructure and mechanical characterization for samples obtained with and without EMF were performed. The application of numerical simulation for hot forging process, using appropriate software, is efficient and highly useful tool for problem prediction in industrial production, reducing the time and costs in the process of development of new products. The input data of high strength Al-alloy EN AW-7075 is used for simulation because it enables the development of parts with complex dimensions and shape.

  20. 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.

  1. Industrialization of hot wire chemical vapor deposition for thin film applications

    NARCIS (Netherlands)

    Schropp, Ruud

    2015-01-01

    The consequences of implementing a Hot Wire Chemical Vapor Deposition (HWCVD) chamber into an existing in-line or roll-to-roll reactor are described. The hardware and operation of the HWCVD production reactor is compared to that of existing roll-to-roll reactors based on Plasma Enhanced Chemical

  2. The effect of active antennas on the hot-restrike of high intensity discharge lamps

    International Nuclear Information System (INIS)

    Hoebing, T; Bergner, A; Ruhrmann, C; Mentel, J; Awakowicz, P; Koch, B; Manders, F

    2014-01-01

    The ignition voltage of high intensity discharge (HID) lamps with mercury as the buffer gas may rise from 3 kV for the cold state up to more than 15 kV for a hot lamp. By coating a lamp burner with an electrically conductive layer, which operates as an active antenna, the ignition voltage of HID lamps can be significantly reduced. An active antenna connected to one of the lamp electrodes transports the potential from this electrode to the vicinity of the opposite electrode and generates an enhanced electric field inside the burner. On applying a symmetrically shaped ignition pulse, a weak pre-discharge within the first half-cycle produces free charge carriers initiating ignition of the lamp within the subsequent second half-cycle. The authors present a set-up for electrical and optical investigations of hot-restrike in HID lamps. The ignition voltage is measured for two different polarities as a function of the cooldown time. An analysis of its reduction is given. Furthermore, the pre-discharge is investigated by means of short-time photography. It is demonstrated that a negative polarity of the active antenna within the first half-cycle and a positive polarity within the second one is the most effective succession. (paper)

  3. Microstructure characteristics of high borated stainless steel fabricated by hot-pressing sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xuan; Wang, Mingjia, E-mail: mingjiawangysu@126.com; Zhao, Hongchang

    2016-04-25

    The present study investigated the microstructure of powder metallurgy (P/M) high borated stainless steel through hot-pressing sintering in a temperature range of 1000–1150 °C within 30 min under 30 MPa. Microstructure and phase examinations were carried out by applying scanning electron microscope, electron backscatter diffraction and X-ray diffraction analysis. The results of as-atomized powders demonstrated that many powders kept egg-type structure with an austenite outer layer and the eutectic borides were much finer than those in traditional cast products. Microstructure studies revealed that borides suffered Ostwald ripening and were significantly influenced by the sintering temperature. Orientation maps indicated that the inter-particle contact areas consisted of equiaxed grains and the regions consisting of large elongated grains partly inherited the microstructure characteristics of as-atomized powder particles. Furthermore, the mechanisms governing the morphological changes in microstructure were discussed. - Highlights: • Near-complete densification could be obtained through hot-pressing sintering. • There was no phase transformation and present phases were M{sub 2}B and austenite. • Borides suffered Ostwald ripening and were significantly influenced by temperature. • Inter-particle contact areas consisted of equiaxed grains for recrystallization. • Deformation-free zones exhibited elongated grains for dendritic arms coarsening.

  4. Nanoscale surface analysis on second generation advanced high strength steel after hot dip galvanizing.

    Science.gov (United States)

    Arndt, M; Duchoslav, J; Preis, K; Samek, L; Stifter, D

    2013-09-01

    Second generation advanced high strength steel is one promising material of choice for modern automotive structural parts because of its outstanding maximal elongation and tensile strength. Nonetheless there is still a lack of corrosion protection for this material due to the fact that cost efficient hot dip galvanizing cannot be applied. The reason for the insufficient coatability with zinc is found in the segregation of manganese to the surface during annealing and the formation of manganese oxides prior coating. This work analyses the structure and chemical composition of the surface oxides on so called nano-TWIP (twinning induced plasticity) steel on the nanoscopic scale after hot dip galvanizing in a simulator with employed analytical methods comprising scanning Auger electron spectroscopy (SAES), energy dispersive X-ray spectroscopy (EDX), and focused ion beam (FIB) for cross section preparation. By the combination of these methods, it was possible to obtain detailed chemical images serving a better understanding which processes exactly occur on the surface of this novel kind of steel and how to promote in the future for this material system galvanic protection.

  5. Setting Mechanical Properties of High Strength Steels for Rapid Hot Forming Processes

    Science.gov (United States)

    Löbbe, Christian; Hering, Oliver; Hiegemann, Lars; Tekkaya, A. Erman

    2016-01-01

    Hot stamping of sheet metal is an established method for the manufacturing of light weight products with tailored properties. However, the generally-applied continuous roller furnace manifests two crucial disadvantages: the overall process time is long and a local setting of mechanical properties is only feasible through special cooling techniques. Hot forming with rapid heating directly before shaping is a new approach, which not only reduces the thermal intervention in the zones of critical formability and requested properties, but also allows the processing of an advantageous microstructure characterized by less grain growth, additional fractions (e.g., retained austenite), and undissolved carbides. Since the austenitization and homogenization process is strongly dependent on the microstructure constitution, the general applicability for the process relevant parameters is unknown. Thus, different austenitization parameters are analyzed for the conventional high strength steels 22MnB5, Docol 1400M, and DP1000 in respect of the mechanical properties. In order to characterize the resulting microstructure, the light optical and scanning electron microscopy, micro and macro hardness measurements, and the X-ray diffraction are conducted subsequent to tensile tests. The investigation proves not only the feasibility to adjust the strength and ductility flexibly, unique microstructures are also observed and the governing mechanisms are clarified. PMID:28773354

  6. Establishment of design space for high current gain in III-N hot electron transistors

    Science.gov (United States)

    Gupta, Geetak; Ahmadi, Elaheh; Suntrup, Donald J., III; Mishra, Umesh K.

    2018-01-01

    This paper establishes the design space of III-N hot electron transistors (HETs) for high current gain by designing and fabricating HETs with scaled base thickness. The device structure consists of GaN-based emitter, base and collector regions where emitter and collector barriers are implemented using AlN and InGaN layers, respectively, as polarization-dipoles. Electrons tunnel through the AlN layer to be injected into the base at a high energy where they travel in a quasi-ballistic manner before being collected. Current gain increases from 1 to 3.5 when base thickness is reduced from 7 to 4 nm. The extracted mean free path (λ mfp) is 5.8 nm at estimated injection energy of 1.5 eV.

  7. Manipulation of Thermally Activated Delayed Fluorescence of Blue Exciplex Emission: Fully Utilizing Exciton Energy for Highly Efficient Organic Light Emitting Diodes with Low Roll-Off.

    Science.gov (United States)

    Wang, Zixing; Wang, Hedan; Zhu, Jun; Wu, Peng; Shen, Bowen; Dou, Dehai; Wei, Bin

    2017-06-28

    The application of exciplex energy has become a unique way to achieve organic light-emitting diodes (OLEDs) with high efficiencies, low turn-on voltage, and low roll-off. Novel δ-carboline derivatives with high triplet energy (T 1 ≈ 2.92 eV) and high glass transition temperature (T g ≈ 153 °C) were employed to manipulate exciplex emissions in this paper. Deep blue (peak at 436 nm) and pure blue (peak at 468 nm) thermally activated delayed fluorescence (TADF) of exciplex OLEDs were demonstrated by utilizing them as emitters with the maximum current efficiency (CE) of 4.64 cd A -1 , power efficiency (PE) of 2.91 lm W -1 , and external quantum efficiency (EQE) of 2.36%. Highly efficient blue phosphorescent OLEDs doped with FIrpic showed a maximum CE of 55.6 cd A -1 , PE of 52.9 lm W -1 , and EQE of 24.6% respectively with very low turn on voltage at 2.7 V. The devices still remain high CE of 46.5 cd A -1 at 100 cd m -2 , 45.4 cd A -1 at 1000 cd m -2 and 42.3 cd A -1 at 5000 cd m -2 with EQE close to 20% indicating low roll-off. Manipulating blue exciplex emissions by chemical structure gives an ideal strategy to fully utilize all exciton energies for lighting of OLEDs.

  8. Pipe Rolling from Continuous Cast Metal

    International Nuclear Information System (INIS)

    Zhordania, I.; Chkhartishvili, I.; Lordkipanidze, J.; Melashvili, Z.; Papava, K.; Khundadze, K.

    2007-01-01

    The approach to manufacturing of high quality pipes as a result of solid and hollow billet rolling from continuous cast metal is shown. Optimal parameters of piercing, temperature of piercing and piercing rolling mill rollers speed have been experimentally established. (author)

  9. 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.

  10. Robust Rudder Roll Damping Control

    DEFF Research Database (Denmark)

    Yang, C.

    The results of a systematic research to solve a specific ship motion control problem, simultaneous roll damping and course keeping using the rudder are presented in this thesis. The fundamental knowledge a priori is that rudder roll damping is highly sensitive to the model uncertainty, therefore H-infinity...... theory is used to deal with the problem. The necessary mathematical tools and the H-Infinity theory as the basis of controller design are presented in Chapter 2 and 3. The mu synthesis and the D-K iteration are introduced in Chapter 3. The ship dynamics and modeling technology are discussed in Chapter 4...

  11. Introduction of anti-rolling active vertical fin and its application to maneuverability for displacement-type super high speed ship. 2nd Report.; Haisuiryogata chokosokusen no yokoyure seishiyo active suichoku fin no donyu to sojuseieno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T; Saito, Y [Yokohama National University, Yokohama (Japan). Faculty of Engineering; Niihara, Y [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1997-12-31

    Discussed herein are the effects of vertical fin projecting downwards from the bottom of a displacement-type superhigh-speed ship, installed to improve its transverse stability and turning ability. The system for simultaneously controlling rudder and vertical fin by the optimum regulator was studied for maneuverability in directional following waves and smooth water, and maneuverability was simulated numerically. A ship is greatly rolled and sloped when running in waves. It is found that the vertical fin shows a high anti-rolling effect when the ship runs straight. The optimum regulator greatly improves maneuverability in waves, reducing rolling by 92%. Increased rolling with the vertical fin, observed in the previous study in directional following waves, is found to be due to the rudder. The optimum position of the fin is determined to control transverse sloping of a turning ship in a superhigh-speed region. 21 refs., 12 figs., 4 tabs.

  12. Introduction of anti-rolling active vertical fin and its application to maneuverability for displacement-type super high speed ship. 2nd Report.; Haisuiryogata chokosokusen no yokoyure seishiyo active suichoku fin no donyu to sojuseieno oyo

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, T.; Saito, Y. [Yokohama National University, Yokohama (Japan). Faculty of Engineering; Niihara, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1996-12-31

    Discussed herein are the effects of vertical fin projecting downwards from the bottom of a displacement-type superhigh-speed ship, installed to improve its transverse stability and turning ability. The system for simultaneously controlling rudder and vertical fin by the optimum regulator was studied for maneuverability in directional following waves and smooth water, and maneuverability was simulated numerically. A ship is greatly rolled and sloped when running in waves. It is found that the vertical fin shows a high anti-rolling effect when the ship runs straight. The optimum regulator greatly improves maneuverability in waves, reducing rolling by 92%. Increased rolling with the vertical fin, observed in the previous study in directional following waves, is found to be due to the rudder. The optimum position of the fin is determined to control transverse sloping of a turning ship in a superhigh-speed region. 21 refs., 12 figs., 4 tabs.

  13. Modeling and Optimization of a High-Tc Hot-Electron Superconducting Mixer for Terahertz Applicaitons

    Science.gov (United States)

    Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.; Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.

    1996-01-01

    The development of a YBa(sub 2)Cu(sub 3)O(sub 7-(kronecker delta))(YBCO) hot-electron bolometer (HEB) quasioptical mixer for a 2.5 heterodyne receiver is discussed. The modeled device is a submicron bridge made from a 10 nm thick film on a high thermal conductance substrate. The mixer performance expected for this device is analyzed in the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of heat diffusion from the film through the substrate and from the film to the normal metal contacts is evaluated....a single sideband temperature of less than 2000k is predicted.

  14. Hot impact densification: a new method for producing high density ceramic pellets with close shape tolerances

    International Nuclear Information System (INIS)

    Hrovat, M.; Huschka, H.; Muhling, G.; Rachor, L.; Zimmerman, H.

    1982-01-01

    Density and correct diameter of nuclear fuel pellets are usually achieved by sintering and subsequent circular grinding. Hot impact densification (HID) thermally squatted ceramic bodies can be directly high speed precision-molded in a cold die. For thermoshock-sensitive materials, a controlled cooling down procedure of some minutes is added. The feasibility of HID has been demonstrated on the laboratory scale on UO 2 , UC, and some more materials at temperatures between 1700 and 2300 0 C, pressures up to 800 N/mm 2 . Shape tolerances are close, density can be exactly reproduced within a wide range. Tool wear seems to be no problem. Currently, a prototype facility for continuous performance is being developed

  15. Functional components for a design strategy: Hot cell shielding in the high reliability safeguards methodology

    Energy Technology Data Exchange (ETDEWEB)

    Borrelli, R.A., E-mail: rborrelli@uidaho.edu

    2016-08-15

    The high reliability safeguards (HRS) methodology has been established for the safeguardability of advanced nuclear energy systems (NESs). HRS is being developed in order to integrate safety, security, and safeguards concerns, while also optimizing these with operational goals for facilities that handle special nuclear material (SNM). Currently, a commercial pyroprocessing facility is used as an example system. One of the goals in the HRS methodology is to apply intrinsic features of the system to a design strategy. This current study investigates the thickness of the hot cell walls that could adequately shield processed materials. This is an important design consideration that carries implications regarding the formation of material balance areas, the location of key measurement points, and material flow in the facility.

  16. Nitrification of archaeal ammonia oxidizers in a high- temperature hot spring

    Science.gov (United States)

    Chen, Shun; Peng, Xiaotong; Xu, Hengchao; Ta, Kaiwen

    2016-04-01

    The oxidation of ammonia by microbes has been shown to occur in diverse natural environments. However, the link of in situ nitrification activity to taxonomic identities of ammonia oxidizers in high-temperature environments remains poorly understood. Here, we studied in situ ammonia oxidation rates and the diversity of ammonia-oxidizing Archaea (AOA) in surface and bottom sediments at 77 °C in the Gongxiaoshe hot spring, Tengchong, Yunnan, China. The in situ ammonia oxidation rates measured by the 15N-NO3- pool dilution technique in the surface and bottom sediments were 4.80 and 5.30 nmol N g-1 h-1, respectively. Real-time quantitative polymerase chain reaction (qPCR) indicated that the archaeal 16S rRNA genes and amoA genes were present in the range of 0.128 to 1.96 × 108 and 2.75 to 9.80 × 105 gene copies g-1 sediment, respectively, while bacterial amoA was not detected. Phylogenetic analysis of 16S rRNA genes showed high sequence similarity to thermophilic Candidatus Nitrosocaldus yellowstonii, which represented the most abundant operational taxonomic units (OTU) in both surface and bottom sediments. The archaeal predominance was further supported by fluorescence in situ hybridization (FISH) visualization. The cell-specific rate of ammonia oxidation was estimated to range from 0.410 to 0.790 fmol N archaeal cell-1 h-1, higher than those in the two US Great Basin hot springs. These results suggest the importance of archaeal rather than bacterial ammonia oxidation in driving the nitrogen cycle in terrestrial geothermal environments.

  17. THREE-DIMENSIONAL ATMOSPHERIC CIRCULATION OF HOT JUPITERS ON HIGHLY ECCENTRIC ORBITS

    International Nuclear Information System (INIS)

    Kataria, T.; Showman, A. P.; Lewis, N. K.; Fortney, J. J.; Marley, M. S.; Freedman, R. S.

    2013-01-01

    Of the over 800 exoplanets detected to date, over half are on non-circular orbits, with eccentricities as high as 0.93. Such orbits lead to time-variable stellar heating, which has major implications for the planet's atmospheric dynamical regime. However, little is known about the fundamental dynamical regime of such planetary atmospheres, and how it may influence the observations of these planets. Therefore, we present a systematic study of hot Jupiters on highly eccentric orbits using the SPARC/MITgcm, a model which couples a three-dimensional general circulation model (the MITgcm) with a plane-parallel, two-stream, non-gray radiative transfer model. In our study, we vary the eccentricity and orbit-average stellar flux over a wide range. We demonstrate that the eccentric hot Jupiter regime is qualitatively similar to that of planets on circular orbits; the planets possess a superrotating equatorial jet and exhibit large day-night temperature variations. As in Showman and Polvani, we show that the day-night heating variations induce momentum fluxes equatorward to maintain the superrotating jet throughout its orbit. We find that as the eccentricity and/or stellar flux is increased (corresponding to shorter orbital periods), the superrotating jet strengthens and narrows, due to a smaller Rossby deformation radius. For a select number of model integrations, we generate full-orbit light curves and find that the timing of transit and secondary eclipse viewed from Earth with respect to periapse and apoapse can greatly affect what we see in infrared (IR) light curves; the peak in IR flux can lead or lag secondary eclipse depending on the geometry. For those planets that have large temperature differences from dayside to nightside and rapid rotation rates, we find that the light curves can exhibit 'ringing' as the planet's hottest region rotates in and out of view from Earth. These results can be used to explain future observations of eccentric transiting exoplanets.

  18. High-BTU gas production from tar-bearing hot coke oven gas over iron catalyst

    Energy Technology Data Exchange (ETDEWEB)

    L.Y. Li; K. Morishita; T. Takarada [Gunma University, Gunma (Japan). Department of Biological and Chemical Engineering

    2005-07-01

    To utilize the tar-bearing hot coke oven gas (the by-product of coke making process) more effectively, a process was developed by converting the hot coke oven gas into a methane rich high-BTU gas over iron-bearing catalysts. The catalytic behaviour of Indonesian limonite ore was mainly discussed. For a reference, a conventional nickel catalyst (Ni/Al{sub 2}O{sub 3}) was employed. Laboratory scale tests were carried out in a two-stage fixed-bed reactor at ambient pressure. A bituminous coal sample was heated at first stage, the volatiles was carried by feed gas and decomposed at second stage. The limonite promoted hydropyrolysis of coal volatiles similar to Ni/Al{sub 2}O{sub 3} catalyst. High yields of total product gas and methane were obtained at 50 vol.% hydrogen atmosphere with a feed gas of 60 ml min{sup -1} hydrogen and 60 ml min{sup -1} nitrogen. After experiments, hydrocarbons heavier than ethane were not observed. Also that, carbon balance was more than 99.8% in coal char, product gases and carbon deposits. It was considered that coal volatiles converted into light gases and carbon almost completely in catalyst bed. Yields of product gas and methane depended upon catalytic temperature. At 923 K, the maximum yield of product gas was achieved at 74.3% for limonite catalyst on carbon balance with methane 83.2 vol.% of the carbonaceous gas products. Comparing with limonite, Fe/Al{sub 2}O{sub 3} and BOF dust samples showed low activities on coal volatiles catalytic decomposition. 21 refs., 5 figs., 3 tabs.

  19. Processing of fine grained AISI 304L austenitic stainless steel by cold rolling and high-temperature short-term annealing

    Science.gov (United States)

    Naghizadeh, Meysam; Mirzadeh, Hamed

    2018-05-01

    An advanced thermomechanical process based on the formation and reversion of deformation-induced martensite was used to refine the grain size and enhance the hardness of an AISI 304L austenitic stainless steel. Both low and high reversion annealing temperatures and also the repetition of the whole thermomechanical cycle were considered. While a microstructure with average austenite grain size of a few micrometers was achieved based on cold rolling and high-temperature short-term annealing, an extreme grain refinement up to submicrometer regime was obtained by cold rolling followed by low-temperature long-term annealing. However, the required annealing time was found to be much longer, which negates its appropriateness for industrial production. While a magnificent grain refinement was achieved by one pass of the high-temperature thermomechanical process, the reduction in grain size was negligible by the repetition of the whole cycle. It was found that the hardness of the thermomechanically processed material is much higher than that of the as-received material. The results of the present work were shown to be compatible with the general trend of grain size dependence of hardness for AISI 304L stainless steel based on the Hall-Petch relationship. The results were also discussed based on the X-ray evaluation of dislocation density by modified Williamson-Hall plots.

  20. Analytical method for establishing indentation rolling resistance

    Directory of Open Access Journals (Sweden)

    Gładysiewicz Lech

    2018-01-01

    Full Text Available Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

  1. Analytical method for establishing indentation rolling resistance

    Science.gov (United States)

    Gładysiewicz, Lech; Konieczna, Martyna

    2018-01-01

    Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

  2. Methodology for the preliminary design of high performance schools in hot and humid climates

    Science.gov (United States)

    Im, Piljae

    A methodology to develop an easy-to-use toolkit for the preliminary design of high performance schools in hot and humid climates was presented. The toolkit proposed in this research will allow decision makers without simulation knowledge easily to evaluate accurately energy efficient measures for K-5 schools, which would contribute to the accelerated dissemination of energy efficient design. For the development of the toolkit, first, a survey was performed to identify high performance measures available today being implemented in new K-5 school buildings. Then an existing case-study school building in a hot and humid climate was selected and analyzed to understand the energy use pattern in a school building and to be used in developing a calibrated simulation. Based on the information from the previous step, an as-built and calibrated simulation was then developed. To accomplish this, five calibration steps were performed to match the simulation results with the measured energy use. The five steps include: (1) Using an actual 2006 weather file with measured solar radiation, (2) Modifying lighting & equipment schedule using ASHRAE's RP-1093 methods, (3) Using actual equipment performance curves (i.e., scroll chiller), (4) Using the Winkelmann's method for the underground floor heat transfer, and (5) Modifying the HVAC and room setpoint temperature based on the measured field data. Next, the calibrated simulation of the case-study K-5 school was compared to an ASHRAE Standard 90.1-1999 code-compliant school. In the next step, the energy savings potentials from the application of several high performance measures to an equivalent ASHRAE Standard 90.1-1999 code-compliant school. The high performance measures applied included the recommendations from the ASHRAE Advanced Energy Design Guides (AEDG) for K-12 and other high performance measures from the literature review as well as a daylighting strategy and solar PV and thermal systems. The results show that the net

  3. 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

  4. 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

  5. Rolling Shutter Motion Deblurring

    KAUST Repository

    Su, Shuochen

    2015-06-07

    Although motion blur and rolling shutter deformations are closely coupled artifacts in images taken with CMOS image sensors, the two phenomena have so far mostly been treated separately, with deblurring algorithms being unable to handle rolling shutter wobble, and rolling shutter algorithms being incapable of dealing with motion blur. We propose an approach that delivers sharp and undis torted output given a single rolling shutter motion blurred image. The key to achieving this is a global modeling of the camera motion trajectory, which enables each scanline of the image to be deblurred with the corresponding motion segment. We show the results of the proposed framework through experiments on synthetic and real data.

  6. Ring rolling process simulation for geometry optimization

    Science.gov (United States)

    Franchi, Rodolfo; Del Prete, Antonio; Donatiello, Iolanda; Calabrese, Maurizio

    2017-10-01

    Ring Rolling is a complex hot forming process where different rolls are involved in the production of seamless rings. Since each roll must be independently controlled, different speed laws must be set; usually, in the industrial environment, a milling curve is introduced to monitor the shape of the workpiece during the deformation in order to ensure the correct ring production. In the present paper a ring rolling process has been studied and optimized in order to obtain anular components to be used in aerospace applications. In particular, the influence of process input parameters (feed rate of the mandrel and angular speed of main roll) on geometrical features of the final ring has been evaluated. For this purpose, a three-dimensional finite element model for HRR (Hot Ring Rolling) has been implemented in SFTC DEFORM V11. The FEM model has been used to formulate a proper optimization problem. The optimization procedure has been implemented in the commercial software DS ISight in order to find the combination of process parameters which allows to minimize the percentage error of each obtained dimension with respect to its nominal value. The software allows to find the relationship between input and output parameters applying Response Surface Methodology (RSM), by using the exact values of output parameters in the control points of the design space explored through FEM simulation. Once this relationship is known, the values of the output parameters can be calculated for each combination of the input parameters. After the calculation of the response surfaces for the selected output parameters, an optimization procedure based on Genetic Algorithms has been applied. At the end, the error between each obtained dimension and its nominal value has been minimized. The constraints imposed were the maximum values of standard deviations of the dimensions obtained for the final ring.

  7. De Novo Design of Boron-Based Host Materials for Highly Efficient Blue and White Phosphorescent OLEDs with Low Efficiency Roll-Off.

    Science.gov (United States)

    Xue, Miao-Miao; Huang, Chen-Chao; Yuan, Yi; Cui, Lin-Song; Li, Yong-Xi; Wang, Bo; Jiang, Zuo-Quan; Fung, Man-Keung; Liao, Liang-Sheng

    2016-08-10

    Borane is an excellent electron-accepting species, and its derivatives have been widely used in a variety of fields. However, the use of borane derivatives as host materials in OLEDs has rarely reported because the device performance is generally not satisfactory. In this work, two novel spiro-bipolar hosts with incorporated borane were designed and synthesized. The strategies used in preparing these materials were to increase the spatial separation of the highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) in the molecules, tune the connecting positions of functional groups, and incorporate specific functional groups with desirable thermal stability. Based on these designs, phosphorescent OLEDs with borane derivatives as hosts and with outstanding device performances were obtained. In particular, devices based on SAF-3-DMB/FIrpic exhibited an external quantum efficiency (EQE) of >25%. More encouragingly, the device was found to have quite a low efficiency roll-off, giving an efficiency of >20% even at a high brightness of 10000 cd/m(2). Furthermore, the EQE of the three-color-based (R + G + B) white OLED employing SAF-3-DMB as a host was also as high as 22.9% with CIE coordinates of (x, y) = (0.40, 0.48). At a brightness of 5000 cd/m(2), there was only a 3% decrease in EQE from its maximum value, implying a very low efficiency roll-off.

  8. High Temperature, High Pressure Equation of State: Solidification of Hydrocarbons and Measurement of Krytox Oil Using Rolling-Ball Viscometer Validation

    Energy Technology Data Exchange (ETDEWEB)

    Gamwo, Isaac K. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Burgess, Ward [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Tapriyal, Deepak [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2014-10-03

    July 31, 2012: High Temperature, High Pressure Equation of State Density Correlations and Viscosity Correlations (Tapriyal et al., 2012). New experimental data were obtained by utilizing density cell and rolling-ball viscometer (both designed by our team) rated up to 533 K and 275 MPa. This report focuses on the solidification of hydrocarbons at elevated temperatures and pressures and

  9. High temperature mechanical performance of a hot isostatically pressed silicon nitride

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, A.A.; Ferber, M.K.; Jenkins, M.G.; Lin, C.K.J. [and others

    1996-01-01

    Silicon nitride ceramics are an attractive material of choice for designers and manufacturers of advanced gas turbine engine components for many reasons. These materials typically have potentially high temperatures of usefulness (up to 1400{degrees}C), are chemically inert, have a relatively low specific gravity (important for inertial effects), and are good thermal conductors (i.e., resistant to thermal shock). In order for manufacturers to take advantage of these inherent properties of silicon nitride, the high-temperature mechanical performance of the material must first be characterized. The mechanical response of silicon nitride to static, dynamic, and cyclic conditions at elevated temperatures, along with reliable and representative data, is critical information that gas turbine engine designers and manufacturers require for the confident insertion of silicon nitride components into gas turbine engines. This final report describes the high-temperature mechanical characterization and analyses that were conducted on a candidate structural silicon nitride ceramic. The high-temperature strength, static fatigue (creep rupture), and dynamic and cyclic fatigue performance were characterized. The efforts put forth were part of Work Breakdown Structure Subelement 3.2.1, {open_quotes}Rotor Data Base Generation.{close_quotes} PY6 is comparable to other hot isostatically pressed (HIPed) silicon nitrides currently being considered for advanced gas turbine engine applications.

  10. The development of a mobile hot cell facility for the conditioning of spent high activity radioactive sources

    International Nuclear Information System (INIS)

    Liebenberg, G.R.; Al-Mughrabi, M.

    2010-01-01

    The International Atomic Energy Agency (IAEA) Waste Technology Section with additional support from the U.S. National Nuclear Security Administration (NNSA) through the IAEA Nuclear Security Fund has funded the design, fabrication, evaluation, and testing of a portable hot cell intended to address the problem of disused Spent High Activity Radioactive Sources (SHARS) in obsolete irradiation devices such as teletherapy heads and dry irradiators. The project is initially targeting the African continent but expected soon to expand to Latin America and Asia. This hot cell allows source removal, characterization, consolidation, repackaging in modern storage shields, and secure storage of high risk SHARS at national radioactive waste storage facilities. (authors)

  11. A novel design and analysis of a MEMS ceramic hot-wire anemometer for high temperature applications

    International Nuclear Information System (INIS)

    Nagaiah, N R; Sleiti, A K; Rodriguez, S; Kapat, J S; An, L; Chow, L

    2006-01-01

    This paper attempts to prove the feasibility of high temperature MEMS hot-wire anemometer for gas turbine environment. No such sensor exists at present. Based on the latest improvement in a new type of Polymer-Derived Ceramic (PDC) material, the authors present a Novel design, structural and thermal analysis of MEMS hot-wire anemometer (HWA) based on PDC material, and show that such a sensor is indeed feasible. This MEMS Sensor is microfabricated by using three types of PDC materials such as SiAlCN, SiCN (lightly doped) and SiCN (heavily doped) for sensing element (hot-wire), support prongs and connecting leads respectively. This novel hot wire anemometer can perform better than a conventional HWA in which the hot wire is made of tungsten or platinum-iridium. This type of PDC-HWA can be used in harsh environment due to its high temperature resistance, tensile strength and resistance to oxidation. This HWA is fabricated using microstereolithography as a novel microfabrication technique to manufacture the proposed MEMS Sensor

  12. Scalable, ambient atmosphere roll-to-roll manufacture of encapsulated large area, flexible organic tandem solar cell modules

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks; Dam, Henrik Friis; Hösel, Markus

    2014-01-01

    the manufacture of completely functional devices in exceptionally high yields. Critical to the ink and process development is a carefully chosen technology transfer to industry method where first a roll coater is employed enabling contactless stack build up, followed by a small roll-to-roll coater fitted to an X...

  13. Using an ultra-thin non-doped orange emission layer to realize high efficiency white organic light-emitting diodes with low efficiency roll-off

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Liping; Chen, Jiangshan; Ma, Dongge, E-mail: mdg1014@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Graduate University of the Chinese Academy of Sciences, Changchun 130022 (China); Zhao, Yongbiao [Luminous Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, Singapore 639798 (Singapore); Zhang, Hongmei [Department of Materials Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023 (China)

    2014-06-28

    By adopting an ultra-thin non-doped orange emission layer sandwiched between two blue emission layers, high efficiency white organic light-emitting diodes (WOLEDs) with reduced efficiency roll-off were fabricated. The optimized devices show a balanced white emission with Internationale de L'Eclairage of (0.41, 0.44) at the luminance of 1000 cd/m{sup 2}, and the maximum power efficiency, current efficiency (CE), and external quantum efficiency reach 63.2 lm/W, 59.3 cd/A, and 23.1%, which slightly shift to 53.4 lm/W, 57.1 cd/A, and 22.2% at 1000 cd/m{sup 2}, respectively, showing low efficiency roll-off. Detailed investigations on the recombination zone and the transient electroluminescence (EL) clearly reveal the EL processes of the ultra-thin non-doped orange emission layer in WOLEDs.

  14. 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.

  15. Ship Roll Damping Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2012-01-01

    limitations and large variations of the spectral characteristics of wave-induced roll motion. This tutorial paper presents an account of the development of various ship roll motion control systems together with the challenges associated with their design. It discusses the assessment of performance...

  16. Cosmology with rolling tachyon

    Indian Academy of Sciences (India)

    Email: sami@iucaa.ernet.in. Abstract. We examine the possibility of rolling tachyon to play the dual role of inflaton at early epochs and dark matter at late times. We argue that enough inflation can be generated with the rolling tachyon either by invoking the large number of branes or brane world assisted inflation. However ...

  17. Origins of Rolling Friction

    Science.gov (United States)

    Cross, Rod

    2017-01-01

    When a hard object rolls on a soft surface, or vice versa, rolling friction arises from deformation of the soft object or the soft surface. The friction force can be described in terms of an offset in the normal reaction force or in terms of energy loss arising from the deformation. The origin of the friction force itself is not entirely clear. It…

  18. 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.

  19. Time-resolved Thomson scattering on high-intensity laser-produced hot dense helium plasmas

    International Nuclear Information System (INIS)

    Sperling, P; Liseykina, T; Bauer, D; Redmer, R

    2013-01-01

    The introduction of brilliant free-electron lasers enables new pump–probe experiments to characterize warm and hot dense matter states, i.e. systems at solid-like densities and temperatures of one to several hundred eV. Such extreme conditions are relevant for high-energy density studies such as, e.g., in planetary physics and inertial confinement fusion. We consider here a liquid helium jet pumped with a high-intensity optical short-pulse laser that is subsequently probed with brilliant soft x-ray radiation. The optical short-pulse laser generates a strongly inhomogeneous helium plasma which is characterized with particle-in-cell simulations. We derive the respective Thomson scattering spectrum based on the Born–Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We observe plasmon modes that are generated in the interior of the target and study their temporal evolution. Such pump–probe experiments are promising tools to measure the important plasma parameters density and temperature. The method described here can be applied to various pump–probe scenarios by combining optical lasers, soft x-rays and hard x-ray sources. (paper)

  20. Synthesis of highly fluorescent hydrophobic carbon dots by hot injection method using Paraplast as precursor

    International Nuclear Information System (INIS)

    Talib, Abou; Pandey, Sunil; Thakur, Mukeshchand; Wu, Hui-Fen

    2015-01-01

    We have reported synthesis of bright blue colored hydrophobic carbon dots (hC-dots) using highly pure blend of polymers called Paraplast. We developed a hot injection method for making nearly monodispersed hC-dots with a diameter in a range: 5–30 nm as confirmed by high resolution transmission electron microscopy (HRTEM). The involvement of various functional groups was confirmed by Fourier transform infra-red (FTIR) spectroscopy. These hC-dots were incubated with breast cancer stem cells in order to check the entry as well as biological imaging. The cells were analyzed using epifluorescent microscopy. hC-dots showed concentration dependent cytotoxicity (LD 50 : 50 mg/ml) and could be used for bioimaging even at lower concentration (0.5 mg/ml). hC-dots were found to be versatile agents for peeping inside the cells which could also be used for delivery of water insoluble chemotherapeutic agents to variety of solid tumors. - Highlights: • Synthesis of hydrophobic carbon dots from polymer based Paraplast • Deep blue color under the influence of UV light • Typical optical properties used for biological imaging • Biological imaging of breast cancer stem cells revealing potential of carbon dots

  1. Structure and blood compatibility of highly oriented PLA/MWNTs composites produced by solid hot drawing.

    Science.gov (United States)

    Li, Zhengqiu; Zhao, Xiaowen; Ye, Lin; Coates, Phil; Caton-Rose, Fin; Martyn, Michasel

    2014-03-01

    Highly oriented poly(lactic acid) (PLA)/multi-walled carbon nanotubes (MWNTs) composites were fabricated through solid hot drawing technology in an effort to improve the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. It was found that proper MWNTs content and drawing orientation can improve the tensile strength and modulus of PLA dramatically. With the increase in draw ratio, the cold crystallization peak became smaller, and the glass transition and the melting peak of PLA moved to high temperature, while the crystallinity increased, and the grain size decreased, indicating the stress-induced crystallization of PLA during drawing. MWNTs showed a nucleation effect on PLA, leading to the rise in the melting temperature, increase in crystallinity and reduction of spherulite size for the composites. Moreover, the intensity of (002) diffraction of MWNTs increased with draw ratio, indicating that MWNTs were preferentially aligned and oriented during drawing. Microstructure observation demonstrated that PLA matrix had an ordered fibrillar bundle structure, and MWNTs in the composite tended to align parallel to the drawing direction. In addition, the dispersion of MWNTs in PLA was also improved by orientation. Introduction of MWNTs and drawing orientation could significantly enhance the blood compatibility of PLA by prolonging kinetic clotting time, reducing hemolysis ratio and platelet activation.

  2. Facile synthesis of high strength hot-water wood extract films with oxygen-barrier performance

    Science.gov (United States)

    Chen, Ge-Gu; Fu, Gen-Que; Wang, Xiao-Jun; Gong, Xiao-Dong; Niu, Ya-Shuai; Peng, Feng; Yao, Chun-Li; Sun, Run-Cang

    2017-01-01

    Biobased nanocomposite films for food packaging with high mechanical strength and good oxygen-barrier performance were developed using a hot-water wood extract (HWE). In this work, a facile approach to produce HWE/montmorillonite (MMT) based nanocomposite films with excellent physical properties is described. The focus of this study was to determine the effects of the MMT content on the structure and mechanical properties of nanocomposites and the effects of carboxymethyl cellulose (CMC) on the physical properties of the HWE-MMT films. The experimental results suggested that the intercalation of HWE and CMC in montmorillonite could produce compact, robust films with a nacre-like structure and multifunctional characteristics. This results of this study showed that the mechanical properties of the film designated FCMC0.05 (91.5 MPa) were dramatically enhanced because the proportion of HWE, MMT and CMC was 1:1.5:0.05. In addition, the optimized films exhibited an oxygen permeability below 2.0 cm3 μm/day·m2·kPa, as well as good thermal stability due to the small amount of CMC. These results provide a comprehensive understanding for further development of high-performance nanocomposites which are based on natural polymers (HWE) and assembled layered clays (MMT). These films offer great potential in the field of sustainable packaging.

  3. Reduced activation ODS ferritic steel - recent development in high speed hot extrusion processing

    Energy Technology Data Exchange (ETDEWEB)

    Oksiuta, Zbigniew [Faculty of Mechanical Engineering, Bialystok Technical University (Poland); Lewandowska, Malgorzata; Kurzydlowski, Krzysztof [Faculty of Materials Science and Engineering, Warsaw University of Technology (Poland); Baluc, Nadine [Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, Villigen PSI (Switzerland)

    2010-05-15

    The paper presents the microstructure and mechanical properties of an oxide dispersion strengthened (ODS), reduced activation, ferritic steel, namely the Fe-14Cr-2W-0.3Ti-0.3Y{sub 2}O{sub 3} alloy, which was fabricated by hot isostatic pressing followed by high speed hydrostatic extrusion (HSHE) and heat treatment HT at 1050 C. Transmission electron microscopy (TEM) observations revealed significant differences in the grain size and dislocation density between the as-HIPped and as-HSHE materials. It was also found that the microstructure of the steel is stable after HT. The HSHE process improves significantly the tensile and Charpy impact properties of the as-HIPped steel. The ultimate tensile strength at room temperature increases from 950 up to 1350 MPa, while the upper shelf energy increases from 3.0 up to 6.0 J. However, the ductile-to-brittle transition temperature (DBTT) remains relatively high (about 75 C).These results indicate that HSHE is a promising method for achieving grain refinement and thus improving the mechanical properties of ODS ferritic steels. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Synthesis of highly fluorescent hydrophobic carbon dots by hot injection method using Paraplast as precursor

    Energy Technology Data Exchange (ETDEWEB)

    Talib, Abou [Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); Pandey, Sunil [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Thakur, Mukeshchand [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Wu, Hui-Fen, E-mail: hui@faculty.nsysu.edu.tw [Department of Chemistry, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, 70, Lien-Hai Road, Kaohsiung 80424, Taiwan (China); Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan (China); School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 800, Taiwan (China); Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung, 80424, Taiwan (China)

    2015-03-01

    We have reported synthesis of bright blue colored hydrophobic carbon dots (hC-dots) using highly pure blend of polymers called Paraplast. We developed a hot injection method for making nearly monodispersed hC-dots with a diameter in a range: 5–30 nm as confirmed by high resolution transmission electron microscopy (HRTEM). The involvement of various functional groups was confirmed by Fourier transform infra-red (FTIR) spectroscopy. These hC-dots were incubated with breast cancer stem cells in order to check the entry as well as biological imaging. The cells were analyzed using epifluorescent microscopy. hC-dots showed concentration dependent cytotoxicity (LD{sub 50}: 50 mg/ml) and could be used for bioimaging even at lower concentration (0.5 mg/ml). hC-dots were found to be versatile agents for peeping inside the cells which could also be used for delivery of water insoluble chemotherapeutic agents to variety of solid tumors. - Highlights: • Synthesis of hydrophobic carbon dots from polymer based Paraplast • Deep blue color under the influence of UV light • Typical optical properties used for biological imaging • Biological imaging of breast cancer stem cells revealing potential of carbon dots.

  5. Effect of Strain Rate on Hot Ductility Behavior of a High Nitrogen Cr-Mn Austenitic Steel

    Science.gov (United States)

    Wang, Zhenhua; Meng, Qing; Qu, Minggui; Zhou, Zean; Wang, Bo; Fu, Wantang

    2016-03-01

    18Mn18Cr0.6N steel specimens were tensile tested between 1173 K and 1473 K (900 °C and 1200 °C) at 9 strain rates ranging from 0.001 to 10 s-1. The tensile strained microstructures were analyzed through electron backscatter diffraction analysis. The strain rate was found to affect hot ductility by influencing the strain distribution, the extent of dynamic recrystallization and the resulting grain size, and dynamic recovery. The crack nucleation sites were primarily located at grain boundaries and were not influenced by the strain rate. At 1473 K (1200 °C), a higher strain rate was beneficial for grain refinement and preventing hot cracking; however, dynamic recovery appreciably occurred at 0.001 s-1 and induced transgranular crack propagation. At 1373 K (1100 °C), a high extent of dynamic recrystallization and fine new grains at medium strain rates led to good hot ductility. The strain gradient from the interior of the grain to the grain boundary increased with decreasing strain rate at 1173 K and 1273 K (900 °C and 1000 °C), which promoted hot cracking. Grain boundary sliding accompanied grain rotation and did not contribute to hot cracking.

  6. High pressure, low pressure and hot water heating systems in hospitals. Hochdruck-, Niederdruck- und Warmwasserheizungsanlagen im Krankenhaus

    Energy Technology Data Exchange (ETDEWEB)

    Riedle, K [H. Riedle GmbH, Wiesbaden (Germany)

    1994-07-01

    In hospital nowadays the limitation of the use of steam boilers and their direct supply network to the possible minimum is aimed at when the heating system is exchanged or retrofitted. Independent of the fact whether high pressure or low pressure steam or hot water is used the optimum water treatment should be carried out with a minimum of chemical substances. Here hydroquinone, neutralizing amines, carbohydrazide, sodium sulphite and tannins can be used. The dimensioning of hot water heating circuits is shown with examples. (BWI)

  7. Formation of microstructure and properties on hot working and heat treatment of high strength modular cast iron

    International Nuclear Information System (INIS)

    Trajno, A.I.; Yusupov, V.S.; Kugushin, A.A.

    1999-01-01

    The possibility of plastic deformation of high strength modular cast iron (HSNCI) is under study. The microstructure and mechanical properties of hot worked and heat treated cast iron are investigated for the composition, %: Fe - 2.9 C - 2.4 Si - 0.7 Ni - 0.05 Mg - 0.04 Ce. It is stated that HSNCI can withstand various types of hot working without fracturing. Graphite inclusions lose their modular shape irreversibly during plastic deformation. Subsequent heat treatment affects the metal matrix only. The heating in oxidizing environment is noted to result in cast iron surface decarbonization [ru

  8. Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100 °C to 1250 °C

    DEFF Research Database (Denmark)

    Alfonso Lopez, Angel; Juul Jensen, Dorte; Luo, G.-N.

    2015-01-01

    plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could......Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high...... suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation....

  9. Effects of high shock pressures and pore morphology on hot spot mechanisms in HMX

    Science.gov (United States)

    Springer, H. K.; Tarver, C. M.; Bastea, S.

    2017-01-01

    The shock initiation and detonation behavior of heterogeneous solid explosives is governed by its microstructure and reactive properties. New additive manufacturing techniques offer unprecedented control of explosive microstructures previously impossible, enabling us to develop novel explosives with tailored shock sensitivity and detonation properties. Since microstructure-performance relationships are not well established for explosives, there is little material design guidance for these manufacturing techniques. In this study, we explore the effects of high shock pressures (15-38 GPa) with long shock durations and different pore morphologies on hot spot mechanisms in HMX. HMX is chosen as the model material because we have experimental data on many of the chemical-thermal-mechanical properties required for pore collapse simulations. Our simulations are performed using the multi-physics arbitrary Lagrangian Eulerian finite element hydrocode, ALE3D, with Cheetah-based models for the unreacted and the product equation-of-states. We use a temperature-dependent specific heat with the unreacted equation-of-state and a temperature-dependent viscosity model to ensure accurate shock temperatures for subsequent chemistry. The Lindemann Law model is used for shock melting in HMX. In contrast to previous pore collapse studies at lower shock pressures (≤10 GPa) in HMX and shorter post-collapse burning times, our calculations show that shock melting occurs above 15 GPa due to higher bulk heating and a prominent elongated ("jet-like") hot spot region forms at later times. The combination of the elongated, post-collapse hot spot region and the higher bulk heating with increasing pressure dramatically increases the growth rate of reaction. Our calculations show that the reaction rate, dF/dt, increases with increasing shock pressure. We decompose the reaction rate into ignition ((dF/dt)ig) and growth ((dF/dt)gr) phases to better analyze our results. We define the ignition phase

  10. Deformation mechanisms of pure Mg materials fabricated by using pre-rolled powders

    Energy Technology Data Exchange (ETDEWEB)

    Shen, J., E-mail: shen-j@jwri.osaka-u.ac.jp [Joining and Welding Research Institute, Osaka University (Japan); Imai, H. [Joining and Welding Research Institute, Osaka University (Japan); Chen, B. [Graduate School of Engineering, Osaka University (Japan); Ye, X.; Umeda, J.; Kondoh, K. [Joining and Welding Research Institute, Osaka University (Japan)

    2016-03-21

    In the present work, a powder rolling process was utilized in the fabrication of fine grained pure Mg via powder metallurgy. Mg flakes were obtained after each rolling process, and broken into pieces for further rolling or sintering. Mg samples of experiencing 0, 5 and 10 rolling passes were obtained following spark plasma sintering (SPS) and hot extrusion. Microstructural results from electron backscatter diffraction (EBSD) revealed that, without experiencing powder rolling, the specimen contained a great number of residual tensile twins; in contrast, after powder rolling the specimen showed uniform and equiaxed grain structures. In addition, the average grain size was measured to be around 9.2, 2.9 and 2.1 µm for the samples subjected to 0, 5 and 10 rolling passes. The powder rolled specimens were found superior in mechanical properties. Post-loading microstructure examinations were also performed for the samples and a discussion regarding the relationship between their mechanical behavior and microstructures was provided.

  11. Deformation mechanisms of pure Mg materials fabricated by using pre-rolled powders

    International Nuclear Information System (INIS)

    Shen, J.; Imai, H.; Chen, B.; Ye, X.; Umeda, J.; Kondoh, K.

    2016-01-01

    In the present work, a powder rolling process was utilized in the fabrication of fine grained pure Mg via powder metallurgy. Mg flakes were obtained after each rolling process, and broken into pieces for further rolling or sintering. Mg samples of experiencing 0, 5 and 10 rolling passes were obtained following spark plasma sintering (SPS) and hot extrusion. Microstructural results from electron backscatter diffraction (EBSD) revealed that, without experiencing powder rolling, the specimen contained a great number of residual tensile twins; in contrast, after powder rolling the specimen showed uniform and equiaxed grain structures. In addition, the average grain size was measured to be around 9.2, 2.9 and 2.1 µm for the samples subjected to 0, 5 and 10 rolling passes. The powder rolled specimens were found superior in mechanical properties. Post-loading microstructure examinations were also performed for the samples and a discussion regarding the relationship between their mechanical behavior and microstructures was provided.

  12. Towards roll-to-roll manufacturing of polymer photonic devices

    Science.gov (United States)

    Subbaraman, Harish; Lin, Xiaohui; Ling, Tao; Guo, L. Jay; Chen, Ray T.

    2014-03-01

    Traditionally, polymer photonic devices are fabricated using clean-room processes such as photolithography, e-beam lithography, reactive ion etching (RIE) and lift-off methods etc, which leads to long fabrication time, low throughput and high cost. We have utilized a novel process for fabricating polymer photonic devices using a combination of imprinting and ink jet printing methods, which provides high throughput on a variety of rigid and flexible substrates with low cost. We discuss the manufacturing challenges that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible polymer photonic systems. Several metrology and instrumentation challenges involved such as availability of particulate-free high quality substrate, development and implementation of high-speed in-line and off-line inspection and diagnostic tools with adaptive control for patterned and unpatterned material films, development of reliable hardware, etc need to be addressed and overcome in order to realize a successful manufacturing process. Due to extreme resolution requirements compared to print media, the burden of software and hardware tools on the throughput also needs to be carefully determined. Moreover, the effect of web wander and variations in web speed need to accurately be determined in the design of the system hardware and software. In this paper, we show the realization of solutions for few challenges, and utilizing these solutions for developing a high-rate R2R dual stage ink-jet printer that can provide alignment accuracy of web speed of 5m/min. The development of a roll-to-roll manufacturing system for polymer photonic systems opens limitless possibilities for the deployment of high performance components in a variety of applications including communication, sensing, medicine, agriculture, energy, lighting etc.

  13. Fabrication of High-T(sub c) Hot-Electron Bolometric Mixers for Terahertz Applications

    Science.gov (United States)

    Burns, M. J.; Kleinsasser, A. W.; Delin, K. A.; Vasquez, R. P.; Karasik, B. S.; McGrath, W. R.; Gaidis, M. C.

    1996-01-01

    Superocnducting hot-electron bolometers (HEB) represent a promising candidate for heterodyne mixing at frequencies exceeding 1 THz. Nb HEB mixers offer performance competitive with tunnel junctions without the frequency limit imposed by the superconducting energy gap.

  14. EBIT spectroscopy of highly charged heavy ions relevant to hot plasmas

    Science.gov (United States)

    Nakamura, Nobuyuki

    2013-05-01

    An electron beam ion trap (EBIT) is a versatile device for studying highly charged ions. We have been using two types of EBITs for the spectroscopic studies of highly charged ions. One is a high-energy device called the Tokyo-EBIT, and another is a compact low-energy device called CoBIT. Complementary use of them enables us to obtain spectroscopic data for ions over a wide charge-state range interacting with electrons over a wide energy range. In this talk, we present EBIT spectra of highly charged ions for tungsten, iron, bismuth, etc., which are relevant to hot plasmas. Tungsten is considered to be the main impurity in the ITER (the next generation nuclear fusion reactor) plasma, and thus its emission lines are important for diagnosing and controlling the ITER plasma. We have observed many previously unreported lines to supply the lack of spectroscopic data of tungsten ions. Iron is one of the main components of the solar corona, and its spectra are used to diagnose temperature, density, etc. The diagnostics is usually done by comparing observed spectra with model calculations. An EBIT can provide spectra under a well-defined condition; they are thus useful to test the model calculations. Laser-produced bismuth plasma is one of the candidates for a soft x-ray source in the water window region. An EBIT has a narrow charge state distribution; it is thus useful to disentangle the spectra of laser-produced plasma containing ions with a wide charge-state range. Performed with the support and under the auspices of the NIFS Collaboration Research program (NIFS09KOAJ003) and JSPS KAKENHI Number 23246165, and partly supported by the JSPS-NRF-NSFC A3 Foresight Program in the field of Plasma Physics.

  15. Hot Flashes

    Science.gov (United States)

    Hot flashes Overview Hot flashes are sudden feelings of warmth, which are usually most intense over the face, neck and chest. Your skin might redden, as if you're blushing. Hot flashes can also cause sweating, and if you ...

  16. Replication of nanopits and nanopillars by roll-to-roll extrusion coating using a structured cooling roll

    DEFF Research Database (Denmark)

    Murthy, Swathi; Pranov, Henrik; Pedersen, Henrik Chresten

    2016-01-01

    This paper investigates a novel, very high throughput, roll-to-roll (R2R) process for nanostructuring of polymer foils, called R2R extrusion coating. It has the potential to accelerate the integration of nanostructured materials in consumer products for a variety of applications, including optical....../height of 100 nm. The best replication was achieved in polypropylene, by running at high roller line-speed of 60 m/min, and high cooling roller temperature of 70°C. Replication in other common polymers like polyethylene and polystyrene was not possible for the parameter range used for the investigation......., technical, and functional surfaces and devices. In roll-to-roll extrusion coating, a molten polymer film is extruded through a flat die forming a melt curtain, and then laminated onto a carrier foil. The lamination occurs as the melt curtain is pressed between a cooling roller and a counter roller...

  17. Roll-to-roll paper sensors (ROPAS); Wireless communicating sensors on paper in the logistic chain

    NARCIS (Netherlands)

    Rentrop, C.; Rubingh, J.E.J.M.; Lelieveld, R.; Sandberg, H.

    2014-01-01

    The ROPAS project (Roll-to-roll paper sensors) combines high end electronics and wireless sensors with low cost paper substrates and processing techniques that can be applied on a large scale. Paper is the next step in the printed electronics roadmap of utilising cheaper substrate materials as a

  18. HOT 2015

    DEFF Research Database (Denmark)

    Hannibal, Sara Stefansen

    2016-01-01

    HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud.......HOT samler og formidler 21 literacykyndiges bud på, hvad der er hot, og hvad der bør være hot inden for literacy – og deres begrundelser for disse bud....

  19. Analysis of a high-Tc hot-electron superconducting mixer for terahertz applications

    International Nuclear Information System (INIS)

    Karasik, B.S.; McGrath, W.R.; Gaidis, M.C.

    1997-01-01

    The prospects of a YBa 2 Cu 3 O 7-δ hot-electron bolometer mixer for a THz heterodyne receiver are discussed. The modeled device is a submicron bridge made from a 10-nm-thick film on a high thermal conductance substrate. The mixer performance expected for this device is analyzed in the framework of a two-temperature model which includes heating both of the electrons and the lattice. Also, the contribution of phonon diffusion from the film through the substrate and from the film to the normal metal contacts is evaluated. The intrinsic conversion efficiency and the noise temperature have been calculated as functions of the device size, local oscillator (LO) power, and ambient temperature. Assuming thermal fluctuations and Johnson noise to be the main sources of noise, a minimum single sideband mixer noise temperature of congruent 2000 K is predicted. For our modeled device the intrinsic conversion loss at an intermediate frequency of 2.5 GHz is less than 10 dB and the required LO power is ∼1 endash 10 μW. copyright 1997 American Institute of Physics

  20. Heat-related deaths in hot cities: estimates of human tolerance to high temperature thresholds.

    Science.gov (United States)

    Harlan, Sharon L; Chowell, Gerardo; Yang, Shuo; Petitti, Diana B; Morales Butler, Emmanuel J; Ruddell, Benjamin L; Ruddell, Darren M

    2014-03-20

    In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax) and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90-97 °F; 32.2-36.1 °C) were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C). Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C) with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C) and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C) and males Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

  1. 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.

  2. The development of a mobile hot cell facility for the conditioning of spent high activity radioactive sources (SHARS)

    International Nuclear Information System (INIS)

    Liebenberg, G.R.; Al-Mughrabi, M.

    2008-01-01

    The International Atomic Energy Agency (IAEA) Waste Technology Section with additional support from the U.S. National Nuclear Security Agency (NNSA) through the IAEA Nuclear Security Fund has funded the design, fabrication, evaluation, and testing of a portable hot cell intended to address the problem of disused SHARS in obsolete irradiation devices such as teletherapy heads and dry irradiators. The project is initially targeting the African continent but expected soon to expand to Latin America and Asia. This hot cell would allow source removal, characterization, consolidation, repackaging in modern storage shields, and secure storage of high risk SHARS at single sites in each IAEA Member State. The mobile hot cell and related equipment is transported in two shipping containers to a specific country where the following process takes place: 1-) Assembly of hot cell; 2-) Removal of SHARS from working shields, encapsulation into a stainless steel capsule and placement into a long term storage shield; 3-) Conditioning of any other spent sources the country may require; 4-) Dismantling of the hot cell; 5-) Shipping equipment out of country. The operation in a specific country is planned to be executed over a three week period. This presentation will discuss the development of the mobile hot cell facility as well as the demonstration of the state of readiness of the system for manipulation of SHARS and the planned execution of the conditioning operations. As a result of this project, excess SHARS could be managed safely and securely and possibly be more easily repatriated to their country of origin for appropriate final disposition. (author)

  3. Finite Element Creep-Fatigue Analysis of a Welded Furnace Roll for Identifying Failure Root Cause

    Science.gov (United States)

    Yang, Y. P.; Mohr, W. C.

    2015-11-01

    Creep-fatigue induced failures are often observed in engineering components operating under high temperature and cyclic loading. Understanding the creep-fatigue damage process and identifying failure root cause are very important for preventing such failures and improving the lifetime of engineering components. Finite element analyses including a heat transfer analysis and a creep-fatigue analysis were conducted to model the cyclic thermal and mechanical process of a furnace roll in a continuous hot-dip coating line. Typically, the roll has a short life, modeling heat convection from hot air inside the furnace. The creep-fatigue analysis was performed by inputting the predicted temperature history and applying mechanical loads. The analysis results showed that the failure was resulted from a creep-fatigue mechanism rather than a creep mechanism. The difference of material properties between the filler metal and the base metal is the root cause for the roll failure, which induces higher creep strain and stress in the interface between the weld and the HAZ.

  4. Proceedings of Prof. Brahm Prakash birth centenary workshop on high temperature materials and hot structures: souvenir and book of abstracts

    International Nuclear Information System (INIS)

    2013-01-01

    Traditionally, monolithic ceramics and refractory metals were identified for use at high temperatures. Considerations such as higher operating temperatures, increased thermostructural loads, lower density, etc. brought exotic materials such as ceramic matrix composites, carbon based composites, ODS alloy, intermetallics and thermal barrier coatings to the horizon. Advent of ultra high temperature ceramics and functionally graded materials further pushed the threshold of applicability of high temperature materials and hot structures. Impressive progress in this area has been possible because of the fact that characterization tools along with design and simulation techniques have constantly kept pace with advancement occurring in the processing methods of these materials. The workshop scope includes: Thermal Protection Systems and Materials, Hot Structures, Ceramic and Carbon Matrix Composites, Ultra High Temperature Ceramics, Coating Technology, Simulation and Characterization. Articles relevant to INIS are indexed separately

  5. 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

  6. Heat-Related Deaths in Hot Cities: Estimates of Human Tolerance to High Temperature Thresholds

    Directory of Open Access Journals (Sweden)

    Sharon L. Harlan

    2014-03-01

    Full Text Available In this study we characterized the relationship between temperature and mortality in central Arizona desert cities that have an extremely hot climate. Relationships between daily maximum apparent temperature (ATmax and mortality for eight condition-specific causes and all-cause deaths were modeled for all residents and separately for males and females ages <65 and ≥65 during the months May–October for years 2000–2008. The most robust relationship was between ATmax on day of death and mortality from direct exposure to high environmental heat. For this condition-specific cause of death, the heat thresholds in all gender and age groups (ATmax = 90–97 °F; 32.2‒36.1 °C were below local median seasonal temperatures in the study period (ATmax = 99.5 °F; 37.5 °C. Heat threshold was defined as ATmax at which the mortality ratio begins an exponential upward trend. Thresholds were identified in younger and older females for cardiac disease/stroke mortality (ATmax = 106 and 108 °F; 41.1 and 42.2 °C with a one-day lag. Thresholds were also identified for mortality from respiratory diseases in older people (ATmax = 109 °F; 42.8 °C and for all-cause mortality in females (ATmax = 107 °F; 41.7 °C and males <65 years (ATmax = 102 °F; 38.9 °C. Heat-related mortality in a region that has already made some adaptations to predictable periods of extremely high temperatures suggests that more extensive and targeted heat-adaptation plans for climate change are needed in cities worldwide.

  7. Multivariable control of a rolling spider drone

    Science.gov (United States)

    Lyu, Haifeng

    The research and application of Unmanned Aerial Vehicles (UAVs) has been a hot topic recently. A UAV is dened as an aircraft which is designed not to carry a human pilot or operated with remote electronic input by the flight controller. In this thesis, the design of a control system for a quadcopter named Rolling Spider Drone is conducted. The thesis work presents the design of two kinds of controllers that can control the Drone to keep it balanced and track different kinds of input trajectories. The nonlinear mathematical model for the Drone is derived by the Newton-Euler method. The rotational subsystem and translational system are derived to describe the attitude and position motion of Drone. Techniques from linear control theory are employed to linearize the highly coupled and nonlinear quadcopter plant around equilibrium points and apply the linear feedback controller to stabilize the system. The controller is a digital tracking system that deploys LQR for system stability design. Fixed gain and adaptive gain scheduled controllers are developed and compared with different LQR weights. Step references and reference trajectories involving signicant variation for the yaw angle in the xy-plane and three-dimensional spaces are tracked in the simulation. The physical implementation and an output feedback controller are considered for future work.

  8. 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.

  9. Perovskite solar cells for roll-to-roll fabrication

    Directory of Open Access Journals (Sweden)

    Uddin Ashraf

    2017-01-01

    Full Text Available Perovskite solar cell (PSCs is considered as the game changer in emerging photovoltaics technology. The highest certified efficiency is 22% with high temperature processed (∼500 °C TiO2 based electron transport layer (ETL. High temperature process is a rudimentary hindrance towards roll-to-roll processing of PSCs on flexible substrates. Low temperature solution process (<150 °C ZnO based ETL is one of the most promising candidate for large scale roll-to-roll fabrication of cells as it has nearly identical electron affinity (4.2 eV of TiO2. The mixed organic perovskite (MA0.6FA0.4PbI3 devices with Al doped ZnO (AZO ETL demonstrate average cell efficiency over 16%, which is the highest ever reported efficiency for this device configuration. The energy level alignment and related interfacial charge transport dynamics at the interface of ZnO and perovskite films and the adjacent charge transport layers are investigated. Significantly improved device stability, hysteresis free device photocurrent have been observed in MA0.6FA0.4PbI3 cells. A systematic electrochemical impedance spectroscopy, frequency dependent capacitance spectra, surface morphology and topography characterization have been conducted to understand the role of interfacial electronic properties between perovskite and neighbouring layers in perovskite device. A standardized degradation study, interfacial electronic property and capacitive spectra analysis of aged device, have been measured to understand the enhanced device stability in mixed MA0.6FA0.4PbI3 cells. Slow perovskite material decomposition rate and augmented device lifetime with AZO based devices have been found to be correlated with the more hydrophobic and acidic nature of AZO surface compared to pristine ZnO film.

  10. Independence of Hot and Cold Executive Function Deficits in High-Functioning Adults with Autism Spectrum Disorder.

    Science.gov (United States)

    Zimmerman, David L; Ownsworth, Tamara; O'Donovan, Analise; Roberts, Jacqueline; Gullo, Matthew J

    2016-01-01

    Individuals with autistic spectrum disorder (ASD) display diverse deficits in social, cognitive and behavioral functioning. To date, there has been mixed findings on the profile of executive function deficits for high-functioning adults (IQ > 70) with ASD. A conceptual distinction is commonly made between "cold" and "hot" executive functions. Cold executive functions refer to mechanistic higher-order cognitive operations (e.g., working memory), whereas hot executive functions entail cognitive abilities supported by emotional awareness and social perception (e.g., social cognition). This study aimed to determine the independence of deficits in hot and cold executive functions for high-functioning adults with ASD. Forty-two adults with ASD (64% male, aged 18-66 years) and 40 age and gender matched controls were administered The Awareness of Social Inference Test (TASIT; emotion recognition and social inference), Letter Number Sequencing (working memory) and Hayling Sentence Completion Test (response initiation and suppression). Between-group analyses identified that the ASD group performed significantly worse than matched controls on all measures of cold and hot executive functions (d = 0.54 - 1.5). Hierarchical multiple regression analyses revealed that the ASD sample performed more poorly on emotion recognition and social inference tasks than matched controls after controlling for cold executive functions and employment status. The findings also indicated that the ability to recognize emotions and make social inferences was supported by working memory and response initiation and suppression processes. Overall, this study supports the distinction between hot and cold executive function impairments for adults with ASD. Moreover, it advances understanding of higher-order impairments underlying social interaction difficulties for this population which, in turn, may assist with diagnosis and inform intervention programs.

  11. High Temperature Logging and Monitoring Instruments to Explore and Drill Deep into Hot Oceanic Crust.

    Science.gov (United States)

    Denchik, N.; Pezard, P. A.; Ragnar, A.; Jean-Luc, D.; Jan, H.

    2014-12-01

    Drilling an entire section of the oceanic crust and through the Moho has been a goal of the scientific community for more than half of a century. On the basis of ODP and IODP experience and data, this will require instruments and strategies working at temperature far above 200°C (reached, for example, at the bottom of DSDP/ODP Hole 504B), and possibly beyond 300°C. Concerning logging and monitoring instruments, progress were made over the past ten years in the context of the HiTI ("High Temperature Instruments") project funded by the european community for deep drilling in hot Icelandic geothermal holes where supercritical conditions and a highly corrosive environment are expected at depth (with temperatures above 374 °C and pressures exceeding 22 MPa). For example, a slickline tool (memory tool) tolerating up to 400°C and wireline tools up to 300°C were developed and tested in Icelandic high-temperature geothermal fields. The temperature limitation of logging tools was defined to comply with the present limitation in wireline cables (320°C). As part of this new set of downhole tools, temperature, pressure, fluid flow and casing collar location might be measured up to 400°C from a single multisensor tool. Natural gamma radiation spectrum, borehole wall ultrasonic images signal, and fiber optic cables (using distributed temperature sensing methods) were also developed for wireline deployment up to 300°C and tested in the field. A wireline, dual laterolog electrical resistivity tool was also developed but could not be field tested as part of HiTI. This new set of tools constitutes a basis for the deep exploration of the oceanic crust in the future. In addition, new strategies including the real-time integration of drilling parameters with modeling of the thermo-mechanical status of the borehole could be developed, using time-lapse logging of temperature (for heat flow determination) and borehole wall images (for hole stability and in-situ stress determination

  12. High density crystalline boron prepared by hot isostatic pressing in refractory metal containers

    Science.gov (United States)

    Hoenig, C.L.

    1993-08-31

    Boron powder is hot isostatically pressed in a refractory metal container to produce a solid boron monolith with a bulk density at least 2.22 g/cc and up to or greater than 2.34 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1,800 C and 30 PSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.34 g/cc. Complex shapes can be made.

  13. Magnetized Converging Flows toward the Hot Core in the Intermediate/High-mass Star-forming Region NGC 6334 V

    Energy Technology Data Exchange (ETDEWEB)

    Juárez, Carmen; Girart, Josep M. [Institut de Ciències de l’Espai, (CSIC-IEEC), Campus UAB, Carrer de Can Magrans, S/N, E-08193 Cerdanyola del Vallès, Catalonia (Spain); Zamora-Avilés, Manuel; Palau, Aina; Ballesteros-Paredes, Javier [Instituto de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, P.O. Box 3-72, 58090, Morelia, Michoacán (Mexico); Tang, Ya-Wen; Koch, Patrick M.; Liu, Hauyu Baobab [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei, 10617, Taiwan (China); Zhang, Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Qiu, Keping, E-mail: juarez@ice.cat [School of Astronomy and Space Science, Nanjing University, 163 Xianlin Avenue, Nanjing 210023 (China)

    2017-07-20

    We present Submillimeter Array (SMA) observations at 345 GHz toward the intermediate/high-mass cluster-forming region NGC 6334 V. From the dust emission we spatially resolve three dense condensations, the brightest one presenting the typical chemistry of a hot core. The magnetic field (derived from the dust polarized emission) shows a bimodal converging pattern toward the hot core. The molecular emission traces two filamentary structures at two different velocities, separated by 2 km s{sup −1}, converging to the hot core and following the magnetic field distribution. We compare the velocity field and the magnetic field derived from the SMA observations with magnetohydrodynamic simulations of star-forming regions dominated by gravity. This comparison allows us to show how the gas falls in from the larger-scale extended dense core (∼0.1 pc) of NGC 6334 V toward the higher-density hot core region (∼0.02 pc) through two distinctive converging flows dragging the magnetic field, whose strength seems to have been overcome by gravity.

  14. Magnetized Converging Flows toward the Hot Core in the Intermediate/High-mass Star-forming Region NGC 6334 V

    International Nuclear Information System (INIS)

    Juárez, Carmen; Girart, Josep M.; Zamora-Avilés, Manuel; Palau, Aina; Ballesteros-Paredes, Javier; Tang, Ya-Wen; Koch, Patrick M.; Liu, Hauyu Baobab; Zhang, Qizhou; Qiu, Keping

    2017-01-01

    We present Submillimeter Array (SMA) observations at 345 GHz toward the intermediate/high-mass cluster-forming region NGC 6334 V. From the dust emission we spatially resolve three dense condensations, the brightest one presenting the typical chemistry of a hot core. The magnetic field (derived from the dust polarized emission) shows a bimodal converging pattern toward the hot core. The molecular emission traces two filamentary structures at two different velocities, separated by 2 km s −1 , converging to the hot core and following the magnetic field distribution. We compare the velocity field and the magnetic field derived from the SMA observations with magnetohydrodynamic simulations of star-forming regions dominated by gravity. This comparison allows us to show how the gas falls in from the larger-scale extended dense core (∼0.1 pc) of NGC 6334 V toward the higher-density hot core region (∼0.02 pc) through two distinctive converging flows dragging the magnetic field, whose strength seems to have been overcome by gravity.

  15. Application of annular centrifugal contactors in the hot test of the improved total partitioning process for high level liquid waste.

    Science.gov (United States)

    Duan, Wuhua; Chen, Jing; Wang, Jianchen; Wang, Shuwei; Feng, Xiaogui; Wang, Xinghai; Li, Shaowei; Xu, Chao

    2014-08-15

    High level liquid waste (HLLW) produced from the reprocessing of the spent nuclear fuel still contains moderate amounts of uranium, transuranium (TRU) actinides, (90)Sr, (137)Cs, etc., and thus constitutes a permanent hazard to the environment. The partitioning and transmutation (P&T) strategy has increasingly attracted interest for the safe treatment and disposal of HLLW, in which the partitioning of HLLW is one of the critical technical issues. An improved total partitioning process, including a TRPO (tri-alkylphosphine oxide) process for the removal of actinides, a CESE (crown ether strontium extraction) process for the removal of Sr, and a CECE (calixcrown ether cesium extraction) process for the removal of Cs, has been developed to treat Chinese HLLW. A 160-hour hot test of the improved total partitioning process was carried out using 72-stage 10-mm-dia annular centrifugal contactors (ACCs) and genuine HLLW. The hot test results showed that the average DFs of total α activity, Sr and Cs were 3.57 × 10(3), 2.25 × 10(4) and 1.68 × 10(4) after the hot test reached equilibrium, respectively. During the hot test, 72-stage 10-mm-dia ACCs worked stable, continuously with no stage failing or interruption of the operation. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. High temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Crossland, C.E.; Shelleman, D.L.; Spear, K.E. [Pennsylvania State Univ., University Park, PA (United States)] [and others

    1996-08-01

    A vertical flow-through furnace has been built to study the effect of corrosion on the morphology and mechanical properties of ceramic hot gas filters. Sections of 3M Type 203 and DuPont Lanxide SiC-SiC filter tubes were sealed at one end and suspended in the furnace while being subjected to a simulated coal combustion environment at 870{degrees}C. X-ray diffraction and electron microscopy is used to identify phase and morphology changes due to corrosion while burst testing determines the loss of mechanical strength after exposure to the combustion gases. Additionally, a thermodynamic database of gaseous silicon compounds is currently being established so that calculations can be made to predict important products of the reaction of the environment with the ceramics. These thermodynamic calculations provide useful information concerning the regimes where the ceramic may be degraded by material vaporization. To verify the durability and predict lifetime performance of ceramic heat exchangers in coal combustion environments, long-term exposure testing of stressed (internally pressurized) tubes must be performed in actual coal combustion environments. The authors have designed a system that will internally pressurize 2 inch OD by 48 inch long ceramic heat exchanger tubes to a maximum pressure of 200 psi while exposing the outer surface of the tubes to coal combustion gas at the Combustion and Environmental Research Facility (CERF) at the Pittsburgh Energy and Technology Center. Water-cooled, internal o-ring pressure seals were designed to accommodate the existing 6 inch by 6 inch access panels of the CERF. Tubes will be exposed for up to a maximum of 500 hours at temperatures of 2500 and 2600{degrees}F with an internal pressure of 200 psi. If the tubes survive, their retained strength will be measured using the high temperature tube burst test facility at Penn State University. Fractographic analysis will be performed to identify the failure source(s) for the tubes.

  17. Performance analysis of high-concentrated multi-junction solar cells in hot climate

    Science.gov (United States)

    Ghoneim, Adel A.; Kandil, Kandil M.; Alzanki, Talal H.; Alenezi, Mohammad R.

    2018-03-01

    Multi-junction concentrator solar cells are a promising technology as they can fulfill the increasing energy demand with renewable sources. Focusing sunlight upon the aperture of multi-junction photovoltaic (PV) cells can generate much greater power densities than conventional PV cells. So, concentrated PV multi-junction solar cells offer a promising way towards achieving minimum cost per kilowatt-hour. However, these cells have many aspects that must be fixed to be feasible for large-scale energy generation. In this work, a model is developed to analyze the impact of various atmospheric factors on concentrator PV performance. A single-diode equivalent circuit model is developed to examine multi-junction cells performance in hot weather conditions, considering the impacts of both temperature and concentration ratio. The impacts of spectral variations of irradiance on annual performance of various high-concentrated photovoltaic (HCPV) panels are examined, adapting spectra simulations using the SMARTS model. Also, the diode shunt resistance neglected in the existing models is considered in the present model. The present results are efficiently validated against measurements from published data to within 2% accuracy. Present predictions show that the single-diode model considering the shunt resistance gives accurate and reliable results. Also, aerosol optical depth (AOD) and air mass are most important atmospheric parameters having a significant impact on HCPV cell performance. In addition, the electrical efficiency (η) is noticed to increase with concentration to a certain concentration degree after which it decreases. Finally, based on the model predictions, let us conclude that the present model could be adapted properly to examine HCPV cells' performance over a broad range of operating conditions.

  18. The development of uranium foil farication technology utilizing twin roll method for Mo-99 irradiation target

    CERN Document Server

    Kim, C K; Park, H D

    2002-01-01

    MDS Nordion in Canada, occupying about 75% of global supply of Mo-99 isotope, has provided the irradiation target of Mo-99 using the rod-type UAl sub x alloys with HEU(High Enrichment Uranium). ANL (Argonne National Laboratory) through co-operation with BATAN in Indonesia, leading RERTR (Reduced Enrichment for Research and Test Reactors) program substantially for nuclear non-proliferation, has designed and fabricated the annular cylinder of uranium targets, and successfully performed irradiation test, in order to develop the fabrication technology of fission Mo-99 using LEU(Low Enrichment Uranium). As the uranium foils could be fabricated in laboratory scale, not in commercialized scale by hot rolling method due to significant problems in foil quality, productivity and economic efficiency, attention has shifted to the development of new technology. Under these circumstances, the invention of uranium foil fabrication technology utilizing twin-roll casting method in KAERI is found to be able to fabricate LEU or...

  19. 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.

  20. Crystal plasticity modeling of through-thickness texture heterogeneity in heavily rolled aluminum

    DEFF Research Database (Denmark)

    Delannay, Laurent; Mishin, Oleg V.

    2013-01-01

    from hot rolling producing shear near the surface and conditions approaching plane strain compression in the center layer. Model predictions confirm experimental observations that such a gradient strengthens significantly during further heavy cold rolling. Copyright © 2013 Trans Tech Publications Ltd....

  1. Hot embossing of photonic crystal polymer structures with a high aspect ratio

    DEFF Research Database (Denmark)

    Schelb, Mauno; Vannahme, Christoph; Kolew, Alexander

    2011-01-01

    ). A nickel tool for the replication of structures with lateral dimensions of 110 nm and heights of approximately 370 nm is fabricated via electroplating of a nanostructured sample resulting in an aspect ratio of approximately 3.5. The structures are subsequently hot embossed into PMMA and COC substrates....

  2. SOPHIE velocimetry of Kepler transit candidates. IV. KOI-196b: a non-inflated hot Jupiter with a high albedo

    Science.gov (United States)

    Santerne, A.; Bonomo, A. S.; Hébrard, G.; Deleuil, M.; Moutou, C.; Almenara, J.-M.; Bouchy, F.; Díaz, R. F.

    2011-12-01

    We report the discovery of a new hot-Jupiter, KOI-196b, transiting a solar-type star with an orbital period of 1.855558 days ± 0.6 s thanks to public photometric data from the Kepler space mission and new radial velocity observations obtained by the SOPHIE spectrograph mounted on the 1.93-m telescope at the Observatoire de Haute-Provence, France. The planet KOI-196b, with a radius of 0.89 ± 0.05 RJup and a mass of 0.55 ± 0.09 MJup, orbits a G6V star with R⋆ = 1.02 ± 0.03 R⊙, M⋆ = 1.12 ± 0.07 M⊙, [Fe/H] = 0.29 ± 0.16 dex, Teff = 5620 ± 140 K, and an age of 650 +2500-300} Myr. KOI-196b is one of the rare close-in hot Jupiters with a radius smaller than Jupiter suggesting that it is a non-inflated planet. The high precision of the Kepler photometry permits us to detect the secondary transit with a depth of 64 +10-12} ppm as well as the optical phase variation. We find a geometric albedo of Ag = 0.30 ± 0.08, which is higher than most of the transiting hot Jupiters with a measured Ag. Assuming no heat recirculation, we find a day-side temperature of Tday = 1730 ± 400 K. The planet KOI-196b seems to be one of the rare hot Jupiters located in the short-period hot-Jupiter desert. Based on observations made with SOPHIE on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS), France.

  3. Modeling of the hot flow behavior of advanced ultra-high strength steels (A-UHSS) microalloyed with boron

    Energy Technology Data Exchange (ETDEWEB)

    Mejía, I., E-mail: imejia@umich.mx [Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio “U”, Ciudad Universitaria, 58066 Morelia, Michoacán (Mexico); Altamirano, G.; Bedolla-Jacuinde, A. [Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio “U”, Ciudad Universitaria, 58066 Morelia, Michoacán (Mexico); Cabrera, J.M. [Departament de Ciència dels Materials i Enginyeria Metallúrgica, ETSEIB – Universitat Politècnica de Catalunya, Av. Diagonal 647, 08028 Barcelona (Spain); Fundació CTM Centre Tecnològic, Av. de las Bases de Manresa, 1, 08240 Manresa (Spain)

    2014-07-29

    In this research work, modeling of the hot flow behavior was carried out in a low carbon advanced ultra-high strength steels (A-UHSS) microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm). For this purpose, experimental stress–strain data of uniaxial hot-compression tests over a wide range of temperatures (1223, 1273, 1323 and 1373 K (950, 1000, 1050 and 1100 °C)) and strain rates (10{sup −3}, 10{sup −2} and 10{sup −1} s{sup −1}) were used. The stress–strain relationships as a function of temperature and strain rate were successfully described on the basis of the approach proposed by Estrin, Mecking, and Bergström, together with the classical Avrami equation and the conventional hyperbolic sine function. The analysis of the modeling parameters of the hot flow curves shows that boron additions to A-UHSS play a major role in softening mechanisms rather than on hardening. The peak stress (σ{sub p}) and steady-state stress (σ{sub ss}) values show a decreasing trend with increasing boron content, which indicates that boron additions promote a solid solution softening effect additional to that produced by DRX. The time for 50% recrystallization (t{sub 50%}) tends to increase with boron additions, revealing that boron additions cause a delay of the DRX kinetics during hot deformation. Similarly, the presence of boron in the steel decreases the apparent activation energy for recrystallization (Q{sub t}), indicating that boron additions accelerate the onset of DRX. The constitutive equations developed in this way provided an excellent description of the experimental hot flow curves.

  4. Modeling of the hot flow behavior of advanced ultra-high strength steels (A-UHSS) microalloyed with boron

    International Nuclear Information System (INIS)

    Mejía, I.; Altamirano, G.; Bedolla-Jacuinde, A.; Cabrera, J.M.

    2014-01-01

    In this research work, modeling of the hot flow behavior was carried out in a low carbon advanced ultra-high strength steels (A-UHSS) microalloyed with different amounts of boron (14, 33, 82, 126 and 214 ppm). For this purpose, experimental stress–strain data of uniaxial hot-compression tests over a wide range of temperatures (1223, 1273, 1323 and 1373 K (950, 1000, 1050 and 1100 °C)) and strain rates (10 −3 , 10 −2 and 10 −1 s −1 ) were used. The stress–strain relationships as a function of temperature and strain rate were successfully described on the basis of the approach proposed by Estrin, Mecking, and Bergström, together with the classical Avrami equation and the conventional hyperbolic sine function. The analysis of the modeling parameters of the hot flow curves shows that boron additions to A-UHSS play a major role in softening mechanisms rather than on hardening. The peak stress (σ p ) and steady-state stress (σ ss ) values show a decreasing trend with increasing boron content, which indicates that boron additions promote a solid solution softening effect additional to that produced by DRX. The time for 50% recrystallization (t 50% ) tends to increase with boron additions, revealing that boron additions cause a delay of the DRX kinetics during hot deformation. Similarly, the presence of boron in the steel decreases the apparent activation energy for recrystallization (Q t ), indicating that boron additions accelerate the onset of DRX. The constitutive equations developed in this way provided an excellent description of the experimental hot flow curves

  5. Rolling cycle amplification based single-color quantum dots–ruthenium complex assembling dyads for homogeneous and highly selective detection of DNA

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chen; Liu, Yufei; Ye, Tai; Xiang, Xia; Ji, Xinghu; He, Zhike, E-mail: zhkhe@whu.edu.cn

    2015-01-01

    Graphical abstract: A universal, label-free, homogeneous, highly sensitive, and selective fluorescent biosensor for DNA detection is developed by using rolling-circle amplification (RCA) based single-color quantum dots–ruthenium complex (QDs–Ru) assembling dyads. - Highlights: • The single-color QDs–Ru assembling dyads were applied in homogeneous DNA assay. • This biosensor exhibited high selectivity against base mismatched sequences. • This biosensor could be severed as universal platform for the detection of ssDNA. • This sensor could be used to detect the target in human serum samples. • This DNA sensor had a good selectivity under the interference of other dsDNA. - Abstract: In this work, a new, label-free, homogeneous, highly sensitive, and selective fluorescent biosensor for DNA detection is developed by using rolling-circle amplification (RCA) based single-color quantum dots–ruthenium complex (QDs–Ru) assembling dyads. This strategy includes three steps: (1) the target DNA initiates RCA reaction and generates linear RCA products; (2) the complementary DNA hybridizes with the RCA products to form long double-strand DNA (dsDNA); (3) [Ru(phen){sub 2}(dppx)]{sup 2+} (dppx = 7,8-dimethyldipyrido [3,2-a:2′,3′-c] phenanthroline) intercalates into the long dsDNA with strong fluorescence emission. Due to its strong binding propensity with the long dsDNA, [Ru(phen){sub 2}(dppx)]{sup 2+} is removed from the surface of the QDs, resulting in restoring the fluorescence of the QDs, which has been quenched by [Ru(phen){sub 2}(dppx)]{sup 2+} through a photoinduced electron transfer process and is overlaid with the fluorescence of dsDNA bonded Ru(II) polypyridyl complex (Ru-dsDNA). Thus, high fluorescence intensity is observed, and is related to the concentration of target. This sensor exhibits not only high sensitivity for hepatitis B virus (HBV) ssDNA with a low detection limit (0.5 pM), but also excellent selectivity in the complex matrix. Moreover

  6. Effects of dry-rolled or high-moisture corn with twenty-five or forty-five percent wet distillers' grains with solubles on energy metabolism, nutrient digestibility, and macromineral balance in finishing beef steers

    Science.gov (United States)

    The effects of feeding dry-rolled corn (DRC) or high-moisture corn (HMC) with 25% and 45% wet distillers grains with solubles (WDGS) on energy metabolism, and nutrient and mineral balance were evaluated in 8 finishing beef steers using a replicated Latin square design. The model included the fixed ...

  7. Strain measurements at high temperatures in a concrete structure representing a cylindrical section of a PCPV with hot liner

    International Nuclear Information System (INIS)

    Schittenhelm, Ch.

    1975-11-01

    In an experimental ring, representing an 1 m high section of the Austrian PCPV-Model with hot liner, different types of strain gauges were installed in the insulating concrete and the prestressed concrete. In this ring the thermal conditions were the same as in the PCPV-Model. In this report the results of measurements of the past two years are brought and comparisons with static calculations is attempted. (author)

  8. High temperature corrosion of advanced ceramic materials for hot gas filters. Topical report for part 1 of high temperature corrosion of advanced ceramic materials for hot gas filters and heat exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Spear, K.E.; Crossland, C.E.; Shelleman, D.L.; Tressler, R.E. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

    1997-12-11

    This program consists of two separate research areas. Part 1, for which this report is written, studied the high temperature corrosion of advanced ceramic hot gas filters, while Part 2 studied the long-term durability of ceramic heat exchangers to coal combustion environments. The objectives of Part 1 were to select two candidate ceramic filter materials for flow-through hot corrosion studies and subsequent corrosion and mechanical properties characterization. In addition, a thermodynamic database was developed so that thermochemical modeling studies could be performed to simulate operating conditions of laboratory reactors and existing coal combustion power plants, and to predict the reactions of new filter materials with coal combustion environments. The latter would make it possible to gain insight into problems that could develop during actual operation of filters in coal combustion power plants so that potential problems could be addressed before they arise.

  9. The most luminous heavily obscured quasars have a high merger fraction: morphological study of wise -selected hot dust-obscured galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Lulu; Gao, Ying; Zhang, Dandan; Jiang, Xiaoming; Wu, Qiaoqian; Yang, Jun; Li, Zhao [Shandong Provincial Key Lab of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Science, Shandong University, Weihai 264209 (China); Han, Yunkun [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Fang, Guanwen, E-mail: llfan@sdu.edu.cn, E-mail: hanyk@ynao.ac.cn [Institute for Astronomy and History of Science and Technology, Dali University, Dali 671003 (China)

    2016-05-10

    Previous studies have shown that Wide-field Infrared Survey Explorer -selected hyperluminous, hot dust-obscured galaxies (Hot DOGs) are powered by highly dust-obscured, possibly Compton-thick active galactic nuclei (AGNs). High obscuration provides us a good chance to study the host morphology of the most luminous AGNs directly. We analyze the host morphology of 18 Hot DOGs at z ∼ 3 using Hubble Space Telescope /WFC3 imaging. We find that Hot DOGs have a high merger fraction (62 ± 14%). By fitting the surface brightness profiles, we find that the distribution of Sérsic indices in our Hot DOG sample peaks around 2, which suggests that most Hot DOGs have transforming morphologies. We also derive the AGN bolometric luminosity (∼10{sup 14} L {sub ⊙}) of our Hot DOG sample by using IR spectral energy distributions decomposition. The derived merger fraction and AGN bolometric luminosity relation is well consistent with the variability-based model prediction. Both the high merger fraction in an IR-luminous AGN sample and relatively low merger fraction in a UV/optical-selected, unobscured AGN sample can be expected in the merger-driven evolutionary model. Finally, we conclude that Hot DOGs are merger-driven and may represent a transit phase during the evolution of massive galaxies, transforming from the dusty starburst-dominated phase to the unobscured QSO phase.

  10. 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,.

  11. Note: Measuring breakdown characteristics during the hot re-ignition of high intensity discharge lamps using high frequency alternating current voltage.

    Science.gov (United States)

    van den Bos, R A J M; Sobota, A; Manders, F; Kroesen, G M W

    2013-04-01

    To investigate the cold and hot re-ignition properties of High Intensity Discharge (HID) lamps in more detail an automated setup was designed in such a way that HID lamps of various sizes and under different background pressures can be tested. The HID lamps are ignited with a ramped sinusoidal voltage signal with frequencies between 60 and 220 kHz and with amplitude up to 7.5 kV. Some initial results of voltage and current measurements on a commercially available HID lamp during hot and cold re-ignition are presented.

  12. Influence of sulphur and phosphorus on the hot deformation of Fe-Cr 13% high purity steel

    International Nuclear Information System (INIS)

    Lahreche, M.; Bouzabata, B.; Kobylanski, A.

    1995-01-01

    A series of Fe-Cr13%-C high purity steels containing increasing volume fractions of Sulphur (30, 60 and 100ppm) and Phosphorus (30, 60 and 100ppm) were prepared in order to study their hot deformation properties by tensile tests at various strain rates (10 -1 s -1 to 10 -4 s -1 ) and at temperatures from 700 C to 1100 C. It is observed that the hot ductility is lowered at 1000 C with the addition of sulphur. However, this decrease is relatively small (about 30% for 100ppm of sulphur) and quite similar for all additions of sulphur. When phosphorus is added, the embrittlement is along the whole deformed specimen. The usual criteria of ductility by parameter Z do not seem to be sufficient to describe this embrittlement. (orig.)

  13. Android-assisted physics mobile learning to improve senior high school students' divergent thinking skills and physics HOTS

    Science.gov (United States)

    Mardiana, Nana; Kuswanto, Heru

    2017-08-01

    The aims of the research concerned here were to reveal (1) the characteristics of Android-assisted PML (physics mobile learning) to improve SMA (sekolah menengah atas, Indonesian senior high school) students' divergent thinking skills and physics HOTS (higher order thinking skills); (2) the feasibility of the Android-assisted PML; and (3) the influence of using the Android-assisted PML on improvement in SMA students' divergent thinking skills and physics HOTS. The7 research was of the R&D (research and development) type, adapted from theBorg-&-Gall development model. The research data were analyzed by means of MANOVA with the significance level of 5%. The results are as follows. (1) The product of the development, a learning media in software form with the android package(apk) format, is named PML (to refer to Physics Mobile Learning), which has such characterictics as being operable with use of Android devicesand being very good in quality in the aspect oflearning, material, software technology, and audiovisual appearance. 2) The developed learning media referred to as PML is appropriate for learning activity according to evaluation by a material expert, a media expert, peer reviewers, and physics teachers as well as according to results of students' tryouts. (3) The use of the Android-assisted PML media product could improve SMA students' divergent thinking skillsand physics HOTS with the respective high-category gain scores of 0.701 and 0.759.

  14. [Rapid detection of hot spot mutations of FGFR3 gene with PCR-high resolution melting assay].

    Science.gov (United States)

    Li, Shan; Wang, Han; Su, Hua; Gao, Jinsong; Zhao, Xiuli

    2017-08-10

    To identify the causative mutations in five individuals affected with dyschondroplasia and develop an efficient procedure for detecting hot spot mutations of the FGFR3 gene. Genomic DNA was extracted from peripheral blood samples with a standard phenol/chloroform method. PCR-Sanger sequencing was used to analyze the causative mutations in the five probands. PCR-high resolution melting (HRM) was developed to detect the identified mutations. A c.1138G>A mutation in exon 8 was found in 4 probands, while a c.1620C>G mutation was found in exon 11 of proband 5 whom had a mild phenotype. All patients were successfully distinguished from healthy controls with the PCR-HRM method. The results of HRM analysis were highly consistent with that of Sanger sequencing. The Gly380Arg and Asn540Lys are hot spot mutations of the FGFR3 gene among patients with ACH/HCH. PCR-HRM analysis is more efficient for detecting hot spot mutations of the FGFR3 gene.

  15. Silver as a highly effective bonding layer for lead telluride thermoelectric modules assembled by rapid hot-pressing

    International Nuclear Information System (INIS)

    Li, C.C.; Drymiotis, F.; Liao, L.L.; Dai, M.J.; Liu, C.K.; Chen, C.L.; Chen, Y.Y.; Kao, C.R.; Snyder, G.J.

    2015-01-01

    Highlights: • Ag serves as a promising bonding material for PbTe operating at T Hot ⩽ 400 °C. • The Ag foils reacted vigorously with PbTe to form Ag 2 Te at 550 °C. • The Seebeck coefficient of Ag/PbTe/Ag is slightly higher than that of pure PbTe. • A cost-effective way for long-term operations at high temperature. - Abstract: We use the rapid hot-pressing method to bond Ag foil onto pure PbTe in order to assess its effectiveness as a bonding layer material for thermoelectric module applications. Scanning electron microscopy and X-ray diffraction are employed to examine intermetallic compound formation and microstructure evolution during isothermal aging at 400 °C and 550 °C. We find that Ag is a promising bonding material for PbTe modules operating at T Hot ⩽ 400 °C. Additionally, our approach highlights a highly effective and inexpensive method to metallize PbTe prior to module assembly

  16. The analysis of senior high school students' physics HOTS in Bantul District measured using PhysReMChoTHOTS

    Science.gov (United States)

    Istiyono, Edi

    2017-08-01

    The purpose of this research is to describe the results of higher order thinking skills in physics (PhysHOTS) measurement including: (1) percentage of PhysHOTS level and (2) percentage of the domination of response in the category of students in each analyzing, evaluating, and creating skill. There were 404 10th grade students in Bantul District as the respondents of this research. The instrument used for measurement was PhysReMChoTHOTS. It was divided into two sets consisting of 44 items and including 8 anchor items stated valid by a Physicist, Physics Education Expert, and Physics Education Measurement Expert. The instrument was fit to PCM. The reliability coefficient of this test is 0.71, while the difficulty index of the items ranges from -0.61 to 0.51. The results of the measurement show that: (1) The percentage of each category of PhysHOTS for the 10th grade students in Bantul District for the very low, low, medium, high, and very high category is 4.75 %, 40.30 %, 33.45 %, 19.50 %, and 2.00 %, respectively; and (2) The order in analyzing skills, starts from the weakest, is attributing, differentiating and organizing. The order in evaluating skills, starts from the weakest, is critiquing and checking. Meanwhile, the order in creating skills, starts from the weakest, is producing, planning, and generating.

  17. Hot steam header of a high temperature reactor as a benchmark problem

    International Nuclear Information System (INIS)

    Demierre, J.

    1990-01-01

    The International Atomic Energy Agency (IAEA) initiated a Coordinated Research Programme (CRP) on ''Design Codes for Gas-Cooled Reactor Components''. The specialists proposed to start with a benchmark design of a hot steam header in order to get a better understanding of the methods in the participating countries. The contribution of Switzerland carried out by Sulzer. The following report summarized the detailed calculations of dimensioning procedure and analysis. (author). 5 refs, 2 figs, 2 tabs

  18. Mechanical Properties and Microstructure of High-Strength Steel Controlled by Hot Stamping Process

    Science.gov (United States)

    Ou, Hang; Zhang, Xu; Xu, Junrui; Li, Guangyao; Cui, Junjia

    2018-03-01

    A novel design and manufacturing method, dubbed "precast," of the cooling system and tools for a hot forming process was proposed in this paper. The integrated structures of the punch and blank holder were determined by analyzing the bending and reverse-bending deformation of the forming parts. The desired crashworthiness performance of an automotive front bumper constructed with this process was obtained by a tailored phase transformation, which generated martensite-bainite in the middle and full martensite transformation in the corner areas. Varying cooling effects in the formed parts caused the highest temperature to be located in the bottom and the lowest on the end of the formed parts. Moreover, the microstructural distributions demonstrated that the bottom possessed a relatively lower content of martensite, while, conversely, the end possessed a higher content. This was precisely the most desired phase distributions for the hot formed parts. For the six-process cycle stamping, the temperatures reached a stable status after an initial rapid increase in the first three process cycles. The microstructural results verified the feasibility of the hot forming tools under multiprocess cycles.

  19. 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%.

  20. Effect of Annealing Temperature on the Microstructure, Tensile Properties, and Fracture Behavior of Cold-Rolled High-Mn Light-Weight Steels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae-Hyun; Cho, Kyung Mox [Pusan National University, Busan (Korea, Republic of); Park, Seong-Jun; Moon, Joonoh; Kang, Jun-Yun; Park, Jun-Young; Lee, Tae-Ho [Korea Institute of Materials Science, Changwon (Korea, Republic of)

    2017-05-15

    The effects of the annealing temperature on the microstructure and tensile properties of cold-rolled light-weight steels are investigated using two Fe-30Mn-xAl-0.9C alloys that contain different Al content. The initial alloy microstructure is composed of a single austenite or a mixture of austenite and ferrite depending on the nominal aluminum content. For the alloy with 9 wt%Al content, the recrystallization and grain growth of austenite occurrs depending on the annealing temperature. However, for the alloy with 11 wt%Al content, the β-Mn phase is observed after annealing for 10 min at 550~800 ℃. The β-Mn transformation kinetics is the fastest at 700 ℃. The formation of the β-Mn phase has a detrimental effect on the ductility, and this leads to significant decreases in the total elongation. The same alloy also forms κ-carbide and DO3 ordering at 550~900 ℃. The investigated alloys exhibit a fully recrystallized microstructure after annealing at 900 ℃ for 10 min, which results in a high total elongation of 25~55%with a high tensile strength of 900~1170 MPa.

  1. Rolling at small scales

    DEFF Research Database (Denmark)

    Nielsen, Kim L.; Niordson, Christian F.; Hutchinson, John W.

    2016-01-01

    The rolling process is widely used in the metal forming industry and has been so for many years. However, the process has attracted renewed interest as it recently has been adapted to very small scales where conventional plasticity theory cannot accurately predict the material response. It is well....... Metals are known to be stronger when large strain gradients appear over a few microns; hence, the forces involved in the rolling process are expected to increase relatively at these smaller scales. In the present numerical analysis, a steady-state modeling technique that enables convergence without...

  2. METHOD OF ROLLING URANIUM

    Science.gov (United States)

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  3. 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.

  4. Preparation of 50Ni-45Ti-5Zr powders by high-energy ball milling and hot pressing

    Energy Technology Data Exchange (ETDEWEB)

    Marinzeck de Alcantara Abdala, Julia, E-mail: juabdala@yahoo.com.b [Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi, 2911, 12244-000 Sao Jose dos Campos (Brazil); Bacci Fernandes, Bruno, E-mail: brunobacci@yahoo.com.b [Divisao de Engenharia Mecanica, Instituto Tecnologico de Aeronautica, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Santos, Dalcy Roberto dos, E-mail: dalcy@iae.cta.b [Instituto de Aeronautica e Espaco, Centro Tecnologico Aeroespacial, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Rodrigues Henriques, Vinicius Andre, E-mail: vinicius@iae.cta.b [Instituto de Aeronautica e Espaco, Centro Tecnologico Aeroespacial, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Moura Neto, Carlos de, E-mail: mneto@ita.b [Divisao de Engenharia Mecanica, Instituto Tecnologico de Aeronautica, Praca Marechal-do-Ar Eduardo Gomes, 50, 12228-904 Sao Jose dos Campos (Brazil); Saraiva Ramos, Alfeu, E-mail: alfeu@univap.b [Instituto de Pesquisa e Desenvolvimento, Universidade do Vale do Paraiba, Av. Shishima Hifumi, 2911, 12244-000 Sao Jose dos Campos (Brazil)

    2010-04-16

    This study reports on the preparation of the 50Ni-45Ti-5Zr (at.%) alloy by high-energy ball milling and hot pressing. The elemental powder mixture was processed in silicon nitride and hardened steel vials, and samples were collected after different milling times. To recover the previous powders in addition wet milling isopropyl alcohol (for 20 min) was adopted. The mechanically alloyed powders were hot-pressed under vacuum at 900 {sup o}C for 1 h using pressure levels close to 200 MPa. The milled powders were characterized by means of scanning electron microscopy, X-ray diffraction, and energy dispersive spectrometry techniques. It was noted that the ductile starting powders were continuously cold-welded during ball milling. This fact was more pronounced during the processing of 50Ni-45Ti-5Zr powders in hardened steel vial. After milling for 5 h, the results suggested that amorphous and nanocrystalline structures were achieved. The complete consolidation was found after hot pressing of mechanically alloyed 50Ni-45Ti-5Zr powders, and a large amount of the B2-NiTi phase was formed mainly after processing in stainless steel balls and vial.

  5. To study the mechanical properties of unidirectionally and cross rolled Ni-Cu alloy produced in VIM

    International Nuclear Information System (INIS)

    Afzal, M.; Ajmal, M.; Butt, Z.T.

    2009-01-01

    Ni-Cu alloy was developed by melting in a vacuum induction furnace using pure elements i.e., Ni, Cu, Fe, Si, Mn and Cr. Four heats of approximately 4 kg each were prepared. All the heats have been casted in an ingot of 10 cm long and 5 cm in diameter in vacuum. These ingots were hot forged at a temperature of 900 deg. C to break down the cast dendritic structure. All forged plates were cut into two halve. One half was rolled in unidirectional while other was rolled in multiple directions (cross rolling). During rolling after every 25 % reduction, the cold rolled samples were annealed at a temperature of 900 deg. C for one hour. Each plate was cold rolled to a final thickness of 0.345 mm. Half of these rolled plate produced either by cross rolling or unidirectional rolling were annealed at 900 deg. C for 20 minutes. The mechanical properties of each rolled plate in cold reduction and in annealed were also measured. Unidirectional rolling and cross rolling has almost similar mechanical properties. The annealing of cross rolled and unidirectional rolling drastically reduced the yield strength. It was observed that the Ni-Cu alloy produced has slightly lower yield and ultimate tensile strength compared to the values reported in standards of Monel-400. However, it is within the acceptable range to be used for the various applications. (author)

  6. Effect of bainitic transformation temperature on the mechanical behavior of cold-rolled TRIP steels studied with in-situ high-energy X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Fu, B. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Yang, W.Y., E-mail: wyyang@ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Li, L.F.; Sun, Z.Q. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-05-01

    The effect of bainitic transformation temperature (400 and 450 °C) after intercritical annealing on the mechanical behavior of a low alloyed C–Mn–Al–Si cold-rolled TRIP steel was investigated using the in-situ high-energy X-ray diffraction technique. It was found that the mechanical behaviors of TRIP steels were dominated by the micromechanical behaviors of constituent phases, such as yield strength of each phase and stress partitioning among different phases, as well as the transformation kinetics of retained austenite during plastic deformation. The microstructures obtained at different bainitic transformation temperatures were similar, but exhibited obviously different mechanical behaviors. The retained austenite in the sample treated at 450 °C with lower carbon content and yield strength was less stable and transformed into martensite at a relatively faster speed during deformation leading to a higher ultimate tensile strength but a smaller uniform elongation. In addition, stress partitioning among constituent phases was also obtained for the investigated steels in such a way that the ferrite matrix undertook smaller stresses and the bainitic ferrite, martensite and retained austenite bore larger ones during plastic deformation. The retained austenite in the sample treated at 400 °C with higher carbon content displayed significantly higher strength and relatively stronger work-hardening capabilities during deformation in comparison to those of the sample treated at 450 °C.

  7. Person og Rolle

    DEFF Research Database (Denmark)

    Szatkowski, Janek

    2011-01-01

    Distinktionen mellem person og rolle forslås som grundlag for et præcist og anlytisk anvendeligt begreb om performativitet. Begrebet tager sigte på at beskrive enkeltindividers og gruppers kommunikation med henblik på hvordan kommunikation etableres. Performativitet gør det muligt at iagttage den...

  8. Ship Roll Motion Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2010-01-01

    . This tutorial paper presents an account of the development of various ship roll motion control systems and the challenges associated with their design. The paper discusses how to assess performance, the applicability of dierent models, and control methods that have been applied in the past....

  9. Rolling Cylinder Phase 1

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Taraborrelli, Valeria Taraborrelli

    Margheritini and Valeria Taraborrelli(valeria.taraborrelli@hotmail.it) with a total of 3 day visit from the developers. Laboratory tests in irregular waves will be performed by Lucia Margheritini. The report is aimed at the first stage testing of the Rolling Cylinder wave energy device. This phase includes...

  10. Computer-aided roll pass design in rolling of airfoil shapes

    Science.gov (United States)

    Akgerman, N.; Lahoti, G. D.; Altan, T.

    1980-01-01

    This paper describes two computer-aided design (CAD) programs developed for modeling the shape rolling process for airfoil sections. The first program, SHPROL, uses a modular upper-bound method of analysis and predicts the lateral spread, elongation, and roll torque. The second program, ROLPAS, predicts the stresses, roll separating force, the roll torque and the details of metal flow by simulating the rolling process, using the slab method of analysis. ROLPAS is an interactive program; it offers graphic display capabilities and allows the user to interact with the computer via a keyboard, CRT, and a light pen. The accuracy of the computerized models was evaluated by (a) rolling a selected airfoil shape at room temperature from 1018 steel and isothermally at high temperature from Ti-6Al-4V, and (b) comparing the experimental results with computer predictions. The comparisons indicated that the CAD systems, described here, are useful for practical engineering purposes and can be utilized in roll pass design and analysis for airfoil and similar shapes.

  11. Incidence and transfer behaviors of high-order hot judder in passenger cars

    OpenAIRE

    Xu, Xinfu

    2016-01-01

    As one of the brake-induced noises and vibrations, hot judder is forced vibration, which is caused by unevenness of the brake disc due to the thermal mechanical interactions in wheel brakes. Brake disc unevenness is normally described and evaluated as the Disc Thickness Variation (DTV) and the disc’ Lateral Run-Out (LRO). DTV and LRO gener-ate Brake Pressure Variation (BPV) and Brake Torque Variation (BTV) in wheel brakes, which are transmitted to the driver and perceived by the driver as the...

  12. Dismantling of a hot cell of high level activity. Method and tools used

    International Nuclear Information System (INIS)

    Jeantet, E.; Miquel, P.; Baudoin, J.C.; Moutonnet, A.

    1981-05-01

    The aim of this operation is the removal of all the equipment and the material introduced and used in the hot cell 'Attila' and its decontamination to obtain an irradiation level as low as possible to allow direct intervention. The Attila facilitie was build in 1964-1966 to study dry processing of irradiated fuels by halogenide volatility process. Dismantling of the out-cell and of the laboratory associated to the shielded cell, dismantling inside the shielded cell with the remote handling equipment of the cell and tools used for these operations are described in this article [fr

  13. 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.

  14. Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100–1250 °C

    Energy Technology Data Exchange (ETDEWEB)

    Alfonso, A., E-mail: aalz@dtu.dk [Section of Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Juul Jensen, D. [Danish-Chinese Center for Nanometals, Section of Materials Science and Advanced Characterization, Department of Wind Energy, Technical University of Denmark, Risø Campus, 4000 Roskilde (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Luo, G.-N. [Fusion Reactor Materials Science and Technology Division, Institute of Plasma Physics, Chinese Academy of Sciences, 230031 Hefei, Anhui (China); Sino-Danish Center for Education and Research, Denmark and China (Denmark); Pantleon, W. [Section of Materials and Surface Engineering, Department of Mechanical Engineering, Technical University of Denmark, 2800 Lyngby (Denmark); Association EURATOM-DTU (Denmark); Sino-Danish Center for Education and Research, Denmark and China (Denmark)

    2015-10-15

    Highlights: • Annealing kinetics of highly-deformed tungsten up to 190 h between 1100 °C and 1250 °C. • Loss of mechanical strength characterized by Vickers hardness measurements. • Two distinct stages of recovery and recrystallization identified and described by established models. • Activation energy of recrystallization lower than after moderate deformation of tungsten. • Comparable to activation energy of grain boundary diffusion due to abundance of low angle boundaries. - Abstract: Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could be rationalized in terms of a logarithmic recovery kinetics and a Johnson–Mehl–Avrami–Kolmogorov recrystallization kinetics accounting for an incubation time of recrystallization. The observed time spans for recrystallization and the corresponding recrystallization activation energy for this highly deformed plate suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation.

  15. Thermal stability of a highly-deformed warm-rolled tungsten plate in the temperature range 1100–1250 °C

    International Nuclear Information System (INIS)

    Alfonso, A.; Juul Jensen, D.; Luo, G.-N.; Pantleon, W.

    2015-01-01

    Highlights: • Annealing kinetics of highly-deformed tungsten up to 190 h between 1100 °C and 1250 °C. • Loss of mechanical strength characterized by Vickers hardness measurements. • Two distinct stages of recovery and recrystallization identified and described by established models. • Activation energy of recrystallization lower than after moderate deformation of tungsten. • Comparable to activation energy of grain boundary diffusion due to abundance of low angle boundaries. - Abstract: Pure tungsten is considered as armor material for the most critical parts of fusion reactors (i.e. the divertor and the first wall), among other reasons due to its high melting point (3422 °C) and recrystallization temperature. The thermal stability of a pure tungsten plate warm-rolled to a high plastic strain by 90% thickness reduction was investigated by isothermal annealing for up to 190 h in the temperature range between 1100 °C and 1250 °C. Vickers hardness testing allowed tracking the changes in mechanical properties caused by recovery and recrystallization. The hardness evolution could be rationalized in terms of a logarithmic recovery kinetics and a Johnson–Mehl–Avrami–Kolmogorov recrystallization kinetics accounting for an incubation time of recrystallization. The observed time spans for recrystallization and the corresponding recrystallization activation energy for this highly deformed plate suggest that large plastic deformations (e.g. applied during shaping) are only suitable to produce tungsten components to be used at relatively low temperatures (up to 900 °C for a 2 years lifespan). Higher operation temperatures will lead to fast degradation of the microstructure during operation.

  16. Numerical Investigation on the Influence of Hot Streak Temperature Ratio in a High-Pressure Stage of Vaneless Counter-Rotating Turbine

    Directory of Open Access Journals (Sweden)

    Zhao Qingjun

    2007-01-01

    Full Text Available The results of recent studies have shown that combustor exit temperature distortion can cause excessive heat load of high-pressure turbine (HPT rotor blades. The heating of HPT rotor blades can lead to thermal fatigue and degrade turbine performance. In order to explore the influence of hot streak temperature ratio on the temperature distributions of HPT airfoil surface, three-dimensional multiblade row unsteady Navier-Stokes simulations have been performed in a vaneless counter-rotating turbine (VCRT. The hot streak temperature ratios from 1.0 (without hot streak to 2.4 were used in these numerical simulations, including 1.0, 1.2, 1.6, 2.0, and 2.4 temperature ratios. The hot streak is circular in shape with a diameter equal to 25% of the span. The center of the hot streak is located at 50% of span and 0% of pitch (the leading edge of the HPT stator vane. The predicted results show that the hot streak is relatively unaffected as it migrates through the HPT stator. The hot streak mixes with the vane wake and convects towards the pressure surface (PS of the HPT rotor when it moves over the vane surface of the HPT stator. The heat load of the HPT rotor increases with the increase of the hot streak temperature ratio. The existence of the inlet temperature distortion induces a thin layer of cooler air in the HPT rotor, which separates the PS of the HPT rotor from the hotter fluid. The numerical results also indicating the migration characteristics of the hot streak in the HPT rotor are predominated by the combined effects of secondary flow and buoyancy. The combined effects that induce the high-temperature fluid migrate towards the hub on the HPT rotor. The effect of the secondary flow on the hotter fluid increases as the hot streak temperature ratio is increased. The influence of buoyancy is directly proportional to the hot streak temperature ratio. The predicted results show that the increase of the hot streak temperature ratio trends to increase

  17. Understanding the emission impacts of high-occupancy vehicle (HOV) to high-occupancy toll (HOT) lane conversions: Experience from Atlanta, Georgia.

    Science.gov (United States)

    Xu, Yanzhi Ann; Liu, Haobing; Rodgers, Michael O; Guin, Angshuman; Hunter, Michael; Sheikh, Adnan; Guensler, Randall

    2017-08-01

    Converting a congested high-occupancy vehicle (HOV) lane into a high-occupancy toll (HOT) lane is a viable option for improving travel time reliability for carpools and buses that use the managed lane. However, the emission impacts of HOV-to-HOT conversions are not well understood. The lack of emission impact quantification for HOT conversions creates a policy challenge for agencies making transportation funding choices. The goal of this paper is to evaluate the case study of before-and-after changes in vehicle emissions for the Atlanta, Georgia, I-85 HOV/HOT lane conversion project, implemented in October 2011. The analyses employed the Motor Vehicle Emission Simulator (MOVES) for project-level analysis with monitored changes in vehicle activity data collected by Georgia Tech researchers for the Georgia Department of Transportation (GDOT). During the quarterly field data collection from 2010 to 2012, more than 1.5 million license plates were observed and matched to vehicle class and age information using the vehicle registration database. The study also utilized the 20-sec, lane-specific traffic operations data from the Georgia NaviGAtor intelligent transportation system, as well as a direct feed of HOT lane usage data from the State Road and Tollway Authority (SRTA) managed lane system. As such, the analyses in this paper simultaneously assessed the impacts associated with changes in traffic volumes, on-road operating conditions, and fleet composition before and after the conversion. Both greenhouse gases and criteria pollutants were examined. A straight before-after analysis showed about 5% decrease in air pollutants and carbon dioxide (CO 2 ). However, when the before-after calendar year of analysis was held constant (to account for the effect of 1 yr of fleet turnover), mass emissions at the analysis site during peak hours increased by as much as 17%, with little change in CO 2 . Further investigation revealed that a large percentage decrease in criteria

  18. High performance in low-flow solar domestic hot water systems

    Energy Technology Data Exchange (ETDEWEB)

    Dayan, M.

    1997-12-31

    Low-flow solar hot water heating systems employ flow rates on the order of 1/5 to 1/10 of the conventional flow. Low-flow systems are of interest because the reduced flow rate allows smaller diameter tubing, which is less costly to install. Further, low-flow systems result in increased tank stratification. Lower collector inlet temperatures are achieved through stratification and the useful energy produced by the collector is increased. The disadvantage of low-flow systems is the collector heat removal factor decreases with decreasing flow rate. Many solar domestic hot water systems require an auxiliary electric source to operate a pump in order to circulate fluid through the solar collector. A photovoltaic driven pump can be used to replace the standard electrical pump. PV driven pumps provide an ideal means of controlling the flow rate, as pumps will only circulate fluid when there is sufficient radiation. Peak performance was always found to occur when the heat exchanger tank-side flow rate was approximately equal to the average load flow rate. For low collector-side flow rates, a small deviation from the optimum flow rate will dramatically effect system performance.

  19. 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.

  20. Effects of Non-metallic Inclusions on Hot Ductility of High Manganese TWIP Steels Containing Different Aluminum Contents

    Science.gov (United States)

    Wang, Yu-Nan; Yang, Jian; Wang, Rui-Zhi; Xin, Xiu-Ling; Xu, Long-Yun

    2016-06-01

    The characteristics of inclusions in Fe-16Mn- xAl-0.6C ( x = 0.002, 0.033, 0.54, 2.10 mass pct) steels have been investigated and their effects on hot ductility of the high manganese TWIP steels have been discussed. Ductility is very poor in the steel containing 0.54 mass pct aluminum, which is lower than 20 pct in the temperature range of 873 K to 1473 K (600 °C to 1200 °C). For the steels containing 0.002 and 2.10 mass pct aluminum, ductility is higher than 40 pct in the same temperature range. The hot ductility of steel containing 0.033 mass pct aluminum is higher than 30 pct throughout the temperature range under examination. With increasing aluminum content, the main inclusions in the steels change along the route of MnO/(MnO + MnS) → MnS/(Al2O3 + MnS) → AlN/(Al2O3 + MnS)/(MgAl2O4 + MnS) → AlN. The thermodynamic results of inclusion types calculated with FactSage software are in agreement with the experimental observation results. The inclusions in the steels containing 0.002 mass pct aluminum do not deteriorate the hot ductility. MnS inclusions whose average size, number density, and volume ratio are 1.12 μm, 15.62 mm-2, and 2.51 × 10-6 in the steel containing 0.033 mass pct aluminum reduce the ductility. In the steel containing 0.54 mass pct aluminum, AlN inclusions whose average size, number density, and volume ratio are 0.878 μm, 16.28 mm-2 and 2.82 × 10-6 can precipitate at the austenite grain boundaries, prevent dynamic recrystallization and deteriorate the hot ductility. On the contrary, in the steel containing 2.10 mass pct aluminum, the average size, number density and volume ratio of AlN inclusions change to 2.418 μm, 35.95 mm-2, and 2.55 × 10-5. They precipitate in the matrix, which do not inhibit dynamic recrystallization and thereby do not lead to poor hot ductility.