Sample records for h13 tool steel

  1. Laser surface hardening of AISI H13 tool steel

    Jae-Ho LEE; Jeong-Hwan JANG; Byeong-Don JOO; Young-Myung SON; Young-Hoon MOON


    An attempt was made to improve the surface hardness and wear properties of AISI H13 tool steel through solid solution hardening and refinement of microstructures using a 200 W fiber laser as a heat generating source. The hardness of laser melted zone was investigated. In order to identify the effect of heat input on the laser melting zone, scanning conditions were controlled. The results show that, the hardness of as-received AISI H13 tool steel is approximately Hv 240, and the hardness after laser surface heat treatment is around Hv 480-510. The hardening depth and width are increased with the increase in the heat input applied. Application of experimental results will be considered in tooling industry.

  2. Application of direct laser metal tooling for AISI H13 tool steel

    Jae-Ho LEE; Jeong-Hwan JANG; Byeong-Don JOO; Hong-Sup YIM; Young-Hoon MOON


    In the die industry, it is commonly agreed that residual tool life can be successfully extended by timely repair of damaged surfaces. Traditionally, the main repair process is tungsten inert gas (TIG) welding, but a new process called direct laser metal tooling (DLMT) emerges. DLMT is a manual process, of which results depend on the materials of the powders and tools, the laser process and parameters. This technology is a direct-metal freeform fabrication technique in which a 200 W fiber laser is used. AISI H13 tool steel is a suitable material for die casting tools because of the high resistance to thermal fatigue and dimensional stability. In this research, AISI HI3 tool steel was melted with metal powder by fiber laser. Before melting AISI H13, the powders were analyzed with XRF equipment. Then, hardness distribution of laser melted zone was investigated. The microstructure in laser melted zone was discussed. In order to identify the effect of particle size of powder on the melted zone, two types of particle sizes of powders were used. Experimental results show that the mold repair process using DLMT can be applied in the mold repair industry.


    H. Yan; J. Hua; R. Shivpuri


    An approach is presented to characterize the stress response of workpiece in hard machining,accounted for the effect of the initial workpiece hardness, temperature, strain and strain rate on flow stress. AISI H13 work tool steel was chosen to verify this methodology. The proposed flow stress model demonstrates a good agreement with data collected from published experiments.Therefore, the proposed model can be used to predict the corresponding flow stress-strain response of AISI H13 work tool steel with variation of the initial workpiece hardness in hard machining.

  4. High Speed Turning of H-13 Tool Steel Using Ceramics and PCBN

    Umer, Usama


    H-13 is the toughest tool steel used in machined die casting and forging dies. Due to its extreme hardness and poor thermal conductivity high speed cutting results in high temperature and stresses. This gives rise to surface damage of the workpiece and accelerated tool wear. This study evaluates the performance of different tools including ceramics and PCBN using practical finite element simulations and high speed orthogonal cutting tests. The machinability of H-13 was evaluated by tool wear, surface roughness, and cutting force measurements. From the 2D finite element model for orthogonal cutting, stresses and temperature distributions were predicted and compared for the different tool materials.

  5. Structural properties of H13 tool steel parts produced with use of selective laser melting technology

    Šafka, J.; Ackermann, M.; Voleský, L.


    This paper deals with establishing of building parameters for 1.2344 (H13) tool steel processed using Selective Laser Melting (SLM) technology with layer thickness of 50 µm. In the first part of the work, testing matrix of models in the form of a cube with chamfered edge were built under various building parameters such as laser scanning speed and laser power. Resulting models were subjected to set of tests including measurement of surface roughness, inspection of inner structure with aid of Light Optical Microscopy and Scanning Electron Microscopy and evaluation of micro-hardness. These tests helped us to evaluate an influence of changes in building strategy to the properties of the resulting model. In the second part of the work, mechanical properties of the H13 steel were examined. For this purpose, the set of samples in the form of “dog bone” were printed under three different alignments towards the building plate and tested on universal testing machine. Mechanical testing of the samples should then reveal if the different orientation and thus different layering of the material somehow influence its mechanical properties. For this type of material, the producer provides the parameters for layer thickness of 30 µm only. Thus, our 50 µm building strategy brings shortening of the building time which is valuable especially for large models. Results of mechanical tests show slight variation in mechanical properties for various alignment of the sample.

  6. Microstructure and Properties of Low Temperature Composite Chromized Layer on H13 Tool Steel

    Cuilan WU; Chengping LUO; Ganfeng ZOU


    Low temperature composite chromizing is a process composed of a plain ion-carbonitriding or ion-nitriding at 550~580℃, followed by a low-temperature chromizing in a salt-bath of 590℃. The microstructure and properties of the low temperature composite chromized layer on H13 tool steel were investigated using metallography,X-ray diffraction, microanalysis, hardness and wear tests. It was found that this low temperature process was thermodynamically and kinetically possible, and the composite chromized layer on H13 steel, with a thickness of 3~6μm,consisted of three sub-layers (bands), viz. the outer Cr-rich one, the intermediate (black) one, and the inner, original white layer. After chromizing, the former diffusion layer was thickened. The results of X-ray diffraction showed that the composite chromized layer contained such nitrides and carbides of chromium as CrN, Cr2N, (Cr, Fe)23C6, and (Cr, Fe)7C3, as well as plain α-(Fe, Cr). A high surface microhardness of 1450~1550 HV0.025, which is much higher than that obtained by the conventional ion carbonitriding and ion nitriding, was obtained. In addition, an excellent wear resistance was gained on the composite chromized layer.

  7. Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

    Umbrello, Domenico; Rizzuti, Stefania; Outeiro, José C.; Shivpuri, Rajiv


    In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change.

  8. Selective laser melting of Fe-Ni-Cr layer on AISI H13 tool steel

    Byeong-Don JOO; Jeong-Hwan JANG; Jae-Ho LEE; Young-Myung SON; Young-Hoon MOON


    An attempt to fabricate Fe-Ni-Cr coating on AISI H13 tool steel was performed with selective laser melting. Fe-Ni-Cr coating was produced by experimental facilities consisting of a 200 W fiber laser which can be focused to 80 μm and atmospheric chamber which can control atmospheric pressure with N2 or Ar. Coating layer was fabricated with various process parameters such as laser power, scan rate and fill spacing. Surface quality and coating thickness were measured and analyzed. Three different surface patterns, such as typeⅠ, typeⅡand type Ⅲ, are shown with various test conditions and smooth regular pattern is obtained under the conditions as 10 μm of fill spacing, 50-350 mm/s of scan rate and 40 μm of fill spacing, 10-150 mm/s of scan rate. The maximum coating thickness is increased with power elevation or scan rate drop, and average thickness of 10 μm fill spacing is lower than that of 40 μm fill spacing.

  9. Temperature and composition profile during double-track laser cladding of H13 tool steel

    He, X.; Yu, G.; Mazumder, J.


    Multi-track laser cladding is now applied commercially in a range of industries such as automotive, mining and aerospace due to its diversified potential for material processing. The knowledge of temperature, velocity and composition distribution history is essential for a better understanding of the process and subsequent microstructure evolution and properties. Numerical simulation not only helps to understand the complex physical phenomena and underlying principles involved in this process, but it can also be used in the process prediction and system control. The double-track coaxial laser cladding with H13 tool steel powder injection is simulated using a comprehensive three-dimensional model, based on the mass, momentum, energy conservation and solute transport equation. Some important physical phenomena, such as heat transfer, phase changes, mass addition and fluid flow, are taken into account in the calculation. The physical properties for a mixture of solid and liquid phase are defined by treating it as a continuum media. The velocity of the laser beam during the transition between two tracks is considered. The evolution of temperature and composition of different monitoring locations is simulated.

  10. Wear and Adhesive Failure of Al2O3 Powder Coating Sprayed onto AISI H13 Tool Steel Substrate

    Amanov, Auezhan; Pyun, Young-Sik


    In this study, an alumina (Al2O3) ceramic powder was sprayed onto an AISI H13 hot-work tool steel substrate that was subjected to sanding and ultrasonic nanocrystalline surface modification (UNSM) treatment processes. The significance of the UNSM technique on the adhesive failure of the Al2O3 coating and on the hardness of the substrate was investigated. The adhesive failure of the coating sprayed onto sanded and UNSM-treated substrates was investigated by a micro-scratch tester at an incremental load. It was found, based on the obtained results, that the coating sprayed onto the UNSM-treated substrate exhibited a better resistance to adhesive failure in comparison with that of the coating sprayed onto the sanded substrate. Dry friction and wear property of the coatings sprayed onto the sanded and UNSM-treated substrates were assessed by means of a ball-on-disk tribometer against an AISI 52100 steel ball. It was demonstrated that the UNSM technique controllably improved the adhesive failure of the Al2O3 coating, where the critical load was improved by about 31%. Thus, it is expected that the application of the UNSM technique to an AISI H13 tool steel substrate prior to coating may delay the adhesive failure and improve the sticking between the coating and the substrate thanks to the modified and hardened surface.

  11. Interface bonding of NiCrAlY coating on laser modified H13 tool steel surface

    Reza, M. S.; Aqida, S. N.; Ismail, I.


    Bonding strength of thermal spray coatings depends on the interfacial adhesion between bond coat and substrate material. In this paper, NiCrAlY (Ni-164/211 Ni22 %Cr10 %Al1.0 %Y) coatings were developed on laser modified H13 tool steel surface using atmospheric plasma spray (APS). Different laser peak power, P p, and duty cycle, DC, were investigated in order to improve the mechanical properties of H13 tool steel surface. The APS spraying parameters setting for coatings were set constant. The coating microstructure near the interface was analyzed using IM7000 inverted optical microscope. Interface bonding of NiCrAlY was investigated by interfacial indentation test (IIT) method using MMT-X7 Matsuzawa Hardness Tester Machine with Vickers indenter. Diffusion of atoms along NiCrAlY coating, laser modified and substrate layers was investigated by energy-dispersive X-ray spectroscopy (EDXS) using Hitachi Tabletop Microscope TM3030 Plus. Based on IIT method results, average interfacial toughness, K avg, for reference sample was 2.15 MPa m1/2 compared to sample L1 range of K avg from 6.02 to 6.96 MPa m1/2 and sample L2 range of K avg from 2.47 to 3.46 MPa m1/2. Hence, according to K avg, sample L1 has the highest interface bonding and is being laser modified at lower laser peak power, P p, and higher duty cycle, DC, prior to coating. The EDXS analysis indicated the presence of Fe in the NiCrAlY coating layer and increased Ni and Cr composition in the laser modified layer. Atomic diffusion occurred in both coating and laser modified layers involved in Fe, Ni and Cr elements. These findings introduce enhancement of coating system by substrate surface modification to allow atomic diffusion.

  12. The Stress Distribution and Thermal Behavior of TiBN and TiBN/TiN Coatings in Milling AISI H13 Work Tool Steel

    YAN Hong; HUA Jiang; SHIVPURI Raja


    The FEM model of TiBN and TiBN/TiN coated cutting tool in milling of H13 steel was developed. Process variables such as temperature and stress in the coating layer as well as in the substrate were analyzed. The efficacy of the present FEM analysis was verified by conducting controlled milling experiments on AISI H13 to collect the relevant tool life and force data.The results show that the stress in a coated tool can significantly be reduced compared to an uncoated cutting tool,possibly due to surface coatings improving the tribological properties of cutting tools.Coatings with good thermal properties also help to improve the thermal behavior of cutting tool.

  13. Effect of Energy Input on the Characteristic of AISI H13 and D2 Tool Steels Deposited by a Directed Energy Deposition Process

    Park, Jun Seok; Park, Joo Hyun; Lee, Min-Gyu; Sung, Ji Hyun; Cha, Kyoung Je; Kim, Da Hye


    Among the many additive manufacturing technologies, the directed energy deposition (DED) process has attracted significant attention because of the application of metal products. Metal deposited by the DED process has different properties than wrought metal because of the rapid solidification rate, the high thermal gradient between the deposited metal and substrate, etc. Additionally, many operating parameters, such as laser power, beam diameter, traverse speed, and powder mass flow rate, must be considered since the characteristics of the deposited metal are affected by the operating parameters. In the present study, the effect of energy input on the characteristics of H13 and D2 steels deposited by a direct metal tooling process based on the DED process was investigated. In particular, we report that the hardness of the deposited H13 and D2 steels decreased with increasing energy input, which we discuss by considering microstructural observations and thermodynamics.

  14. Effects of Deep Cryogenic Treatment on the Wear Resistance and Mechanical Properties of AISI H13 Hot-Work Tool Steel

    Çiçek, Adem; Kara, Fuat; Kıvak, Turgay; Ekici, Ergün; Uygur, İlyas


    In this study, a number of wear and tensile tests were performed to elucidate the effects of deep cryogenic treatment on the wear behavior and mechanical properties (hardness and tensile strength) of AISI H13 tool steel. In accordance with this purpose, three different heat treatments (conventional heat treatment (CHT), deep cryogenic treatment (DCT), and deep cryogenic treatment and tempering (DCTT)) were applied to tool steel samples. DCT and DCTT samples were held in nitrogen gas at -145 °C for 24 h. Wear tests were conducted on a dry pin-on-disk device using two loads of 60 and 80 N, two sliding velocities of 0.8 and 1 m/s, and a wear distance of 1000 m. All test results showed that DCT improved the adhesive wear resistance and mechanical properties of AISI H13 steel. The formation of small-sized and uniformly distributed carbide particles and the transformation of retained austenite to martensite played an important role in the improvements in the wear resistance and mechanical properties. After cleavage fracture, the surfaces of all samples were characterized by the cracking of primary carbides, while the DCT and DCTT samples displayed microvoid formation by decohesion of the fine carbides precipitated during the cryo-tempering process.

  15. High Power Picosecond Laser Surface Micro-texturing of H13 Tool Steel and Pattern Replication onto ABS Plastics via Injection Moulding

    Otanocha, Omonigho B.; Li, Lin; Zhong, Shan; Liu, Zhu


    H13 tool steels are often used as dies and moulds for injection moulding of plastic components. Certain injection moulded components require micro-patterns on their surfaces in order to modify the physical properties of the components or for better mould release to reduce mould contamination. With these applications it is necessary to study micro-patterning to moulds and to ensure effective pattern transfer and replication onto the plastic component during moulding. In this paper, we report an investigation into high average powered (100 W) picosecond laser interactions with H13 tool steel during surface micro-patterning (texturing) and the subsequent pattern replication on ABS plastic material through injection moulding. Design of experiments and statistical modelling were used to understand the influences of laser pulse repetition rate, laser fluence, scanning velocity, and number of scans on the depth of cut, kerf width and heat affected zones (HAZ) size. The characteristics of the surface patterns are analysed. The process parameter interactions and significance of process parameters on the processing quality and efficiency are characterised. An optimum operating window is recommended. The transferred geometry is compared with the patterns generated on the dies. A discussion is made to explain the characteristics of laser texturing and pattern replication on plastics.

  16. Comparison of surface roughness and chip characteristics obtained under different modes of lubrication during hard turning of AISI H13 tool work steel.

    Raj, Anil; Wins, K. Leo Dev; Varadarajan, A. S.


    Surface roughness is one of the important parameters, which not only affects the service life of a component but also serves as a good index of machinability. Near Dry Machining, methods (NDM) are considered as sustainable alternative for workshops trying to bring down their dependence on cutting fluids and the hazards associated with their indiscriminate usage. The present work presents a comparison of the surface roughness and chip characteristics during hard turning of AISI H13 tool work steel using hard metal inserts under two popular NDM techniques namely the minimal fluid application and the Minimum Quantity Lubrication technique(MQL) using an experiment designed based on Taguchi's techniques. The statistical method of analysis of variance (ANOVA) was used to determine the relative significance of input parameters consisting of cutting speed, feed and depth of cut on the attainable surface finish and the chip characteristics. It was observed that the performance during minimal fluid application was better than that during MQL application.

  17. The effect of deep cryogenic treatments on the mechanical properties of an AISI H13 steel

    Pérez, Marcos, E-mail:; Belzunce, Francisco Javier


    Cryogenic treatments are considered a good way to reduce the retained austenite content and improve the performance of tool steels. Four different heat treatments, two of which included a deep cryogenic stage, were applied in this study to an H13 tool steel, subsequently determining its mechanical properties by means of tensile, hardness and fracture toughness tests. Furthermore, scanning electron microscopy and X-ray diffraction analysis were performed to gain an insight into the microstructural evolution of these heat treatments during all the stages. It was concluded that the application of a deep cryogenic treatment to H13 steel induces higher thermal stresses and structural defects, producing a dispersed network of fine carbides after the subsequent tempering stages, which were responsible for a significant improvement in the fracture toughness of this steel without modifying other mechanical properties. Although the application of a deep cryogenic treatment reduces the retained austenite content, there is a minimum innate content which cannot be transformed by heat treatment. Nevertheless, this austenite is hence believed to be stable enough and should not transform during the normal service life of forging dies.

  18. Study on Heterogeneous Nuclei in Cast H13 Steel Modified by Rare Earth

    兰杰; 贺俊杰; 丁文江; 王渠东; 朱燕萍


    The dendrite segregation in cast H13 steel was weakened with RE modification treatment. Grain boundary carbide during quenching was also under control and impact toughness was improved greatly. By thermodynamic calculation, analysis of two-dimensional lattice misfitting and electron probe analysis, it is found that Ce2O3 may act as the heterogeneous nuclei of modified cast H13 steel.

  19. Thermal fatigue behavior of niobium microalloyed H13 steel%铌微合金化H13钢的热疲劳行为



    @@ AISI H13 hot work tool steel is widely used for hot forging, hot-extrusion and die-casting because of its high temperature strength, impact toughness, heat checking resistance and wear resistance, etc. The thermally induced surface damage, i. e., thermal fatigue, is believed to be controlled by the magnitude of the imposed cyclic strain. The thermal fatigue on the surface of hot working die, which is responsible to the initiation of the cracks, is reported to result in more than 80 % of the failure of dies.

  20. Tool steels

    Højerslev, C.


    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...

  1. Prediction and Analysis on Oxidation of H13 Hot Work Steel

    MIN Yong-an; WU Xiao-chun; WANG Rong; LI Lin; XU Luo-ping


    The understanding of oxidation behaviors on H13 steel was helpful to improve the service life and performance of hot work moulds and dies. Thermal-Calc Software was performed to calculate the oxidation phases on H13 steel along with different partial oxygen pressures in the interesting temperature range of 500-700 ℃. In this range H13 steel samples were treated respectively in different atmosphere including flowing water vapor (0.2 MPa), normal pressure air (0.1 MPa) and low pressure air (0.001 MPa). The different oxidation films were detected with optical microscopy and X-ray diffraction. The microstructures and phase constitutions of the films formed in low pressure air were similar to those of the films formed in water vapor, and obviously different to those of the films formed in normal pressure air. The oxidation mechanisms of H13 steel in different atmosphere were also discussed.

  2. Erosion Resistance Behaviours of H13 Steel to Molten ADC12 Alloy

    MIN Yong-an; XU Luo-ping; WU Xiao-chun; LI Lin; WANG Rong


    H13 hot work steel samples and surface water vapor oxidized H13 samples were immersed into molten ADC12alloy under static resting or dynamic rotating conditions. Weigh-losing method was used to discover the influences of temperature, time and surface conditions on the erosion resistance of H13 steel. The interfaces between the steel and the molten alloy were studied with optical microscopy to compare the different erosion resistance behaviours. The results show that the composite layer outside of the compounds layers changes obviously with increasing temperature, lasting time or sample movement. The better erosion resistance of H13 steel can be endowed with the oxide films, which would gradually decrease along with the dissolve of the films.

  3. Influence of plasma peening on oxidation of H13 hot work steel in water vapor

    MIN Yong-an; XU Xiao; WU Xiao-chun; LI Lin; XU Luo-ping


    The surface oxidation films on H13 steel samples, obtained by different oxidation processes were observed by optical microscope. It is shown that the oxidation speed of H13 steel is increased remarkably due to the surface modification of plasma peening. Further researches were made by XRD, SEM and EDS. The activation of H13 surface caused by plasma peening and the subsequent higher oxygen diffusion rate into the steel seem to be the main reasons of higher oxidation speed. The nitride layer, generally formed on the steel surface under plasma nitriding process, can be substituted by oxide in subsequent oxidation process, which can reduce the risk of heat cracking in some hot work applications. Therefore, the plasma nitriding plus oxidation process is a proper choice for some hot work dies, which demands high hardness to avoid indentation as well as high toughness to avoid cracks.

  4. Development of Flow Stress of AISI H13 Die Steel in Hard Machining

    YAN Hong; QIAN Guohua; HU Qiang


    An approach was presented to characterize the stress response of workpiece in hard machining, accounting for the effect of the initial workpiece hardness in addition to temperature, strain and strain rate on flow stress in this paper. AISI H13 die steel was chosen to verify this methodology. The proposed flow stress model demonstrates a good agreement with experimental data. Therefore, the proposed model can be used to predict the corresponding flow stress-strain response of AISI H13 die steel with variation of the initial workpiece hardness in hard machining.

  5. Microstructure and Properties of Coating from Cemented Carbide on Surface of H13 Steel


    The microstructures and properties of coating from cemented carbide on the substrate of H13 by vacuum powder sintering were studied. The effect of sintering temperature on the microstructures of coating was discussed. The interface characteristics between coating and H13 steel substrate, microhardness distribution and wear resistance in the coating were analyzed. The coating from cemented carbide with thickness of 1-3 mm by vacuum powder sintering at temperature ranging from 1280 ℃ to 1300 ℃ was obtained. The experimental results indicated that the coating with microhardness of HV 1600 favorable to wear resistance is strongly bonded with the H13 steel substrate by mutual diffusion and penetration of Fe,Cr, Mo,V in substrate towards the coating and W, Co,Ni in coating towards the substrate.

  6. Abnormal Failure Analysis of H13 Punches in Steel Squeeze Casting Process

    ZHANG Mi-lan; XING Shu-ming; XIN Qiao; XIAO Li-ming; GOU Jun-nian; WU Xia-ling


    In steel squeeze casting process, the working condition of a punch was very rigorous. The abnormal failure models of an H13 punch, such as plastic rubbed damnification, could not be avoided easily. Based on the analysis of the flow stress and the friction-shearing stress of an H13 punch in steel squeeze casting process, the following results were obtained: if the flow stress of an H13 punch was smaller than its friction-shearing stress, these abnormal failures could not be avoided; and if there were some protection measures that enable the flow stress to have a greater value than its friction-shearing one, the abnormal failures would not occur. In the production of 45# steel valves and eatenary system components, the flow stress of a lateral H13 punch without any protection measure was about 29 MPa and its friction-shearing stress.was about 51 MPa, then, the abnormal failures occurred: however, when the protection measures of the punch enabled its working temperature to have a value below 682 "C, its flow stress was greater than its friction-shearing stress, and the abnormal failures were avoided.

  7. Wear Resistance of H13 and a New Hot-Work Die Steel at High temperature

    Li, Shuang; Wu, Xiaochun; Chen, Shihao; Li, Junwan


    The friction and wear behaviors of a new hot-work die steel, SDCM-SS, were studied at high temperature under dry air conditions. The wear mechanism and microstructural characteristics of the SDCM-SS steel were also investigated. The results showed that the SDCM-SS steel had greater wear resistance compared with H13 steel; this was owed to its high oxidizability and temper stability. These features facilitate the generation, growth, and maintenance of a tribo-oxide layer at high temperature under relatively stable conditions. The high oxidizability and thermal stability of the SDCM-SS steel originate from its particular alloy design. No chromium is added to the steel; this ensures that the material has high oxidizability, and facilitates the generation of tribo-oxides during the sliding process. Molybdenum, tungsten, and vanadium additions promote the high temper resistance and stability of the steel. Many fine Mo2C and VC carbides precipitate during the tempering of SDCM-SS steel. During sliding, these carbides can delay the recovery process and postpone martensitic softening. The high temper stability postpones the transition from mild to severe wear and ensures that conditions of mild oxidative wear are maintained. Mild oxidative wear is the dominant wear mechanism for SDCM-SS steel between 400 and 700 °C.

  8. The corrosion behavior of nano-meter embedded phase in Ti implanted H13 steel

    张通和; 吴瑜光; 邓志威; 马芙蓉; 王晓妍; 梁宏; 周固; 赵渭江; 薛建明


    On the SEM micrographs of Ti implanted H13 steel, a tree-branch-like structure can be observed. Further investigation with TEM shows that the newly tormed composition is a formation of nann-meter FeTi2 phase in Ti implanted layer. The layer with a relatively high corrosion resistance has been formed in Ti implanted H13 steel with this structure.The results of electrochemical measurement show that the corrosion current density decreases obviously with an increase of ion dose. The corrosion current density in Ti implanted steel with a dose of 1.3×1018/cm2 is 8-20 times less than that of Ti implanted steel with a dose of 6×1017/cm2. The corrosion behavior of Ti implanted steel with a dose of 6×1017/cm2 could be further improved as the sample was annealed at 500℃ for 20 min and the corrosion current density decreases by 48-80 times compared to that of non-implanted samples. The corrosion trace was not observed on the annealing sample by SEM, after multi-sweep cyclic voltammetry of 40 cycles

  9. Wear Resistance of Mo-Implanted H13 Steel by a Metal Vapour Vacuum Arc Source

    Yang, Jian-Hua; Zhang, Tong-He


    Pulsed molybdenum ion beams extracted from a metal vapour vacuum arc ion source at voltage of 25 kV or 48 kV were implanted into H13 steel with a high implantation dose of 5×1017 ions·cm-2 and a time-averaged ion beam current density of about 300 µA·cm-2. We have investigated the steel implanted for wear resistance by an optical interference microscope and a pin-on-disc apparatus. The Rutherford backscattering spectroscopy demonstrated that rather low-energy ions could penetrate quite deep into the substrates. It was observed by x-ray photoelectron spectroscopy and transmission-electron microscopy that carbide of molybdenum appeared in the doped region. The results showed that dramatically improved wear resistance of H13 steel after molybdenum ion implantation at 48 kV was attributed to the development of Mo2C precipitates in the doped zone and to the formation of the implantation affected zone below the doped zone.

  10. Wear Resistance of Mo-Implanted H13 Steel by a Metal Vapour Vacuum Arc Source

    杨建华; 张通和


    Pulsed molybdenum ion beams extracted from a metal vapour vacuum arc ion source at voltage of 25kV or 48kV were implanted into H13 steel with a high implantation dose of 5×1017 inons·cm-2 and a time-averaged ion beam current density of about 300μA·cm-2. We have investigated the steel implanted for wear resistance by an optical interference microscope and a pin-on-disc apparatus. The Rutherford backscattering spectroscopy demonstrated that rather low-energy ions could penetrate quite deep into the substrates. It was observed by x-ray photoelectron spectroscopy and transmission-electron microscopy that carbide of molybdenum appeared in the doped region. The results showed that dramatically improved wear resistance of H13 steel after molybdenum ion implantation at 48 kV was attributed to the development of Mo2 C precipitates in the doped zone and to the formation of the implantation affected zone below the doped zone.

  11. Inclusion Variations of Hot Working Die Steel H13 in Refining Process

    LIU Jiamhua; WANG Guo-xuan; BAO Yan-ping; YANG Yan; YAO Wei; CUI Xiao-ning


    Inclusion variations of die steel H13, including changes of species, morphologies, compositions, amounts and sizes, in the production of EAF-LF--VD-ingot casting-electro slag refining (ESR) procedure, were investi- gated by systematic sampling, and analyzed with scanning electron microscope (SEM), energy dispersive spectrum (EDS) , and metallographic microscope. The variation mechanism was studied by comprehensive analysis of total oxygen, nitrogen, and acid soluble aluminum as well as chemical test of refining slag. Based on the investigations, technical measures for cleanness improvement were discussed. The resuhs show that oxide inclusions in H13 steel change from irregular Al2O3- near globular CaO-MgO-Al2O3 and CaO-Al2O3-SiO2 complex inclusions-finer CaO- Al2O3-SiO2 inclusions with higher CaO content-CaO-Al2O3-SiO2 inclusions with higher Al2O3 content and irregular MgO-AI203 inclusions--fine irregular MgO-Al2O3-CaS inclusions in various steps of the production; the variations are related with changes of acid soluble aluminum content, reactions between slag and steel, re-oxidation of liquid steel during casting, and refining of ESR. It is also found that Al2O3 inclusions are modified by refining slag in LF and VD refining~ and ESR plays a good role in inclusion removal, especially in controlling the large linear VC-CrC- MoC inclusions distributed in grain boundaries. It is suggested that casting protection should be improved, and the basicity of refining slag and acid soluble aluminum content in steel should be raised.

  12. Wear Behavior and Mechanism of H13 Steel in Different Environmental Media

    Li, Xinxing; Zhou, Yin; Cao, Huan; Li, Yixian; Wang, Lan; Wang, Shuqi


    Sliding wear tests were performed for H13 steel in atmosphere, distilled water, 3.5% NaCl, and 5% NaOH water solutions under various loads on a pin-on-disk wear tester. The results showed that for different environmental media, the wear rate of H13 steel in atmosphere was the maximum and that in 3.5% NaCl solution was the minimum. The maximum wear rate in atmosphere was caused by a larger quantity of heat produced in the friction process. In this case, the adhesive wear prevailed. In three wet environments, the mild wear prevailed due to the good lubrication and cooling capacity of media as well as corrosion product film on worn surface. In distilled water, the wear mechanism was a typical fatigue wear. On the other hand, in 3.5% NaCl and 5% NaOH solutions, corrosive wear prevailed. The minimum wear rate in 3.5% NaCl solution was attributed to the protective function of corrosion product film. On the contrary, noncompact corrosion product film in 5% NaOH solution resulted in higher wear rate.

  13. Effect of magnesium addition on inclusions in H13 die steel

    Zheng Wu; Jing Li; Cheng-bin Shi; Liang-liang Wang


    The effect of magnesium addition on the number, morphology, composition, size, and density of inclusions in H13 die steel was studied. The results show that the total oxygen content in the steel can be significantly decreased to 0.0008wt%. Al2O3 and MnS inclusions are changed into nearly spherical MgO·Al2O3 spinel and spherical MgO·MgS inclusions, respectively. The number of inclusions larger than 1μm decreases and the number of inclusions smaller than 1μm increases with increasing magnesium content. V(N,C) precipitates around MgO·Al2O3 and MgO·MgS inclusions during solidification of liquid steel. The densities of MgO·Al2O3 spinel inclusions are lower than that of alumina inclusions. With increasing magnesium content in the Mg-containing inclusions, the density of inclusions decreases, leading to the improvement of inclusion removal efficiency.

  14. Adherence of ion beam sputter deposited metal films on H-13 steel

    Mirtich, M. J.


    An electron bombardment argon ion source sputter deposited 17 metals and metal oxides on H-13 steel. The films ranged 1 to 8 micrometers in thickness and their adherence was generally greater than the capacity of the measuring device; adherence quality depended on proper precleaning of the substrate before deposition. N2 or air was introduced for correct stoichiometry in metallic compounds. Au, Ag, MgO, and Ta5Si3 films 8 microns thick have bond strength equal to 1 micron coatings; the bond strength of pure metallic films up to 5 microns thick was greater than the epoxy to film bond (8000 psi). The results of exposures of coated material to temperatures up to 700 C are presented.

  15. Sprayformed Hot Work Steels for Rapid Tooling

    Yunfeng Yang; Simo-Pekka Hannula


    The present work compares microstructures of hot work steels made by different processes, that is, by sprayforming,by casting, and a commercially supplied H13 steel. Material benefits are recognized by sprayforming hot working tools such as die inserts fo

  16. Experimental investigation and modelling of surface roughness and resultant cutting force in hard turning of AISI H13 Steel

    Boy, M.; Yaşar, N.; Çiftçi, İ.


    In recent years, turning of hardened steels has replaced grinding for finishing operations. This process is compared to grinding operations; hard turning has higher material removal rates, the possibility of greater process flexibility, lower equipment costs, and shorter setup time. CBN or ceramic cutting tools are widely used hard part machining. For successful application of hard turning, selection of suitable cutting parameters for a given cutting tool is an important step. For this purpose, an experimental investigation was conducted to determine the effects of cutting tool edge geometry, feed rate and cutting speed on surface roughness and resultant cutting force in hard turning of AISI H13 steel with ceramic cutting tools. Machining experiments were conducted in a CNC lathe based on Taguchi experimental design (L16) in different levels of cutting parameters. In the experiments, a Kistler 9257 B, three cutting force components (Fc, Ff and Fr) piezoelectric dynamometer was used to measure cutting forces. Surface roughness measurements were performed by using a Mahrsurf PS1 device. For statistical analysis, analysis of variance has been performed and mathematical model have been developed for surface roughness and resultant cutting forces. The analysis of variance results showed that the cutting edge geometry, cutting speed and feed rate were the most significant factors on resultant cutting force while the cutting edge geometry and feed rate were the most significant factor for the surface roughness. The regression analysis was applied to predict the outcomes of the experiment. The predicted values and measured values were very close to each other. Afterwards a confirmation tests were performed to make a comparison between the predicted results and the measured results. According to the confirmation test results, measured values are within the 95% confidence interval.

  17. WC coating on H13 steel surface prepared by electrospark deposition%H13钢表面电火花沉积WC涂层

    王明伟; 潘仁; 李姝; 周茂军; 张立文


    利用DZ-4000(Ⅲ)型电火花沉积/堆焊机,以WC为电极材料,采用氩气为保护气对H13钢基体进行了电火花表面强化.利用扫描电镜、能谱分析仪、X射线衍射仪和显微硬度计等对沉积层的成分、组织、硬度和表面粗糙度进行了研究.结果表明,利用电火花沉积工艺可获得组织均匀、致密,且与基体呈冶金结合的沉积层,沉积层平均厚度约60μm.沉积层主要由Fe3W3C、(CrFe)7C3和W2C等相组成.沉积层的平均显微硬度为1321.4 HV0.05,约为基体硬度的3倍.%The surface of H13 steel was strengthened by electro-spark deposition (ESD) machine of model DZ-4000 (Ⅲ) with WC electrode in the argon medium.The microstructure,element distribution,hardness and surface roughness of strengthened coating is analyzed by means of scanning electron microscopic,energy-dispersive spectrum,X-ray diffraction and micro-hardness testing machine.The results show that excellent metallurgical bonding between the coating and the substrate is obtained by ESD.The coating had an average thickness of about 60 μm.The microstructure of the coating is mainly composed of Fe3W3 C phase,(CrFe) 7 C3 phase and W2C phase.The average micro-hardness of the coating is 1321.4 HV0.05 which is three times than that of the substrates.

  18. Investigation of plume dynamics during picosecond laser ablation of H13 steel using high-speed digital holography

    Pangovski, Krste; Otanocha, Omonigho B.; Zhong, Shan; Sparkes, Martin; Liu, Zhu; O'Neill, William; Li, Lin


    Ablation of H13 tool steel using pulse packets with repetition rates of 400 and 1000 kHz and pulse energies of 75 and 44 μ {J}, respectively, is investigated. A drop in ablation efficiency (defined here as the depth per pulse or μ {m}{/}μ {J}) is shown to occur when using pulse energies of E_{{pulse}} > 44 μ {J}, accompanied by a marked difference in crater morphology. A pulsed digital holographic system is applied to image the resulting plumes, showing a persistent plume in both cases. Holographic data are used to calculate the plume absorption and subsequently the fraction of pulse energy arriving at the surface after traversing the plume for different pulse arrival times. A significant proportion of the pulse energy is shown to be absorbed in the plume for E_{{pulse}} > 44 μ {J} for pulse arrival times corresponding to {>}1 MHz pulse repetition rate, shifting the interaction to a vapour-dominated ablation regime, an energetically costlier ablation mechanism.

  19. H13钢电渣锭热变形本构模型的研究%Constitutive Equation of Hot Deformation for H13 Steel Electroslag Ingot

    梁宝钱; 张驰; 徐春



  20. Influence of Thermal Homogenization Treatment on Structure and Impact Toughness of H13 ESR Steel

    MA Dang-shen; ZHOU Jian; CHEN Zai-zhi; ZHANG Zhong-kan; CHEN Qi-an; LI De-hui


    The as-cast microstrueture of H13 ESR ingot and the influence of high temperature diffusion treatment on the structure and impact toughness have been investigated. The results show that the dendrite arm spacing gradually becomes wide from the surface to the center of ingot, and the large primary carbide particles always exist in interdendritic segregation areas; by means of high temperature diffusion treatment of ingot prior to hot forging, the banded segregation is nearly eliminated, the annealed structure is more uniform and the isotropic properties have been improved remarkably.

  1. 离子渗氮压力对H13钢摩擦磨损性能的影响%Effect of ion nitriding pressure on wear resistance of H13 steel

    罗顺; 林义民; 唐维学; 侯惠君


    研究了等离子渗氮压力对H13模具钢渗层组织、显微硬度和摩擦学性能的影响,对磨损后的显微形貌进行了分析,对磨损机理进行了探讨.结果表明:选择N2与H2的体积比为2∶ 1,渗氮温度为540 ℃,渗氮压力为1066 Pa的工艺条件,渗氮层厚度值最大,硬度曲线最平缓,摩擦因数低,磨损量最小,具有相对较好的耐摩擦磨损性能.%Effect of plasma nitriding pressure on nitriding layer microstructure, microhardness and wear resistance of HI3 tool steel was studied, morphologies were analyzed and wear mechanism was discussed. The results show that under the volume of nitrogen and hydrogen ratio 2: 1, nitriding temperature 540 ℃, nitriding pressure 1066 Pa, the nitriding thickness is the largest, the hardness profile is relatively flat,the friction coefficient is the lowest and the wear is the smallest, so the nitrided layer has good abrasion wear resistance.

  2. Characterization of an AISI H-13 steel for work in hot; Caracterizacion del acero H-13 AISI para trabajado en caliente

    Godinez, J.; Robles, E. [Instituto Nacional de Investigaciones Nucleares, Departamento de Sintesis y Caracterizacion de Materiales, A.P. 18-1027, 11801 Mexico D.F. (Mexico)


    Two materials were acquired which elaborated through secondary refining processes known as electroslag refusing (ESR) and electric arc in vacuum refusing (VAR) were acquired. These materials were thermically treated, for subsequently to determine their mechanical properties in longitudinal and transversal directions with respect to rolling direction, moreover they were characterized through scanning electron microscopy and X-ray diffraction determining microstructure, carbides and non-metallic inclusions. The results of the mechanical essays allowed to evaluate the fracture toughness to this steel by the Barsom and Rolfe method. (Author)


    José Britti Bacalhau


    Full Text Available Aluminum extrusion dies are an important segment of application on industrial tools steels, which are manufactured in steels based on AISI H13 steel. The main properties of steels applied to extrusion dies are: wear resistance, impact resistance and tempering resistance. The present work discusses the characteristics of a newly developed hot work steel to be used on aluminum extrusion dies. The effects of Cr and Mo contents with respect to tempering resistance and the Al addition on the nitriding response have been evaluated. From forged steel bars, Charpy impact test and characterization via EPMA have been conducted. The proposed contents of Cr, Mo, and Al have attributed to the new VEX grade a much better tempering resistance than H13, as well as a deeper and harder nitrided layer. Due to the unique characteristics, this new steel provides an interesting alternative to the aluminum extrusion companies to increase their competitiveness.


    石楠楠; 吴晓春; 周青春


    主要研究了在自约束条件下,表面脱碳层对H13钢热疲劳性能的影响.结果显示,含脱碳层试样表面开裂严重,表层硬度急剧下降,热疲劳损伤因子大大高于半脱碳和无脱碳的试样.说明脱碳造成材料表层含碳量减少,强度降低,使热疲劳时产生的交变热应力超过材料的屈服强度,引起往复塑性变形,逐渐造成损伤累积,从而导致钢的热疲劳强度下降.%The effect of surface decarbonization layer on thermal fatigue property of steel H13 under self restrained condition was studied.Results showed that the decarbonized layer featured with serious cracking and decline surface hardness, its thermal fatigue damage factor was higher than that of the other samples.This meant that the decarbonization made lower carbon content on steel surface and the reduced hardness.The stress induced by temperature exceeded the yield strength of steel during thermal fatigue process, which led to reciprocal plastic deformation, resulted in cumulative damage and deteriorated the thermal fatigue property of steel.

  5. Influence of Different Surface Treatments of H13 Hot Work Die Steel on Its Thermal Fatigue Behaviors


    Thermal fatigue checking is the general failure of hot work die steels, which is relative with the structures and properties of the steels and the stress alternated during the employment. The Uddeholm test method on thermal fatigue is used to compare the behaviors of different samples, which are treated with plasma nitriding、plasma sulfur-carbon-nitriding、 boronizing or not treated. The results show that the nitriding improves the thermal fatigue property of the tool steel, while the plasma sulfur-carbon-nitriding and the boronizing impair the property. The mechanisms are induced as follows. By increasing the hardness and changing the stress distribution in the surface layer, surface treatment can decrease the plastic deformation and the tensile stress during the cycling. Therefore,the generation and growth of the cracks are restrained. On the other hand, as results of surface treating, in the surface layer the toughness declines and the expanding coefficient ascendes; the latter change caused the strengthening of the tensile and compressive stress during the cycling. Thus the resistance to thermal fatigue is weakened. Whether or not the surface treatment is favor to thermal fatigue of tool steels relies on which factor is dominant.

  6. H13钢表面电火花强化层的热疲劳性能%Thermal Fatigue Properties of Strengthening Layer on H13 Steel Surface by ESD

    葛志宏; 邓静


    H13钢表面电火花强化层的热疲劳性能进行了研究.结果表明,电火花强化层在热循环时涂层区域出现裂纹,扩散层区域出现组织粗化和氧化痕迹,但电阻损伤显示,强化层对H13钢基体的热疲劳性能影响不大.电火花强化层的存在,有效提高了基体硬度,并有效保护基体不受氧化和不产生脱碳.%The thermal fatigue properties of strengthening layer on H13 steel surface by ESD were studied.The research results indicate that,during thermal cycling,cracks occur in the coating area of electrospark strengthening layer,while coarse structure and oxidation trace occur in transition region.The resistance damage indicates that,the strengthening layer has no effect on thermal fatigue properties of base.Electrospark strengthening layer can improve the hardness of base,and protecte the substrate from oxidation and decarburization.

  7. Improved life of die casting dies of H13 steel by attaining improved mechanical properties and distortion control during heat treatment. Year 1 report, October 1994--September 1995

    Wallace, J.F.; Schwam, D. [Case Western Reserve Univ., Cleveland, OH (United States)


    Optimum heat treatment of dies (quenching) is critical in ensuring satisfactory service performance: rapid cooling rates increase the thermal fatigue/heat checking resistance of the steel, although very fast cooling rates can also lead to distortion and lower fracture toughness, increasing the danger of catastrophic fracture. Goal of this project is to increase die life by using fast enough quenching rates (> 30 F/min ave cooling rate from 1750 to 550 F, 1/2 in. below working surfaces) to obtain good toughness and fatigue resistance in Premium grade H-13 steel dies. An iterative approach of computer modeling validated by experiment was taken. Cooling curves during gas quenching of H-13 blocks and die shapes were measured under 2, 5, and 7.5 bar N2 and 4 bar Ar. Resulting dimensional changes and residual stresses were determined. To facilitate the computer modeling work, a database of H-13 mechanical and physical properties was compiled. Finite element analysis of the heat treated shapes was conducted. Good fit of modeled vs measured quenched rates was demonstrated for simple die shapes. The models predict well the phase transformation products from the quench. There is good fit between predicted and measured distortion contours; however magnitude of predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required.

  8. Improved Life of Die Casting Dies of H13 Steel by Attaining Improved Mechanical Properties and Distortion Control During Heat Treatment

    J. F. Wallace; D. Schwam


    The ultimate goal of this project is to increase die casting die life by using fast enough quenching rates to obtain good toughness and fatigue resistance in premium grade H-13 steel dies. The main tasks of the project were to compile a database on physical and mechanical properties of H-13; conduct gas quenching experiments to determine cooling rates of dies in difference vacuum furnaces; measure the as-quenched distortion of dies and the residual stresses; generate finite element analysis models to predict cooling rates, distortion, and residual stress of gas quenched dies; and establish rules and create PC-based expert system for prediction of cooling rates, distortion, and residual stress in vacuum/gas quenched H-13 dies. Cooling curves during gas quenching of H-13 blocks and die shapes have been measured under a variety of gas pressure. Dimensional changes caused by the gas quenching processes have been determined by accurate mapping of all surfaces with coordinate measuring machines before and after the quench. Residual stresses were determined by the ASTM E837 hole-drilling strain gage method. To facilitate the computer modeling work, a comprehensive database of H-13 mechanical and physical properties has been compiled. Finite element analysis of the heat treated shapes has been conducted using the TRAST/ABAQUS codes. There is a good fit between the predicted and measured distortion contours. However, the magnitude of the predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required before it can be used to predict distortion and residual stress in a quantitative manner. This last step is a prerequisite to generating rules for a reliable expert system.

  9. Microstructure and property modifications of an AISI H13 (4Cr5MoSiV) steel induced by pulsed electron beam treatment

    Zhang Kemin; Zou Jianxin; Grosdidier, Thierry; Dong Chuang [School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China); Shanghai Engineering Research Center of Mg Materials and Applications and School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China) and Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM, CNRS 3143), Universite Paul Verlaine Metz, Ile du Saulcy, 57045 Metz (France); Laboratoire d' Etude des Textures et Applications aux Materiaux (LETAM, CNRS 3143), Universite Paul Verlaine Metz, Ile du Saulcy, 57045 Metz (France) and Laboratory of Materials Modification by Laser, Electron and Ion Beams, Dalian University of Technology, Dalian 116024 (China); Laboratory of Materials Modification by Laser, Electron and Ion Beams, Dalian University of Technology, Dalian 116024 (China)


    In the present work, surface modifications generated by the low energy high current pulsed electron beam (LEHCPEB) treatments have been investigated on an AISI H13 (4Cr5MoSiV) steel. From the observations of scanning electron microscopy, x-ray diffraction, and electron back scattering diffraction determinations, it could be established that the final structure in the melted layer is a mixture of ultrafine {delta} phase, martensite, and residual austenite. The formation of the heterogeneous microstructures on the surface layer is related to the very rapid heating, melting, solidification, and cooling induced by the LEHCPEB irradiation. After the LEHCPEB treatment, the wear resistance of the steel effectively improved. This can be mainly attributed to the higher hardness of the ultrafine structures formed on the top surface and the hardened subsurface layers after the treatment.

  10. A low temperature aluminizing treatment of hot work tool steel

    Matijevic, B., E-mail: [University of Zagreb, Faculty of Mechanical Engineering and Naval Architecture, Zagreb (Croatia)


    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to hot tool steel H13. The aluminizing treating temperature was from 550 to 620°C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the aluminized layer thickness and the oxide layer were studied. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), glow discharge optical spectroscopy (GDOS) were applied to observe the cross-sections and the distribution of elements. (author)

  11. 碳氮共渗及离子氮化H13钢的抗热疲劳性能%Thermal Fatigue Resistance of Nitrocarburized and Ion Nitrided H13 Steel

    李志刚; 胡兰青; 许并社


    分别制备了调质、离子氮化和碳氮共渗处理的H13钢试样,借助X射线衍射仪、扫描电子显微镜和能谱仪对其渗层进行了分析,检测了不同处理后H13钢的抗热疲劳性能.结果表明:经过1000次18℃→700℃热疲劳试验后,碳氮共渗H13钢表面萌生了少量的热裂纹;而离子氮化H13钢表面的热裂纹已经形成网状,并且穿透渗氮层扩展到基体内约300 μm;经调质处理的H13钢表面的热裂纹有轻微的发展,扩展到基体内约100μm;三种试样中碳氮共渗处理H13钢的抗热疲劳性能最好.

  12. Optimization of Minimum Quantity Lubricant Conditions and Cutting Parameters in Hard Milling of AISI H13 Steel

    The-Vinh Do


    Full Text Available As a successful solution applied to hard machining, the minimum quantity lubricant (MQL has already been established as an alternative to flood coolant processing. The optimization of MQL parameters and cutting parameters under MQL condition are essential and pressing. The study was divided into two parts. In the first part of this study, the Taguchi method was applied to find the optimal values of MQL condition in the hard milling of AISI H13 with consideration of reduced surface roughness. The L9 orthogonal array, the signal-to-noise (S/N ratio and analysis of variance (ANOVA were employed to analyze the effect of the performance characteristics of MQL parameters (i.e., cutting fluid type, pressure, and fluid flow on good surface finish. In the results section, lubricant and pressure of MQL condition are determined to be the most influential factors which give a statistically significant effect on machined surfaces. A verifiable experiment was conducted to demonstrate the reliability of the results. In the second section, the optimized MQL parameters were applied in a series of experiments to find out cutting parameters of hard milling. The Taguchi method was also used to optimize the cutting parameters in order to obtain the best surface roughness. The design of the experiment (DOE was implemented by using the L27 orthogonal array. Based on an analysis of the signal-to-noise response and ANOVA, the optimal values of cutting parameters (i.e., cutting speed, feed rate, depth-of-cut and hardness of workpiece were introduced. The results of the present work indicate feed rate is the factor having the most effect on surface roughness.

  13. H13模具钢低温盐浴氮碳钒共渗工艺研究%Study on Vanadium-nitrocarburizing in Low Temperature Salt-bath for Die Steel H13

    李延辉; 刘金水; 周惦武; 张楚惠; 林峰




    H. Cifuentes


    Full Text Available In this scientific research paper, the microstructure and corrosion resistance of chromium nitrides obtained from a duplex treatment consisting of an electroplated hard chromium coating applied on a steel AISI H13 follow by a thermochemical treatment in vacuum using NH3 as precursor gas of nitrogen, is evaluated. This type of duplex treatments combine the benefits of each individual treatment in order to obtain, with this synergic effect, compounds type CrxN more economic than those obtained by other kind of treatments e.g. physical vapor deposition (PVD. The results obtained by X-Ray Diffraction (XRD indicate the surface and subsurface transformation of the electrolytic hard chromium coating by formation of CrN and Cr2N phases. Likewise, potentiodynamic polarization tests indicate an increase in corrosion resistance of such kind of compounds in comparison with the obtained results with electroplated hard chromium.

  15. An Analysis on Quality of Slanting Roller Blank of Steel H13 Produced by Centrifugal Induction Electroslag Casting%感应电渣离心浇铸生产H13钢斜轧辊毛坯的质量分析

    陈希春; 徐卫国; 周德光; 傅杰


    感应电渣离心浇铸H13钢斜轧辊毛坯中夹杂物分布均匀,最大直径不大于7μm,大部分小于2μm。铸件毛坯的二次枝晶间距仅为400 μm,晶粒度为9~10级。结果表明,感应电渣离心浇铸H13钢毛坯制造的斜轧辊,其使用寿命不低于电渣重熔锻材制造的斜轧辊。%The inclusions in the blank of steel H13 for slanting roller produced by centrifugal induction electroslag casting (CIESC) is dispersed uniformly in blank, most of which the diameters are less than 2 μm and maximum diameter of inclusion is 7 μm. The second dendrite space in the blank casting is 400 μm with grain size 9~10. The application results show that the service life of slanting roller made of CIESC steel H13 blank is up to that made of ESR forged steel H13 blank.

  16. Study on Tribological Behaviors of Molybdenum Coating on H13 Steel Surface by Electrospark Deposition%H13钢表面电火花沉积钼涂层的摩擦磨损特性研究

    冯弘; 王耀武; 田林海; 唐宾


    H13钢表面电火花沉积钼合金涂层,研究了其组织结构及摩擦磨损特性.结果表明,钼合金涂层由白亮层、扩散层和热影响区组成;钼元素与基体元素相互扩散形成冶金结合;合金层的显微硬度(约为1482HK0.025)较H13钢(280 HK0.025)提高5倍左右;电火花沉积Mo合金层后摩擦系数明显降低,磨损质量损失仅为基材的1/7,抗磨性能显著提高.

  17. Effects of Ti catalysis salt bath nitrocarburizing on surface properties of H13 steel%钛催渗盐浴氮碳共渗对H13表面性能的影响




  18. Surface Treatment and Thermal Fatigue-Erosion Properties of Die Steel H13%H13模具钢表面处理和热疲劳-热熔损性能

    胡正前; 张文华; 马晋



  19. Structure and properties of composite ceramic coatings on H13 steel by hot dipping aluminum and plasma electrolytic oxidation%H13热作模具钢微弧氧化复合陶瓷层的组织和性能

    赵建华; 赵国华; 李涛; 刘鑫; 李佳丽; 韩二静


    通过热浸镀铝/微弧氧化复合工艺对H13模具钢进行表面改性以提高模具表面质量。在热浸镀铝过程中,将H13钢基体浸入710℃纯铝液6 min,得到了以Fe2Al5为主中间合金层,使得镀层与基体紧密结合。经过微弧氧化处理后,镀铝试样表面铝层转化为氧化铝陶瓷,主要由α-Al2O3和γ-Al2O3相组成。用带有能谱分析装置(EDX)的扫描电镜(SEM)、X射线衍射(XRD)分析了膜层的形貌、成分和相组成。微弧氧化陶瓷层主要由Al、O、Si元素组成,其中O、Si主要来源于硅酸盐电解液。%Hot dipping pure aluminum on a H13 steel followed by plasma electrolytic oxidation(PEO) was performed to prepare composite ceramic coating on the H13 steel surface.H13 steel bars were first dipped in pure aluminum melts(710 ℃) for 6 min,and a Fe2Al5 intermetallic layer was obtained at the interface between the melt and the steel substrate.The intermetallic layer significantly improved the adhesion strength between Al layer and substrate.After PEO processing,uniform Al2O3 ceramic coatings were deposited on the surface of aluminized steel.The composition,phases and morphology of the aluminized layer and the ceramic coatings were characterized by SEM/EDX and XRD.The PEO layers mainly consist of α-Al2O3 and γ-Al2O3.The element O and Si in the ceramic layers came from the alkaline electrolytle.

  20. Abrasive Wear Resistance of Tool Steels Evaluated by the Pin-on-Disc Testing

    Bressan, José Divo; Schopf, Roberto Alexandre


    Present work examines tool steels abrasion wear resistance and the abrasion mechanisms which are one main contributor to failure of tooling in metal forming industry. Tooling used in cutting and metal forming processes without lubrication fails due to this type of wear. In the workshop and engineering practice, it is common to relate wear resistance as function of material hardness only. However, there are others parameters which influences wear such as: fracture toughness, type of crystalline structure and the occurrence of hard precipitate in the metallic matrix and also its nature. In the present investigation, the wear mechanisms acting in tool steels were analyzed and, by normalized tests, wear resistance performance of nine different types of tool steels were evaluated by pin-on-disc testing. Conventional tool steels commonly used in tooling such as AISI H13 and AISI A2 were compared in relation to tool steels fabricated by sintering process such as Crucible CPM 3V, CPM 9V and M4 steels. Friction and wear testing were carried out in a pin-on-disc automated equipment which pin was tool steel and the counter-face was a abrasive disc of silicon carbide. Normal load of 5 N, sliding velocity of 0.45 m/s, total sliding distance of 3000 m and room temperature were employed. The wear rate was calculated by the Archard's equation and from the plotted graphs of pin cumulated volume loss versus sliding distance. Specimens were appropriately heat treated by quenching and three tempering cycles. Percentage of alloying elements, metallographic analyses of microstructure and Vickers microhardness of specimens were performed, analyzed and correlated with wear rate. The work is concluded by the presentation of a rank of tool steel wear rate, comparing the different tool steel abrasion wear resistance: the best tool steel wear resistance evaluated was the Crucible CPM 9V steel.

  1. Automated Steel Cleanliness Analysis Tool (ASCAT)

    Gary Casuccio (RJ Lee Group); Michael Potter (RJ Lee Group); Fred Schwerer (RJ Lee Group); Dr. Richard J. Fruehan (Carnegie Mellon University); Dr. Scott Story (US Steel)


    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel

  2. High Temperature Wear Resistance of HI3 Steel with Different Surface Treatments%不同表面处理工艺下H13钢的高温耐磨性能

    刘英坤; 朱峰; 伍超群; 侯惠君


    首先对调质处理状态的H13钢进行了渗氮、物理气相沉积(PVD)镀膜、渗氮+PVD镀膜三种不同的表面处理,然后在UMT-3型摩擦磨损试验机上,对处理后的试样进行600℃的高温摩擦磨损试验,研究了不同工艺下H13钢的高温耐磨性能。结果表明:试样的磨损形式主要是粘着磨损+磨粒磨损,经表面处理后试样的表面硬度大幅度提高,摩擦系数大幅度降低;其中渗氮+PVD镀膜表面处理试样的高温耐磨性能最好。%First the hardened and tempered H13 steel was surface treated by three methods of nitridation, physical vapor deposition(PVD) coating, and Mtridation and PVD coating, and then the friction wear performance at high temperature of 600℃ of the specimens with different surface treatment states was studied on UMT-3 friction wear testing machine. The results indicate that the main wear forms of all speeimens were adhesion wear and abrasive particle wear. After the different surface treatments, the hardness of the H13 steel increased obviously, and the friction coefficient reduced obviously. Specimens surface treated by nitridation and PVD coating method showed the best high temperature wear resistance.

  3. Method for machining steel with diamond tools

    Casstevens, John M.


    The present invention is directed to a method for machining optical quality inishes and contour accuracies of workpieces of carbon-containing metals such as steel with diamond tooling. The wear rate of the diamond tooling is significantly reduced by saturating the atmosphere at the interface of the workpiece and the diamond tool with a gaseous hydrocarbon during the machining operation. The presence of the gaseous hydrocarbon effectively eliminates the deterioration of the diamond tool by inhibiting or preventing the conversion of the diamond carbon to graphite carbon at the point of contact between the cutting tool and the workpiece.

  4. Mechanism of Annealing Softening of Rolled or Forged Tool Steel


    In order to reduce hardness of rolled or forged steels after annealing and improve processability, the diameter and dispersity of carbides were measured by SEM and quantitative metallography. The microstructure of annealed steel was analyzed by TEM. The effects of the factors such as solute atoms, carbides, grain boundary and interphase boundary were studied. The mechanism of annealing softening of steels was analyzed on the examples of steels H13, S5, S7, X45CrNiMo4, which are treated with new technology. The results showed that the softening of H13, S7, S5 is easier obtained by isothermal or slow cooling annealing from slightly below A1, but hardness of X45CrNiMo4 after annealing is reduced effectively by obtaining coarse lamellar pearlite. Economic results can be obtained from good processability.

  5. Study on Heterogeneous Nuclei in Cast H13 Steel Modified by Rare Earths%变质CH13钢中Ce2O3异质核心作用的研究

    兰杰; 贺俊杰; 丁文江; 王渠东; 朱燕萍


    The dendrite segregation in cast H13 steel is weakened with RE modification treatment. Carbide on grain boundary disappeared after quenching, and impact toughness improved greatly. By two-dimensional lattice misfitting calculation and analysis by electron probe, it is found that Ce2O3 may act as the heterogeneous nuclei of modified cast H13 steel.%采用变质处理大大减弱了CH13钢枝晶组织的元素偏析,使未变质CH13钢中的晶界碳化物得以消除, CH13钢的冲击韧性大大提高。通过热力学计算及二维点阵错配度计算,并采用电子探针定量分析等手段,证实Ce2O3型稀土夹杂物可作为CH13钢中初生奥氏体的异质核心,细化枝晶组织,减弱合金元素偏析。

  6. Effects of MgO Contents in Slag on Inclusions in H13 Steel Deoxidized with Mg-Al-Fe Alloy%渣系中 MgO 含量对镁铝铁合金脱氧 H13钢中夹杂物的影响

    吴政; 李晶; 史成斌; 杜刚


    采用 CaO-MgO-Al2 O 3-SiO 2-CaF2渣系的精炼渣,研究了渣系中 MgO 含量对镁铝铁合金脱氧 H13钢中夹杂物密度、尺寸和成分的影响.结果表明:采用质量分数5%MgO 精炼渣精炼后,钢中的夹杂物最少,密度为55.62个.mm-2,夹杂物尺寸均小于8μm;当 MgO 的质量分数低于或高于5%时,夹杂物数量都较多,都含有尺寸为8~10μm 的大型夹杂物;当精炼渣中 MgO 的质量分数为0时,钢中夹杂物主要为 MgO.Al2 O 3和 Al2 O 3-SiO 2,当精炼渣中 MgO 的质量分数为5%,8%和12%时,钢中的夹杂物分别主要为 MgO.Al2 O 3和 Al2 O 3-SiO 2、MgO.Al2 O 3和 Al2 O 3-SiO 2-CaO、MgO.Al2 O 3和 Al2 O 3-SiO 2-CaO-MgO;通过热力学数据计算得到的与钢中镁、铝相对应的氧化物稳定区图与试验得到的 A 类夹杂物的成分一致.%The effects of MgO contents in slag system CaO-SiO 2-Al2 O 3-MgO-CaF2 on the number,size and composition of inclusions in H13 steel deoxidized with Mg-Al-Fe alloy were studied.Results show that when the content of MgO in the slag was 5wt%,the minimum number of inclusions was 55.62 per square millimeter,and the size of all inclusions was less than 8 μm.When the content of MgO in the slag was less than or more than 5wt%, there was more number of inclusions in the steel,and the size of some inclusions was 8-10 μm.When the content of MgO in the slag was 5wt%,8wt%,12wt%,respectively,the inclusions were MgO.Al2 O 3 and Al2 O 3-SiO 2 , MgO.Al2 O 3 and Al2 O 3-SiO 2-CaO,MgO.Al2 O 3 and Al2 O 3-SiO 2-CaO-MgO,respectively.A stability diagram of inclusions corresponding to magnesium and alumina contents in the steel was calculated employing available thermodynamic data,and the A-type inclusion composition experimentally obtained well agreed with the diagram.

  7. Study of hot hardness characteristics of tool steels

    Chevalier, J. L.; Dietrich, M. W.; Zaretsky, E. V.


    Hardness measurements of tool steel materials in electric furnace at elevated temperatures and low oxygen environment are discussed. Development of equation to predict short term hardness as function of intial room temperature hardness of steel is reported. Types of steel involved in the process are identified.


    Yusuf ŞAHİN


    Full Text Available The investigation of machining AISI 1050 carbon steels hardened to the 60 HRC hardness was carried out to determine the tool life and wear behaviour of the various cutting tools under different conditions. These experiments were conducted at using coated ceramic cutting tools and carbide cutting tools. The experimental results showed that the coated ceramic tools exhibited better performance than those of the coated carbide tools when machining the hardened steels. Moreover, wear behaviour of cutting tools were investigated in a scanning electron microscope. Electron microscopic examination also indicated that flank wear, thermal cracks on the tool nose combined with the nose deformation on the tools were responsible for the wear behaviour of the ceramic tools. For the carbide tools, however, removal of coated material from the substrate tool and combined with the crater wear were effective for the machining the hardened steel.

  9. Investigation on Electro Discharge Machining of H13

    Nosratollah Solhjoei


    Full Text Available Electrical Discharge Machining (EDM is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests. AISI H13 hot work steel is the tool material most commonly used in hot working processes. In this paper an attempt has been made to develop mathematical models for relating the Material Removal Rate (MRR and Stability factor (Sf to input parameters (current, pulse-on time and voltage in the EDM of H13. A Central Composite Design (CCD involving three variables with three levels has been employed. Furthermore, a study was carried out to analyze the effects of machining parameters in respect of listed technological characteristics. The results of analysis of variance (ANOVA indicate that the proposed mathematical models, can adequately describe the performance of the process within the range of the factors being studied. The experimental and predicted values were in a good agreement.




    Full Text Available This paper deals with the study of the performance of coated tools in machining hardening steel under dry conditions. This paper involves of machining AISI 4340 hardened steel using coated carbide tools is studied using full factorial experiments. Many parameters influence the quality of the products in hard turning process. The objective of this study is on the effect of the cutting conditions such as cutting velocity, feed, and depth of cut on the surface finish in machining AISI 4340 hardened steel. Machining of hardened steels has become an important manufacturing process, particularly in the automotive and bearing industries.

  11. Metallographic Characterization of the Microstructure of Tool Steels

    George F. Vander Voort; Elena P. Manilova


    Examination of selectively etched tool steel microstructures by light microscopy provides more information than standard etchants, such as nital, picral or Vilella's reagent. Further, the images are more suitable for quantitative measurements, especially by image analysis. Specimens must be properly prepared, damage free, if selective etchants are to be applied successfully. A number of etchants have been claimed to selectively etch certain carbides in tool steels. The response of these etchants has been evaluated using a variety of well-characterized tool steel compositions. While many are selective, they are often selective to more than one type of carbide. Furthermore, their use in image analysis must be evaluated carefully as measurements showed that the amount and size of the carbides are often greater after selective etching as many of these reagents outline and color or attack the carbides. Selective etching of the matrix, leaving the carbides unaffected works well, but no one etchant will cover the broad spectrum of tool steel compositions. No etchant has been found that will color retained austenite in tool steels and image analysis of retained austenite in tool steels are always much lower than by x-ray diffraction unless retained austenite is the dominant phase present in grossly over-austenitized steels.

  12. Nanostructuring steel for injection molding tools

    Al-Azawi, A.; Smistrup, Kristian; Kristensen, Anders


    and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro-and nanostructuring the surface of the steel molds. We investigate...

  13. Dimensional and material characteristics of direct deposited tool steel by CO II laser

    Choi, J.


    Laser aided direct metalimaterial deposition (DMD) process builds metallic parts layer-by-layer directly from the CAD representation. In general, the process uses powdered metaUmaterials fed into a melt pool, creating fully dense parts. Success of this technology in the die and tool industry depends on the parts quality to be achieved. To obtain designed geometric dimensions and material properties, delicate control of the parameters such as laser power, spot diameter, traverse speed and powder mass flow rate is critical. In this paper, the dimensional and material characteristics of directed deposited H13 tool steel by CO II laser are investigated for the DMD process with a feedback height control system. The relationships between DMD process variables and the product characteristics are analyzed using statistical techniques. The performance of the DMD process is examined with the material characteristics of hardness, porosity, microstructure, and composition.

  14. The challenge of PM tool steels for the innovation

    M. Rosso


    Full Text Available Purpose: The economical impacts and complexity of tool steels justify the lot of efforts for their development,processing and application. In particular the main goal is the attainment of isotropic microstructures characterisedby homogeneous distribution of fine carbide particles and segregation free. The paper offers a review of thePowder Metallurgy tool steels currently manufactured, their properties are discussed with particular regard totheir main application and attained performances.Design/methodology/approach: Powder Metallurgy is the way to make the goal, its alloying flexibility allowsthe production of new tool steels that cannot be made by conventional processes, because of segregation andrelated hot workability problems.Findings: In practice, through the Powder Metallurgy route it is possible to achieve the highest levels ofproperties, specifically related to toughness, mechanical behaviour, wear and corrosion resistances of theproduced alloys.Research limitations/implications: The use of Powder Metallurgy route allows, through the HIP consolidationfrom tiny powder particles, to facilitate the production of tool alloy grades able to reach very high performances.Moreover the application of coatings can determin e further advantages.Practical implications: When using thin coatings, like PVD deposited layers, the PM steels more uniformlydistributed and fine carbide structure was found to give a clear improvement in the interface quality of therelative coated systems. Conversely, the less uniform traditional steels carbide distribution resulted in a lesscontinuous contact between the substrate and the coating.Originality/value: The paper demonstrate the superior value and perfomances of PM tool steels and theirbetter adaptability to PVD coatings. In particular, cold working, plastics and high speed applications are themain interested and advantageously affected by the uniqueness of PM tool steels. Some comparison betweenequivalent

  15. Thick tool steel coatings with laser cladding

    Ocelik, V.; de Oliveira, U.; De Hosson, J. Th. M.; DeHosson, JTM; Brebbia, CA; Nishida, SI


    This paper concentrates on thick and crack-free laser clad coatings (up to 3 mm). The coating material is a chromium-molybdenum-tungsten-vanadium alloyed high-speed steel that shows high wear resistance, high compressive strength, good toughness, very good dimensional stability on heat treatment and

  16. Thick tool steel coatings with laser cladding

    Ocelik, V.; de Oliveira, U.; De Hosson, J. Th. M.; DeHosson, JTM; Brebbia, CA; Nishida, SI


    This paper concentrates on thick and crack-free laser clad coatings (up to 3 mm). The coating material is a chromium-molybdenum-tungsten-vanadium alloyed high-speed steel that shows high wear resistance, high compressive strength, good toughness, very good dimensional stability on heat treatment and

  17. Experimental and Theoretical Investigations of Hot Isostatically Pressed-Produced Stainless Steel/High Alloy Tool Steel Compound Materials

    Lindwall, Greta; Flyg, Jesper; Frisk, Karin; Sandberg, Odd


    Consolidation of tool steel powders and simultaneous joining to a stainless 316L steel are performed by hot isostatic pressing (HIP). Two tool steel grades are considered: a high vanadium alloyed carbon tool steel, and a high vanadium and chromium alloyed nitrogen tool steel. The boundary layer arising during diffusion bonding is in focus and, in particular, the diffusion of carbon and nitrogen over the joint. Measurements of the elemental concentration profiles and corrosion tests by the double loop-electrochemical potentiokinetic reactivation (DL-EPR) method are performed. Comparative calculations with the DICTRA software are performed and are found to be in agreement with the experimental results. It is found that the carbon tool steel grade has a more critical influence on the corrosion resistance of the stainless 316L steel in comparison to the nitrogen tool steel grade.

  18. Tool Steel Heat Treatment Optimization Using Neural Network Modeling

    Podgornik, Bojan; Belič, Igor; Leskovšek, Vojteh; Godec, Matjaz


    Optimization of tool steel properties and corresponding heat treatment is mainly based on trial and error approach, which requires tremendous experimental work and resources. Therefore, there is a huge need for tools allowing prediction of mechanical properties of tool steels as a function of composition and heat treatment process variables. The aim of the present work was to explore the potential and possibilities of artificial neural network-based modeling to select and optimize vacuum heat treatment conditions depending on the hot work tool steel composition and required properties. In the current case training of the feedforward neural network with error backpropagation training scheme and four layers of neurons (8-20-20-2) scheme was based on the experimentally obtained tempering diagrams for ten different hot work tool steel compositions and at least two austenitizing temperatures. Results show that this type of modeling can be successfully used for detailed and multifunctional analysis of different influential parameters as well as to optimize heat treatment process of hot work tool steels depending on the composition. In terms of composition, V was found as the most beneficial alloying element increasing hardness and fracture toughness of hot work tool steel; Si, Mn, and Cr increase hardness but lead to reduced fracture toughness, while Mo has the opposite effect. Optimum concentration providing high KIc/HRC ratios would include 0.75 pct Si, 0.4 pct Mn, 5.1 pct Cr, 1.5 pct Mo, and 0.5 pct V, with the optimum heat treatment performed at lower austenitizing and intermediate tempering temperatures.

  19. Research on steel-fibber polymer concrete machine tool structure

    XU Ping; YU Ying-hua


    Researched on the design and manufacturing of machine tool bed made by Steel-fibber Polymer Concrete(SFPC),which analyzed the static,dynamic and thermal performances of the bed.The results of study prove that machine tool bed made with SFPC is much more superiority than made in cast iron in dynamic and thermal performances,and is more superiority then made in Polymer Concrete (PC) in static performances.It can be concluded that the static,dynamic and thermal properties of machine tool can be improved by manufacturing machine tool bed with SFPC.Also SFPC machine tool bed posses some other advantages in the following: short development time,simple production process,reducing cost cost,saving energy,iron and steel.

  20. Research on steel-fibber polymer concrete machine tool structure

    XU Ping; YU Ying-hua


    Researched on the design and manufacturing of machine tool bed made by Steel-fibber Polymer Concrete(SFPC), which analyzed the static, dynamic and thermal performances of the bed. The results of study prove that machine tool bed made with SFPC is much more superiority than made in cast iron in dynamic and thermal perform-ances, and is more superiority then made in Polymer Concrete (PC) in static perform-ances. It can be concluded that the static, dynamic and thermal properties of machine tool can be improved by manufacturing machine tool bed with SFPC. Also SFPC machine tool bed posses some other advantages in the following: short development time, simple pro-duction process, reducing cost cost, saving energy, iron and steel.

  1. 30 CFR 57.7050 - Tool and drill steel racks.


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tool and drill steel racks. 57.7050 Section 57.7050 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling...

  2. 30 CFR 56.7050 - Tool and drill steel racks.


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tool and drill steel racks. 56.7050 Section 56.7050 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and...

  3. Experimental Study on Material Surface Modification of Tool Steel

    沈丽如; 童洪辉; 王珂; 铁军; 孙爱萍


    This paper presents the surface temperature behavior of M42 high-speed tool steel samples during N+ implantation in an industrialized GLZ-100 metal-ion implantation machine. A detail study has been made on the parameters ofN+ implantation. Optimized technical parameters have been presented. The microhardness of the sample surface implanted under these parameters has been increased by a factor of 2.3, and the wear-resistance has been improved by about 5.4 times.The research on the mechanism of surface modification of M42 steel by nitrogen ion implantation has also been made.


    Matijević, Božidar


    Conventional aluminizing processes by pack cementation are typically carried out at elevated temperatures. A low temperature powder aluminizing technology was applied to the X40CrMoV5-1 hot tool steel. The aluminizing temperature was from 550 °C to 620 °C. Effects of temperature and time on the microstructure and phase evolution were investigated. Also, the intermetallic layer thickness was measured in the aluminized layer of a steel substrate. The cross-sectional microstructures, the alumini...

  5. Tool steel quality and surface finishing of plastic molds

    Rafael Agnelli Mesquita


    Full Text Available Plastic industry is today in a constant growth, demanding several products from other segments, which includes the plastic molds, mainly used in the injection molding process. Considering all the requirements of plastic molds, the surface finishing is of special interest, as the injected plastic part is able to reproduce any details (and also defects from the mold surface. Therefore, several aspects on mold finishing are important, mainly related to manufacturing conditions - machining, grinding, polishing and texturing, and also related to the tool steel quality, in relation to microstructure homogeneity and non-metallic inclusions (cleanliness. The present paper is then focused on this interrelationship between steel quality and manufacturing process, which are both related to the final quality of plastic mold surfaces. Examples are discussed in terms of surface finishing of plastic molds and the properties or the microstructure of mold steels.

  6. Rapid tooling for functional prototyping of metal mold processes: Literature review on cast tooling

    Baldwin, M.D. [Sandia National Labs., Albuquerque, NM (United States); Hochanadel, P.W. [Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering


    This report is a literature review on cast tooling with the general focus on AISI H13 tool steel. The review includes processing of both wrought and cast H13 steel along with the accompanying microstructures. Also included is the incorporation of new rapid prototyping technologies, such as Stereolithography and Selective Laser Sintering, into the investment casting of tool steel. The limiting property of using wrought or cast tool steel for die casting is heat checking. Heat checking is addressed in terms of testing procedures, theories regarding the mechanism, and microstructural aspects related to the cracking.

  7. Evolution of carbides in cold-work tool steels

    Kim, Hoyoung [Department of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Kang, Jun-Yun, E-mail: [Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Son, Dongmin [Seah Changwon Special Steel, 147 Jeokhyeon-ro, Seongsan-gu, Changwon, Gyeongnam 642-370 (Korea, Republic of); Lee, Tae-Ho [Korea Institute of Materials Science, 797 Changwon-daero, Seongsan-gu, Changwon, Gyeongnam 642-831 (Korea, Republic of); Cho, Kyung-Mox, E-mail: [Department of Materials Science and Engineering, Pusan National University, 2 Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 609-735 (Korea, Republic of)


    This study aimed to present the complete history of carbide evolution in a cold-work tool steel along its full processing route for fabrication and application. A sequence of processes from cast to final hardening heat treatment was conducted on an 8% Cr-steel to reproduce a typical commercial processing route in a small scale. The carbides found at each process step were then identified by electron diffraction with energy dispersive spectroscopy in a scanning or transmission electron microscope. After solidification, MC, M{sub 7}C{sub 3} and M{sub 2}C carbides were identified and the last one dissolved during hot compression at 1180 °C. In a subsequent annealing at 870 °C followed by slow cooling, M{sub 6}C and M{sub 23}C{sub 6} were added, while they were dissolved in the following austenitization at 1030 °C. After the final tempering at 520 °C, fine M{sub 23}C{sub 6} precipitated again, thus the final microstructure was the tempered martensite with MC, M{sub 7}C{sub 3} and M{sub 23}C{sub 6} carbide. The transient M{sub 2}C and M{sub 6}C originated from the segregation of Mo and finally disappeared due to attenuated segregation and the consequent thermodynamic instability. - Highlights: • The full processing route of a cold-work tool steel was simulated in a small scale. • The carbides in the tool steel were identified by chemical–crystallographic analyses. • MC, M{sub 7}C{sub 3}, M{sub 2}C, M{sub 6}C and M{sub 23}C{sub 6} carbides were found during the processing of the steel. • M{sub 2}C and M{sub 6}C finally disappeared due to thermodynamic instability.

  8. Transverse rupture strength of a PM tool steel

    Oscar Olimpio de Araujo Filho


    Full Text Available Powder Metallurgy has been reported as a suitable alternate processing route for the manufacture of tool steels. The advantage of this technique is in being able to obtain a refined and more uniform microstructure that improves properties such high wear resistance and toughness. A molybdenum containing AISI M3:2 tool steel, (trade name Sinter 23, manufactured from spherical gas-atomized powders by hot isostatic pressing followed by hot working was tested in three-point bending tests after various heat treatments. Transverse rupture strength (TRS samples were cut and heat treated at four distinct austenitizing temperatures. Each austenitizing temperature was combined with three tempering temperatures, giving a total of twelve different hardening conditions. Hardness tests were carried out to establish correlations among the effectiveness of heat treatment, the hardness values and the TRS results. At least five parallel samples were tested in each heat treatment condition.

  9. Laser grooving of surface cracks on hot work tool steel

    D. Klobčar


    Full Text Available The paper presents the analysis of laser grooving of 1.2343 tool steel hardened to 46 HRC. The effect of laser power and grooving speed on groove shape (i.e. depth and width, the material removal rate and the purity of produced groove as a measure of groove quality was investigated and analyzed using response surface methodology. Optimal parameters of laser grooving were found, which enables pure grooves suitable for laser welding.

  10. Influence of the Magnetic High-speed Steel Cutting Tool on Cutting Capability


    The high-speed steel cutting tool has advantaged i n modern cutting tool for its preferable synthetical performance, especially, in a pplication of complicated cutting tools. Therefore, the study of the high-speed steel cutting tools that occupied half of cutting tools has become an importa nt way of studying on modern cutting technology. The cutting performance of hi gh speed-steel cutting tools will be improved by magnetization treating method. Microstructure of high-speed steel will be changed as a ...


    Peter Jurči


    Full Text Available Specimens made from Vanadis 6 cold work tool steel were machined, ground, heat processed by standard regime and finally mirror polished. After that, they were layered with CrAgN. The Ag-content in the layers was chosen to 3 wt% and 15 wt% respectively. Microstructural analysis revealed that the addition of 3 wt%Ag did not influence the growth manner of the films but the addition of 15 wt%Ag has made considerable changes in the film growth. The layer with 3 wt%Ag had excellent adhesion on the steel substrate. On the other hand, the addition of 15%Ag had strongly negative impact on the coating adhesion. Similar effect of different Ag addition has been established also to both the hardness and the Young modulus of the films, also. Both films have superior tribological properties against hard material (alumina as well as against soft counterpart (CuSn6 as-cast bronze.


    Peter Jurči


    Full Text Available Specimens made from Vanadis 6 cold work tool steel were machined, ground, heat processed by standard regime and finally mirror polished. After that, they were layered with CrAgN. The Ag-content in the layers was chosen to 3 wt% and 15 wt% respectively. Microstructural analysis revealed that the addition of 3 wt%Ag did not influence the growth manner of the films but the addition of 15 wt%Ag has made considerable changes in the film growth. The layer with 3 wt%Ag had excellent adhesion on the steel substrate. On the other hand, the addition of 15%Ag had strongly negative impact on the coating adhesion. Similar effect of different Ag addition has been established also to both the hardness and the Young modulus of the films, also. Both films have superior tribological properties against hard material (alumina as well as against soft counterpart (CuSn6 as-cast bronze.

  13. Laser hardening processing on tool steel SKD61



    This paper is aimed at overcoming different degree defects of crystalline structure in SKD61 carbide tool steel under quenching in solid phase and liquid phase. The paper studies the micro-structure and properties of laser strengthening SKD61 by using the method of laser hardening on the rein-forcement to improve the wear resistance of SKD61 . The results showed that the laser strengthening meth-od can improve the wear resistance of SKD61 . The study can provide reference for laser hardening metal materials.

  14. Factors influencing the surface quality of polished tool steels

    Rebeggiani, S.; Rosén, B.-G.


    Today’s demands on surface quality of moulds for injection moulding of plastic components involve no/low defect contents and roughness levels in the nm-range for high gloss applications. Material properties as well as operating conditions influence the mould finish, and thus the final surface of moulded products. This paper focuses on how particle content and different polishing strategies influence final surface qualities of moulds. Visual estimations of polished tool steel samples were combined with non-contact 3D-surface texture analysis in order to correlate traditional assessments to more quantitative methods, and to be able to analyse the surfaces at nanometre-level. It was found that steels with a lower proportion of particles, like carbides and oxides, gave rise to smoother polished surfaces. In a comparative study of polishers from different polishing shops, it was found that while different surface preparation strategies can lead to similar final roughness, similar preparation techniques can produce high-quality surfaces from different steel grades. However, the non-contact 3D-surface texture analysis showed that not all smooth polished surfaces have desirable functional topographies for injection moulding of glossy plastic components.

  15. Cutting Forces Analysis in Additive Manufactured AISI H13 Alloy

    Montevecchi, Filippo; Grossi, Niccolò; Takagi, Hisataka; Scippa, Antonio; Sasahara, Hiroyuki; Campatelli, Gianni


    Combining Additive Manufacturing (AM) and traditional machining processes is essential to meet components functional requirements. However significant differences arise in machining AM and wrought parts. Previous works highlighted the increasing of tool wear and worse surface finish. In this paper cutting forces are investigated as an indicator of material machinability. Milling cutting force coefficients are identified using mechanistic approach, comparing AISI-H13 wrought and AM specimen. C...

  16. Tool degradation during sheet metal forming of three stainless steel alloys

    Wadman, Boel; Nielsen, Peter Søe; Wiklund, Daniel


    To evaluate if changes in tool design and tool surface preparation are needed when low-Ni stainless steels are used instead of austenitic stainless steels, the effect on tool degradation in the form of galling was investigated with three different types of stainless steel. The resistance to tool...... degradation was analysed by the strip reduction test, simulating resistance to galling during ironing. It was shown that the surface condition of both the tools and the sheet metal was of importance to the galling resistance. Numerical simulations of the experimental tests were compared with the experimental...



  18. R-Curve Approach to Describe the Fracture Resistance of Tool Steels

    Picas, Ingrid; Casellas, Daniel; Llanes, Luis


    This work addresses the events involved in the fracture of tool steels, aiming to understand the effect of primary carbides, inclusions, and the metallic matrix on their effective fracture toughness and strength. Microstructurally different steels were investigated. It is found that cracks nucleate on carbides or inclusions at stress values lower than the fracture resistance. It is experimentally evidenced that such cracks exhibit an increasing growth resistance as they progressively extend, i.e., R-curve behavior. Ingot cast steels present a rising R-curve, which implies that the effective toughness developed by small cracks is lower than that determined with long artificial cracks. On the other hand, cracks grow steadily in the powder metallurgy tool steel, yielding as a result a flat R-curve. Accordingly, effective toughness for this material is mostly independent of the crack size. Thus, differences in fracture toughness values measured using short and long cracks must be considered when assessing fracture resistance of tool steels, especially when tool performance is controlled by short cracks. Hence, material selection for tools or development of new steel grades should take into consideration R-curve concepts, in order to avoid unexpected tool failures or to optimize microstructural design of tool steels, respectively.

  19. Thermophysical Properties of a Hot-Work Tool-Steel with High Thermal Conductivity

    Kaschnitz, E.; Hofer, P.; Funk, W.


    In the highly productive permanent mold-casting process, the released enthalpy of the solidifying metal has to be transported through the surrounding hot-work tool-steel to the cooling system. For that reason, the thermal conductivity is a key property of the employed tool-steel. Recently, a new type of steel (Rovalma HTCS 130) has been developed and superior thermal properties have been claimed. In this study, measurements of the thermal diffusivity, heat capacity, and thermal expansion as a function of temperature are described for this steel and results of the computed thermal conductivity are reported. There is quite a discrepancy between the specification of the steel supplier and the results of this study; however, an improvement of the thermal conductivity for this type of steel can be confirmed.

  20. Laser surface texturing of tool steel: textured surfaces quality evaluation

    Šugár, Peter; Šugárová, Jana; Frnčík, Martin


    In this experimental investigation the laser surface texturing of tool steel of type 90MnCrV8 has been conducted. The 5-axis highly dynamic laser precision machining centre Lasertec 80 Shape equipped with the nano-second pulsed ytterbium fibre laser and CNC system Siemens 840 D was used. The planar and spherical surfaces first prepared by turning have been textured. The regular array of spherical and ellipsoidal dimples with a different dimensions and different surface density has been created. Laser surface texturing has been realized under different combinations of process parameters: pulse frequency, pulse energy and laser beam scanning speed. The morphological characterization of ablated surfaces has been performed using scanning electron microscopy (SEM) technique. The results show limited possibility of ns pulse fibre laser application to generate different surface structures for tribological modification of metallic materials. These structures were obtained by varying the processing conditions between surface ablation, to surface remelting. In all cases the areas of molten material and re-cast layers were observed on the bottom and walls of the dimples. Beside the influence of laser beam parameters on the machined surface quality during laser machining of regular hemispherical and elipsoidal dimple texture on parabolic and hemispherical surfaces has been studied.

  1. Photoemission Electron Microscopy as a Tool for Studying Steel Grains

    Roese, Peter; Keutner, Christoph; Berges, Ulf; Espeter, Philipp; Westphal, Carsten


    Key properties of steel like stability, weldability, or ability for absorbing deformation energy are defined by their grain structure. The knowledge about their micrometer and submicrometer structure is of particular interest for tailor-cut macroscopic steel properties. We report on photoemission electron microscopy studies which in principle yield a higher magnification than comparable optical techniques. A flat surface without any topographic features was obtained by applying a non-etching preparation procedure. PEEM images showed very tiny phase islands embedded within a steel phase matrix. Furthermore, we developed an analysis procedure for PEEM images for dual-phase steels. As a result, it is possible to identify the individual work functions of different steel phases at the surface.

  2. Photoemission Electron Microscopy as a Tool for Studying Steel Grains

    Roese, Peter; Keutner, Christoph; Berges, Ulf; Espeter, Philipp; Westphal, Carsten


    Key properties of steel like stability, weldability, or ability for absorbing deformation energy are defined by their grain structure. The knowledge about their micrometer and submicrometer structure is of particular interest for tailor-cut macroscopic steel properties. We report on photoemission electron microscopy studies which in principle yield a higher magnification than comparable optical techniques. A flat surface without any topographic features was obtained by applying a non-etching preparation procedure. PEEM images showed very tiny phase islands embedded within a steel phase matrix. Furthermore, we developed an analysis procedure for PEEM images for dual-phase steels. As a result, it is possible to identify the individual work functions of different steel phases at the surface.

  3. Comparison of the secondary hardness effect after tempering of the hot-work tool steels

    J. Mazurkiewicz


    Full Text Available Purpose: of this paper was to examine of the secondary hardness effect after tempering of the developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 in relation to standard hot-work tool steel X40CrMoV5-1.Design/methodology/approach: The investigations steels were made using the specimens made from the experimental steel, for which the working 47CrMoW¬V¬TiCe¬Zr16-26-8 denotation was adopted, similar to the ones used in the ISO Standard on using the standard alloy hot-work tool steel X40CrMoV5-1. Both investigated steels were melted in a vacuum electric furnace. Specimens made from the investigated steels were heat treated with austenitizing in salt bath furnaces for 30 minutes in the temperature range of 970-1180°C with gradation of 30°C. Next, the specimens were tempered twice in the temperature range of 450-660°C for 2 hours.Findings: The secondary hardness effect after tempering from temperature of 540oC in the 47CrMoW¬V¬Ti¬CeZr16-26-8 steel and from temperature of 510°C for the X40CrMoV5-1 steel, which is caused by the carbides M4C3 and M7C3 in the 47CrMoWVTiCeZr16-26-8 steel and M7C3 in the X40CrMoV5-1 steel.Practical implications: The developed complex hot-work tool steel 47CrMoWVTiCeZr16-26-8 can be used to the hot work small-size tools which requires higher strength properties at elevated temperatureOriginality/value: The obtained results show the influence of the chemical compositions on the secondary hardness effect after tempering in the hot-work tool steel. The secondary hardness effect after tempering determined structure and mechanical properties in the this kinds of steels group.

  4. Wear of soft tool materials in sliding contact with zinc coated steel sheet

    Heide, van der E.; Burlat, M.; Bolt, P.J.; Schipper, D.J.


    In order to reduce costs of tooling for press operations, efforts are made to use alternative tool materials like wood or plastic. Friction and wear characteristics in sliding contact with zinc-coated steel sheet could, however, limit the applicability of these tool materials for automotive applicat

  5. Microstructural Quantification of Rapidly Solidified Undercooled D2 Tool Steel

    Valloton, J.; Herlach, D. M.; Henein, H.; Sediako, D.


    Rapid solidification of D2 tool steel is investigated experimentally using electromagnetic levitation (EML) under terrestrial and reduced gravity conditions and impulse atomization (IA), a drop tube type of apparatus. IA produces powders 300 to 1400 μm in size. This allows the investigation of a large range of cooling rates ( 100 to 10,000 K/s) with a single experiment. On the other hand, EML allows direct measurements of the thermal history, including primary and eutectic nucleation undercoolings, for samples 6 to 7 mm in diameter. The final microstructures at room temperature consist of retained supersaturated austenite surrounded by eutectic of austenite and M7C3 carbides. Rapid solidification effectively suppresses the formation of ferrite in IA, while a small amount of ferrite is detected in EML samples. High primary phase undercoolings and high cooling rates tend to refine the microstructure, which results in a better dispersion of the eutectic carbides. Evaluation of the cell spacing in EML and IA samples shows that the scale of the final microstructure is mainly governed by coarsening. Electron backscattered diffraction (EBSD) analysis of IA samples reveals that IA powders are polycrystalline, regardless of the solidification conditions. EBSD on EML samples reveals strong differences between the microstructure of droplets solidified on the ground and in microgravity conditions. While the former ones are polycrystalline with many different grains, the EML sample solidified in microgravity shows a strong texture with few much larger grains having twinning relationships. This indicates that fluid flow has a strong influence on grain refinement in this system.

  6. Heat Treatment of Cr- and Cr-V ledeburitic tool steels

    Peter Jurči


    Full Text Available Cr- and Cr-V ledeburitic cold work tool steels belong to the most important tool materials for large series manufacturing. To enable high production stability, the tools must be heat treated before use. This overview paper brings a comprehensive study on the heat treatment of these materials, starting from the soft annealing and finishing with the tempering. Also, it describes the impact of any step of the heat treatment on the most important structural and mechanical characteristics, like the hardness, the toughness and the wear resistance. The widely used AIS D2- steel (conventionally manufactured and Vanadis 6 (PM are used as examples in most cases.

  7. Fatigue crack Behaviour in a High Strength Tool Steel

    Højerslev, Christian; Carstensen, Jesper V.; Brøndsted, Povl


    value of maximally 80% of the yield strength of the steel. The size of this carbide damage zone increases with increasing load amplitude, and the zone is apparently associated with crack nucleation. On fatigue crack propagation plastic deformation of the matrix occurs in a radius of approximately 4...


    Porankiewicz, B.; P. Iskra; K. Jóźwiak; Tanaka, C.; W. Zborowski


    Wear patterns were analyzed for High Speed Steel (HSS) SKH51 cutting tools after milling wood of four wood species having very different High Temperature Tribochemical Reactions (HTTR), wood density and very low hard mineral contamination (HMC). The experimental results showed that the HTTR can be an important factor influencing acceleration of cutting tool wear.



    The cutting temperature of CBN tools when machining hardened steel was investigated at different cutting regime and cutting tool geometry. An unusual phenomenon that the depth of cut influenced the temperature more significantly than the feed rate was analysed via partial differentiation. A chamfered cutting edge generally raised the cutting temperature and the significance of the temperature increase was associated with the cutting speed.


    B. Porankiewicz


    Full Text Available Wear patterns were analyzed for High Speed Steel (HSS SKH51 cutting tools after milling wood of four wood species having very different High Temperature Tribochemical Reactions (HTTR, wood density and very low hard mineral contamination (HMC. The experimental results showed that the HTTR can be an important factor influencing acceleration of cutting tool wear.

  11. Micromilling of hardened tool steel for mould making applications

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo


    The implementation of replication techniques for mass production of micro components relies on the availability of tooling technologies for manufacturing of tools and moulds. Micromilling is a suitable technique for manufacturing of microstructures characterized by high aspect ratios and complex ...

  12. Acoustic Emission Methodology to Evaluate the Fracture Toughness in Heat Treated AISI D2 Tool Steel

    Mostafavi, Sajad; Fotouhi, Mohamad; Motasemi, Abed; Ahmadi, Mehdi; Sindi, Cevat Teymuri


    In this article, fracture toughness behavior of tool steel was investigated using Acoustic Emission (AE) monitoring. Fracture toughness ( K IC) values of a specific tool steel was determined by applying various approaches based on conventional AE parameters, such as Acoustic Emission Cumulative Count (AECC), Acoustic Emission Energy Rate (AEER), and the combination of mechanical characteristics and AE information called sentry function. The critical fracture toughness values during crack propagation were achieved by means of relationship between the integral of the sentry function and cumulative fracture toughness (KICUM). Specimens were selected from AISI D2 cold-work tool steel and were heat treated at four different tempering conditions (300, 450, 525, and 575 °C). The results achieved through AE approaches were then compared with a methodology proposed by compact specimen testing according to ASTM standard E399. It was concluded that AE information was an efficient method to investigate fracture characteristics.

  13. Characterization of Tool Wear in High-Speed Milling of Hardened Powder Metallurgical Steels

    Fritz Klocke


    Full Text Available In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC and the high speed steel HS 6-5-3 PM (S790 Microclean/64 HRC. The milling tests were performed at effective cutting speeds of 225, 300, and 400 m/min with a four fluted solid carbide ball-end mill (0 = 6, TiAlN coating. It was observed that by means of analytically optimised chipping parameters and increased cutting speed, the tool life can be drastically enhanced. Further, in machining the harder material HS 4-2-4 PM, the tool life is up to three times in regard to the less harder material HS 6-5-3 PM. Thus, it can be assumed that not only the hardness of the material to be machined plays a vital role for the high-speed dry-hard cutting performance, but also the microstructure and thermal characteristics of the investigated powder metallurgical steels in their hardened state.

  14. Tooling solutions for sheet metal forming and punching of lean duplex stainless steel

    Wadman, Boel; Madsen, Erik; Bay, Niels


    .4509 and lean duplex EN1.4162 in a production designed for austenitic stainless steels, such as EN1.4301 and 1.4401. The result is a guideline that summarizes how stainless material properties may affect tool degradation, and suggests tool solutions for reduced production disturbances and tool maintenance cost.......For producers of advanced stainless components the choice of stainless material influences not only the product properties, but also the tooling solution for sheet metal stamping. This work describes how forming and punching tools will be affected when introducing the stainless alloys ferritic EN1...

  15. Analysis of carbides and inclusions in high speed tool steels

    Therkildsen, K.T.; Dahl, K.V.


    The fracture surfaces of fatigued specimens were investigated using scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). The aim was to quantify the distribution of cracked carbides and non-metallic inclusions on the fracturesurfaces as well as on polished cross......-metallic inclusions and the crack initiation. Surprisingly, no differences were found between the carbide size distributions of the micro-clean and conventional grades.Also, the distribution of the fractured carbides was found to be the same regardless of steel type, manufacturing method or location on the specimen....

  16. Tool Steels in Die-Casting Utilization and Increased Mold Life

    Sepanta Naimi


    Full Text Available In die-casting molds, heat-checking is the typical failure mechanism. Optimizing the parameters that decrease this failure venture should be considered when designing and heat treating steels. The quality of die steels and their treatment continue to improve. This research investigated properties of the traditional materials 1.2343 and 1.2344 and the new steels (Dievar and TOOLOX 44 when applied to the die-casting mold specimens, after different experimental cycles. Also microstructures of the mentioned materials were analyzed by scanning electron microscopy (SEM test. Chrome-molybdenum-silicon-vanadium steels have good hardening ability in oil and in air. Therefore, the hot-work steels have considerable toughness and plastic attributes through both regular and higher temperatures. So, it is a good traditional die-casting material. However, another special die steel, such as Dievar, is a particularly developed steel grade; its exclusivity profile is exceptional due to its chemical composition and the use of the latest production techniques. Dievar has good heat-checking and gross-cracking resistance as a result of both high toughness and good hot strength. An additional material, a new prehardened tool steel known as TOOLOX 44, exhibits control of the failure described above by optimizing the parameters of impact toughness that could reduce the heat-checking failures. A variety of heat treatment parameters exist for various reasons because the heat treatment operation is performed by a variety of companies. This issue of the diversity in heat treatments is resolved by TOOLOX 44; this steel is quenched and tempered in delivered state.

  17. Microstructure and Properties of Selective Laser Melted High Hardness Tool Steel

    Feuerhahn, F.; Schulz, A.; Seefeld, T.; Vollertsen, F.

    A secondary hardening tool steel material X110CrMoVAl 8-2 was successfully processed by selective laser melting (SLM), producing defect free samples of high density. The microstructure appeared irregular after SLM, which was attributed to locally different temper states in consequence of the SLM process pattern. By a subsequent heat treatment, a homogeneous microstructure with ultrafine carbide precipitations and a very high resulting hardness of 765 HV were achieved. The hardness came very close to that of the same material processed by spray forming and forging, whilst the SLM microstructure was significantly finer. Therefore this tool steel material was considered as highly promising for SLM manufacturing of tools, e.g. for micro tooling applications.

  18. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    Carvalho, N.J.M.; Huis in 't Veld, A.J.; Hosson, J.T. de


    Titanium-nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test

  19. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    Carvalho, N.J.M.; Huis in ’t Veld, A.J.; Hosson, J.Th. De


    Titanium–nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test techniqu

  20. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    Carvalho, N.J.M.; Huis in 't Veld, A.J.; Hosson, J.T. de


    Titanium-nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test techniqu

  1. Machine Tool Layout: Outlining a Basic Shape on Flat Steel. Fordson Bilingual Demonstration Project.

    Ochsner, Alan

    This vocational instructional module on outlining a basic shape on flat steel is one of eight such modules designed to assist recently arrived Arab students, limited in English proficiency (LEP), in critical instructional areas in a comprehensive high school. Goal stated for this module is for the student enrolled in a machine tool course to…

  2. Microstructure Charaterization of a Hardened and Tempered Tool Steel: from Macro to Nano Scale

    Højerslev, Christian; Somers, Marcel A. J.; Carstensen, Jesper V.


    The microstructure of a conventionally heat treated PM AISI M3:2 tool steel, was characterised by a combination of light optical and electron microscopy, covering the range from micro to nano scale. Dilatometry and X-ray diffractometry were used for an overall macro characterisation of the phases...

  3. Effect of Cutting Parameters on Microhardness in 2 mm Slot Milling Hardened Tool Steel

    Bissacco, Giuliano; Hansen, Hans Nørgaard; De Chiffre, Leonardo


    This paper presents an experimental study on the dependency of surface integrity on cutting parameters in slot milling of hardened tool steel. A series of 2 mm slot milling tests have been performed with different cutting parameters. Microhardness was chosen for evaluation of subsurface integrity...

  4. Problems in repair-welding of duplex-treated tool steels

    T. Muhič


    Full Text Available The present paper addresses problems in laser welding of die-cast tools used for aluminum pressure die-castings and plastic moulds. To extend life cycle of tools various surface improvements are used. These surface improvements significantly reduce weldability of the material. This paper presents development of defects in repair welding of duplex-treated tool steel. The procedure is aimed at reduction of defects by the newly developed repair laser welding techniques. Effects of different repair welding process parameters and techniques are considered. A microstructural analysis is conducted to detect defect formation and reveal the best laser welding method for duplex-treated tools.

  5. The Effect of Grinding and Polishing Procedure of Tool Steels in Sheet Metal Forming

    Lindvall, F.; Bergström, J.; Krakhmalev, P.


    The surface finish of tools in sheet metal forming has a large influence on the performance of the forming tool. Galling, concern of wear in sheet metal forming, is a severe form of adhesive wear where sheet material is transferred on to the tool surface. By polishing the tools to a fine surface...... 40 and Vanadis 6 and up to ten different grinding and polishing treatments were tested against AISI 316 stainless steel. The tests showed that an optimum surface preparation might be found at the transition between abrasive and adhesive wear....




    Full Text Available AISI 304 austenitic stainless steel is a popularly used grade in the various fields of manufacturing because of its high ductility, high durability and excellent corrosion resistance. High work hardening, low heat conductivity and high built up edge (BUE formation made this as difficult-to- machine material. Poor surface quality and rapid tool wear are the common problems encountered while machining it. In the present work, an attempt has been made to explore the influence of machining parameters on the performance measures, surface roughness and flank wear in turning of AISI 304 austenitic stainless steel with a two layer Chemical vapour deposition(CVD coated tool. In order to achieve this, Taguchi approach has been employed. The results revealed that the cutting speed most significantly, influences both surface roughness and flank wear. In addition to this the optimal setting of process parameters and optimal ranges of performance measures are predicted.

  7. Development of Cutting Tool Through Superplastic Boronizing of Duplex Stainless Steel

    Jauhari, Iswadi; Harun, Sunita; Jamlus, Siti Aida; Sabri, Mohd Faizul Mohd


    In this study, a cutting tool is developed from duplex stainless steel (DSS) using the superplastic boronizing technique. The feasibility of the development process is studied, and the cutting performances of the cutting tool are evaluated and compared with commercially available carbide and high-speed steel (HSS) tools. The superplastically boronized (SPB) cutting tool yielded a dense boronized layer of 50.5 µm with a surface hardness of 3956 HV. A coefficient of friction value of 0.62 is obtained, which is lower than 1.02 and 0.8 of the carbide and HSS tools. When tested on an aluminum 6061 surface under dry condition, the SPB cutting tool is also able to produce turning finishing below 0.4 µm, beyond the travel distance of 3000 m, which is comparable to the carbide tool, but produces much better results than HSS tool. Through superplastic boronizing of DSS, it is possible to produce a high-quality metal-based cutting tool that is comparable to the conventional carbide tool.

  8. Development of Cutting Tool Through Superplastic Boronizing of Duplex Stainless Steel

    Jauhari, Iswadi; Harun, Sunita; Jamlus, Siti Aida; Sabri, Mohd Faizul Mohd


    In this study, a cutting tool is developed from duplex stainless steel (DSS) using the superplastic boronizing technique. The feasibility of the development process is studied, and the cutting performances of the cutting tool are evaluated and compared with commercially available carbide and high-speed steel (HSS) tools. The superplastically boronized (SPB) cutting tool yielded a dense boronized layer of 50.5 µm with a surface hardness of 3956 HV. A coefficient of friction value of 0.62 is obtained, which is lower than 1.02 and 0.8 of the carbide and HSS tools. When tested on an aluminum 6061 surface under dry condition, the SPB cutting tool is also able to produce turning finishing below 0.4 µm, beyond the travel distance of 3000 m, which is comparable to the carbide tool, but produces much better results than HSS tool. Through superplastic boronizing of DSS, it is possible to produce a high-quality metal-based cutting tool that is comparable to the conventional carbide tool.

  9. Experimental research on the durability cutting tools for cutting-off steel profiles

    Cristea Alexandru


    Full Text Available The production lines used for manufacturing U-shaped profiles are very complex and they must have high productivity. One of the most important stages of the fabrication process is the cutting-off. This paper presents the experimental research and analysis of the durability of the cutting tools used for cutting-off U-shaped metal steel profiles. The results of this work can be used to predict the durability of the cutting tools.

  10. Effects of machining parameters on tool life and its optimization in turning mild steel with brazed carbide cutting tool

    Dasgupta, S.; Mukherjee, S.


    One of the most significant factors in metal cutting is tool life. In this research work, the effects of machining parameters on tool under wet machining environment were studied. Tool life characteristics of brazed carbide cutting tool machined against mild steel and optimization of machining parameters based on Taguchi design of experiments were examined. The experiments were conducted using three factors, spindle speed, feed rate and depth of cut each having three levels. Nine experiments were performed on a high speed semi-automatic precision central lathe. ANOVA was used to determine the level of importance of the machining parameters on tool life. The optimum machining parameter combination was obtained by the analysis of S/N ratio. A mathematical model based on multiple regression analysis was developed to predict the tool life. Taguchi's orthogonal array analysis revealed the optimal combination of parameters at lower levels of spindle speed, feed rate and depth of cut which are 550 rpm, 0.2 mm/rev and 0.5mm respectively. The Main Effects plot reiterated the same. The variation of tool life with different process parameters has been plotted. Feed rate has the most significant effect on tool life followed by spindle speed and depth of cut.

  11. Machining Duplex Stainless Steel: Comparative Study Regarding End Mill Coated Tools

    Ronny M. Gouveia


    Full Text Available The difficulties in the machining of duplex stainless steel are well known. However, research on this matter is rather limited. Suppliers offer quite different cutting tools for the same raw material, with end mills of two, three or even four knives and a huge number of distinct coatings, some of them under commercial brands, making it difficult to assess the advantages they offer. Furthermore, there is a remarkable difference among the several types of duplex stainless steel available nowadays on the market. The present work intends to assess the machining performance of different tools, analyzing the behavior and wear mechanisms with two different cutting lengths, keeping constant the machining trajectory. Some other parameters were also kept constant, such as cutting speed, depth of cut and cutting width, as well as feed per tooth. The machining process was carried out under lubricated conditions, using an emulsion of 5% oil in water. Tools provided with a different number of teeth and surface coatings were tested, analyzing the wear behavior of each cutting length using scanning electron microscopy, trying to identify wear performance and how each coating contributes to increased tool life. The surfaces produced were also analyzed by means of profilometry measurements, correlating tool wear and part surface roughness. This comparative study allows determining the advantages of different tools relative to others, based on coatings and tool geometry.

  12. Determining Ms temperature on a AISI D2 cold work tool steel using magnetic Barkhausen noise

    Huallpa, Edgar Apaza, E-mail: [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil); Sánchez, J. Capó, E-mail: [Departamento de Física, Facultad de Ciencias Naturales, Universidad de Oriente, Av. Patricio Lumumba s/n 90500, Santiago de Cuba (Cuba); Padovese, L.R., E-mail: [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil); Goldenstein, Hélio, E-mail: [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil)


    Highlights: ► MBN was used to follow the martensite transformation in a tool steel. ► The results were compared with resistivity experiments. ► The Ms was estimated with Andrews equation coupled to ThermoCalc calculations. The experimental results showed good agreement. -- Abstract: The use of Magnetic Barkhausen Noise (MBN) as a experimental method for measuring the martensite start (Ms) temperature was explored, using as model system a cold-work tool steel (AISI D2) austenitized at a very high temperature (1473 K), so as to transform in sub-zero temperatures. The progress of the transformation was also followed with electrical resistance measurements, optical microscopy and scanning electron microscopy. Both MBN and resistivity measurements showed a change near 230 K during cooling, corresponding to the Ms temperature, as compared with 245 K, estimated with Andrews empirical equation applied to the austenite composition calculated using ThermoCalc.

  13. Effect of Initial Hardness on Interfacial Features in Underwater Explosive Welding of Tool Steel SKS3

    Sun, Wei; Li, Xiaojie; Yan, Honghao; Hokamoto, Kazuyuki


    This paper aims at investigating effects of initial hardness on interfacial features for identical compositional materials under identical welding conditions. Two underwater explosive welding experiments on tool steel SKS3 with copper foil were carried out: one as-received and the other heat-treated. The welding process was simulated using the commercially available software package LS-DYNA. Numerical simulation gave deformation of the flyer/base plate and pressure distribution during the welding process. Microstructure and hardness at interface of the welded metals were evaluated. The results indicate that decreasing impact energy is accompanied by a shift from wavy to linear interface. Moreover, a comparison of the two experiments allows the conclusion that high initial hardness results in a decrease of wavelength and amplitude under identical welding conditions. Hardness profiles of as-received tool steel-copper welding reveal the hardening effect of impact in the vicinity of the interface. However, of interest is that a decrease in hardness was seen in the case of heat-treated martensitic tool steel with copper, fundamentally differing from previous explosive welding research; phase transition is proposed to discuss the relation between the effects of impact and heat, and those of work hardening and softening.

  14. On The Enhancement of Wear Resistance of Hardened Carbon Tool Steel (AISI 1095) With Cryogenic Quenching

    V.Soundararajan; N.Alagurmurthi; K.Palaniradja


    Many experimental investigations reveal that it is very difficult to have a completely martensitic structure by any hardening process. Some amount of austenite is generally present in the hardened steel. This austenite existing along with martensite is normally referred as the retained austenite. The presence of retained austenite greatly reduces the mechanical properties and such steels do not develop maximum hardness even after cooling at rates higher than the critical cooling rates.Strength can be improved in hardened steels containing retained austenite by a process known as cryogenic quenching.Untransformed austenite is converted into martensite by this treatment. This conversion of retained austenite into martensite results in increased hardness, wear resistance and dimensional stability of steel. Wear can be defined as the progressive loss of materials from the operating surface of a body occurring as a result of relative motion at the surface. Hardness, load,speed, surface roughness, temperature are the major factors which influences wear. Many studies on wear indicate that increasing hardness decreases the wear of a material. With this in mind, to study the surface wear on a surface modified(Cryogenic treated) steel material an attempt has been made in this paper. In this study as a Part -I Hardening was carried out on carbon tool steel (AISI 1095) of different L/D ratio with conventional quenchants like purified water, aqueous solution and Hot mineral oil. As a Part -Ⅱ hardening was followed by quenching was carried out as said in Part- I and the hardened specimen were quenched in liquid Nitrogen which is at sub zero condition. The specimens were tested for its microstructure, hardness and wear loss. The results were compared and analyzed. The alloying elements increases the content of retained austenite hence the material used was AISI1095 (Carbon 0.9%, Si 0.2%, Mn0.4% and the rest Iron)

  15. Characterization and wear performance of boride phases over tool steel substrates

    Edgar E Vera Cárdenas


    Full Text Available This research work was conducted to characterize boride phases, obtained from the powder-pack process, on AISI H13 and D2 steel substrates, and investigate their tribological behavior. The boriding was developed at a temperature of 1273 K with an exposure time of 8 h. X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were conducted on the borided material to characterize the presence of the FeB, Fe2B, and CrB phases and the distribution of heavy elements on the surface of the substrates. The adherence of the boride layers was evaluated, in a qualitative form, through the Daimler-Benz Rockwell-C indentation technique. Sliding wear tests were then performed using a reciprocating wear test machine. All tests were conducted in dry conditions at room temperature. A frequency of 10 Hz and 15-mm sliding distance were used. The applied Hertzian pressure was 2.01 GPa. Scanning electron microscopy was used to observe and analyze the wear mechanisms. Additionally, the variation of the friction coefficient versus the number of cycles was obtained. Experimental results showed that the characteristic wear mechanism for the borided surface was plastic deformation and mild abrasive wear; for unborided substrates, cracking and spalling were observed.

  16. Cutting Temperature and Tool Wear of Hard Turning Hardened Bearing Steel


    A study was undertaken to investigate the performan ce of PCBN tool in the finish turning GCr15 bearing steel with different hardness between 30~64 HRC. The natural thermocouple was used to measure the cutting tem p erature, tool life and cutting temperature were investigated and compared. The m aterial can be heated by this instrument which using low voltage and high elec trical current, while PCBN can't be heated by electrifying directly, so the ke ntanium layer coating over the PCBN is heated, so th...

  17. Crack propagation in X38CrMoV5 (AISI H11) tool steel

    Shah, Masood; Mabru, Catherine; Boher, Christine; Le Roux, Sabine; Rezaï-Aria, Farhad


    A method is proposed for the evaluation of surface fatigue damage of hot forming tools that undergo severe thermo mechanical loading. Fatigue crack propagation in a hot work tool steel X38CrMoV5-47HRC is investigated using single-edge cracked tension specimens (SET). The effect of thickness (ranging from 2,5mm to 0.10mm) and R values is investigated. Numerical simulation is performed by ABAQUS® Standard to evaluate J integral and stress intensity factor KI. The Paris curves are established. S...

  18. Toughess and Bending Resistance of Nitrided Tool Steels%工具钢渗氮后的韧性和抗弯性能

    Jan.; Vatavuk; Lauralice; C.; F.; Canale; Sérgio; G.; Cardoso; George; E.; Totten


    Recently a detailed study was performed with nitrided and non nitrided tool steels including AISI H13,AISI D2,K 340,AISI D6 and AISI M2.Different nitriding processes including:gas,salt bath and also salt bath plus diffusion heat treatment were performed and compared.Performance of the tool steels was evaluated using bending tests and impact tests.Microstructure characterization was performed using optical microscopy.The nitriding treatment prompts a reduction in the rupture modulus and absorbed energy in un-notched impact specimen.The lower mechanical properties were obtained in the gas nitrided samples due to the deeper diffusion layers achieved by these thermo-chemical processes.The reduction in the white layer thickness by the diffusion treatment in the salt nitrided samples,have no effect in the mechanical response of the tested samples.The results show that the impact absorption energy tests show the worst effect in terms of reduction due to the nitriding processes.%最近,对经渗氮和未渗氮的AISI H13、AISI D2、K340、AISI D6和AISI M2等工具钢进行了详细的研究.采用了不同的渗氮工艺,包括气体渗氮、液体渗氮以及液体渗氮+扩散处理,并进行了对比.对这些钢进行了弯曲试验和冲击试验,以评定其性能.用光学金相技术表征其显微组织.渗氮处理会降低无缺口冲击试样的断裂模数和冲击吸收功.由于扩散层较深,导致经气体渗氮处理的试样的力学性能下降.通过扩散处理来减薄液体渗氮试样的白亮层厚度并不会影响试样的力学性能.试验结果表明,渗氮对工具钢的最有害的影响是使冲击试验的冲击吸收功降低.

  19. Thixoforming of Steel: New Tools Conception to Analyse Thermal Exchanges and Strain Rate Effects

    Cezard, P.; Bigot, R.; Becker, E.; Mathieu, S.; Pierret, J. C.; Rassili, A.


    Through different papers, authors shown that the influence of thermal exchanges was a first order parameter on the semi-solid steel behaviour, and certainly for every semi-solid metallic materials. These thermal exchanges hide other parameters effect like, for example, the strain rate influence. This paper tries to determine the influence of these two parameters by using a new extrusion device on a hydraulic press. This new tools conception annihilated the influence of the decrease of the punch speed before stopping and permitted to have a constant speed during the experiment. This work also deals with the homogeneous flow during thixoforming of steel and shows the importance to couple initial temperature of the slug with punch speed. This paper presents different conditions which permitted to have a homogeneous flow by keeping a low load.

  20. Numerical modelling of tools steel hardening. A thermal phenomena and phase transformations

    T. Domański


    Full Text Available This paper the model hardening of tool steel takes into considerations of thermal phenomena and phase transformations in the solid state are presented. In the modelling of thermal phenomena the heat equations transfer has been solved by Finite Elements Method. The graph of continuous heating (CHT and continuous cooling (CCT considered steel are used in the model of phase transformations. Phase altered fractions during the continuous heating austenite and continuous cooling pearlite or bainite are marked in the model by formula Johnson-Mehl and Avrami. For rate of heating >100 K/s the modified equation Koistinen and Marburger is used. Modified equation Koistinen and Marburger identify the forming fraction of martensite.

  1. Tool Wear Analysis due to Machining In Super Austenitic Stainless Steel

    Polishetty Ashwin


    Full Text Available This paper presents tool wear study when a machinability test was applied using milling on Super Austenitic Stainless Steel AL6XN alloy. Eight milling trials were performed under two cutting speeds, 100 m/min and 150 m/min, combined with two feed rates at 0.1mm/tooth and 0.15 mm/tooth and two depth of cuts at 2 mm and 3 mm. An Alicona 3D optical surface profilometer was used to scan cutting inserts flank and rake face areas for wear. Readings such as maximum and minimum deviations were extracted and used to analyse the outcomes. Results showed various types of wear were generated on the tool rake and flank faces. The common formed wear was the crater wear. The formation of the build-up edge was observed on the rake face of the cutting tool.

  2. Surface characteristics analysis of dry EDMed AISI D2 steel using modified tool design

    Pragadish, N.; Kumar, M. Pradeep [Anna University, Chennai (China)


    A modified tool design is proposed which helps in drilling holes without any central core, and also enables the effective removal of the debris particles. Experiments were conducted on AISI D2 Steel using copper electrode as tool in both conventional EDM and dry EDM processes and the performance of both processes is compared. Experiments were designed using Taguchi's L27 orthogonal array. Discharge current (I), gap voltage (V), pulse on time (T{sub ON}), gas pressure (P) and tool rotational speed (N) were chosen as the various input parameters, and their effect on the material removal rate (MRR), surface roughness (SR), surface morphology, microstructure and elemental composition of the machined surface is analyzed. The experimental results show better surface characteristics in the surface machined under dry EDM process.

  3. An ALMA Survey of DCN/H13CN and DCO+/H13CO+ in Protoplanetary Disks

    Huang, Jane; Öberg, Karin I.; Qi, Chunhua; Aikawa, Yuri; Andrews, Sean M.; Furuya, Kenji; Guzmán, Viviana V.; Loomis, Ryan A.; van Dishoeck, Ewine F.; Wilner, David J.


    The deuterium enrichment of molecules is sensitive to their formation environment. Constraining patterns of deuterium chemistry in protoplanetary disks is therefore useful for probing how material is inherited or reprocessed throughout the stages of star and planet formation. We present ALMA observations at ∼0.″6 resolution of DCO+, H13CO+, DCN, and H13CN in the full disks around T Tauri stars AS 209 and IM Lup, in the transition disks around T Tauri stars V4046 Sgr and LkCa 15, and in the full disks around Herbig Ae stars MWC 480 and HD 163296. We also present ALMA observations of HCN in the IM Lup disk. DCN, DCO+, and H13CO+ are detected in all disks, and H13CN in all but the IM Lup disk. We find efficient deuterium fractionation for the sample, with estimates of disk-averaged DCO+/HCO+ and DCN/HCN abundance ratios ranging from ∼0.02–0.06 and ∼0.005–0.08, respectively, which is comparable to values reported for other interstellar environments. The relative distributions of DCN and DCO+ vary between disks, suggesting that multiple formation pathways may be needed to explain the diverse emission morphologies. In addition, gaps and rings observed in both H13CO+ and DCO+ emission provide new evidence that DCO+ bears a complex relationship with the location of the midplane CO snowline.

  4. Multi-Parameter Analysis of Surface Finish in Electro-Discharge Machining of Tool Steels

    Cornelia Victoria Anghel


    Full Text Available The paper presents a multi- parameter analysis of surface finish imparted to tool-steel plates by electro-discharge machining (EDM is presented. The interrelationship between surface texture parameters and process parameters is emphasized. An increased number of parameters is studied including amplitude, spacing, hybrid and fractal parameters,, as well. The correlation of these parameters with the machining conditions is investigated. Observed characteristics become more pronounced, when intensifying machining conditions. Close correlation exists between certain surface finish parameters and EDM input variables and single and multiple statistical regression models are developed.

  5. Characterisation of Wear Resistant Boride Layers on a Tool Steel by Activity Controlled Pack Boronising

    Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin; Somers, Marcel A. J.


    The present work addresses the production and characterisation of iron boride layers by pack boronising of a Vanadis 6 tool steel. The boride layers were produced at 900°C for 2h using different pack compositions in order to obtain a single-phase boride layer. The layers were characterized...... by electron microscopy, glow discharge optical emission spectroscopy, X-ray diffraction, Vickers hardness tests and wear testing with a pin-on-disc tribometer. It was found that the type of boride phases (FeB and/or Fe2B) present in the treated layer can be controlled by changing the boron activity...

  6. Effect of TiC addition on surface oxidation behavior of SKD11 tool steel composites

    Cho, Seungchan; Jo, Ilguk; Kim, Heebong; Kwon, Hyuk-Tae; Lee, Sang-Kwan; Lee, Sang-Bok


    Titanium carbide (TiC) reinforced tool steel matrix composites were successfully fabricated by a liquid pressing infiltration process and research was subsequently conducted to investigate the composites' oxidation resistance. The mass gain of the tested TiC-SKD11 composite held at 700 °C for 50 h in an air environment decreased by about 60%, versus that of the SKD11, which indicates improved oxidation resistance. Improved oxidation resistance of the TiC-SKD11 composite originates from uniformly reinforced TiC, with a phase transition to thermodynamically stable, volume-expanded TiO2.


    V. N. Fedulov


    Full Text Available The influence of complexly experimental tool steels: C (0,4–0,50%, Si (0,6–1,2%, Mn (0,17–0,8%, Cr (0,8–3%, W (0,9– 4%, Mo (0,01–3.5% and V (0,28–1,8% on their ability to hardening due to only high-temperature tempering after induction melting, casting in the ceramic mold and air cooling (without deformation and after the various modes of complete heat treatment cycle

  8. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    Carvalho, N. J. M.; Huis in ’t Veld, A.J.; Hosson, J.Th. De


    Titanium–nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test technique (modified pin-on-ring test) to obtain some clarifications of the mechanism of interfacial failure. Tests were run using PVD-coated rings finished by polishing or grinding to produce different sur...

  9. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    Carvalho, N.J.M.; Huis in ’t Veld, A.J.; Hosson, J.Th. De


    Titanium–nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test technique (modified pin-on-ring test) to obtain some clarifications of the mechanism of interfacial failure. Tests were run using PVD-coated rings finished by polishing or grinding to produce different sur...

  10. Soundness of spray formed disc shape tools of hot-work steels

    Yang, Y.; Hannula, S.P


    This paper presents metallurgical factors causing porosity in the spray formed die inserts and the corresponding solutions. High quality die inserts can be produced by spray forming if a good control of deposition parameters and the sprayed material is assured. Mechanism of the pore formation is discussed. Deoxidation of the melt at tapping for porosity reduction is found to be very difficult because it causes great variation in viscosity of the melt so that the process is difficult to control. Often the tundish nozzle is also blocked or frozen. Modification of the steel composition is found to be an effective method to improve the soundness of the deposition. Effects of different alloying elements on the soundness of the deposition are discussed. Especially influential on improving the soundness is the increased alloying of high temperature carbide-forming elements such as vanadium. A new series of hot-work steels is developed for spray forming high quality tools, which have not only improved soundness, but also longer lifetimes than the conventional hot-work steels.

  11. Development of a robust modeling tool for radiation-induced segregation in austenitic stainless steels

    Yang, Ying [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Field, Kevin G [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Allen, Todd R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Busby, Jeremy T [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)


    Irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steels in Light Water Reactor (LWR) components has been linked to changes in grain boundary composition due to irradiation induced segregation (RIS). This work developed a robust RIS modeling tool to account for thermodynamics and kinetics of the atom and defect transportation under combined thermal and radiation conditions. The diffusion flux equations were based on the Perks model formulated through the linear theory of the thermodynamics of irreversible processes. Both cross and non-cross phenomenological diffusion coefficients in the flux equations were considered and correlated to tracer diffusion coefficients through Manning’s relation. The preferential atomvacancy coupling was described by the mobility model, whereas the preferential atom-interstitial coupling was described by the interstitial binding model. The composition dependence of the thermodynamic factor was modeled using the CALPHAD approach. Detailed analysis on the diffusion fluxes near and at grain boundaries of irradiated austenitic stainless steels suggested the dominant diffusion mechanism for chromium and iron is via vacancy, while that for nickel can swing from the vacancy to the interstitial dominant mechanism. The diffusion flux in the vicinity of a grain boundary was found to be greatly influenced by the composition gradient formed from the transient state, leading to the oscillatory behavior of alloy compositions in this region. This work confirms that both vacancy and interstitial diffusion, and segregation itself, have important roles in determining the microchemistry of Fe, Cr, and Ni at irradiated grain boundaries in austenitic stainless steels.

  12. Feasibility of surface-coated friction stir welding tools to join AISI 304 grade austenitic stainless steel



    An attempt is made to develop the tools that are capable enough to withstand the shear, impact and thermal forces that occur during friction stir welding of stainless steels. The atmospheric plasma spray and plasma transferred arc hardfacing processes are employed to deposit refractory ceramic based composite coatings on the Inconel 738 alloy. Five different combinations of self-fluxing alloy powder and 60% ceramic rein-forcement particulate mixtures are used for coating. The best friction stir welding tool selected based on tool wear analysis is used to fabricate the austenitic stainless steel joints.

  13. Statistical analysis of the V-tool bending process parameters in the bending of HC260Y steel

    J. Cumin


    Full Text Available This paper presents statistical analysis of the parameters in the V-tool bending process of the HC260Y steel. Assessment of the mathematical model and analysis of variance (ANOVA were performed within the design of experiments. The hydraulic testing machine Amsler and the developed V-tool were used in the experiments.

  14. Crystalline gamma-Al2O3 physical vapour deposition-coating for steel thixoforging tools.

    Bobzin, K; Hirt, G; Bagcivan, N; Khizhnyakova, L; Ewering, M


    The process of thixoforming, which has been part of many researches during the last decades, combines the advantages of forging and casting for the shaping of metallic components. But due to the high temperatures of semi-solid steel alloys high demands on the tools are requested. To resists the thermal and mechanical loads (wear, friction, thermal and thermomechanical fatigue) protecting thin films are necessary. In this regard crystalline gamma-Al2O3 deposited via Physical Vapour Deposition (PVD) is a promising candidate: It exhibits high thermal stability, high oxidation resistance and high hot hardness. In the present work the application of a (Ti, Al)N/gamma-Al2O3 coating deposited by means of Magnetron Sputter Ion Plating in an industrial coating unit is presented. The coating was analysed by means of Rockwell test, nanoindentation, and Scanning Electron Microscopy (SEM). The coated tool was tested in thixoforging experiments with steel grade X210CrW12 (AlSI D6). The surface of the coated dies was examined with Scanning Electron Microscope (SEM) after 22, 42, 90 and 170 forging cycles.

  15. Surface Roughness Prediction Model in Machining of Carbon Steel by PVD Coated Cutting Tools

    Yusuf Sahin


    Full Text Available The surface roughness model in the turning of AISI 1040 carbon steel was developed in terms of cutting speed, feed rate and depth of cut using response surface methodology. Machining tests were carried out using PVD-coated tools under different cutting conditions. The surface roughness equations of cutting tools when machining the carbon steels were achieved by using the experimental data. The results are presented in terms of mean values and confidence levels. The established equation shows that the feed rate was found to be a main influencing factor on the surface roughness. It increased with increasing the feed rate, but decreased with increasing the cutting speed and the depth of cut, respectively. The variance analysis for the second-order model shows that the interaction terms and the square terms were statically insignificant. However, it could be seen that the first-order effect of feed rate was significant while cutting speed and depth of cut was insignificant. The predicted surface roughness of the samples was found to lie close to that of the experimentally observed ones with 95% confident intervals.

  16. Static and Dynamic Performance Improvement of Conventional Computer Numerical Control Machine Tool Bed with Hybrid Welded Steel

    S. S. Abuthakeer


    Full Text Available Problem statement: The advancements in machine tools to maximize the production by increasing spindle speeds have caused vibration in machine tools. The two functional requirements of machine tool bed for machine tools are high structural stiffness and high damping, which cannot be satisfied simultaneously if conventional metallic materials such as cast iron are employed. Hence there is a need to replace cast iron with alternate materials. Approach: The objective of this study is to improve the stiffness, natural frequency and damping capability of machine tool bed using a composite material containing welded steel and polymer concrete. Welded steel material has high stiffness but low damping and polymer concrete has high damping but low stiffness. So in this study, a machine tool bed made of sandwich structures of welded steel and polymer concrete is designed and manufactured. Modal and static analyses were conducted numerically and experimentally to determine the modal frequencies, damping ratio, deformation and strain. Results: The results at first mode showed that the natural frequency improved by 24.7% and damping ratio was 2.7 times higher than cast iron. The comparison of strain and deformation also showed significant improvement. Conclusion: This study proposed a hybrid welded steel bed as a replacement for cast iron as a machine tool bed material and the results showed that the static and dynamic characteristics were superior to cast iron.

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

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


    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.

  18. Influence of Workpiece Material on Tool Wear Performance and Tribofilm Formation in Machining Hardened Steel

    Junfeng Yuan


    Full Text Available In addition to the bulk properties of a workpiece material, characteristics of the tribofilms formed as a result of workpiece material mass transfer to the friction surface play a significant role in friction control. This is especially true in cutting of hardened materials, where it is very difficult to use liquid based lubricants. To better understand wear performance and the formation of beneficial tribofilms, this study presents an assessment of uncoated mixed alumina ceramic tools (Al2O3+TiC in the turning of two grades of steel, AISI T1 and AISI D2. Both workpiece materials were hardened to 59 HRC then machined under identical cutting conditions. Comprehensive characterization of the resulting wear patterns and the tribofilms formed at the tool/workpiece interface were made using X-ray Photoelectron Spectroscopy and Scanning Electron Microscopy. Metallographic studies on the workpiece material were performed before the machining process and the surface integrity of the machined part was investigated after machining. Tool life was 23% higher when turning D2 than T1. This improvement in cutting tool life and wear behaviour was attributed to a difference in: (1 tribofilm generation on the friction surface and (2 the amount and distribution of carbide phases in the workpiece materials. The results show that wear performance depends both on properties of the workpiece material and characteristics of the tribofilms formed on the friction surface.

  19. Experimental investigation of cutting tool performance in high speed cutting of hardened X210 Cr12 cold-work tool steel (62 HRC)

    Aslan, E


    This study explored the performance and wear behaviour of different cutting tools in end milling of X210 Cr12 cold-work tool steel hardened to 62 HRC. The purpose of the experiments reported in this paper is to investigate the wear of TiCN coated tungsten carbide, TiCN + TiAlN coated tungsten carbide, TiAlN coated cermet, mixed ceramic with Al{sub 2}O{sub 3} + TiCN and cubic boron nitride (CBN) tools. Tool performance evaluation was based on the surface finish and tool flank wear. Tool flank wear was studied carefully through JSM 5600 (30 kW) scanning electron microscope. Surface roughness values were measured by Mitutoyo Metusurf 310 equipment. CBN tool exhibited the best cutting performance in terms of both flank wear and surface finish. The highest volume of metal removal was obtained with CBN tool.

  20. Acetylene Flow Rate as a Crucial Parameter of Vacuum Carburizing Process of Modern Tool Steels

    Rokicki P.


    Full Text Available Carburizing is one of the most popular and wide used thermo-chemical treatment methods of surface modification of tool steels. It is a process based on carbon diffusive enrichment of the surface material and is applied for elements that are supposed to present higher hardness and wear resistance sustaining core ductility. Typical elements submitted to carburizing process are gears, shafts, pins and bearing elements. In the last years, more and more popular, especially in highly advanced treatment procedures used in the aerospace industry is vacuum carburizing. It is a process based on chemical treatment of the surface in lower pressure, providing much higher uniformity of carburized layer, lower process cost and much lesser negative impact on environment to compare with conventional carburizing methods, as for example gas carburizing in Endo atmosphere. Unfortunately, aerospace industry requires much more detailed description of the phenomena linked to this process method and the literature background shows lack of tests that could confirm fulfilment of all needed requirements and to understand the process itself in much deeper meaning. In the presented paper, authors focused their research on acetylene flow impact on carburized layer characteristic. This is one of the most crucial parameters concerning homogeneity and uniformity of carburized layer properties. That is why, specific process methodology have been planned based on different acetylene flow values, and the surface layer of the steel gears have been investigated in meaning to impact on any possible change in potential properties of the final product.

  1. Numerical predicting of the structure and stresses state in hardened element made of tool steel

    A. Bokota


    Full Text Available The paper presents numerical model of thcrmal phcnomcna, phasc transformation and mcchanical phcnomcna associated with hardeningof carbon tool steel. Model for evaluation or fractions OF phases and their kinetics bascd on continuous heating diagram (CHT andcontinuous cooling diagram (CCT. The stresses generated during hardening were assumed to rcsult from ~hermal load. stntcturaI plasticdeformations and transformation plasricity. Thc hardened material was assumed to be elastic-plastic, and in ordcr to mark plastic strains the non-isothermal plastic law of flow with the isotropic hardening and condition plasticity of Huber-Misses were used. TherrnophysicaI values of mechanical phenomena dependent on bo~hth e phase composition and temperature. In the numerical example thc simulated estimation of the phasc Fraction and strcss distributions in the hardened axisimmetrical elemcnt was performed.

  2. The development and production of thermo-mechanically forged tool steel spur gears

    Bamberger, E. N.


    A development program to establish the feasibility and applicability of high energy rate forging procedures to tool steel spur gears was performed. Included in the study were relatively standard forging procedures as well as a thermo-mechanical process termed ausforming. The subject gear configuration utilized was essentially a standard spur gear having 28 teeth, a pitch diameter of 3.5 inches and a diametral pitch of 8. Initially it had been planned to use a high contact ratio gear design, however, a comprehensive evaluation indicated that severe forging problems would be encountered as a result of the extremely small teeth required by this type of design. The forging studies were successful in achieving gear blanks having integrally formed teeth using both standard and thermo-mechanical forging procedures.

  3. Induction hardening of tool steel for heavily loaded aircraft engine components

    Rokicki P.


    Full Text Available Induction hardening is an innovative process allowing modification of the materials surface with more effective, cheaper and more reproducible way to compare with conventional hardening methods used in the aerospace industry. Unfortunately, high requirements and strict regulation concerning this branch of the industry force deep research allowing to obtain results that would be used for numerical modelling of the process. Only by this way one is able to start the industrial application of the process. The main scope of presented paper are results concerning investigation of microstructure evolution of tool steel after single-frequency induction hardening process. The specimens that aim in representing final industrial products (as heavily loaded gears, were heat- -treated with induction method and subjected to metallographic preparation, after which complex microstructure investigation was performed. The results obtained within the research will be a basis for numerical modelling of the process of induction hardening with potential to be introduced for the aviation industrial components.

  4. The Influence of Method of Carburizing and Nitrocarburizing on the Microstructure and Properties of Tool Steels

    Tomasz Babul; Natalia Kucharieva; Aleksander Nakonieczny; Jan Senatorski


    The paper presents the results of wear and metallography tests of tool steel grades: ASTM A681, Chl2M and Ch12FS per GOST, AMS 6437E i BS X46Cr13, all surface hardened by the Carbo process (carburizing) and by the NiCar process (nitrocarburizing). The thermo-chemical treatment was conducted in powder pack for a duration of 6 h (carburizing)and for 4 h in the case of nitrocarburizing. Factors investigated were: morphology, depth and microhardness of the cases obtained, their microstructure, as well as phase composition. Wear tests were conducted by the three cylinder-cone method.Wear velocity was 0.58 m/s, unit load was 50 MPa and 400Mpa, wear path was 3470 m. Oil SAE30 was applied at the rate of 30 drops per minute.


    D. M. Kukui


    Full Text Available The technological aspects of processing and remelting of dispersed metal scrap, generated during polishing and grinding of tools made from high speed steel and carbide and lump scrap for the manufacture of drilling equipment and mining equipment are investigated.

  6. Influence of Cutting Parameters on Chatter and Tool Wear During End Milling of Stainless Steel Conducted on VMC



    Full Text Available Stainless steels are a group of difficult to machine work materials. The difficulty in machining stainless steels is manifested in high contact length and stresses, formation of serrated chips and development of chatter resulting in high tool wear rates and poor machined surface finish. The paper focuses on the performance of TiN coated-carbide inserts in machining stainless steel specimens in end milling operation performed on vertical machining centre (VMC. The performance of the tool is evaluated from the point of view of its wear intensity, mechanism of failure and generation and effect of chatter on tool wear and vice versa. The investigations were aimed at determining the effect of cutting parameters, specifically cutting speed, feed and depth of cut, on chatter amplitude, tool wear rate, mechanism of tool wear and using these data and machined surface roughness values from previous work to come up with recommended values of cutting parameters for semi-finish and finish end milling operation of stainless steel work materials. For recording vibration signals a dual channel portable signal analyzers was used and the signals were analyzed using Pulse Multi-analyzer version 4.2 software. Tool wear was measured using an optical microscope with digital readout capabilities along 3 axes. The tool wear mechanisms were studied under a scanning electron microscope (SEM. Results of the investigation show that acceleration amplitudes generally increase with cutting speed and the magnitude of tool flank wears. It has been also found that an increase in feed and depth of cut leads to higher acceleration amplitudes. The most common wear mechanisms observed during machining of stainless steel are attrition, micro and macro chipping of the tool at lower cutting speeds, and diffusion and mechanical failures due to intensive chatter at higher speeds. It has been also established that stable cutting speeds with relatively low tool wear intensity and

  7. The toughness module of the PERFECT platform: A predictive tool for the fracture toughness of RPV steels

    Bugat, S., E-mail: stephane.bugat@edf.f [EDF Research and Development Division, Les Renardieres Site, Route des Renardieres, F77818 MORET-SUR-LOING Cedex (France); El Gharib, J., E-mail: joumana.el-gharib@edf.f [EDF Research and Development Division, Clamart Site, 1 avenue du General de Gaulle, F92141 CLAMART Cedex (France); Proix, J.-M., E-mail: jean-michel.proix@edf.f [EDF Research and Development Division, Clamart Site, 1 avenue du General de Gaulle, F92141 CLAMART Cedex (France); Zeghadi, A., E-mail: asmahana.zeghadi@edf.f [EDF Research and Development Division, Les Renardieres Site, Route des Renardieres, F77818 MORET-SUR-LOING Cedex (France)


    The PERFECT project of the 6th Framework Program aims at developing a predictive tool for irradiation effects on Reactor Pressure Vessel steels. In this work, we focuse on the mechanical part of the numerical platform, the Toughness Module. Its main objective is to predict the probability of failure of the considered RPV steel, using more or less complex approaches. Six submodules are integrated in the Toughness Module. Three of them allow to estimate the macroscopic stress-strain curve of the material and the three others allow to predict the toughness drop of the material due to irradiation.

  8. Measurement of surface roughness and flank wear on hard martensitic stainless steel by CBN and PCBN cutting tools

    S. Thamizhmanii


    Full Text Available Purpose: The experiments with different operating parameters using CBN and PCBN tools on hard AISI 440 C material were investigated in this paper.Design/methodology/approach: In this research AISI 440 C stainless was used under hard condition. The cutting tools are having three cutting edges and each edge repeated for 5 times. The test conducted by each cutting edge was termed as trail 1, 2, 3, 4 & 5. The length of cutting was 150 mm and each trail. The surface roughness and flank wear, crater wear and BUE were measured by SEM.Findings: The surface roughness was low by CBN at high turning cutting speed and the flank wear was high. The surface roughness was high by PCBN tool than CBN tool and flank wear recorded was low for PCBN tool than CBN tool. The chips produced were saw tooth in all operating parameters. The CBN tool was unable to withstand heat at cutting zone and hence more flank wear occurred. The PCBN tool sustained the temperature and less tool wear occurred. More crater wear formed on PCBN tools where as CBN tool produced less crater wear. The formation of crater wear on the rake face was due to rough surface of the saw tooth chips.Practical implications: The investigation results will provide useful information to applying CBN and PCBN cutting tools in hard turning stainless steels.Originality/value: Hard turning is a latest technology and possible to turn all hard materials. The hard turning produce net shaped products and reduces machining time, low cost per products, etc. The difficult to cut materials like stainless steels was turned by super hard cutting tools like CBN and PCBN to achieve good surface roughness, dimensional control and reduced tool wear.

  9. Acoustic Emission Detection of Macro-Cracks on Engraving Tool Steel Inserts during the Injection Molding Cycle Using PZT Sensors

    Aleš Hančič


    Full Text Available This paper presents an improved monitoring system for the failure detection of engraving tool steel inserts during the injection molding cycle. This system uses acoustic emission PZT sensors mounted through acoustic waveguides on the engraving insert. We were thus able to clearly distinguish the defect through measured AE signals. Two engraving tool steel inserts were tested during the production of standard test specimens, each under the same processing conditions. By closely comparing the captured AE signals on both engraving inserts during the filling and packing stages, we were able to detect the presence of macro-cracks on one engraving insert. Gabor wavelet analysis was used for closer examination of the captured AE signals’ peak amplitudes during the filling and packing stages. The obtained results revealed that such a system could be used successfully as an improved tool for monitoring the integrity of an injection molding process.

  10. A study of the influence of cutting parameters on micromilling of steel with cubic boron nitride (CBN) tools

    Klocke, Fritz; Quito, Fernando; Arntz, Kristian; Souza, Alexandre


    It has been concluded in previous studies that Cubic Boron Nitride (CBN) tools have greater wear resistance and superior tool life than other tool materials used in conventional milling, due to chemically stability at high temperatures, high abrasive wear resistance and high degree of hardness; however no research has been conducted about its performance on micro milling. Burr formation has a direct negative effect on product quality and assembly automation in micro milling, therefore adoption of machining strategies and influencing factors were investigated intending to reduce burr formation. This paper also aims at analyzing the interference of cutting parameters on micro milling with CBN tools, such as the influence of cutting speed and feed per tooth on the surface quality and tool life. These outcomes enable us to know which parameters and strategies must be used to achieve better results when micro milling steel with CBN tools.

  11. Influence of minimum quantity of lubricant (MQL on tool life of carbide cutting tools during milling process of steel AISI 1018

    Diego Núñez


    Full Text Available Nowadays, high productivity of machining is an important issue to obtain economic benefits in the industry. This purpose could be reached with high cutting velocity and feed rate. However, the inherently behavior produce high temperatures in the interface of couple cutting tool/workpiece. Many cutting fluids have been developed to control temperature in process and increase tool life. The objective of this paper is to compare the carbide milling tool wear using different systems cutting fluids: flood and minimum quantity of lubrication (MQL. The values of carbide milling cutting tool wear was evaluate according with the standard ISO 8688-1 1989. The experimental results showed that using MQL reduces significantly (about 40% tool wear in milling AISI 1018 steel at industrial cutting conditions.

  12. Study on Surface Integrity of AISI 1045 Carbon Steel when machined by Carbide Cutting Tool under wet conditions

    Tamin N. Fauzi


    Full Text Available This paper presents the evaluation of surface roughness and roughness profiles when machining carbon steel under wet conditions with low and high cutting speeds. The workpiece materials and cutting tools selected in this research were AISI 1045 carbon steel and canela carbide inserts graded PM25, respectively. The cutting tools undergo machining tests by CNC turning operations and their performances were evaluated by their surface roughness value and observation of the surface roughness profile. The machining tests were held at varied cutting speeds of 35 to 53 m/min, feed rate of 0.15 to 0.50 mm/rev and a constant depth of cut of 1 mm. From the analysis, it was found that surface roughness increased as the feed rate increased. Varian of surface roughness was suspected due to interaction between cutting speeds and feed rates as well as nose radius conditions; whether from tool wear or the formation of a built-up edge. This study helps us understand the effect of cutting speed and feed rate on surface integrity, when machining AISI 1045 carbon steel using carbide cutting tools, under wet cutting conditions.

  13. Comparison of surface laser alloying of chosen tool steel using Al2O3 and ZrO2 powder

    K. Labisz


    Full Text Available Purpose: In this work there are presented the investigation results of mechanical properties and microstructure of the hot work tool steel 32CrMoV12-28 alloyed with oxide powders like aluminium oxide and zirconium oxide. The purpose of this work was also to determine the laser treatment conditions for surface hardening of the investigation alloys with appliance of transmission electron microscopy.Design/methodology/approach: The investigations were performed using optical microscopy for the microstructure determination. By mind of the transmission electron microscopy the high resolution and phase determination was possible to obtain. The morphology of the ceramic powder particles was studied as well the lattice parameters for the Fe matrix and phase identification using diffraction methods was applied.Findings: After the laser alloying of the hot work tool steel with the selected oxide powders the structure of the samples changes in a way, that there are zones detected like the remelting zone the heat influence zone where the grains are larger and not so uniform as in the metal matrix. The used oxide powders are not present after the laser treatment in the steel matrix.Research limitations/implications: The investigated steel samples were examined metallographically using optical microscope with different image techniques, SEM, TEM and analyzed using a Rockwell hardness tester, also EDS microanalysis and electron diffraction with Fourier transform was made.Practical implications: As an implication for the practice a new technology can be possible to develop, based no diode laser usage. Some other investigation should be performed in the future, but the knowledge found in this research shows an interesting investigation direction.Originality/value: The combination of TEM investigation for laser alloying of hot work tool steels makes the investigation very attractive for automotive and other heavy industries.

  14. Low-temperature martensitic transformation and deep cryogenic treatment of a tool steel

    Tyshchenko, A.I. [G.V. Kurdyumov Institute for Metal Physics, 03142 Kiev (Ukraine); Theisen, W.; Oppenkowski, A.; Siebert, S. [Ruhr University Bochum, Chair of Materials Technology, 44780 Bochum (Germany); Razumov, O.N.; Skoblik, A.P.; Sirosh, V.A.; Petrov, Yu.N. [G.V. Kurdyumov Institute for Metal Physics, 03142 Kiev (Ukraine); Gavriljuk, V.G., E-mail: [G.V. Kurdyumov Institute for Metal Physics, 03142 Kiev (Ukraine)


    Research highlights: {yields} Low-temperature martensitic transformation is important for beneficial effect of DCT. {yields} Plastic deformation occurs in the course of low-temperature martensitic transformation. {yields} Carbon clouds around dislocations are formed due to the capture of immobile carbon atoms by gliding dislocations. {yields} Carbide phase is partially dissolved during DCT. - Abstract: The tool steel X220CrVMo 13-4 (DIN 1.2380) containing (mass%) 2.2C, 13Cr, 4V, 1Mo and the binary alloy Fe-2.03 mass% C were studied using transmission electron microscopy, Moessbauer spectroscopy, X-ray diffraction and internal friction with the aim of shedding light on processes occurring during deep cryogenic treatment. It is shown that the carbon atoms are essentially immobile at temperatures below -50 deg. C, whereas carbon clustering in the virgin martensite occurs during heating above this temperature. An increase in the density of dislocations, the capture of immobile carbon atoms by moving dislocations, the strain-induced partial dissolution of the carbide phase, and the abnormally low tetragonality of the virgin martensite are found and interpreted in terms of plastic deformation that occurs during martensitic transformation at low temperatures where the virgin martensite is sufficiently ductile.


    Peter Jurči


    Full Text Available Specimens made of Vanadis 6 steel were heat treated, plasma nitrided and coated with Cr2N. The microstructure, phase constitution and mechanical properties of plasma nitrided areas and duplex-coatings have been investigated using the light microscopy, scanning electron microscopy, X-ray diffraction and microhardness measurements. The adhesion of the coatings and the wear performance were studied using the scratch test and ring-on-plate tribological testing. Worn surfaces were examined by scanning electron microscopy. Nitrided areas formed at lower temperature were free of compound “white” layer while hose developed at higher temperatures contained as the white layer so the nitrided network. Significant increase in substrate hardness was detected due to the nitriding. Beneficial effect of the nitriding on the adhesion of Cr2N coatings was clearly determined whereas the extent in improvement of the adhesion depends on the presence/no presence of “white” layer on the surface. The extent of beneficial effect of plasma nitriding on the wear performance follows the impact of the constitution of nitrided areas on the adhesion. The amelioration of wear performance of Cr2N coatings can be attributed to the supporting effect of hard nitrided intermediate region, which provides excellent resistance of the substrate against plastic deformation, under heavy loading in particular. Practical testing demonstrated many times prolonged service-time of duplex-treated tools for sheet metal working.

  16. Properties Evaluation of Thin Microhardened Surface Layer of Tool Steel after Wire EDM

    Ľuboslav Straka


    Full Text Available This paper describes results of experimental research on the thin microhardened surface layer of a machined surface that occurs in materials using wire electrical discharge machining (WEDM with brass wire electrode. The direct influence of microhardened surface layer on resulting machined surface quality of tool steel EN X210Cr12 (W.-Nr. 1.2080 was examined. The aim of the experiment was to contribute to the knowledge of mutual interactions between main WEDM technological parameters, the influence of these parameters on the total affected depth, and on the variation of microhardness of sub-surface layers of machined surface. Based on the microhardness experimental measurements, mathematical models were established by the Least Square Method (LSM in order to simulate and predict final quality of machined surface after WEDM. Recommendations are given for setting the main technological parameters of the discharge process concerning minimization of total microhardened surface layer depth and microhardened surface layer homogeneity along the whole cross-section profile of the machined surface.

  17. Spray-formed tooling for injection molding and die casting applications

    K. M. McHugh; B. R. Wickham


    Rapid Solidification Process (RSP) Tooling{trademark} is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described.

  18. Spray-formed Tooling for Injection Molding and Die Casting Applications

    Mc Hugh, Kevin Matthew


    Rapid Solidification Process (RSP) ToolingTM is a spray forming technology tailored for producing molds and dies. The approach combines rapid solidification processing and net-shape materials processing in a single step. The ability of the sprayed deposit to capture features of the tool pattern eliminates costly machining operations in conventional mold making and reduces turnaround time. Moreover, rapid solidification suppresses carbide precipitation and growth, allowing many ferritic tool steels to be artificially aged, an alternative to conventional heat treatment that offers unique benefits. Material properties and microstructure transformation during heat treatment of spray-formed H13 tool steel are described.

  19. Multi-objective optimization in WEDM of D3 tool steel using integrated approach of Taguchi method & Grey relational analysis

    Shivade, Anand S.; Shinde, Vasudev D.


    In this paper, wire electrical discharge machining of D3 tool steel is studied. Influence of pulse-on time, pulse-off time, peak current and wire speed are investigated for MRR, dimensional deviation, gap current and machining time, during intricate machining of D3 tool steel. Taguchi method is used for single characteristics optimization and to optimize all four process parameters simultaneously, Grey relational analysis (GRA) is employed along with Taguchi method. Through GRA, grey relational grade is used as a performance index to determine the optimal setting of process parameters for multi-objective characteristics. Analysis of variance (ANOVA) shows that the peak current is the most significant parameters affecting on multi-objective characteristics. Confirmatory results, proves the potential of GRA to optimize process parameters successfully for multi-objective characteristics.


    A. V. Alifanov


    Full Text Available The magnetic pulse installation, intended for hardening of cylindrical steel articles by strong pulse electromagnetic field, is developed and produced. Results of researches show high efficiency and prospects of the developed method for hardening of steel articles. 

  1. Nanostructured Multilayer Composite Coatings on Ceramic Cutting Tools for Finishing Treatment of High-Hardness Quenched Steels

    Vereshchaka, A. A.; Batako, A. D.; Sotova, E. S.; Vereshchaka, A. S.


    The functional role of nanostructured multilayer composite coatings (NMCC) deposited on the operating surfaces of replaceable faceted cutting inserts (CI) from cutting ceramics based on aluminum oxides with additives of titanium carbides is studied. It is shown that the developed NMCC not only raise substantially the endurance of the ceramic tools under high-speed dry treatment of quenched steels but also improve the quality and accuracy of processing of the parts and the ecological parameters of the cutting process.

  2. The Synergy of the Surface Layer after Carburizing of Tool Steel as a Measure of Operational Quality

    Wencel, Z.


    Full Text Available In the paper the results of the investigation on surface layer of carburized X150CrMoV12-1 tool steel are presented. Abrasive wearing of the surface was determined according the ASTM G77-98 method. The microstructure of the matrix and distribution of carbides were observed in a Scanning Electron Microscope (SEM. A correlation between the investigated parameters (microstructure/carbides distribution was found.

  3. The Cutting Front Side Geometry in The Applications of D3 Cold Work Tool Steel Material Via Abrasive Water Jet

    Adnan AKKURT


    Abrasive water jet cutting that is used as cold cutting technology in industrial applications is preferred as most productive method when especially metallurgic and mechanic specialties of materials are taken into consideration. When the surface quality, speed of processing period and part cost are taken into consideration, which are targeted in D3 cold work tool steel materials used frequently in especially metal industry, it appears that the most appropriate method is ab...

  4. Investigation And Optimization Of EDM Process Of AISI 4140 Alloy Steel Using Various Tool Electrodes: A Review Paper

    Kishor Lal ,


    Full Text Available The purpose of this research work is to determine the optimized settings of key machining factors like pulse on time, discharge current and duty cycle for AISI 4140 alloy steel using various tool electrodes. The output responses will be measured are material removal rate (MRR,surface roughness(SR and tool wear rate(TWR. Mathematical models are proposed for the above are L27 orthogonal array. The micro structural changes in the work piece after machining process will also be examined by the use of SEM.

  5. Investigation of crack propagation in X38CrMoV5 (AISI H11) tool steel at elevated temperatures

    Shah, Masood; Mabru, Catherine; Rezaï-Aria, Farhad


    A method is developed to evaluate the surface fatigue damage of hot forming tools (forging, HPDC) that undergo thermo mechanical loading and environmental attack. Crack propagation under fatigue loading in a hot work tool steel X38CrMoV5-47HRC is investigated using SENT (single edge notched tension) specimens of 2.5*8 mm*mm section. The effect of different testing conditions has been investigated: effect of thickness (ranging from 2.5mm – 0.10mm), effect of R value and effect of temperature a...

  6. Tool life equation for blanking 18-8 stainless steel strips

    Faura, F.


    Full Text Available Hereinafter it is presented a model for the behaviour and life of circular blanking tool used in sheet forming processes of 18-8 stainless steel (sheet thickness: 1 mm. Firstly it has analyzed the different studies that have previously delt with this problem. Secondly taking into account recently made experiments, it is proposed a simple formulation to predict tool life with enough reliability. To this purpose it has examined different parameters in the wear process, inferring from these the fundamental parameters that regulate them and about which the different equations have been configurated. Blanking tests were performed using a 20 t press at a speed of 150 strokes/min. Punch materials used in these tests were AISI A2 and AISI D2 with diameters between 1.5 and 10 mm. The blanking tests were performed at a clearance between 5 and 20 % of the work material thickness.

    En el presente artículo se presenta un modelo de ecuación de vida de herramientas para punzonado circular de chapa de acero inoxidable 18-8 (1 mm de espesor. Se han analizado inicialmente los diferentes estudios que previamente han abordado este problema. Posteriormente, teniendo en cuenta los experimentos realizados recientemente, se propone una formulación simple para predecir con Habilidad suficiente la vida de la herramienta. Para este propósito se han examinado los diferentes parámetros que afectan al proceso de desgaste, infiriendo a partir de estos, los parámetros fundamentales que lo regulan y sobre los cuales se han configurado las diferentes ecuaciones. Los ensayos fueron realizados en una prensa de 20 t y una velocidad de punzonado de 150 golpes/min. Los materiales de los punzones usados en los ensayos fueron AISI A2 y AISI D2 con diámetros comprendidos entre 1,5 y 10 mm. Los ensayos se realizaron para juegos de corte comprendidos entre un 5 y 20 % del espesor de la chapa.

  7. A study on the microstructure and mechanical properties of AISI D2 tool steel modified by niobium

    Hamidzadeh, M.A.; Meratian, M. [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Mohammadi Zahrani, M., E-mail: [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)


    The microstructure and mechanical properties of AISI D2 tool steel with up to 1.5 wt% niobium additions were investigated. The microstructural evolutions were characterized by means of optical microscopy and scanning electron microscopy techniques. Mechanical properties of the samples were measured using tensile testing, hardness measurements and Charpy impact test. The results indicated that modification of the microstructure was effectively achieved through the addition of 1.5 wt% of niobium, which refined the prior-austenite grains and decreased the volume fraction of eutectic carbides. Also, the eutectic carbide network tended to break thereby forming blocky and ribbon-like morphologies in the eutectic structures. The ductility and impact toughness of the niobium-contained steels were increased considerably and reached to about 5.8% and 15 J/cm{sup 2}, respectively. Generally, the results of this study suggest that niobium can be used as an alloying element to significantly enhance the ductility and impact toughness of D2 tool steel without affecting the hardness.

  8. Microstructure, morphology, adhesion and tribological behavior of sputtered niobium carbide and bismuth films on tool steel

    Laura Angélica Ardila Rodríguez


    Full Text Available Normal 0 21 false false false ES-CO X-NONE AR-SA Normal 0 21 false false false ES-CO X-NONE AR-SA NbC, Bi and Bi/NbC coatings were deposited on AISI M2 steel substrates using unbalanced magnetron sputtering at room temperature with zero bias voltage. Were studied the phase structure, the morphology, the adhesion and the tribological behavior of the three coatings. The niobium carbide film crystallized in the NbC cubic structure, and the bismuth layers had a rhombohedral phase with random orientation. The NbC coating had a smooth surface with low roughness, while the Bi layers on steel and on NbC coating had higher roughness and a morphology composed of large particles. By using a ductile Nb interlayer good adhesion between the NbC coating and the steel substrate was achieved. The Bi coating had better adhesion with the NbC layer than with the steel substrate. The tribological performance of the Bi coating on steel was not satisfactory, but according to the preliminary results, the produced NbC and Bi/NbC coatings have the potential to improve the tribological performance of the steel.

  9. Influence of processing parameters on lattice parameters in laser deposited tool alloy steel

    Sun, G.F., E-mail: [Center for Laser-Aided Intelligent Manufacturing, University of Michigan, Ann Arbor, MI, 48109 (United States); School of Mechanical Engineering, Jiangsu University, Zhenjiang, Jiangsu, 212013 (China); Bhattacharya, S. [Center for Laser-Aided Intelligent Manufacturing, University of Michigan, Ann Arbor, MI, 48109 (United States); Dinda, G.P.; Dasgupta, A. [Center for Advanced Technologies, Focus: Hope, Detroit, MI, 48238 (United States); Mazumder, J. [Center for Laser-Aided Intelligent Manufacturing, University of Michigan, Ann Arbor, MI, 48109 (United States)


    Highlights: {yields} Orientation relationships among phases in the DMD are given. {yields} Martensite lattice parameters increased with laser specific energy. {yields} Austenite lattice parameters decreased with laser specific energy. - Abstract: Laser aided direct metal deposition (DMD) has been used to form AISI 4340 steel coating on the AISI 4140 steel substrate. The microstructural property of the DMD coating was analyzed by means of scanning electron microscopy, transmission electron microscopy and X-ray diffractometry. Microhardness of the DMD was measured with a Vickers microhardness tester. Results indicate that DMD can be used to form dense AISI 4340 steel coatings on AISI 4140 steel substrate. The DMD coating is mainly composed of martensite and retained austenite. Consecutive thermal cycles have a remarkable effect on the microstructure of the plan view of the DMD coating and on the corresponding microhardness distribution. Orientation relationships among austenite, martensite and cementite in the DMD coating followed the ones in conventional heat treated steels. As the laser specific energy decreased, cooling rate increased, and martensite peaks broadened and shifted to a lower Bragg's angle. Also martensite lattice parameters increased and austenite lattice parameters decreased due to the above parameter change.

  10. Criterion for tool wear limitation on blanking 18-8 stainless steel strips

    Faura, F.


    Full Text Available The present article shows a wear limiting criterion for 18-8 stainless steel punching process. For this reason, different factors such as length of the tool, clearance or materials, have been considered in order to obtain the number of possible strokes between grindings and the total number of blanks until a complete total failure. Finally, the maximum number of possible strokes which it will give the economically accepted wear can be obtained. The results obtained by the present method are in good agreement with the previous experimental and theoretical work. Blanking tests were performed using a 20 t press at a speed of 150 strokes/min. The punching material used in these tests was AISI A2 with diameters between 6 and 14 mm. The blanking tests were performed at a clearance between 5 and 20 % of the thickness of the work material.

    El presente artículo desarrolla un criterio para la limitación del desgaste en procesos de punzonado de chapa de acero inoxidable 18-8. Se han considerado diferentes factores, tales como longitud de la herramienta, juego de corte o materiales, para establecer dicho criterio. El objetivo final es determinar el máximo número de operaciones entre dos reacondicionados consecutivos de la herramienta hasta el completo deterioro de la misma. En consecuencia, se ha obtenido el máximo número posible de operaciones que puede realizarse en unas condiciones de trabajo determinadas para llegar a un desgaste económicamente aceptable. Los resultados obtenidos por el presente método tienen una excelente correspondencia con estudios teóricos y experimentales previos. Los ensayos fueron realizados utilizando una prensa de 20 t y una velocidad de 150 golpes/min para juegos de corte comprendidos entre un 5 y 20 % del espesor de la chapa. El material del punzón usado en los ensayos fue un AISI A2 con diámetros comprendidos entre 6 y 14 mm.

  11. Property Estimation of Functionally Graded Materials Between M2 Tool Steel and Cu Fabricated by Powder Metallurgy

    Jeong, Jong-Seol; Shin, Ki-Hoon [Seoul National University of Science and Technology, Seoul (Korea, Republic of)


    The use of functionally graded materials (FGMs) may enhance thermal conductivity without reducing the desired strength in many applications such as injection molds embedding conformal cooling channels and cutting tools with heat sinks (or cooling devices). As a fundamental study for cutting tools having FGM heat sinks between M2 tool steel and Cu, six FGM specimens (M2 and Cu powders were premixed such that the relative compositions of M2 and Cu were 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 wt%) were fabricated by powder metallurgy in this study. The cross sections of these specimens were observed by optical microscopy, and then the material properties (such as thermal conductivity, specific heat, and coefficient of thermal expansion) related to heat transfer were measured and analyzed.

  12. Application of response surface methodology for determining cutting force model in turning hardened AISI H11 hot work tool steel

    B Fnides; M A Yallese; T Mabrouki; J-F Rigal


    This experimental study is conducted to determine statistical models of cutting forces in hard turning of AISI H11 hot work tool steel (∼ 50 HRC). This steel is free from tungsten on Cr–Mo–V basis, insensitive to temperature changes and having a high wear resistance. It is employed for the manufacture of highly stressed diecasting moulds and inserts with high tool life expectancy, plastic moulds subject to high stress, helicopter rotor blades and forging dies. The workpiece is machined by a mixed ceramic tool (insert CC650 of chemical composition 70%Al23+30%TiC) under dry conditions. Based on 33 full factorial design, a total of 27 tests were carried out. The range of each parameter is set at three different levels, namely low, medium and high. Mathematical models were deduced by software Minitab (multiple linear regression and response surface methodology) in order to express the influence degree of the main cutting variables such as cutting speed, feed rate and depth of cut on cutting force components. These models would be helpful in selecting cutting variables for optimization of hard cutting process. The results indicate that the depth of cut is the dominant factor affecting cutting force components. The feed rate influences tangential cutting force more than radial and axial forces. The cutting speed affects radial force more than tangential and axial forces.

  13. Parametric Optimization of Wire Electrical Discharge Machining of Powder Metallurgical Cold Worked Tool Steel using Taguchi Method

    Sudhakara, Dara; Prasanthi, Guvvala


    Wire Cut EDM is an unconventional machining process used to build components of complex shape. The current work mainly deals with optimization of surface roughness while machining P/M CW TOOL STEEL by Wire cut EDM using Taguchi method. The process parameters of the Wire Cut EDM is ON, OFF, IP, SV, WT, and WP. L27 OA is used for to design of the experiments for conducting experimentation. In order to find out the effecting parameters on the surface roughness, ANOVA analysis is engaged. The optimum levels for getting minimum surface roughness is ON = 108 µs, OFF = 63 µs, IP = 11 A, SV = 68 V and WT = 8 g.

  14. Influence of minimum quantity lubrication parameters on tool wear and surface roughness in milling of forged steel

    Yan, Lutao; Yuan, Songmei; Liu, Qiang


    The minimum quantity of lubrication (MQL) technique is becoming increasingly more popular due to the safety of environment. Moreover, MQL technique not only leads to economical benefits by way of saving lubricant costs but also presents better machinability. However, the effect of MQL parameters on machining is still not clear, which needs to be overcome. In this paper, the effect of different modes of lubrication, i.e., conventional way using flushing, dry cutting and using the minimum quantity lubrication (MQL) technique on the machinability in end milling of a forged steel (50CrMnMo), is investigated. The influence of MQL parameters on tool wear and surface roughness is also discussed. MQL parameters include nozzle direction in relation to feed direction, nozzle elevation angle, distance from the nozzle tip to the cutting zone, lubricant flow rate and air pressure. The investigation results show that MQL technique lowers the tool wear and surface roughness values compared with that of conventional flood cutting fluid supply and dry cutting conditions. Based on the investigations of chip morphology and color, MQL technique reduces the cutting temperature to some extent. The relative nozzle-feed position at 120°, the angle elevation of 60° and distance from nozzle tip to cutting zone at 20 mm provide the prolonged tool life and reduced surface roughness values. This fact is due to the oil mists can penetrate in the inner zones of the tool edges in a very efficient way. Improvement in tool life and surface finish could be achieved utilizing higher oil flow rate and higher compressed air pressure. Moreover, oil flow rate increased from 43.8 mL/h to 58.4 mL/h leads to a small decrease of flank wear, but it is not very significant. The results obtained in this paper can be used to determine optimal conditions for milling of forged steel under MQL conditions.

  15. Application of Magnetic Kinds of Nondestructive Inspection to Parts From Die Tool Steels

    Kornilova, A. V.; Selishchev, A. I.; Idarmachev, I. M.


    Possibilities of control of the level of accumulated damage in dies for cold and hot forming as a function of the coercivity are considered. The coercivity of the material of dies for hot forging and cold stamping is studied. Formulas are obtained for determining the coercivity in steels for hot die forging in the state as delivered.

  16. Recent developments in turning hardened steels - A review

    Sivaraman, V.; Prakash, S.


    Hard materials ranging from HRC 45 - 68 such as hardened AISI H13, AISI 4340, AISI 52100, D2 STL, D3 STEEL Steel etc., need super hard tool materials to machine. Turning of these hard materials is termed as hard turning. Hard turning makes possible direct machining of the hard materials and also eliminates the lubricant requirement and thus favoring dry machining. Hard turning is a finish turning process and hence conventional grinding is not required. Development of the new advanced super hard tool materials such as ceramic inserts, Cubic Boron Nitride, Polycrystalline Cubic Boron Nitride etc. enabled the turning of these materials. PVD and CVD methods of coating have made easier the production of single and multi layered coated tool inserts. Coatings of TiN, TiAlN, TiC, Al2O3, AlCrN over cemented carbide inserts has lead to the machining of difficult to machine materials. Advancement in the process of hard machining paved way for better surface finish, long tool life, reduced tool wear, cutting force and cutting temperatures. Micro and Nano coated carbide inserts, nanocomposite coated PCBN inserts, micro and nano CBN coated carbide inserts and similar developments have made machining of hardened steels much easier and economical. In this paper, broad literature review on turning of hardened steels including optimizing process parameters, cooling requirements, different tool materials etc., are done.

  17. Effect of vacuum oxy-nitrocarburizing on the microstructure of tool steels: an experimental and modeling study

    Nikolova Maria


    Full Text Available The thermochemical treatments of tool steels improve the performance of the components with respect to surface hardness, wear and tribological performance as well as corrosion resistance. Compared to the conventional gas ferritic nitrocarburizing process, the original vacuum oxy-nitrocarburizing is a time-, cost-effective and environmentally-friendly gas process. Because of the oxidizing nature of the gas atmosphere, there is no need to perform subsequent post-oxidation.In this study, a vacuum oxynitrocarburizing process was carried out onto four tool steels (AISI H10, H11, H21 and D2 at 570 °C, after hardening and single tempering. The structural analysis of the compound and diffusion layers was performed by optical and electron microscopy, X-ray diffraction and glow discharge optical emission spectrometry (GDOES methods. A largely monophase ε- layer is formed with a carbon accumulation at the substrate adjacent area. The overlaying oxides adjacent to the ε-carbonitride phase contained Fe3O4 (magnetite as a main constituent. A thermodynamic modelling approach was also performed to understand and optimize the process. The “Equilib module” of FactSage software which uses Gibbs energy minimization method, was used to estimate the possible products during vacuum oxynitrocarburising process.

  18. Compaction of tool steels by pulsed electric current (PECS) sintering process

    Postal, Stefano


    This study had two major purposes: the microstructural investigation of High Chromium White Iron (HCWI) sintered with Pulsed Electric Current Sintering (PECS) and the evaluation of the abrasion resistance of high chromium white iron mixed with different amounts of Hadfield Steel. The objective was to obtain dense high chromium white iron compacts with fine and uniform carbide and grain structure. The materials included in the study were gas atomized high chromium white iron (2.60 wt% C, 19.48...

  19. A numerical analysis as a good tool for a prediction of final sulphur steel ladle content

    Z. Slović


    Full Text Available This work presents the industrial results of sulfur level prediction at the end of vacuum degassing (VD of low carbon Al-Si killed steels. The effect of plant conditions, such as slag chemistry, temperature, oxygen levels of the molten steel, and slag weight on desulphurization was investigated based on the measured results and thermodynamic calculations. The variables which influence steel desulfurization such as the sulfur capacity, the initial sulfur content, and the amount of ladle slag at the end of the VD process are also defined. The desulfurization procedure was numerically analyzed using the results of 31 heats under real plant conditions in which the measured final sulfur content had been reduced to less than of 10 ppm. A method for prediction of the slag amount based on the material balance of sulfur and aluminum is also presented. The values of the sulfur capacity were determined according to the well-known KTH and optical basicity based models. The obtained results of the regression equation show a predictive final sulfur level ability of R=0.911. This was proved as satisfactory.

  20. In-Process Prediction of Tool Wear and Workpiece Surface Temperature in Turning of AISI D2 Steel

    Sudhansu Ranjanjan Das


    Full Text Available Present days increasing the productivity and the quality of the machined parts are the main challenges of metal cutting industry during turning processes. Optimization methods in turning processes, considered being a vital role for continual improvement of output quality in product and processes include modeling of input-output and in process parameters relationship and determination of optimal cutting conditions. This paper presents an optimization method of the cutting parameters (cutting speed, depth of cut and feed in dry turning of AISI D2 steel to achieve minimum tool wear and low workpiece surface temperature. The experimental layout was designed based on the Taguchi’s L9 (34 Orthogonal array technique and analysis of variance (ANOVA was performed to identify the effect of the cutting parameters on the response variables. The results showed that depth of cut and cutting speed are the most important parameter influencing the tool wear. The minimum tool wear was found at cutting speed of 150 m/min, depth of cut of 0.5 mm and feed of 0.25 mm/rev. Similarly low workpiece surface temperature was obtained at cutting speed of 150 m/min, depth of cut of 0.5 mm and feed of 0.25 mm/rev. Thereafter, optimal ranges of tool wear and workpiece surface temperature values were predicted. Finally, the relationship between factors and the performance measures were developed by using multiple regression analysis.

  1. Functional properties of surface layers of X38CrMoV5-3 hot work tool steel alloyed with HPDL laser

    L.A. Dobrzański; M. Piec; K. Labisz; M. Bonek; A. Klimpel


    Purpose: Improvement of functional properties alloyed of hot work tool steel surface layers is one of the goals of this paper.Design/methodology/approach: The material used for investigation was the hot work tool steel X38CrMoV5-3. Remelting and alloying of surface layers were made using the HPDL high power diode laser Rofin DL 020 in the laser power range of 1.2-2.3 kW. The carbide powders were applied on specimens prepared and degreased in this way; the powder was mixed with the sodium glas...

  2. Applications of ArcelorMittal Thermodynamic Computation Tools to Steel Production

    Lehmann, Jean

    CEQCSI is an ArcelorMittal in-house built thermodynamic equilibrium calculation software which is used both at high temperatures typically for slag-metal reactions but also at "low" temperatures to study solid phase transformations and precipitation in solid steel. It has been built to accommodate different thermodynamic models for slag (the Cell model, the Generalized Central Atom model - product of a collaboration between ArcelorMittal Global R&D Maizieres and CSIRO Melbourne), for steel (sublattice model, Wagner Interaction Parameter Formalism) as well as for oxide, sulfide, carbide… solid solutions. Examples of application concern Si, Mn, S slag-metal equilibrium in Blast-Furnace, P partition in BOF slags, slag-metal equilibrium for flat and long products in ladle… Apart from data relating to mass transfer between different phases at equilibrium, CEQCSI proposes several estimates for slag viscosities with among them one delivered by a new model based on the Generalized Central Atom thermodynamic model for slags. CEQCSI conception allows also handling some kinetic problems such as desulfurization in ladle or slag/metal reaction in mold.

  3. Formation of Hard Composite Layer on Tool Steel by Laser Alloying

    Bonek M.


    Full Text Available Investigations include alloying the PMHSS6-5-3 steel surface layer with carbide and ceramic powders WC, VC, TiC, SiC, Si3N4 and Al2O3, using the high power diode laser (HPDL. Laser treatment is especially promising for solving contemporary surface engineering problems making it possible to focus precisely the delivered energy in the form of heat in the surface layer. The structural mechanism was determined of surface layers development, effect was studied of alloying parameters, method on structure refinement and influence of these factors on the mechanical properties of surface layer, and especially on its abrasive wear resistance. The fine grained martensite structure is responsible for hardness increase of the alloyed layer. The tribological wear relationships were determined for laser treated surface layers, determining friction coefficient, and wear trace shape developed due to the abrasive wear of the investigated surfaces. Comparison of the laser treatment parameters and tribological properties of surface layer after remelting and alloying with hard particles of the PMHSS6-5-3 steel using the high power diode laser to obtain the optimum service properties is the outcome of the investigations carried out.

  4. Formation of laser-induced periodic surface structures (LIPSS) on tool steel by multiple picosecond laser pulses of different polarizations

    Gregorčič, Peter; Sedlaček, Marko; Podgornik, Bojan; Reif, Jürgen


    Laser-induced periodic surface structures (LIPSS) are produced on cold work tool steel by irradiation with a low number of picosecond laser pulses. As expected, the ripples, with a period of about 90% of the laser wavelength, are oriented perpendicular to the laser polarization. Subsequent irradiation with the polarization rotated by 45° or 90° results in a corresponding rotation of the ripples. This is visible already with the first pulse and becomes almost complete - erasing the previous orientation - after as few as three pulses. The phenomenon is not only observed for single-spot irradiation but also for writing long coherent traces. The experimental results strongly defy the role of surface plasmon-polaritons as the predominant key to LIPSS formation.

  5. Study on Interface Structure and Bond Properties between Cemented Carbide and Tool Steel Blazing with amorphous alloy

    Bao Ming-dong; Xu Jin-fu; Xu Xue-bo; Zou Gui-sheng; Huang Geng-hua


    Cemented Carbide YG11C and Tool Steel Crl2MoV was blazed with Ni-base amorphous alloys, QG-1011,MBF-20 and MBF-75, using dynamics thermodynamics analogue testing machine Gleeble 1500D. The effects of brazing temperature, holding time and holding pressure on micro-structure and bond strength were investigated. Results showed that YG11C and Cr12MoV were all wetted well by these three Ni-base alloys, and the bond strength was as high as 220MPa,320MPa, 320MPa respectively. When the blazing temperature was at the point over the melting point 60-70℃ of Ni-base alloy, the holding time was about 2-10min, the suitable pressure was benefit for improving the brazing quality.Microanalysis showed Co in cemented carbide diffused into liquid brazing alloy and formed the Fe-Co solid .solution.

  6. Effect of cutting parameters on sustainable machining performance of coated carbide tool in dry turning process of stainless steel 316

    Bagaber, Salem A.; Yusoff, Ahmed Razlan


    The manufacturing industry aims to produce many products of high quality with relatively less cost and time. Different cutting parameters affect the machining performance of surface roughness, cutting force, and material removal rate. Nevertheless, a few studies reported on the effects of sustainable factors such as power consumed, cycle time during machining, and tool life on the dry turning of AISI 316. The present study aims to evaluate the machining performance of coated carbide in the machining of hard steel AISI 316 under the dry turning process. The influence of cutting parameters of cutting speed, feed rate, and depth of cut with their five (5) levels is established by a central composite design. Highly significant parameters were determined by analysis of variance (ANOVA), and the main effects of power consumed and time during machining, surface roughness, and tool wear were observed. Results showed that the cutting speed was proportional to power consumption and tool wear. Meanwhile, insignificant to surface roughness, feed rate most significantly affected surface roughness and power consumption followed by depth of cut.

  7. Invisible casing : new density logging tool measures rock properties through steel and cement

    Ross, E.


    This article described an open hole and cased hole logging tool developed by Calgary-based RECON Petrotechnologies Ltd. The geological interpretation tool has helped oil and gas producers in North America to maximize value from their drilling investment. The advanced tool provides geologists with a high definition view of the wellbore and formation in real-time. It has the ability to capture more samples per foot than any other system available. As such, it provides better information for accurate identification of pay zones and more complete reservoir and production evaluations. The tool has been used successfully to correlate well logs and map horizons in oil and gas fields in western Canada as well as the Barnett Shale in the United States. 1 ref., 1 fig.

  8. Dry metal forming of high alloy steel using laser generated aluminum bronze tools

    Freiße Hannes


    Full Text Available Regarding the optimization of forming technology in economic and environmental aspects, avoiding lubricants is an approach to realize the vision of a new green technology. The resulting direct contact between the tool and the sheet in non-lubricated deep drawing causes higher stress and depends mainly on the material combination. The tribological system in dry sliding has to be assessed by means on the one hand of the resulting friction coefficient and on the other hand of the wear of the tool and sheet material. The potential to generate tailored tribological systems for dry metal forming could be shown within the investigations by using different material combinations and by applying different laser cladding process parameters. Furthermore, the feasibility of additive manufacturing of a deep drawing tool was demonstrated. The tool was successfully applied to form circular cups in a dry metal forming process.

  9. Tool life and cutting speed for the maximum productivity at the drilling of the stainless steel X22CrMoV12-1

    Vlase, A.; Blăjină, O.; Iacob, M.; Darie, V.


    Two addressed issues in the research regarding the cutting machinability, establishing of the optimum cutting processing conditions and the optimum cutting regime, do not yet have sufficient data for solving. For this reason, in the paper it is proposed the optimization of the tool life and the cutting speed at the drilling of a certain stainless steel in terms of the maximum productivity. For this purpose, a nonlinear programming mathematical model to maximize the productivity at the drilling of the steel is developed in the paper. The optimum cutting tool life and the associated cutting tool speed are obtained by solving the numerical mathematical model. Using this proposed model allows increasing the accuracy in the prediction of the productivity for the drilling of a certain stainless steel and getting the optimum tool life and the optimum cutting speed for the maximum productivity. The results presented in this paper can be used in the production activity, in order to increase the productivity of the stainless steels machining. Also new research directions for the specialists in this interested field may come off from this paper.

  10. Substrate Strengthening of CVD Coated Steels

    O.Kessler; M.Heidkamp; F.Hoffmann; P.Mayr


    Properties of components and tools can be improved by the combination of coating and heat treatment processes due to the addition of single process advantages and due to the utilization of process interactions. Several low and high alloyed, structural and tool steels (AISI 4140, 52100, H13, A2, D2, etc.) have been treated by CVD-TiN-coating plus laser beam hardening respectively carburizing plus CVD-TiN-coating. Homogeneous, dense TiN-coatings with high hardness,high compressive residual stresses and good adhesion were supported by high strength substrate surfaces. Especially CVD plus laser beam hardening offers the possibility to reduce distortion due to the small heated surface volume.

  11. Plasma nitriding of steels

    Aghajani, Hossein


    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  12. New tools for steel catenary risers inspection; Novas ferramentas para inspecao de risers tipo SCR

    Camerini, Claudio Soligo; Marinho, Carla Alves; Raphael, Fabiana N.; Maia, Carlos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Freitas, Miguel [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil); Lopes, Ricardo Tadeu; Rocha, Henrique [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia


    The Research Center of PETROBRAS and two of the Federal Brazilian Universities, PUC-Rio and UFRJ, have been developing two new projects in order to inspect risers of petroleum production. The first tool is an instrumented pig for profiling internal corrosion, having flexibility under diameter variations and independence related to thickness wall pipeline. The second one is a gammagraphy system remotely operated by ROVs, to be employed in alveoli corrosion and fatigue cracks detection in underwater pipelines. This work shows the trajectory of these two tools, describing laboratory and field tests and the future activities. (author)

  13. UPIOM: a new tool of MFA and its application to the flow of iron and steel associated with car production.

    Nakamura, Shinichiro; Kondo, Yasushi; Matsubae, Kazuyo; Nakajima, Kenichi; Nagasaka, Tetsuya


    Identification of the flow of materials and substances associated with a product system provides useful information for Life Cycle Analysis (LCA), and contributes to extending the scope of complementarity between LCA and Materials Flow Analysis/Substances Flow Analysis (MFA/SFA), the two major tools of industrial ecology. This paper proposes a new methodology based on input-output analysis for identifying the physical input-output flow of individual materials that is associated with the production of a unit of given product, the unit physical input-output by materials (UPIOM). While the Sankey diagram has been a standard tool for the visualization of MFA/SFA, with an increase in the complexity of the flows under consideration, which will be the case when economy-wide intersectoral flows of materials are involved, the Sankey diagram may become too complex for effective visualization. An alternative way to visually represent material flows is proposed which makes use of triangulation of the flow matrix based on degrees of fabrication. The proposed methodology is applied to the flow of pig iron and iron and steel scrap that are associated with the production of a passenger car in Japan. Its usefulness to identify a specific MFA pattern from the original IO table is demonstrated.

  14. Comparison of the PVD gradient coatings deposited onto X40CrMoV5-1 and HS6-5-2 tool steel substrate

    K. Lukaszkowicz; L.A. Dobrzański; M. Staszuk; M. Pancielejko


    Purpose: The main aim of this research was investigation and comparison of selected properties of gradient coatings TiCN and AlSiCrN. In this paper both coatings were deposited by cathode arc evaporation physical vapour deposition (CAE-PVD) method onto high speed steel HS6-5-2 and hot work tool steel X40CrMoV5-1.Design/methodology/approach: Observations of surface and structures of the deposited coatings were carried out on cross sections in the scanning electron microscope. The phase composi...

  15. The Application of Acoustic Emission and Artificial Neural Networks in an Analysis of Kinetics in the Phase Transformation of Tool Steel During Austempering

    Łazarska M.


    Full Text Available During the course of the study it involved tool steel C105U was used. The steel was austempered at temperatures of 130°C, 160°C and 180°C respectively. Methods of acoustic emission (AE were used to investigate the resulting effects associated with transformations and a large number of AE events were registered. Neural networks were applied to analyse these phenomena. In the tested signal, three groups of events were identified of: high, medium and low energy. The average spectral characteristics enabled the power of the signal spectrum to be determined. After completing the process, the results were compiled in the form of diagrams of the relationship of the AE incidence frequency as a function of time. Based on the results, it was found that in the austempering of tool steel, in the first stage of transformation midrib morphology is formed. Midrib is a twinned thin plate martensite. In the 2nd stage of transformation, the intensity of the generation of medium energy events indicates the occurrence of bainite initialised by martensite. The obtained graphic of AE characteristics of tool steel austempering allow conclusions to be drawn about the kinetics and the mechanism of this transformation.

  16. Computer simulation of the relationship between selected properties of laser remelted tool steel surface layer

    Bonek, Mirosław; Śliwa, Agata; Mikuła, Jarosław


    Investigations >The language in this paper has been slightly changed. Please check for clarity of thought, and that the meaning is still correct, and amend if necessary.include Finite Element Method simulation model of remelting of PMHSS6-5-3 high-speed steel surface layer using the high power diode laser (HPDL). The Finite Element Method computations were performed using ANSYS software. The scope of FEM simulation was determination of temperature distribution during laser alloying process at various process configurations regarding the laser beam power and method of powder deposition, as pre-coated past or surface with machined grooves. The Finite Element Method simulation was performed on five different 3-dimensional models. The model assumed nonlinear change of thermal conductivity, specific heat and density that were depended on temperature. The heating process was realized as heat flux corresponding to laser beam power of 1.4, 1.7 and 2.1 kW. Latent heat effects are considered during solidification. The molten pool is composed of the same material as the substrate and there is no chemical reaction. The absorptivity of laser energy was dependent on the simulated materials properties and their surface condition. The Finite Element Method simulation allows specifying the heat affected zone and the temperature distribution in the sample as a function of time and thus allows the estimation of the structural changes taking place during laser remelting process. The simulation was applied to determine the shape of molten pool and the penetration depth of remelted surface. Simulated penetration depth and molten pool profile have a good match with the experimental results. The depth values obtained in simulation are very close to experimental data. Regarding the shape of molten pool, the little differences have been noted. The heat flux input considered in simulation is only part of the mechanism for heating; thus, the final shape of solidified molten pool will depend

  17. Prediction of Surface Roughness Based on Machining Condition and Tool Condition in Boring EN31 Steel

    P. Mohanaraman


    Full Text Available Prediction of Surface roughness plays a vital role in manufacturing process. In manufacturing industries, productions of metallic materials require high surface finish in various components. In the present work, the effect of spindle speed, feed rate, depth of cut and flank wear of the tool on the surface roughness has been studied. Carbide tipped insert was used for boring operation. Experiments were conducted in CNC lathe. The experimental setup was prepared with sixteen levels of cutting parameters and was conducted with two tool tip conditions in dry machining. A piezoelectric accelerometer was used to measure the vibrational signals while machining. The data acquisition card which connected between accelerometer and lab-view software to record the signals. Simple linear and least median regression models were used for prediction of surface roughness. The models were developed by weka analysis software. The best suitable regression model is implemented based on maximum correlation coefficient and the minimum error values.

  18. Dry metal forming of high alloy steel using laser generated aluminum bronze tools

    Freiße Hannes; Köhler Henry; Seefeld Thomas; Vollertsen Frank


    Regarding the optimization of forming technology in economic and environmental aspects, avoiding lubricants is an approach to realize the vision of a new green technology. The resulting direct contact between the tool and the sheet in non-lubricated deep drawing causes higher stress and depends mainly on the material combination. The tribological system in dry sliding has to be assessed by means on the one hand of the resulting friction coefficient and on the other hand of the wear of the too...

  19. BEBEtr and BUBI: J-compensated concurrent shaped pulses for 1H-13C experiments

    Ehni, Sebastian; Luy, Burkhard


    Shaped pulses designed for broadband excitation, inversion and refocusing are important tools in modern NMR spectroscopy to achieve robust pulse sequences especially in heteronuclear correlation experiments. A large variety of mostly computer-optimized pulse shapes exist for different desired bandwidths, available rf-field strengths, and tolerance to B1-inhomogeneity. They are usually derived for a single spin 1/2, neglecting evolution due to J-couplings. While pulses with constant resulting phase are selfcompensated for heteronuclear coupling evolution as long as they are applied exclusively on a single nucleus, the situation changes for concurrently applied pulse shapes. Using the example of a 1H,13C two spin system, two J-compensated pulse pairs for the application in INEPT-type transfer elements were optimized: a point-to-point pulse sandwich called BEBEtr, consisting of a broadband excitation and time-reversed excitation pulse, and a combined universal rotation and point-to-point pulse pair called BUBI, which acts as a refocusing pulse on 1H and a corresponding inversion pulse on 13C. After a derivation of quality factors and optimization protocols, a theoretical and experimental comparison with conventionally derived BEBOP, BIBOP, and BURBOP-180° pulses is given. While the overall transfer efficiency of a single pulse pair is only reduced by approximately 0.1%, resulting transfer to undesired coherences is reduced by several percent. In experiments this can lead to undesired phase distortions for pairs of uncompensated pulse shapes and even differences in signal intensities of 5-10% in HSQC and up to 68% in more complex COB-HSQC experiments.

  20. Design optimization of the tool structure for stamping an automotive part with the high strength steel

    Kim, S. H.; Choi, H. J.; Rho, J. D.; Kim, K. P.; Park, K. D.; Kwon, B. K.; Cho, C. H.; Kang, M. J.; Bae, S. M.


    Optimum shape design of the tool structure is carried out in order to decrease the deformation and the stress from the large amount of stamping load with a simultaneous effect of weight reduction. Topology optimization is carried out to design the shape of the rib structure and Taguchi method is utilized to optimize the core shape. As a result of optimization, the weight of the rib and the core structures is reduced to 3.1% and the deformation and the stress of the rib and the core structures are decreased to 10.6% and 3.7% comparing to the initial design, respectively.

  1. Research of Tool Durability in Surface Plastic Deformation Processing by Burnishing of Steel Without Metalworking Fluids

    Grigoriev, S. N.; Bobrovskij, N. M.; Melnikov, P. A.; Bobrovskij, I. N.


    Modern vector of development of machining technologies aimed at the transition to environmentally safe technologies - “green” technologies. The concept of “green technology” includes a set of signs of knowledge intended for practical use (“technology”). One of the ways to improve the quality of production is the use of surface plastic deformation (SPD) processing methods. The advantage of the SPD is a capability to combine effects of finishing and strengthening treatment. The SPD processing can replace operations: fine turning, grinding or polishing. The SPD is a forceful contact impact of indentor on workpiece’s surface in condition of their relative motion. It is difficult to implement the core technology of the SPD (burnishing, roller burnishing, etc.) while maintaining core technological advantages without the use of lubricating and cooling technology (metalworking fluids, MWF). The “green” SPD technology was developed by the authors for dry processing and has not such shortcomings. When processing with SPD without use of MWF requirements for tool’s durability is most significant, especially in the conditions of mass production. It is important to determine the period of durability of tool at the design stage of the technological process with the purpose of wastage preventing. This paper represents the results of durability research of natural and synthetic diamonds (polycrystalline diamond - ASPK) as well as precision of polycrystalline superabrasive tools made of dense boron nitride (DBN) during SPD processing without application of MWF.

  2. Inverse Processing of Undefined Complex Shape Parts from Structural High Alloyed Tool Steel

    Katarina Monkova


    Full Text Available The paper deals with the process of 3D digitization as a tool for increasing production efficiency of complex shaped parts. Utilizes the concept of reverse engineering and new the model of NC program generation STEP-NC, for the of templates production for winding the stator coil of electromotors that is for electric household appliances. The manual production of prototype was substituted by manufacturing with NC machines. A 3D scanner was used for data digitizing, CAD/CAM system Pro/Engineering was used for NC program generation, and 3D measuring equipment was used for verification of new produced parts. The company estimated that only due to the implementation of STEP NC standard into production process it was allowed to read the 3D geometry of the product without problems. It helps the workshop to shorten the time needed for part production by about 30%.

  3. Size Effects in Residual Stress Formation during Quenching of Cylinders Made of Hot-Work Tool Steel

    Manuel Schemmel


    Full Text Available The present work investigates the residual stress formation and the evolution of phase fractions during the quenching process of cylindrical specimens of different sizes. The cylinders are made of hot-work tool steel grade X36CrMoV5-1. A phase transformation kinetic model in combination with a thermomechanical model is used to describe the quenching process. Two phase transformations are considered for developing a modelling scheme: the austenite-to-martensite transformation and the austenite-to-bainite transformation. The focus lies on the complex austenite-to-bainite transformation which can be observed at low cooling rates. For an appropriate description of the phase transformation behaviour nucleation and growth of bainite are taken into account. The thermomechanical model contains thermophysical data and flow curves for each phase. Transformation induced plasticity (TRIP is modelled by considering phase dependent Greenwood-Johnson parameters for martensite and bainite, respectively. The influence of component size on residual stress formation is investigated by the finite element package Abaqus. Finally, for one cylinder size the simulation results are validated by X-ray stress measurements.

  4. A Comparison between Microfabrication Technologies for Metal Tooling

    Uriarte, L.; Ivanov, A.; Oosterling, H


    The current paper is based on the information gathered within 4M Network activities, specifically in the "Processing of Metals" Division (Task 7.2 "Tooling"). The aim of the task involves a systematic analysis of the partners' expertise in different technologies for processing tooling inserts made...... of metal. The following technologies have been analysed: micromilling, microEDM (microelectro discharge machining, including wire-EDM, sinking-EDM and EDM-milling), laser micromachining, electroforming and ECF (an innovative process proposed by HSG-IMAT). Considered materials are nickel for electroforming......, stainless steel for ECF, and tool steel (AISI H13) for the other processes. Typical features (ribs, channels, pins and holes) required by microoptics, microfluidics and sensors and actuators applications have been selected to carry out this analysis The task results provide a global comparison between...

  5. Influencia del tiempo de nitruración en baño de sales en el comportamiento tribológico de un acero de herramientas AISI H13

    Castro, G.


    Full Text Available Tribological high temperature characteristics of a H13 tool steel treated by salt bath have been studied. AISI H13 steel samples were nitrided by a sursulf bath, varying nitriding time from 1 to 24 h. Optical microscopy and micro-hardness deep profile through the nitrided layer were performed for each nitriding time. Standard pin-on-disk wear tests were conducted at high temperature. Sliding distance was varied from 150 m to 900 m. It has been observed that friction coefficient does not change with nitriding time and wear rate varies as a function of the sliding distance due to the presence of different wear mechanisms. For short sliding distances, the wear mechanisms that contribute to the total wear were plastic deformation and abrasion, whereas for greater sliding distances the mechanisms that control wear behaviour were oxidation and abrasion.

    Se han investigado las características tribológicas a alta temperatura de un acero de herramientas para trabajo en caliente nitrurado en baño de sales sursulf. Se ha variado el tiempo de nitruración desde 1 hasta 24 h, para analizar su influencia en la microestructura obtenida y en el comportamiento frente al desgaste. Se han realizado ensayos de desgaste a alta temperatura y se ha evaluado la ratio de desgaste y el coeficiente de fricción. Se ha observado que el coeficiente de fricción no varía con el tiempo de nitruración y que la ratio de desgaste varía con la distancia de deslizamiento debido a la presencia de distintos mecanismos de desgaste, pero es independiente del tiempo de nitruración. Así, para distancias de ensayo cortas, los mecanismos de desgaste que contribuyen al desgaste total son deformación plástica y abrasión, mientras que para mayores distancias de deslizamiento los mecanismos observados son oxidación y abrasión.

  6. Assessment of the effect of Nd:YAG laser pulse operating parameters on the metallurgical characteristics of different tool steels using DOE software

    T. Muhič


    Full Text Available To ensure the reliability of repair welded tool surfaces, clad quality should be improved. The relationships between metallurgical characteristics of cladding and laser input welding parameters were studied using the design of experiments software. The influence of laser power, welding speed, focal point position and diameter of welding wire on the weld-bead geometry (i.e. penetration, cladding zone width and heat-affected-zone width, microstructural homogeneity, dilution and bond strength was investigated on commonly used tool steels 1,2083, 1,2312 and 1,2343, using DOE software.

  7. The material performance of HSS (high speed steel) tools and its relation with chemical composition and carbide distribution

    Darmawan, B.; Kusman, M.; Hamdani, R. A.


    The study aims to compare the performance of two types of material HSS (High Speed Steel) are widely used. It also will be the chemical composition and distribution of carbide particles therein. Two types of HSS are available in the market: HSS from Germany (Bohler) and HSS from China. This research employed the pure experimental design. It consists of two stages. The first, aims to test/operate lathe machines to determine the lifetime and performance of tools based on specified wear criteria. The second, characterization of microstructure using SEM-EDS was conducted. Firstly, grinding of toolss was done so that the toolss could be used for cutting metal in the turning process. Grinding processes of the two types of toolss were done at the same geometry, that is side rake angle (12°-18°), angle of keenness (60°-68°), and side relief angle (10°-12°). Likewise, machining parameters were set in the same machining conditions. Based on the results of the tests, it is found that to reach 0.2 mm wear point, toolss made of HSS from Germany needed 24 minutes, while toolss made of HSS from China needed 8 minutes. Next, microstructure tests using SEM/EDS were done. The results of the SEM tests indicate that the carbide particles of HSS from Germany were more evenly distributed than the carbide particles of HSS from China. Carbide compounds identified in HSS from China were Cr23C6 and Fe4Mo2C. Oxide impurity of Al2O3 was also found in the material. On the other hand, in HSS from Germany, no impurity and other carbide compounds were identified, except Cr23C6 and Fe4Mo2C, also Fe4W2C, and VC or V4C3.

  8. On the cutting tool of coated high speed steel%现代刀具材料系列讲座(三) 涂层高速钢刀具



    In this paper, the cutting performance of the cutting tool of coated high speed steel is introduced. Some cutting data of coated and uncoated high speed steel cutting tools are listed.%介绍了涂层高速钢刀具的切削性能,并列出了涂层与未涂层高速钢刀具的对比切削数据。

  9. A multi-scale approach to investigate the non linear subsurface behavior and strain localization of X38CrMoV5-1 martensitic tool steel: experiment and numerical analysis

    Zouaghi, A; Velay, V.; Soveja, A; Pottier, T; Cheikh, M.; Rézaï-Aria, F


    International audience; The cyclic mechanical behavior, the wear and fatigue resistances and damage developments of working surface of tool steels are dependent on microstructural features. A multi-scale approach combining experimental testing, numerical treatments and simulations is developed to model the surface behavior of X38CrMoV5-1 martensitic tool steels. The multi-scale modeling is coupled with finite element calculations. The elasto-viscoplastic constitutive equations used are based ...

  10. The refinement of the surface layer of HS 7425 high speed tool steel by laser and electric arc plasma

    W. Bochnowski


    Full Text Available The paper present two different techniques: laser remelting surface and plasma remelting surface of the high speed steel HS 7425. Thestructure of the remelted layers were examined by means of SEM – microscopy. Measurement of microhardness in remelting zone usingVickers method. The remelting zone consist of dendritic cells and columnar crystals. Increase of hardness was observed in remelted zonein comparison to the substrate of the steel. The hardness in the remelted zone increases with the increasing cooling rate.

  11. Synthesis, structural characterization, and reactivity studies of 5-CF3SO3-B10H13.

    Berkeley, Emily R; Ewing, William C; Carroll, Patrick J; Sneddon, Larry G


    In contrast to previous reactions carried out in cyclopentane solvent at room temperature that produced 6-TfO-B10H13 (TfO = CF3SO3), the reaction of closo-B10H10(2-) with a large excess of trifluoromethanesulfonic acid in the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate (bmimOTf) gave exclusively the previously unknown 5-TfO-B10H13 isomer. Experimental and computational studies demonstrated that the difference in the products of the two reactions is a result of 6-TfO-B10H13 isomerizing to 5-TfO-B10H13 above room temperature in bmimOTf solutions. Reactivity studies showed that 5-TfO-B10H13: (1) is deprotonated by reaction with 1,8-bis(dimethylamino)naphthalene to form the 5-TfO-B10H12(1-) anion; (2) reacts with alcohols to produce 6-RO-B10H13 boryl ethers (R = Me and 4-CH3O-C6H4); (3) undergoes olefin-hydroboration reactions to form 5-TfO-6,9-R2-B10H11 derivatives; and (4) forms a 5-TfO-6,9-(Me2S)2-B10H11 adduct at its Lewis acidic 6,9-borons upon reaction with dimethylsulfide. The 5-TfO-6,9-(Me2S)2-B10H11 adduct was also found to undergo alkyne-insertion reactions to form a range of previously unreported triflate-substituted 4-TfO-ortho-carboranes (1-R-4-TfO-1,2-C2B10H10) and reactions with triethylamine or ammonia to form the first TfO-substituted decaborate [R3NH(+)]2[2-TfO-B10H9(2-)], and [R3NH(+)]2[1-TfO-B10H9(2-)] (R = H, Et) salts.

  12. Functional properties of surface layers of X38CrMoV5-3 hot work tool steel alloyed with HPDL laser

    L.A. Dobrzański


    Full Text Available Purpose: Improvement of functional properties alloyed of hot work tool steel surface layers is one of the goals of this paper.Design/methodology/approach: The material used for investigation was the hot work tool steel X38CrMoV5-3. Remelting and alloying of surface layers were made using the HPDL high power diode laser Rofin DL 020 in the laser power range of 1.2-2.3 kW. The carbide powders were applied on specimens prepared and degreased in this way; the powder was mixed with the sodium glass as inorganic binder in proportion of 30% binder and 70% powder. Paste coating 0.5 mm thick was put down in each case.Findings: The hardness changes of the surface layers obtained by remelting and alloying with carbides using the high power diode laser are accompanied with the improved tribological properties compared to the conventionally heat treated steel. The highest abrasion wear resistance, more than 2.5 times higher than that of the base material, was revealed in case the steel alloyed with vanadium carbide.Research limitations/implications: These advantages are the result of features unique to the HPDL, such as: shorter wavelength (thus better beam absorption for most metallic materials, and smaller absorption length and better temporal beam stability (due to beam integration compared to Nd:YAG and CO2 lasers. HPDL materials processing is, therefore, expected to produce better quality and more consistent and repeatable results for applications requiring beam spot sizes larger than 0.5mm diameter. One of the issues of concern in the practical applications of the lasers in materials processing for mass production is the repeatability.Practical implications: The research results indicate to the feasibility and purposefulness of the practical use of remelting and alloying with the ceramic particles using the high power diode laser for manufacturing and regeneration of various tools from the X38CrMoV5-3 hot-work tool steel.Originality/value: The laser

  13. Experimental investigation on flank wear and tool life, cost analysis and mathematical model in turning hardened steel using coated carbide inserts

    Ashok Kumar Sahoo


    Full Text Available Turning hardened component with PCBN and ceramic inserts have been extensively used recently and replaces traditional grinding operation. The use of inexpensive multilayer coated carbide insert in hard turning is lacking and hence there is a need to investigate the potential and applicability of such tools in turning hardened steels. An attempt has been made in this paper to have a study on turning hardened AISI 4340 steel (47 ± 1 HRC using coated carbide inserts (TiN/TiCN/Al2O3/ZrCN under dry environment. The aim is to assess the tool life of inserts and evolution of flank wear with successive machining time. From experimental investigations, the gradual growth of flank wear for multilayer coated insert indicates steady machining without any premature tool failure by chipping or fracturing. Abrasion is found to be the dominant wear mechanisms in hard turning. Tool life of multilayer coated carbide inserts has been found to be 31 minute and machining cost per part is Rs.3.64 only under parametric conditions chosen i.e. v = 90 m/min, f = 0.05 mm/rev and d = 0.5 mm. The mathematical model shows high determination coefficient, R2 (99% and fits the actual data well. The predicted flank wear has been found to lie very close to the experimental value at 95% confidence level. This shows the potential and effectiveness of multilayer coated carbide insert used in hard turning applications.

  14. Optimization of Composition and Heat Treating of Die Steels for Extended Lifetime

    David Schwam; John F. Wallace; Quanyou Zhou


    An ''average'' die casting die costs fifty thousand dollars. A die used in making die cast aluminum engine blocks can cost well over one million dollars. These costs provide a strong incentive for extension of die life. While vacuum quenched Premium Grade H13 dies have become the most widely used in the United States, tool makers and die casters are constantly searching for new steels and heat treating procedures to extend die life. This project was undertaken to investigate the effects of composition and heat treating on die life and optimize these parameters.

  15. H12CN and H13CN excitation analysis in the circumstellar outflow of R Sculptoris

    Saberi, M.; Maercker, M.; De Beck, E.; Vlemmings, W. H. T.; Olofsson, H.; Danilovich, T.


    Context. The 12CO/13CO isotopologue ratio in the circumstellar envelope (CSE) of asymptotic giant branch (AGB) stars has been extensively used as the tracer of the photospheric 12C/13C ratio. However, spatially-resolved ALMA observations of R Scl, a carbon rich AGB star, have shown that the 12CO/13CO ratio is not consistent over the entire CSE. Hence, it can not necessarily be used as a tracer of the 12C/13C ratio. The most likely hypothesis to explain the observed discrepancy between the 12CO/13CO and 12C/13C ratios is CO isotopologue selective photodissociation by UV radiation. Unlike the CO isotopologue ratio, the HCN isotopologue ratio is not affected by UV radiation. Therefore, HCN isotopologue ratios can be used as the tracer of the atomic C ratio in UV irradiated regions. Aims: We aim to present ALMA observations of H13CN(4-3) and APEX observations of H12CN(2-1), H13CN(2-1, 3-2) towards R Scl. These new data, combined with previously published observations, are used to determine abundances, ratio, and the sizes of line-emitting regions of the aforementioned HCN isotopologues. Methods: We have performed a detailed non-LTE excitation analysis of circumstellar H12CN(J = 1-0, 2-1, 3-2, 4-3) and H13CN(J = 2-1, 3-2, 4-3) line emission around R Scl using a radiative transfer code based on the accelerated lambda iteration (ALI) method. The spatial extent of the molecular distribution for both isotopologues is constrained based on the spatially resolved H13CN(4-3) ALMA observations. Results: We find fractional abundances of H12CN/H2 = (5.0 ± 2.0) × 10-5 and H13CN/H2 = (1.9 ± 0.4) × 10-6 in the inner wind (r ≤ (2.0 ± 0.25) ×1015 cm) of R Scl. The derived circumstellar isotopologue ratio of H12CN/H13CN = 26.3 ± 11.9 is consistent with the photospheric ratio of 12C/13C 19 ± 6. Conclusions: We show that the circumstellar H12CN/H13CN ratio traces the photospheric 12C/13C ratio. Hence, contrary to the 12CO/13CO ratio, the H12CN/H13CN ratio is not affected by UV

  16. (1)H-(13)C NMR-Based Profiling of Biotechnological Starch Utilization.

    Sundekilde, Ulrik K; Meier, Sebastian


    Starch is used in food- and nonfood applications as a renewable and degradable source of carbon and energy. Insight into the chemical detail of starch degradation remains challenging as the starch constituents amylose and amylopectin are homopolymers. We show that considerable molecular detail of starch fragmentation can be obtained from multivariate analysis of spectral features in optimized (1)H-(13)C NMR spectroscopy of starch fragments to identify relevant features that distinguish processes in starch utilization. As a case study, we compare the profiles of starch fragments in commercial beer samples. Spectroscopic profiles of homooligomeric starch fragments can be excellent indicators of process conditions. In addition, differences in the structure and composition of starch fragments have predictive value for downstream process output such as ethanol production from starch. Thus, high-resolution (1)H-(13)C NMR spectroscopic profiles of homooligomeric fragment mixtures in conjunction with chemometric methods provide a useful addition to the analytical chemistry toolbox of biotechnological starch utilization.




    Full Text Available Electric discharge machining (EDM is a thermoelectric process in which electrical energy is converted into thermal energy and this thermal energy is used for the machining purpose. It is the common practice in EDM to make tool negative and work piece positive (direct polarity , but researches shows that reverse of it is also possible in which tool is positive and work piece is negative ( reverse polarity, but not much work has been carried out on the reverse polarity till now. This paper discusses the effect of tool polarity on the machining characteristics in electric discharge machining of silver steel. High metal removal rate, low relative electrode wear and good surface finish are conflicting goals, which can not be achieved simultaneously with a particular combination of control settings. To achieve the best machining results, the goal has to be taken separately in different phases of work with different emphasis. A 32 factorial design has been used for planning of experimental conditions. Copper is used as tool material and Silver steel of 28 grade is selected as work piece material with positive and negative polarities. The effectiveness of EDM process with silver steel is evaluated in terms of metal removal rate (MRR, percent relative electrode wear (%REW and the surface roughness (S.R ofthe work piece produced at different current and pulse duration levels. In this experimental work spark erosion oil (trade name IPOL is taken as a dielectric and experiments have been conducted at 50% duty factor. The study reveals that direct polarity is suitable for higher metal removal rate and lower relative electrode wear but reverse polarity gives better surface finish as compared to direct polarity. Direct polarity gives 4-11 times more MRR and 5 times less relative electrode wear as compared to reverse polarity, and reverse polarity gives 1.3-2.7 times better surface finish as compared to direct polarity. Second order regression model is also

  18. 1H-13C NMR-based profiling of biotechnological starch utilization

    Sundekilde, Ulrik K.; Meier, Sebastian


    Starch is used in food-and non-food applications as a renewable and degradable source of carbon and energy. Insight into the chemical detail of starch degradation remains challenging as the starch constituents amylose and amylopectin are homopolymers. We show that considerable molecular detail......-resolution 1H-13C NMR spectroscopic profiles of homooligomeric fragment mixtures in conjunction with chemometric methods provide a useful addition to the analytical chemistry toolbox of biotechnologi-cal starch utilization....

  19. Surface Layer States of Worn Uncoated and TiN-Coated WC/Co-Cemented Carbide Cutting Tools after Dry Plain Turning of Carbon Steel

    Johannes Kümmel


    Full Text Available Analyzing wear mechanisms and developments of surface layers in WC/Co-cemented carbide cutting inserts is of great importance for metal-cutting manufacturing. By knowing relevant processes within the surface layers of cutting tools during machining the choice of machining parameters can be influenced to get less wear and high tool life of the cutting tool. Tool wear obviously influences tool life and surface integrity of the workpiece (residual stresses, surface quality, work hardening, etc., so the choice of optimised process parameters is of great relevance. Vapour-deposited coatings on WC/Co-cemented carbide cutting inserts are known to improve machining performance and tool life, but the mechanisms behind these improvements are not fully understood. The interaction between commercial TiN-coated and uncoated WC/Co-cemented carbide cutting inserts and a normalised SAE 1045 steel workpiece was investigated during a dry plain turning operation with constant material removal under varied machining parameters. Tool wear was assessed by light-optical microscopy, scanning electron microscopy (SEM, and EDX analysis. The state of surface layer was investigated by metallographic sectioning. Microstructural changes and material transfer due to tribological processes in the cutting zone were examined by SEM and EDX analyses.

  20. Optimization of Round Steel Material Quota by Using Lean Tools%运用精益工具优化圆钢材料定额

    马广涛; 高志红; 贾丽蓉


    By using lean concept and lean tools,it was down that mathematics material preparation method optimization of round steel to get material quota.Through Combination of material preparation,reduced remanent material and improved material utilization.%运用精益理念,借助精益工具,采用数学下料法优化圆钢的材料定额,通过对零件组合下料,减少了余料,提高了材料利用率。

  1. Investigation of Surface Roughness and Material Removal Rate (MRR on Tool Steel Using Brass and Copper Electrode for Electrical Discharge Grinding (EDG Process

    M. Hafiz Helmi


    Full Text Available This paper presents the investigation on surface roughness and material removal rate (MRR of tool steel machined with brass and copper electrode for Electrical Discharge Grinding (EDG process. The machining parameter include pulse ON time, pulse OFF time, peak current and capacitance. Analysis of variance (ANOVA with Taguchi method is used to investigate the significant effect on the performance characteristic and the optimal cutting parameters of EDG. The result shows that, the surface roughness value when using of both tool materials are mostly influenced by pulse ON time and peak current. The capacitance parameter in both experiments was not giving any significant effect. The significant factors for the material removal rate due to the machining parameter are peak current parameter and ON time parameter but it also can increase the machining time

  2. Comparison between microfabrication technologies for metal tooling

    Uriarte, L.; Herrero, A.; Ivanov, A.


    This paper is based on the information gathered within the Multi-Material Micro-Manufacture (4M) Network activities in the Processing of Metals Division (Task 7.2 'Tooling') ( The aim of the task involves a systematic analysis of the partners' expertise in different microtechnolog......This paper is based on the information gathered within the Multi-Material Micro-Manufacture (4M) Network activities in the Processing of Metals Division (Task 7.2 'Tooling') ( The aim of the task involves a systematic analysis of the partners' expertise in different...... microtechnologies for processing tooling inserts made of metal. The following technologies have been analysed: micromilling, micro-electrodischarge machining (EDM, including wire-EDM, sinking-EDM, and EDM-milling), laser micromachining, electroforming, and electrochemical milling (ECF) (an electrochemical machining...... innovative process proposed by HSG-IMAT). Considered tool-insert materials are nickel for electroforming, stainless steel for ECF, and tool steel (AISI H13) for all other processes. Typical features (ribs, channels, pins, and holes) required by micro-optics, microfluidics, and sensor and actuator...

  3. Numerical Simulation and Experimental Verification of CMOD in SENT Specimen: Application on FCGR of Welded Tool Steel

    Amir SULTAN; Riffat Asim PASHA; Mifrah ALI; Muhammad Zubair KHAN; Muhammad Afzal KHAN; Naeem Ullah DAR; Masood SHAH


    Single-edged notched tension (SENT) specimen is used to study the fatigue crack growth rate (FCGR) behavior of AISI 50100 steel using MTS 810.Calibration tests are run to get plots of crack mouth opening displacement (CMOD) vs.load and CMOD vs.crack length-to-width ratio with the known crack lengths.Numerical simulation is also done to try to establish a relation between crack length and CMOD.FCGR of welded and un-welded specimens are plotted against stress intensity factor range to show the effect of welding on fatigue crack growth rate of AISI 50100 steel.The experimentally obtained CMOD values are compared with values obtained by numerical simulation using ABAQUS/StandardTM software package.Results show that numerical values are in good agreement with experimental data for small crack lengths and lower values of applied load.

  4. Static and Dynamic Performance Improvement of Conventional Computer Numerical Control Machine Tool Bed with Hybrid Welded Steel

    S. S. Abuthakeer; P. V. Mohanram; G. Mohankumar


    Problem statement: The advancements in machine tools to maximize the production by increasing spindle speeds have caused vibration in machine tools. The two functional requirements of machine tool bed for machine tools are high structural stiffness and high damping, which cannot be satisfied simultaneously if conventional metallic materials such as cast iron are employed. Hence there is a need to replace cast iron with alternate materials. Approach: The objective of this study is to improve t...

  5. Key to steel. 16. rev. and enlarged ed. Stahlschluessel

    Wegst, C.W.


    The DIN substance reference numbers and abbreviations have been related to the trademarks of the steelworks and steel supplies. DIN specifications are compared with foreign specifications for different types of steel (e.g. structural steel, tool steel, noble steel, high-temperature steel). (MM).

  6. Effect of cutting speed and feed in turning hardened stainless steel using coated carbide cutting tool under minimum quantity lubrication using castor oil

    Mohamed Handawi Saad Elmunafi


    Full Text Available Minimum quantity lubrication is a technique to have the advantages that cutting fluids bring yet keeping their use at minimum. For the cutting fluids, inedible vegetable oils are potential for minimum quantity lubrication machining. Castor oil was selected in this study as the cutting fluid for turning of hardened stainless steel (hardness of 47–48 HRC. The hard turning was with minimum quantity lubrication (50 mL/h flow rate and 5 bar air pressure at various cutting speeds (100, 135, and 170 m/min and feeds (0.16, 0.20, and 0.24 mm/rev. The machining responses were tool life, surface roughness, and cutting forces. Design of experiments was applied to quantify the effects of cutting parameters to the machining responses. Empirical models for tool life, surface roughness, and cutting forces were developed within the range of cutting parameters selected. All machining responses are significantly influenced by the cutting speed and feed. Tool life is inversely proportional to cutting speed and feed. Surface roughness is inversely proportional to cutting speed yet is proportional to feed. Cutting forces are more influenced by feed than by cutting speed. A combination of low cutting speed and feed was the optimum cutting parameters to achieve long tool life, low surface roughness, and low cutting forces.

  7. Material selection,hardness after heat treatment and use specification of steel extrusion toolings%钢挤压工模具材质选择、热处理硬度及使用规范

    包进平; 赵云路; 薛荣敬


    For the high temperature strength and toughness of the traditional hot working die steel materials can not meet the requirement of the steel extrusion toolings, and their comprehensive costs are high, so the hot working die steel material 1. 2367 suiting for steel extrusion toolings was proposed. And the differences between them and the traditional hot working die steel materials were compared. The material selection, suitable hardness after heat treatment and use specification of each steel extrusion toolings were described in detail. The frequently water cooling usually resulted in the die steel thermal fatigue, so the viewpoint of water cooling replaced by several toolings cycle use and natural cooling was proposed.%由于传统热作模具钢的高温强韧性不能满足钢挤压工模具的要求以及综合成本较高等原因,提出了适合用于钢挤压工模具的热作模具钢材质1.2367,并将其与传统热作模具钢进行对比;对各种钢挤压工模具材质选择、适宜的热处理硬度及使用规范进行了较为详细的叙述;对频繁水冷容易造成模具钢热疲劳的问题,提出了利用多件工模具循环使用并采取自然冷却的方法代替水冷的观点.

  8. GFT projection NMR for efficient (1)H/ (13)C sugar spin system identification in nucleic acids.

    Atreya, Hanudatta S; Sathyamoorthy, Bharathwaj; Jaipuria, Garima; Beaumont, Victor; Varani, Gabriele; Szyperski, Thomas


    A newly implemented G-matrix Fourier transform (GFT) (4,3)D HC(C)CH experiment is presented in conjunction with (4,3)D HCCH to efficiently identify (1)H/(13)C sugar spin systems in (13)C labeled nucleic acids. This experiment enables rapid collection of highly resolved relay 4D HC(C)CH spectral information, that is, shift correlations of (13)C-(1)H groups separated by two carbon bonds. For RNA, (4,3)D HC(C)CH takes advantage of the comparably favorable 1'- and 3'-CH signal dispersion for complete spin system identification including 5'-CH. The (4,3)D HC(C)CH/HCCH based strategy is exemplified for the 30-nucleotide 3'-untranslated region of the pre-mRNA of human U1A protein.

  9. Development of flank wear model of cutting tool by using adaptive feedback linear control system on machining AISI D2 steel and AISI 4340 steel

    Orra, Kashfull; Choudhury, Sounak K.


    The purpose of this paper is to build an adaptive feedback linear control system to check the variation of cutting force signal to improve the tool life. The paper discusses the use of transfer function approach in improving the mathematical modelling and adaptively controlling the process dynamics of the turning operation. The experimental results shows to be in agreement with the simulation model and error obtained is less than 3%. The state space approach model used in this paper successfully check the adequacy of the control system through controllability and observability test matrix and can be transferred from one state to another by appropriate input control in a finite time. The proposed system can be implemented to other machining process under varying range of cutting conditions to improve the efficiency and observability of the system.

  10. Development of a carburizing and quenching simulation tool: A material model for low carbon steels undergoing phase transformations

    Bammann, D.; Prantil, V.; Kumar, A. [Sandia National Labs., Livermore, CA (United States)] [and others


    An internal state variable formulation for phase transforming alloy steels is presented. We have illustrated how local transformation plasticity can be accommodated by an appropriate choice for the corresponding internal stress field acting between the phases. The state variable framework compares well with a numerical micromechanical calculation providing a discrete dependence of microscopic plasticity on volume fraction and the stress dependence attributable to a softer parent phase. The multiphase model is used to simulate the stress state of a quenched bar and show qualitative trends in the response when the transformation phenomenon is incorporated on the length scale of a global boundary value problem.

  11. Efficient syntheses of 5-X-B(10)H(13) Halodecaboranes via the photochemical (X = I) and/or base-catalyzed (X = Cl, Br, I) isomerization reactions of 6-X-B(10)H(13).

    Ewing, William C; Carroll, Patrick J; Sneddon, Larry G


    High yield syntheses of the 5-X-B(10)H(13) (5X) halodecaboranes have been achieved through the photochemical (X = I) or base-catalyzed (X = Cl, Br, I) isomerization reactions of their 6-X-B(10)H(13) (6X) isomers. 5I was obtained in 80% isolated yield upon the UV photolysis of 6I. Treatment of 6X (X = Cl, Br, I) with catalytic amounts of triethylamine at 60 degrees C led to the formation of 78:22 (Cl), 82:18 (Br), and 86:14 (I) ratio 5X/6X equilibrium mixtures. The 5X isomers were then separated from these mixtures by selective crystallization (Br and I) or column chromatography (Cl), with the supernatant mixtures in each case then subjected to another round of isomerization/separation to harvest a second crop of 5X. The combined isolated yields of pure products after two cycles were 71% 5-Cl-B(10)H(13), 83% 5-Br-B(10)H(13), and 68% 5-I-B(10)H(13). The previously proposed structures of 5-Br-B(10)H(13) and 5-I-B(10)H(13) were crystallographically confirmed. Deprotonation of 6X and 5X with 1,8-bis(dimethylamino)naphthalene (PS) resulted in the formation of [PSH(+)][6X(-)] and [PSH(+)][5X(-)]. Density functional theory-gauge-independent atomic orbital (DFT/GIAO) calculations and crystallographic determinations of [PSH(+)][6Cl(-)] and [PSH(+)][6Cl(-)] confirmed bridge-deprotonation at a site adjacent to the halogen-substituted borons. NMR studies of the 6-Br-B(10)H(13) isomerization induced by stoichiometric amounts of PS showed that following initial deprotonation to form 6-Br-B(10)H(12)(-), isomerization occurred at 60 degrees C to form an equilibrium mixture of 6-Br-B(10)H(12)(-) and 5-Br-B(10)H(12)(-). DFT calculations also showed that the observed 5-X-B(10)H(13)/6-X-B(10)H(13) equilibrium ratios in the triethylamine-catalyzed reactions were consistent with the energetic differences of the 5-X-B(10)H(12)(-) and 6-X-B(10)H(12)(-) anions. These results strongly support a mechanistic pathway for the base-catalyzed 6X to 5X conversions involving the formation and

  12. Magnetic Hysteresis Loop as a Tool for the Evaluation of Microstructure and Mechanical Properties of DP Steels

    Mohapatra, J. N.; Kumar, Satendra; Akela, Arbind Kumar; Prakash Rao, S.; Kaza, Marutiram


    DP steel of 1.3-mm thickness full hard sheet was heat treated at different temperatures in the range of 700-850 °C with 25 °C step for 15 min soaking followed by water quenching. The variation of the soaking temperatures leads to variation of volume fraction of martensite which was measured by image analysis software in optical microscopy. Mechanical properties of the samples were evaluated using micro Vicker's hardness test and tensile test machine. Magnetic properties of the samples were measured by MagStar to correlate with the microstructure and mechanical properties of the samples. It was observed that the coercivity of the samples increased linearly with the increase in volume fraction of martensite and mechanical properties. Hence monitoring coercivity would help non-destructive evaluation of mechanical properties of the DP steels. Additionally, it would also helpful for the non-destructive evaluation of variation in heat treatment conditions since coercivity also found to increase linearly with the increase in soaking temperature.

  13. Regression Modeling Of Cutting Parameters' Effect To Cutting Forces And Hole Surface Qualities In Drilling Of Dievar Hot Work Tool Steel

    İskender Özkul


    Full Text Available In this study, cutting moments, surface roughness, dimensional accuracy and circularity deviation values were investigated during drilling on Dievar degree of hot work tool steels with various drill bits. The experiments, was completed with Ø16 mm diameter uncoated carbide drill bits and TiAlN coated self-reamed carbide drill bits using coolant fluid on vertical machining center. In experiments, feed rate 0,16 mm/rev and the cutting speed 36, 40, 44, 48 m/min rates were used. The results were modeled by the method of linear regression and polynomial regression curve. Then they were compared with values equal significance. At the same time by analysis of variance, the cutting speed and drill type were investigated on the results of axial feed force, cutting torque, surface roughness, dimensional accuracy and circularity the deviation.

  14. An estimation of stress intensity factor in a clamped SE(T)specimen through numerical simulation and experimental verification: case of FCGR of AISI H11 tool steel

    Masood Shah; Catherine Mabru; Farhad Rezai-Aria; Ines Souki; Riffat Asim Pasha


    A finite element analysis of stress intensity factors (KI) in clamped SE(T)c specimens (dog bone profile) is presented.A J-integral approach is used to calculate the values of stress intensity factors valid for 0.125≤a/W≤0.625.A detailed comparison is made with the work of other researchers on rectangular specimens.Different boundary conditions are explored to best describe the real conditions in the laboratory.A sensitivity study is also presented to explore the effects of variation in specimen position in the grips of the testing machine.Finally the numerically calculated SIF is used to determine an FCGR curve for AISI H11 tool steel on SE(T)c specimens and compared with C(T) specimen of the same material.


    Henrik Jesperson


    Full Text Available Gross cracking of die-casting dies with inferior toughness sometimes occurs through too low preheating temperature and/or too slow cooling during quenching. This study aimed to clarify the influence of cooling rate on the toughness of the hot-work tool steel grade Uddeholm Vidar Superior at ambient temperature and at 200 °C, a typical preheating temperature for aluminium die-casting dies. Toughness was measured through instrumented Charpy V-notch impact testing. The decrease in energy absorption with increasing cooling time between 800°C and 500°C both at both ambient temperature and 200 °C was pronounced. At ambient temperature, the decrease in total energy was a consequence of a decrease in initiation energy whereas, at 200 °C, the decrease in total energy was due to a decrease in propagation energy.


    Özgür TEKASLAN


    Full Text Available In this study, cutting forces occurring in the machining process of AISI 304 austenitic stainless steel specimen using titanium coated cutting tools are investigated experimentally and the results are compared to theoretical calculations. In the experimental study, various cutting speeds, feed rates and cutting depths are considered. Cutting forces are measured by 3-dimensional Kistler dynamometer. In the theoretically study, cutting forces are determined by Kienzle formulation. Consequently, it is found that the calculation of cutting forces in the theoretical method doesn't yield the exact results because of various factors and there is a % 25 average differences in accordance with the experimental results. Hence it is evaluated that the experimental technique in the determination of cutting forces yields more accurate results.

  17. Modeling and multi-objective optimization of surface roughness and productivity in dry turning of AISI 52100 steel using (TiCN-TiN coating cermet tools

    Ouahid Keblouti


    Full Text Available The present work concerns an experimental study of turning with coated cermet tools with TiCN-TiN coating layer of AISI 52100 bearing steel. The main objectives are firstly focused on the effect of cutting parameters and coating material on the performances of cutting tools. Secondly, to perform a Multi-objective optimization for minimizing surface roughness (Ra and maximizing material removal rate by desirability approach. A mathematical model was developed based on the Response Surface Methodology (RSM. ANOVA method was used to quantify the cutting parameters effects on the machining surface quality and the material removal rate. The results analysis shows that the feed rate has the most effect on the surface quality. The effect of coating layers on the surface quality is also studied. It is observed that a lower surface roughness is obtained when using PVD (TiCN-TiN coated insert when compared with uncoated tool. The values of root mean square deviation and coefficient of correlation between the theoretical and experimental data are also given in this work where the maximum calculated error is 2.65 %.

  18. Plasma nitriding and simultaneous tempering of VF 800AT tool steel; Nitretacao por plasma com revenimento simultaneo do aco ferramenta VF 800AT

    Prass, Andre Ricardo; Fontana, Luis Cesar; Recco, Abel Andre Candido, E-mail:, E-mail:, E-mail: [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil)


    Plasma nitriding of tool steels improves the surface hardness due to formation of diffusion zone and/or compound layer. The process parameters such as temperature, gas composition and dwell time, allow to control the layer thickness, the microstructure, the crystalline phases and the type of layer (for example white layer or diffusion zone). This paper discusses an alternative procedure for the heat treatment of tempering and surface treatment, both in plasma or combining conventional heat treatment with subsequent plasma nitriding. Carrying out both treatments in plasma could enable reduction in manufacturing costs, lower energy consumption and less time for tools manufacturing. Samples of VF800AT steel were treated and characterized (at surface and core of samples) through the following technique: X-ray diffraction, optical microscopy, scanning electron microscopy, micro-hardness profile and Rockwell C measurement. Temperature measurements during the plasma treatment, show that arise thermal gradient between the surface and the core of the samples. In this work, it was observed that the surface was up to 7% hotter than the core of sample, during the plasma treatment with temperature of magnitude about 5 x 10{sup 2} °C. This thermal gradient seems inherent to the plasma process, so that it can produce different microstructure, hardness and crystalline phases between core and edge of samples. However, when two tempering operations are prior carried out in a muffle furnace and the third tempering treatment is subsequently carried out simultaneously with the plasma nitriding, it is observed that the microstructure, the crystalline phases, hardness and micro hardness (in both, edge and core) are similar to treatments done in conventional mode cycle (in muffle furnace) with subsequent plasma nitriding. (author)

  19. EBSD as a tool to identify and quantify bainite and ferrite in low-alloyed Al-TRIP steels.

    Zaefferer, S; Romano, P; Friedel, F


    Bainite is thought to play an important role for the chemical and mechanical stabilization of metastable austenite in low-alloyed TRIP steels. Therefore, in order to understand and improve the material properties, it is important to locate and quantify the bainitic phase. To this aim, electron backscatter diffraction-based orientation microscopy has been employed. The main difficulty herewith is to distinguish bainitic ferrite from ferrite because both have bcc crystal structure. The most important difference between them is the occurrence of transformation induced geometrically necessary dislocations in the bainitic phase. To determine the areas with larger geometrically necessary dislocation density, the following orientation microscopy maps were explored: pattern quality maps, grain reference orientation deviation maps and kernel average misorientation maps. We show that only the latter allow a reliable separation of the bainitic and ferritic phase. The kernel average misorientation threshold value that separates both constituents is determined by an algorithm that searches for the smoothness of the boundaries between them.

  20. Surface Roughness and Tool Wear on Cryogenic Treated CBN Insert on Titanium and Inconel 718 Alloy Steel

    Thamizhmanii, S.; Mohideen, R.; Zaidi, A. M. A.; Hasan, S.


    Machining of materials by super hard tools like cubic boron nitride (cbn) and poly cubic boron nitride (pcbn) is to reduce tool wear to obtain dimensional accuracy, smooth surface and more number of parts per cutting edge. wear of tools is inevitable due to rubbing action between work material and tool edge. however, the tool wear can be minimized by using super hard tools by enhancing the strength of the cutting inserts. one such process is cryogenic process. this process is used in all materials and cutting inserts which requires wear resistance. the cryogenic process is executed under subzero temperature -186° celsius for longer period of time in a closed chamber which contains liquid nitrogen. in this research, cbn inserts with cryogenically treated was used to turn difficult to cut metals like titanium, inconel 718 etc. the turning parameters used is different cutting speeds, feed rates and depth of cut. in this research, titanium and inconel 718 material were used. the results obtained are surface roughness, flank wear and crater wear. the surface roughness obtained on titanium was lower at high cutting speed compared with inconel 718. the flank wear was low while turning titanium than inconel 718. crater wear is less on inconel 718 than titanium alloy. all the two materials produced saw tooth chips.

  1. BEBE(tr) and BUBI: J-compensated concurrent shaped pulses for 1H-13C experiments.

    Ehni, Sebastian; Luy, Burkhard


    Shaped pulses designed for broadband excitation, inversion and refocusing are important tools in modern NMR spectroscopy to achieve robust pulse sequences especially in heteronuclear correlation experiments. A large variety of mostly computer-optimized pulse shapes exist for different desired bandwidths, available rf-field strengths, and tolerance to B1-inhomogeneity. They are usually derived for a single spin 1/2, neglecting evolution due to J-couplings. While pulses with constant resulting phase are selfcompensated for heteronuclear coupling evolution as long as they are applied exclusively on a single nucleus, the situation changes for concurrently applied pulse shapes. Using the example of a (1)H,(13)C two spin system, two J-compensated pulse pairs for the application in INEPT-type transfer elements were optimized: a point-to-point pulse sandwich called BEBE(tr), consisting of a broadband excitation and time-reversed excitation pulse, and a combined universal rotation and point-to-point pulse pair called BUBI, which acts as a refocusing pulse on (1)H and a corresponding inversion pulse on (13)C. After a derivation of quality factors and optimization protocols, a theoretical and experimental comparison with conventionally derived BEBOP, BIBOP, and BURBOP-180° pulses is given. While the overall transfer efficiency of a single pulse pair is only reduced by approximately 0.1%, resulting transfer to undesired coherences is reduced by several percent. In experiments this can lead to undesired phase distortions for pairs of uncompensated pulse shapes and even differences in signal intensities of 5-10% in HSQC and up to 68% in more complex COB-HSQC experiments.

  2. Simulation of Drawing of Small Stainless Steel Platinum Medical Tubes—Influence of the Tool Parameters on the Forming Limit

    Linardon, Camille; Affagard, Jean-Sébastien; Chagnon, Grégory; Favier, Denis; Gruez, Benoit


    Tube cold drawing processes are used to reduce tube diameters and thickness, while pulling them through a conical converging die with or without inner plug. An accurate modelling of the material deformation and friction behaviour is required in order to well describe these processes. The study concerns a stainless steel platinum alloy. The material behaviour is characterised through tensile tests at strain rates as close as possible to the high strain rates reached during the drawing process. The results are fitted with an isotropic temperature-independent Johnson Cook constitutive equation. The modelling of floating plug drawing is performed on a ABAQUS/Explicit model. Friction coefficient is difficult to estimate with mechanical experimental tests, thus an inverse analysis is carried out to fit this parameter thanks to finite element simulation and experimental drawing tests. Drawing force measurements are recorded during the forming process. The Cockroft-Latham criterion is applied to understand the different process parameters influence on tube drawing and its accuracy for drawing process is evaluated.

  3. Improvement of the surface finish obtained by laser ablation with a Nd: YAG laser on pre-ablated tool steel

    Steyn, J


    Full Text Available Surface finish is an important requirement for tool and die makers and remains a challenge with conventional machining technologies. Nd: YAG lasers have been utilised for many years in the area of laser marking, engraving and micro machining...

  4. Study on the influence of fluid application parameters on tool vibration and cutting performance during turning of hardened steel

    P. Sam Paul


    Full Text Available Recently the concept of hard turning has gained much attention in the metal cutting industry. In hard turning, multiple operations can be performed in single step, thereby it replaces the traditional process cycle. But it involves very large quantities of cutting fluid. Procurement, storage and disposal of cutting fluid involve expenses and environmental problem. Pure dry turning is a solution to this problem as it does not require any cutting fluid at all. But pure dry turning requires ultra hard cutting tools and extremely rigid machine tools, and also it is difficult to implement in the existing shop floor as the machine tool may not be rigid enough to support hard turning. In this context, turning with minimal fluid application is a viable alternative wherein, extremely small quantities of cutting fluid are introduced at critical contact zones as high velocity pulsing slugs, so that for all practical purposes it resembles pure dry turning and at the same time free from all the problems related to large scale use of cutting fluid as in conventional wet turning. In this study, fluid application parameters that characterize the minimal fluid application scheme were optimized and its effect on cutting performance and tool vibration was studied. From the results, it was observed that minimal fluid application in the optimized mode brought forth low vibration levels and better cutting performance.

  5. Tool life of the edges coated with the c-BN+h-BN coatings with different structures during hard machinable steel machining

    Kupczyk, M.


    Full Text Available In the presented paper the experimental results concerning the functional quality (durability during steel machining of thin, superhard coatings produced on the cutting edges are described. Differences among mentioned properties of coatings mainly result from a coating structure. But the structure of coatings results from deposition parameters Superhard boron nitride coatings were deposited on insert cutting edges made of cemented carbides by the pulse-plasma method applying different values of the discharge voltage. The comparative investigations of mentioned coatings have been concerned of tool life of edges during hard machinable material machining (nitriding steel hardened in oil. In these investigations for the purpose of additional increase of coatings adhesion to substrates an interfacial layers were applied.

    En este trabajo se describen los resultados experimentales referentes a la calidad funcional (durabilidad durante el mecanizado del acero de recubrimientos delgados, de elevada dureza del filo de corte. Las diferencias en las propiedades de los recubrimientos se deben, principalmente, a la estructura del recubrimiento. No obstante, la estructura del recubrimiento está relacionada con los parámetros de la deposición. Recubrimientos de nitruro de boro de elevada dureza se depositaron sobre filos de corte insertados, fabricados con carburos cementados mediante el método de pulsos de plasma aplicando diferentes valores de voltaje de descarga. Las investigaciones comparativas de los mencionados recubrimientos han relacionado la vida del filo de la herramienta durante el mecanizado del material (acero nitrurado endurecido en aceite. En estas investigaciones se aplicaron capas interfaciales para aumentar la adherencia del recubrimiento.

  6. Study on the PcBN cutting tools proprerties during hardened steel machining%PcBN加工淬硬钢刀具材料的研究

    李启泉; 张旺玺


    PcBN cutting tool materials were prepared using two kinds of binder and in three different concentrations of cBN . Through cutting experiment on hardened steel , it was found that cBN concentration played a key role on the performances of PcBN. After cutting for the same distance, PcBN tools of low concentration had smaller amount of flank wear. SEM observation revealed that CoAl alloy powder improved the density of the PcBN tool material. Based on the results of wear resistance test , it is suggested that the technical indicators of wear test for PCD is not suitable for PcBN.%介绍了立方氮化硼刀具材料( PcBN)的制备过程,并制备了六种不同配方的样品加工淬硬钢.通过切削实验和性能检测,发现PcBN刀片在加工淬硬钢时cBN浓度起着关键作用,切削同样的路程,低浓度PcBN的后刀面磨损量小.经扫描电镜观察,CoAl合金粉能够提高PcBN烧结刀具材料的致密度.测量耐磨性时,证明用于金刚石复合片PCD性能检测的磨耗比技术指标不适用于PcBN材料的检测.

  7. Geological Mapping of the Ac-H-13 Urvara Quadrangle of Ceres from NASA's Dawn Mission

    Sizemore, Hanna; Williams, David; Platz, Thomas; Mest, Scott; Yingst, Aileen; Crown, David; O'Brien, David; Buczkowski, Debra; Schenk, Paul; Scully, Jennifer; Jaumann, Ralf; Roatsch, Thomas; Preusker, Frank; Nathues, Andreas; De Sanctis, Maria Cristina; Russell, Christopher; Raymond, Carol


    The Dawn Science Team is conducting a geologic mapping campaign for Ceres similar to that done for Vesta [1,2], including production of a Survey- and High Altitude Mapping Orbit (HAMO)-based global map, and a series of 15 Low Altitude Mapping Orbit (LAMO)-based quadrangle maps. In this abstract we discuss the geologic evolution of the Ac-H-13 Urvara Quadrangle. At the time of this writing LAMO images (35 m/pixel) are just becoming available. Thus, our geologic maps are based on HAMO images (140 m/pixel) and Survey (400 m/pixel) digital ter-rain models (for topographic information). Dawn Framing Camera (FC) color images are also used to provide context for map unit identification. The maps to be presented as posters will be updated from analyses of LAMO images. The Urvara Quadrangle is dominated by the 170-km diameter impact basin Urvara (46.4°S, 248.6°E) and includes cratered terrain to the west. Named features include the impact craters Meanderi (40.9°S, 193.7°E, 103 km diameter), Sekhet (66.4°S, 254.9°E, 41 km diameter), and Fluusa (31.5°S, 277.9°E), as well as the crater chains Gerber Catena (38.1°S, 214.8°E) and Sam-hain Catena (19.6°S, 210.3°E). Based on preliminary geologic mapping [3,4], we interpret the two prominent catenae as pit craters associated with large scale tectonism rather than secondary impacts. We interpret two large curvilinear depressions near the eastern quadrangle boundary as secondary crater chains resulting from the Urvara impact. Textural and morphological asymme-tries in crater materials within the quadrangle indicate heterogeneities in subsurface composition and volatile content. Features on the Urvara basin floor are consistent with impact fluidization of target materials; post impact extrusion of volatile rich material may have also played a minor role. References: [1] Williams D.A. et al. (2014) Icarus, 244, 1-12. [2] Yingst R.A. et al. (2014) PSS, 103, 2-23. [3] Sizemore et al. (2015) GSA Abstracts with Program

  8. The metal-tool contact friction at the ultrasonic vibration drawing of ball-bearing steel wires

    Susan, Mihai


    Full Text Available The friction reversion mechanism during the ultrasonic vibration drawing (UVD of wires has been detailed for the case when the die is located at the oscillation maxima of the waves and actuated parallel to the friction force direction. The decrease of the drawing force for the UVD technology as compared to classical drawing has been explained by means of the intermittent contact in the metal-die forming area. A relationship has been derived for the UVD friction coefficient, μUS that allowed the analytical determination of the drawing force. In the case of the Romanian RUL 1V (AISI 52100 ball bearing steel wires, a good agreement has been found between the analytical and the experimental values of the drawing forces that have decreased, as compared to classical drawing, by more than 5 % for drawing rates lower than 0.66m/s.

    Se hace un análisis pormenorizado del mecanismo de reversión de la fricción al estirado por vibraciones ultrasonoras (EVU de los alambres, para el caso en que la trefiladora está ubicada en los máximos de oscilación de las ondas y activada paralelamente a la dirección de estirado. La disminución de la fuerza de estirado para la tecnología EVU en comparación con el estirado clásico, se ha explicado a través del contacto intermitente en el área de deformación metal-herramienta. Se halló una relación para el coeficiente de fricción EVU, μUS que permitió la determinación analítica de la fuerza de estirado. En el caso de los alambres de acero rumano de rodamientos RUL 1V (AISI 52100 se encontró una justa concordancia entre los valores analítico y experimental de la fuerza de estirado que, en comparación con los de estirado clásico, se encontraron disminuidos en más de un 5 % para velocidades de estirado menores de 0,66m/s.

  9. Molecular characterization and phylogenetics of a reassortant H13N8 influenza virus isolated from gulls in Mongolia

    A double reassortant H13N8 influenza A virus was isolated from gulls in Mongolia. The basic virological characteristics were studied. Complete genome sequence analysis indicated the complicated evolutionary history. The PA gene belongs to classical Avian-like lineage and more likely originated fro...

  10. Probing interactions between B-glucan and bile salts at atomic detail by 1H-13C NMR assays

    Mikkelsen, Mette Skau; Cornali, Sofia Bolvig; Jensen, Morten G


    -glucans and conjugated bile salts are among the possible molecular mechanisms explaining the hypocholesterolemic effects of β-glucans. The present study shows that 1H-13C NMR assays on a time scale of minutes detect minute signal changes in both bile salts and β-glucans, thus indicating dynamic interactions between bile...

  11. Stahlschüssel key to steel

    Wegst, W S


    The Key to Steel (Stahlschlüssel/Stahlschluessel) cross reference book will help you to decode / decipher steel designations and find equivalent materials worldwide. The 2016 edition includes more than 70,000 standard designations and trade names from approximately 300 steelmakers and suppliers. Presentation is trilingual: English, French, and German. Materials covered include structural steels, tool steels, valve steels, high temperature steels and alloys, stainless and heat-resisting steels, and more. Standards and designations from 25 countries are cross-referenced.

  12. Optimization of process parameters on EN24 Tool steel using Taguchi technique in Electro-Discharge Machining (EDM)

    Jeykrishnan, J.; Vijaya Ramnath, B.; Akilesh, S.; Pradeep Kumar, R. P.


    In the field of manufacturing sectors, electric discharge machining (EDM) is widely used because of its unique machining characteristics and high meticulousness which can't be done by other traditional machines. The purpose of this paper is to analyse the optimum machining parameter, to curtail the machining time with respect to high material removal rate (MRR) and low tool wear rate (TWR) by varying the parameters like current, pulse on time (Ton) and pulse off time (Toff). By conducting several dry runs using Taguchi technique of L9 orthogonal array (OA), optimized parameters were found using analysis of variance (ANOVA) and the error percentage can be validated and parameter contribution for MRR and TWR were found.

  13. Performance Steel Castings


    alloys , foundry, muzzle brake, supply center, tooling, sources Notice Distribution Statement A Format Information Report created in Microsoft Word...Development of Sand Properties 103 Advanced Modeling Dataset.. 105 High Strength Low Alloy (HSLA) Steels 107 Steel Casting and Engineering Support...University, University of Northern Iowa, Non- Ferrous Founders’ Society, QuesTek,, Spokane Industries, Nova Precision Casting, Waukesha

  14. Influence of Hardness, Matrix and Carbides in Combination with Nitridation on Abrasive Wear Resistance of X210Cr12 Tool Steel

    Martin Orečný


    Full Text Available Materials used in abrasive wear conditions are usually selected according to their microstructure and hardness, however, other factors such as grain size, matrix saturation, carbides size and morphology are rarely considered. Therefore, the present study deals with the influence of different heat and chemical-heat treatments including their combination on abrasive wear resistance of X210Cr12 tool steel. The effects of material hardness, carbide morphology and microstructure on wear resistance after quenching and nitriding were also investigated. One sample series was quenched after austenitization at 960 °C for 20 min and tempered at 180 °C for 2 h. The second sample series was quenched from 1060 °C austenitization for 20 min and afterwards twice tempered at 530 °C for 1 h. From both the quenched and tempered states, one half of the samples was gas nitrided in NH3 atmosphere for 3 h and then diffusion annealed in N2 atmosphere for 4 h. Abrasion wear tests were performed by sliding the samples on Al2O3 paper. The samples weight loss was considered the main criterion for the wear resistance evaluation. The microstructures, nitrided layers and worn surfaces were observed using SEM microscopy. The highest abrasion wear resistance was obtained for the nitrided samples that were previously quenched from 1060 °C and tempered at 530 °C.

  15. Atom probe study of the carbon distribution in a hardened martensitic hot-work tool steel X38CrMoV5-1.

    Lerchbacher, Christoph; Zinner, Silvia; Leitner, Harald


    The microstructure of the hardened common hot-work tool steel X38CrMoV5-1 has been characterized by atom probe tomography with the focus on the carbon distribution. Samples quenched with technically relevant cooling parameters λ from 0.1 (30 K/s) to 12 (0.25 K/s) have been investigated. The parameter λ is an industrially commonly used exponential cooling parameter, representing the cooling time from 800 to 500 °C in seconds divided with hundred. In all samples pronounced carbon segregation to dislocations and cluster formation could be observed after quenching. Carbon enriched interlath films with peak carbon levels of 6-10 at.%, which have been identified to be retained austenite by TEM, show a thickness increase with increasing λ. Therefore, the fraction of total carbon staying in the austenite grows. This carbon is not available for the tempering induced precipitation of secondary carbides in the bulk. Through all samples no segregation of any substitutional elements takes place. Charpy impact testing and fracture surface analysis of the hardened samples reveal the cooling rate induced microstructural distinctions.

  16. Metabolite Characterization in Peritoneal Dialysis Effluent Using High-resolution 1H and 1H-13C NMR Spectroscopy

    Guleria, Anupam; Rawat, Atul; Khetrapal, C L; Prasad, Narayan; Kumar, Dinesh


    Metabolite analysis of peritoneal dialysis (PD) effluent may provide information regarding onset and progression of complications associated with prolonged PD therapy. In this context, the NMR detectable small metabolites of PD effluent samples were characterized using high resolution 1H and 1H-13C NMR spectroscopy. The various spectra were recorded (at 800 MHz proton frequency) on PD effluent samples obtained after 4 hour (intraperitoneal) dwell time from patients with end stage renal failure (ESRF) and continuing normally on PD therapy. Inspite of devastating spectral feature of PD effluent due to the presence of intense resonances from glucose and lactate, we were able to identify about 53 small endogenous metabolites (including many complex coupled spin systems) and more than 90 % of the total CH cross peaks of 1H-13C HSQC spectrum were identified specific to various metabolites of PD effluent. We foresee that the characteristic fingerprints of various metabolites of control PD effluent samples will be us...

  17. Steel making

    Chakrabarti, A K


    "Steel Making" is designed to give students a strong grounding in the theory and state-of-the-art practice of production of steels. This book is primarily focused to meet the needs of undergraduate metallurgical students and candidates for associate membership examinations of professional bodies (AMIIM, AMIE). Besides, for all engineering professionals working in steel plants who need to understand the basic principles of steel making, the text provides a sound introduction to the subject.Beginning with a brief introduction to the historical perspective and current status of steel making together with the reasons for obsolescence of Bessemer converter and open hearth processes, the book moves on to: elaborate the physiochemical principles involved in steel making; explain the operational principles and practices of the modern processes of primary steel making (LD converter, Q-BOP process, and electric furnace process); provide a summary of the developments in secondary refining of steels; discuss principles a...

  18. Steel Spring


    Tarnished Hebei Iron and Steel Group regains chance to shine A lthough it is too early to tell whether the steel-making sector has emerged [from its gloom, a big divide is openling between China’s large and small producers. While most of the marginal players are still reeling from a market contagion, steel titans like the Shanghai-based Baosteel

  19. Una herramienta para la selección automatizada de aceros en el contexto // A tool for the automated selection of steels in the Mechanical Engineering´s context

    L. Dumitrescu


    Full Text Available ResumenEl diseno de Ingenieria de un producto o componente constituye una actividad dificil, compleja ymultidisciplinaria, enfocada a la resolucion de problemas. En el presente trabajo se muestra eldesarrollo de una herramienta automatizada para la seleccion de los aceros mas utilizados en laconstruccion de maquinarias. La herramienta constituye una ayuda para la seleccion de losmateriales desde la etapa conceptual del proceso de diseno, donde se identifican las diferentescategorias de materiales a utilizar. La herramienta comprende las caracteristicas y propiedades masrelevantes de los aceros de Ingenieria disponibles en seis normas internacionales: Japonesa (JIS,Alemana (DIN, Vbn, DIN-Vbn, Rusa (GOST, Americana (AISI, SAE, AISI-SAE, ASTM, Inglesa (BS, EN,GB, Francesa (AFNOR y la Norma Cubana (NC vigente.Palabras claves: materiales, automatizada, aceros, ingenieria.____________________________________________________________AbstractThe product or component design constitutes a difficult, complex and multidisciplinary activity,focused to the resolution of problems. Presently work show the development of an automated toolfor the selection of the more used steels in the construction of machineries. The tool constitute ahelp for the selection of the materials from the conceptual stage of the design process, where thedifferent categories of materials are identified to use. The tool analyze the characteristics and morecommon properties of the available steels in six international standards: JIS (Japan, DIN, Vbn, DINVbn(Germany, GOST (Russia, AISI, SAE, AISI-SAE, ASTM (USA, BS, IN, GB (England, AFNOR(France and NC (Cuba.Key words: materials, automated, steels, engineering.

  20. Micromilling of hardened tool steels

    Li, P.


    Miniaturized parts are increasingly demanded in different fields like medical, transportation, environmental, and communication industries. In order to manufacture these parts in an economical way, mass replication methods, such as micro injection molding, have to be applied. Currently, Electro Disc

  1. Performance evaluation of minimum quantity lubrication by vegetable oil in terms of cutting force, cutting zone temperature,tool wear, job dimension and surface finish in turning AISI-1060 steel

    KHAN M.M.A.; DHAR N.R.


    In all machining processes, tool wear is a natural phenomenon and it leads to tool failure. The growing demands for high productivity of machining need use of high cutting velocity and feed rate. Such machining inherently produces high cutting temperature, which not only reduces tool life but also impairs the product quality. Metal cutting fluid changes the performance of machining operations because of their lubrication, cooling and chip flushing functions, but the use of cutting fluid has become more problematic in terms of both employee health and environmental pollution. The minimization of cutting fluid also leads to economical benefits by way of saving lubricant costs and workpiece/tool/machine cleaning cycle time. The concept of minimum quantity lubrication (MQL) has been suggested since a decade ago as a means of addressing the issues of environmental intrusiveness and occupational hazards associated with the airborne cutting fluid particles on factory shop floors. This paper deals with experimental investigation on the role of MQL by vegetable oil on cutting temperature, tool wear, surface roughness and dimensional deviation in turning AISI-1060 steel at industrial speed-feed combinations by uncoated carbide insert. The encouraging results include significant reduction in tool wear rate, dimensional inaccuracy and surface roughness by MQL mainly through reduction in the cutting zone temperature and favorable change in the chip-tool and work-tool interaction.

  2. The Numerical Analysis of the Phenomena of Superficial Hardening of the Hot-Work Tool Steel Elements / Analiza Numeryczna Zjawisk Przypowierzchniowego Hartowania Elementów Ze Stali Narzędziowej Do Pracy Na Gorąco

    Bokota A.


    Full Text Available In the paper the complex model of hardening of the hot-work tool steel is presented. Model of estimation of phase fractions and their kinetics is based on the continuous heating diagram (CHT and cooling diagram (CCT. Phase fractions which occur during the continuous heating and cooling (austenite, pearlite or bainite are described by Johnson-Mehl (JM formula. To determine of the formed martensite the modified Koistinen-Marburger (KM equation is used. Model takes into account the thermal, structural, plastic strains and transformation plasticity. To calculate the plastic strains the Huber-Mises plasticity condition with isotopic hardening is used. Whereas to determine transformations induced plasticity the Leblond model is applied. The numerical analysis of phase compositions and residual stresses in the hot-work steel (W360 element is considered.

  3. Fracture Mechanisms in Steel Castings

    Z. Stradomski


    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  4. Analysis of Damage of Carbide Welding Cutting Tool for Drilling High Manganese Steel%硬质合金焊接刀具钻削高锰钢破损原因分析

    许立; 董航; 杨亮; 施志辉; 曹春风


    High manganese steel is a typical of hard - machining material. It has the characteristic of high strength, hardness and good wearing ability, so it' s machining is poor, mostly because tool' s wearing and machining efficiency is very low. This article focuses on dry cutting for ZGMn13 high manganese steel and through plenary academic analysis and scientific experiments, to improve Carbide drill with Multi - facet on the geometric parameters and the structure. This provides scientific basis for the high manganese steel' s drilling.%作为一种典型的难加工材料,高锰钢的加工硬化现象很严重,加工性能很差,特别是钻削时刀具容易破损,加工效率低下.本文基于工厂实地调研,详细分析了导致钻头破损的各方面原因,并针对工厂现实情况提出了改进措施与设想,为减少刀具破损,提高生产效率提供了科学依据.

  5. Genomic analysis of a 1 Mb region near the telomere of Hessian fly chromosome X2 and avirulence gene vH13

    Chen Ming-Shun


    Full Text Available Abstract Background To have an insight into the Mayetiola destructor (Hessian fly genome, we performed an in silico comparative genomic analysis utilizing genetic mapping, genomic sequence and EST sequence data along with data available from public databases. Results Chromosome walking and FISH were utilized to identify a contig of 50 BAC clones near the telomere of the short arm of Hessian fly chromosome X2 and near the avirulence gene vH13. These clones enabled us to correlate physical and genetic distance in this region of the Hessian fly genome. Sequence data from these BAC ends encompassing a 760 kb region, and a fully sequenced and assembled 42.6 kb BAC clone, was utilized to perform a comparative genomic study. In silico gene prediction combined with BLAST analyses was used to determine putative orthology to the sequenced dipteran genomes of the fruit fly, Drosophila melanogaster, and the malaria mosquito, Anopheles gambiae, and to infer evolutionary relationships. Conclusion This initial effort enables us to advance our understanding of the structure, composition and evolution of the genome of this important agricultural pest and is an invaluable tool for a whole genome sequencing effort.

  6. Preliminary Geological Map of the Ac-H-13 Urvara Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data

    Williams, D. A.; Sizemore, H. G.; Platz, T.; O'Brien, D. P.; Mest, S. C.; Yingst, R. A.; Crown, D. A.; Buczkowski, D.; Schenk, P.; Scully, J. E. C.; Jaumann, R.; Roatsch, T.; Preusker, F.; Nathues, A.; De Sanctis, M. C.; Russell, C. T.; Raymond, C. A.


    We used geologic mapping applied to Dawn spacecraft data as a tool to understand the geologic history of the Ac-H-13 Urvara Quadrangle of dwarf planet Ceres. This region, located between 21˚S-66˚S and 180-270˚E, is dominated by the Urvara basin in the east and cratered plains in the west. The elevation of the cratered plains is intermediate between the identified "highland" and "lowland" units of Ceres. Plains in the SW corner of the quadrangle are hummocky and heavily cratered, while the NW corner is smoother and less densely cratered. Features of note include 1) the 200 km diameter Urvara basin, which includes a degraded northern rim and smooth interior and exterior material that hosts a significantly lower impact crater density than most of the rest of Ceres' surface; 2) semi-radial curvilinear structures extending to the east and west of Urvara; 3) two large-scale dome structures 10s of km in diameter exterior to Urvara; and 4) numerous small-scale domical structures (digital terrain models derived from stereo images. In Fall 2015 images from the High Altitude Mapping Orbit (140 m/px) will be used to refine the mapping, followed by Low Altitude Mapping Orbit (35 m/px) images starting in December 2015. Support of the Dawn Instrument, Operations, and Science Teams is acknowledged. This work is supported by grants from NASA, the Max Planck Society and from the German and Italian Space Agencies.

  7. Effect of steel composition and slag properties on NMI in clean steel production

    Elfawakhry Mohamed K


    Full Text Available The modern steel plants for clean steel production depend to large extent on the efficiency of the refining processes that applied for the production. Refining processes that applied for low alloy and alloyed steel production include degassing via vacuum or ladle and ladle furnace units. This technique could help in producing homogeneous steel with low gas content and minimum internal defects. In certain grades of steel for tools and penetration and impact resistance uses, non-metallic inclusions (NMI and sulphur content are the key factors for the steel performance and applications. ESR, Electro-salg refining (or remelting, is the technique that can efficiently produce clean steel with minimum content of NMI and sulphur due to the special nature and mechanism of this technique. In this study, the effect of initial chemical composition of steel and slag properties on the efficiency of ESR process in removal of NMI and sulphur from steel are evaluated. Different grades of steels were refined using ESR process. The efficiency of ESR in modifying and enhancing NMI shape, size and counts as well as removal of sulphur in different steel grades was evaluated at different slag composition and physical properties. The effect of chemical composition of steel on the efficiency of ESR process was studied. It was found that ESR process has a great effect in producing clean steel where both viscosity and initial composition of steel have influence on the final NMI status and sulphur content in the produced steel.

  8. (1)H, (13)C, and (15)N resonance assignments for the pro-inflammatory cytokine interleukin-36α.

    Goradia, Nishit; Wißbrock, Amelie; Wiedemann, Christoph; Bordusa, Frank; Ramachandran, Ramadurai; Imhof, Diana; Ohlenschläger, Oliver


    Interleukin-36α (IL-36α) is a recently characterised member of the interleukin-1 superfamily. It is involved in the pathogenesis of inflammatory arthritis in one third of psoriasis patients. By binding of IL-36α to its receptor IL-36R via the NF-κB pathway other cytokines involved in inflammatory and apoptotic cascade are activated. The efficacy of complex formation is controlled by N-terminal processing. To obtain a more detailed view on the structure function relationship we performed a heteronuclear multidimensional NMR investigation and here report the (1)H, (13)C, and (15)N resonance assignments for the backbone and side chain nuclei of the pro-inflammatory cytokine interleukin-36α.

  9. Wear properties of H13 with micron scale and nano scale grains bionic units processed by laser remelting

    Zhang, Peng; Zhou, Hong; Wang, Cheng-tao; Liu, Yan; Ren, Lu-quan


    By simulating the cuticles of some soil animals, a combination of soft part (untreated substrate) and hard part (laser remelting area) structure was designed on metal surface to get an improved performance. Different specimens were prepared which contained units with micro and nano scale grains. The microstructures were observed by environmental field emission scanning electron microscopy. X-ray diffraction was used to identify the phases. The results of these tests indicate that due to the rapid solidification condition in the water, nano scale grains have a high microhardness between 1300 and 1000 HV. Retained austenite was found in it. Some of them transform to martensite in block on ring wear test. Specimens with bionic unit have a better wear resistance. Especially, the units with nano grains bring a further enhancement. The alternate soft and hard in macroscopic (substrate and laser remelting area) and microscopic (austenite and martensite) structure played a key role in improving the H13 wear resistance.

  10. Steel Planning


    China releases a new plan for the iron and steel industry centered on industrial upgrades The new 12th Five-Year Plan (2011-15) for China’s iron and steel industry, recently released on the website of the Ministry of Industry and Information

  11. Statistical Approach to Optimize the Process Parameters of HAZ of Tool Steel EN X32CrMoV12-28 after Die-Sinking EDM with SF-Cu Electrode

    L’uboslav Straka


    Full Text Available The paper describes the results of the experimental research of the heat affected zone (HAZ of an eroded surface after die-sinking electrical discharge machining (EDM. The research was carried out on chrome-molybdenum-vanadium alloyed tool steel EN X32CrMoV12-28 (W.-Nr. 1.2365 after die-sinking EDM with a SF-Cu electrode. The aim of the experimental measurements was to contribute to the database of knowledge that characterizes the significant impact of the main technological and process parameters on the eroded surface properties during die-sinking EDM. The quality of the eroded surface was assessed from the viewpoint of surface roughness, microhardness variation, and the total HAZ depth of the thin sub-surface layer adjacent to the eroded surface. On the basis of measurement results, mathematical models were established by statistical methods. These models can be applied for computer simulation and prediction of the resultant quality of the machined surface after die-sinking EDM. The results achieved by simulation were compared with the results of experimental measurements and high correlation indexes between the predicted and real values were achieved. Suggested mathematical models can be also applied for the determination of the optimal combination of significant technological parameters in order to minimize microhardness and total HAZ depth variations of tool steel EN X32CrMoV12-28 after die-sinking EDM with a SF-Cu electrode.

  12. 切削淬硬合金钢42CrMo的PCBN刀具磨损机理研究%Research on Cutting Speed and Cutting Temperature of Cutting Hardened Steel 42CrMo with PCBN Tool

    朱振国; 李旗号


    进行了PCBN刀具切削淬硬合金钢42CrMo的实验.通过JSM649OLV型扫描电子显微镜(SEM)观察PCBN刀具的磨损,利用INCA能量分散光谱仪(EDS)分析了刀具磨损面的金属元素成分,对刀具磨损的机理进行分析和探讨.通过对比几种切削速度下刀具的磨损量,获得切削速度的最佳值.%This paper deals with the experiment of hardened steel 42CrMo with PCBN cutting tool, using JSM6490LV type scanning electron microscopy (SEM) to observe PCBN tool wear and using scattered INCA energy spectrometer (EDS) to analyze the metal elements in tool wear, and tool wear mechanism was analysised and discussed. Through comparing with tool wear quantity under several cutting speeds, the optimal cutting speed was obtained.

  13. Research of Machine Tool for Planning off the Rolling Edge of Hinge Profile Steel%汽车门铰链型钢刨耳子专用机床研究

    郭好强; 孙爱军; 马会民


    门铰链型钢是专门为制造汽车门铰链轧制而成的型钢条料.在型钢轧制过程中,由于轧辊辊缝的存在而不可避免地出现耳子(即飞边).原来通过人工使用角磨机来打磨耳子,我们对原来的加工方法进行革新,而设计制造了一种汽车门铰链型钢刨耳子专用机床.文章重点对此机床的总体结构、导向传动结构、压紧结构、刀具结构进行了分析,相信文章对研制同类型的刨耳子专用机床具有一定的参考价值.%Hinge profile steel are used for making automobile door hinge. In the steel rolling process, due to the presence of the gap between rollers, rolling edge is inevitably produced. Orininally the rolling edge is removed by manual grinder, after innovating of the former processing methods, we designed and manufactured a special machine tool for planning off the rolling edge. This text is emphasized on the analysis of overall structure of this machine tool,the structure of transmission and compaction,cutter etc. The research of this paper makes contributions to the designing of familiar machine tool.

  14. Simultaneous Modification of Alumina and MgO·Al2O3 Inclusions by Calcium Treatment During Electroslag Remelting of Stainless Tool Steel

    Shi, Cheng-Bin; Yu, Wen-Tao; Wang, Hao; Li, Jing; Jiang, Min


    Calcium modification of both alumina and MgO·Al2O3 inclusions during protective gas electroslag remelting (P-ESR) of 8Cr17MoV stainless steel and its effect on nitrides and primary carbides were studied by analyzing the transient evolution of oxide and sulfide inclusions in the P-ESR process. The oxide inclusions that were not removed during P-ESR without calcium treatment were found to retain their original state until in as-cast ingot. Calcium treatment modified all MgO·Al2O3 and alumina inclusions that had not been removed in the P-ESR process to liquid/partially liquid CaO-Al2O3-(MgO) with uniformly distributed elements, in addition to a small proportion of partially modified inclusions of a CaO-MgO-Al2O3 core surrounded by a liquid CaO-Al2O3. The modification of low-MgO-containing MgO·Al2O3 inclusions involves the preferential reduction of MgO from the MgO·Al2O3 inclusion by calcium and the reaction of calcium with Al2O3 in the inclusion. It is the incomplete/complete reduction of MgO from the spinel by calcium that contributes to the modification of spinels. Alumina inclusions were liquefied by direct reaction with calcium. Calcium treatment during P-ESR refining also provided an effective approach to prevent the formation of nitrides and primary carbides in stainless steel through modifying their preferred nucleation sites (alumina and MgO·Al2O3 inclusions) to calcium aluminates, which made no contribution to improving the steel cleanliness.

  15. Simultaneous Modification of Alumina and MgO·Al2O3 Inclusions by Calcium Treatment During Electroslag Remelting of Stainless Tool Steel

    Shi, Cheng-Bin; Yu, Wen-Tao; Wang, Hao; Li, Jing; Jiang, Min


    Calcium modification of both alumina and MgO·Al2O3 inclusions during protective gas electroslag remelting (P-ESR) of 8Cr17MoV stainless steel and its effect on nitrides and primary carbides were studied by analyzing the transient evolution of oxide and sulfide inclusions in the P-ESR process. The oxide inclusions that were not removed during P-ESR without calcium treatment were found to retain their original state until in as-cast ingot. Calcium treatment modified all MgO·Al2O3 and alumina inclusions that had not been removed in the P-ESR process to liquid/partially liquid CaO-Al2O3-(MgO) with uniformly distributed elements, in addition to a small proportion of partially modified inclusions of a CaO-MgO-Al2O3 core surrounded by a liquid CaO-Al2O3. The modification of low-MgO-containing MgO·Al2O3 inclusions involves the preferential reduction of MgO from the MgO·Al2O3 inclusion by calcium and the reaction of calcium with Al2O3 in the inclusion. It is the incomplete/complete reduction of MgO from the spinel by calcium that contributes to the modification of spinels. Alumina inclusions were liquefied by direct reaction with calcium. Calcium treatment during P-ESR refining also provided an effective approach to prevent the formation of nitrides and primary carbides in stainless steel through modifying their preferred nucleation sites (alumina and MgO·Al2O3 inclusions) to calcium aluminates, which made no contribution to improving the steel cleanliness.

  16. Influence of the austenite-martensite transformation in the dimensional stability of a new tool steel alloyed with niobium (0.08% wt.) and vanadium (0.12% wt.); Influencia de la transformacion austenita-martensita en la estabilidad dimensional de un nuevo acero para herramientas aleado con niobio (0,08%) y vanadio (0,12%)

    Conejero Ortega, G.; Candela Vazquez, N.; Pichel Martinez, M.; Barea del Cerro, R.; Carsi Cebrian, M.


    Austenite-martensite transformation influence on the dimensional stability of a new experimental tool steel alloyed with niobium (0.08% wt.) and vanadium (0.12% wt.) has been studied. The dimensional stability of this new steel was compared with the dimensional stability of commercial steel, after and before two thermal treatments, T1 (860 degree centigrade) and T2 (900 degree centigrade). The thermal treatments consisted on heating and cooling, at 1 atmosphere of pressure, in N{sub 2} atmosphere furnace, following by heating in a conventional furnace at 180 degree centigrade during 1 hour. Initially, the experimental steel composition and Ac{sub 1} and Ac{sub 3} transformation temperatures were determined by glow-discharge luminescence (GDL) and dilatometric tests, respectively, in order to select the austenization temperatures of T1 and T2 treatments. After hardness measurement, the microstructure of both steels was characterized by X-Ray Diffraction (XRD) and optical metallography, before and after of T1 and T2 thermal treatments. Finally, longitudinal and angular dimensional stability analyses were realized for both commercial and experimental steels. After a contrastive hypothesis analysis, the results showed that the longitudinal relative variation of the experimental steel calculated was around 0.2% and the angular relative variation was not significant. (Author)

  17. Study of Casting and Solidification of Slab Ingot from Tool Steel Using Numerical Modelling / Modelowanie Numeryczne Odlewania I Krzepnięcia Wlewków Stalowych Ze Stali Narzędziowej

    Tkadlečková M.


    Full Text Available The main problem in the production of forgings from tool steels, especially thick plates, blocks, pulleys and rods which are used for special machine components for demanding applications, it is the inhomogeneous structure with segregations, cracks in segregations or complex type of non-metallic inclusions MnS and TiCN. These forgings are actually produced from conventional forging ingots. Due to the size of forgings, it would be interesting the production of these forgings from slab ingots. It is possible that the production of forgings from slab ingots (which are distinguished by a characteristic aspect ratio A/B, it would reduce the occurrence of segregations. The paper presents the verification of the production process of slab steel ingots in particular by means of numerical modelling using finite element method. The paper describes the pre-processing, processing and post-processing phases of numerical modelling. The attention was focused on the prediction of behavior of hot metal during the mold filling, on the verification of the final porosity, of the final segregation and on the prediction of risk of cracks depending on the actual geometry of the mold.

  18. Analysis of the effect of ultrasonic vibrations on the performance of micro-electrical discharge machining of A2 tool steel

    Puthumana, Govindan


    The application of ultrasonic vibrations to a workpiece or tool is a novel hybrid approach in micro-electrical discharge machining. The advantages of this method include effective flushing out of debris, higher machining efficiency and lesser short-circuits during machining. This paper presents...... a systematic analysis of the influence of kinetic effects of the ultrasonic vibrations on the material removal rate (MRR) and tool electrode wear rate (TWR). The tool wear ratio was estimated for the process at all processing conditions. The maximum variation in tool wear ratio is observed to be 82%. Therefore......, MRR and TWR were independently analyzed by using three scientific tools: i) AOM plots, ii) interaction plots and iii) three-dimensional scatter plots. The increase in MRR is 47% corresponding to an increase in the maximum power of vibrations by 30%. The ultrasonic vibrations are found to be very...

  19. Genome and proteome analysis of 7-7-1, a flagellotropic phage infecting Agrobacterium sp H13-3

    Kropinski Andrew M


    Full Text Available Abstract Background The flagellotropic phage 7-7-1 infects motile cells of Agrobacterium sp H13-3 by attaching to and traveling along the rotating flagellar filament to the secondary receptor at the base, where it injects its DNA into the host cell. Here we describe the complete genomic sequence of 69,391 base pairs of this unusual bacteriophage. Methods The sequence of the 7-7-1 genome was determined by pyro(454sequencing to a coverage of 378-fold. It was annotated using MyRAST and a variety of internet resources. The structural proteome was analyzed by SDS-PAGE coupled electrospray ionization-tandem mass spectrometry (MS/MS. Results Sequence annotation and a structural proteome analysis revealed 127 open reading frames, 84 of which are unique. In six cases 7-7-1 proteins showed sequence similarity to proteins from the virulent Burkholderia myovirus BcepB1A. Unique features of the 7-7-1 genome are the physical separation of the genes encoding the small (orf100 and large (orf112 subunits of the DNA packaging complex and the apparent lack of a holin-lysin cassette. Proteomic analysis revealed the presence of 24 structural proteins, five of which were identified as baseplate (orf7, putative tail fibre (orf102, portal (orf113, major capsid (orf115 and tail sheath (orf126 proteins. In the latter case, the N-terminus was removed during capsid maturation, probably by a putative prohead protease (orf114.

  20. 浅谈磁化对高速钢钻头耐用度的影响%Discussion on Influence of Magnetization on Tool Life of High Speed Steel Drills



    The tool life of magnetized high speed steel drills was studied via means of experiments.The study result shows that during drilling,the magnetized drills were proved to have 1.4 times longer tool life than conventional ones,and the stronger the residu-al magnetism after magnetization,the longer the tool life has.At the same time some special phenomena in drilling with magnetized drills are discussed primarily.%利用试验手段对经过磁化后的高速钢钻头刀具耐用度进行了研究。研究结果表明:在钻削时,经过磁化处理的钻头比普通钻头的耐用度提高1.4倍。充磁后的剩磁强度越大,耐用度越高。通过实验研究,对磁化钻削中的一些现象进行了初步的探讨。

  1. Nanostructure and Properties of Corrosion Resistance in C+Ti Multi-Ion-Implanted Steel

    张通和; 吴瑜光; 刘安东; 张旭; 王晓妍


    The corrosion and pitting corrosion resistance of C+ Ti dual and C+Ti+C ternary implanted H13 steel were studied by using a multi-sweep cyclic voltammetry and a scanning electron microscope. The effects of phase formation on corrosion and pitting corrosion resistance were explored. The x-ray diffraction analysis shows that the nanometer-sized precipitate phases consist of compounds of Fe2 Ti, TiC, Fe2C and Fe3 C in dual implanted layer and even in ternary implanted layer. The passivation layer consists of these nanometer phases. It has been found that the corrosion and pitting corrosion resistance of dual and ternary implanted H13 steel are improved extremely. The corrosion resistance of ternary implanted layer is better than that of dual implantations and is enhanced with the increasing ion dose. When the ion dose of Ti is 6 × 1017/cm2 in the ternary implantation sample, the anodic peak current density is 95 times less than that of the H13 steel. The pitting corrosion potential of dual and ternary implantation samples is in the range from 55mV to 160mV which is much higher than that of the H13 steel. The phases against the corrosion and pitting corrosion are nanometer silkiness phases.

  2. Tribological and mechanical properties of Ti/TiAlN/TiAlCN nanoscale multilayer PVD coatings deposited on AISI H11 hot work tool steel

    AL-Bukhaiti, M. A.; Al-hatab, K. A.; Tillmann, W.; Hoffmann, F.; Sprute, T.


    A new [Ti/TiAlN/TiAlCN]5 multilayer coatings were deposited onto polished substrate AISI H11 (DIN 1.2343) steel by an industrial magnetron sputtering device. The tribological performance of the coated system was investigated by a ball-on-disk tribometer against 100Cr6 steel and Al2O3 balls. The friction coefficients and specific wear rates were measured at various normal loads (2, 5, 8, and 10 N) and sliding velocities (0.2, 0.4, and 0.8 m/s) in ambient air and dry conditions. The phase structure, composition, wear tracks morphologies, hardness, and film/substrate adhesion of the coatings were characterized by light-microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), 3D-surface analyzer, nanoindentation, and scratch tests. Results showed that the deposited coatings showed low wear rates in the scale of 10-15 m3/N m, low friction coefficients against 100Cr6 and Al2O3 balls in the range of 0.25-0.37, and good hardness in the range of 17-20 GPa. Results also revealed that the friction coefficients and disc wear rates decrease and increase, respectively with the increase in normal load and sliding velocity for both coating/Al2O3 and coating/100Cr6 sliding system. Compared with the uncoated-H11 substrate, the deposited coating exhibited superior tribological and mechanical properties. The dominant wear mechanism was abrasive wear for coating/Al2O3 pair, while for coating/100Cr6 pair, a combination of mild adhesive wear, severe adhesive wear, and abrasive wear (extensive plowing) were the dominant wear mechanisms at different applied normal loads.

  3. 高速切削淬硬模具钢刀具磨损的对比实验研究%Tool wear when high-speed cutting hardened die steel

    于静; 赵琰巍; 倪清泉; 董海


    使用PCBN和陶瓷两种材质的刀具对淬硬模具钢Cr12MoV进行高速切削试验,深入研究了高速切削时的刀具寿命、刀具磨损形态和磨损原因,得出如下结论:相同的切削条件下,PCBN刀具寿命约为陶瓷刀具的2~3倍,当切削速度由153 m/min增大到241 m/min时,两种材质刀具寿命均下降50%以上;在相对低速下切削时,PCBN刀具和陶瓷刀具磨损形态主要为月牙洼和后刀面磨损,在相对高速下切削时,两种刀具均出现破损,破损形态主要包括崩刃和片状剥落等;PCBN刀具磨损原因主要为黏结磨损、氧化磨损和扩散磨损,陶瓷刀具的主要磨损原因有磨粒磨损、黏结磨损和扩散磨损;相同切削条件下,PCBN刀具抗磨粒磨损的能力好于陶瓷刀具,而陶瓷刀具的抗氧化性能要好于PCBN刀具;切削速度对刀具磨损原因有重要影响,随着切削速度的增大,磨粒磨损程度和黏结磨损程度均减弱.%PCBN tool and ceramic tool were used to cut hardened die steel Crl2MoV at high speed. Tool life, tool wear forms and mechanisms were studied. Results showed that; under the same conditions, tool life of PCBN tool was 2 to 3 times than that of ceramic tool; when cutting speed increased from 153 m/min to 241 m/min, tool life of both tools decreased by more than 50% ; wear form of both tools was crater and flank wear under relatively low speed, but it became breakage under the relatively high speed, including tipping and exfoliated, etc; wear mechanisms of PCBN tool were mainly adhesive wear, oxidation wear and diffusion wear, while those of ceramic tool were mainly abrasive wear, adhesive wear and diffusion wear; under the same cutting conditions, the abrasive wear resistance of PCBN tool was better than that of ceramic tool, but its oxidation resistance was lower. Cutting speed had a significant effect on wear mechanism, which was that as the cutting speed increased, abrasive wear and adhesive wear became

  4. SKD11铣削刀具寿命试验研究及工艺参数优化%Experimental study on milling tool life for SKD1 1 steel and optimization of cutting parameters



    In order to improve tool life for hardened steel SKD1 1 during the mil ing process,the related mil ing experiments are carried out and the influence of cutting parameters on tool life is analyzed based on range method.It is found that the influence of axial cutting depth on tool wear is pretty strong,and the influence of radial cutting width on tool wear is very weak.Based on the mil ing experiments,the mathematical model of tool wear is established by using of regression a-nalysis method.In order to solve the actual mil ing problem,the cutting parameters are optimized by using of SQP optimization method based on MATLAB software.During the optimization process,the machining efficiency and the tool wear quantity are set as the objective function. The optimized cutting parameters could greatly improve the machining efficiency in the premise of ensuring smal er tool wear,and it provides the important theory evidence and case reference for NC machining enterprises to reduce compositive production costs.%为提高SKD11模具钢铣削刀具的寿命,对SKD11模具钢进行了刀具寿命铣削试验,基于极差方法分析了各工艺参数对刀具寿命的影响规律。基于刀具寿命铣削试验,利用多元线性回归方法,推导并求解出了SKD11模具钢铣削刀具磨损的数学模型。利用最优化设计方法和MATLAB优化工具箱,以加工效率和刀具磨损为目标函数,针对实际的铣削问题优选了工艺参数。优化的工艺参数能兼顾刀具寿命和加工效率,为加工企业降低综合生产成本提供了重要的理论依据和案例参考。


    Rastislav Mintách


    Full Text Available The aim of this work was the experimental research of damascus steel from point of view of the structural analyze, impact strength and failure analyzes. The damascus steel was produced by method of forged welding from STN 41 4260 spring steel and STN 41 9312 tool steel. The damascus steel consisted of both 84 and 168 layers. The impact strength was experimentally determined for original steels and damascus steels after heat treatment in dependence on temperature in the range from -60 to 160 °C. It has been found that the impact strength of experimental steels decreased with decreasing temperature behind with correlated change of damage mode. In the case of experimental tests performed at high temperature ductile fracture was revealed and with decreasing temperature proportion of cleavage facets increased. Only the STN 41 9312 steel did not show considerable difference in values of the impact strength with changing temperature.

  6. Long-Term Effect of Serial Infections with H13 and H16 Low-Pathogenic Avian Influenza Viruses in Black-Headed Gulls

    Verhagen, Josanne H.; van Amerongen, Geert; van de Bildt, Marco; Majoor, Frank; Fouchier, Ron A. M.


    ABSTRACT Infections of domestic and wild birds with low-pathogenic avian influenza viruses (LPAIVs) have been associated with protective immunity to subsequent infection. However, the degree and duration of immunity in wild birds from previous LPAIV infection, by the same or a different subtype, are poorly understood. Therefore, we inoculated H13N2 (A/black-headed gull/Netherlands/7/2009) and H16N3 (A/black-headed gull/Netherlands/26/2009) LPAIVs into black-headed gulls (Chroicocephalus ridibundus), their natural host species, and measured the long-term immune response and protection against one or two reinfections over a period of >1 year. This is the typical interval between LPAIV epizootics in wild birds. Reinfection with the same virus resulted in progressively less virus excretion, with complete abrogation of virus excretion after two infections for H13 but not H16. However, reinfection with the other virus affected neither the level nor duration of virus excretion. Virus excretion by immunologically naive birds did not differ in total levels of excreted H13 or H16 virus between first- and second-year birds, but the duration of H13 excretion was shorter for second-year birds. Furthermore, serum antibody levels did not correlate with protection against LPAIV infection. LPAIV-infected gulls showed no clinical signs of disease. These results imply that the epidemiological cycles of H13 and H16 in black-headed gulls are relatively independent from each other and depend mainly on infection of first-year birds. IMPORTANCE Low-pathogenic avian influenza viruses (LPAIVs) circulate mainly in wild water birds but are occasionally transmitted to other species, including humans, where they cause subclinical to fatal disease. To date, the effect of LPAIV-specific immunity on the epidemiology of LPAIV in wild birds is poorly understood. In this study, we investigated the effect of H13 and H16 LPAIV infection in black-headed gulls on susceptibility and virus excretion of

  7. Statistical analysis of AISI304 austenitic stainless steel machining using Ti(C, N/Al2O3/TiN CVD coated carbide tool

    Sofiane Berkani


    Full Text Available The present research work investigated the machining of AISI304 austenitic stainless steel in terms of machining force evolution, power consumption, specific cutting force and surface roughness where a factorial experiment design and analysis of variance technique were used and several factors were evaluated for their effects on each level. The case of dry turning process was studied based on design of experiments in order to obtain empirical equations characterizing material machinability according to cutting conditions such as cutting speed, feed rate and depth of cut and the latter ones were put in relationship with the machining output variables (Ra, Fc, Kc and Pc through the response surface methodology (RSM. Results revealed that feed rate was the most preponderant factor affecting surface roughness (71.04%. However, the depth of cut affects considerably cutting force and cutting power by (60.74% and 67.11%, respectively. In addition, the specific cutting force was found affected significantly by cutting speed with a contribution of 41.43%. The quadratic model of RSM associated with response optimization technique and composite desirability was used to find optimum values of machining parameters (104.54 m/min, 0.08 mm/rev and 0.295 mm.

  8. FEM Simulation of Bending Formability for Laminate Steel/Resin/Steel Lightweight Composite Sheet

    Guancheng Ll; Yonglin KANG


    The ANSYS simulation software was used to analyze the bending formability of laminate steel/resin/steel lightweight composite sheet. The skin steel at external side produces relative slipping-off change during the bending due to its composite structure. The internal stress strain states, materials effect tools parameters and intermediate layer resin of lightweight sheet on slipping-off change were analyzed. The spring back and shear stress state after bending have also been discussed.

  9. Fabrication of stainless steel foil utilizing chromized steel strip

    Loria, Edward A.


    Stainless steel foil has properties which are, in many respects, unmatched by alternative thin films. The high strength to weight ratio and resistance to corrosion and oxidation at elevated temperatures are generally advantageous. The aerospace and automotive industries have used Type 430 and 304 foil in turbine engine applications. Foil around 2 mils (5.1 × 10-3 cm) thick has been appropriate for the recuperator or heat exchanger and this product has also been used in honeycomb and truss-core structures. Further, such foil has been employed as a wrap to protect tool steel parts from contamination during heat treating. A large part of the high cost of producing stainless steel foil by rolling is due to the complicated and expensive rolling mill and annealing equipment involved. A method will be described which produces (solid) stainless steel foil from chromized (coated) steel which can be cheaper than the conventional processing stainless steel, such as Type 430, from ingot to foil. Also, the material is more ductile and less work hardenable during processing to foil and consequently intermediate annealing treatments are eliminated and scrap losses minimized.

  10. Anisotropic Distortion of D2 Tool Steel During Gas Quenching and Tempering%D2工具钢在气淬和回火过程中的各向异性畸变

    魏建飞; O.Kessler; F.Hoffmann; P.Mayr


    The distortion behavior of high alloyed cold work tool steel D2 during gas quenching and tempering was investigated.The steels were studied in casted,as well as casted and forged state with two different forging degrees.Experimental results showed that the distortion of cast specimens was nearly isotropic but the distortion of forged specimens was apparently anisotropic.The anisotropic distortion was increased with higher austenitizing temperature.The influence of different forging degrees on anisotropic distortion was small in the investigated range.After tempering,anisotropic distortion was partially reduced.Using dilatometric and metallographic examination the possible mechanism of the anisotropic distrotion was investigated and discussed.%分别使用铸造试样及两种不同锻造程度的锻件试样,对高合金冷作模具钢D2在气淬和回火过程中的畸变行为进行了研究.试验结果表明,铸造试样的畸变是等向性的,而锻造试样的畸变显然呈各向异性.各向异性畸变程度随奥氏体化温度的升高而增加.在本试验范围内,不同的锻造程度对各向异性的畸变程度影响不大.回火后各向异性畸变程度有所降低.使用测膨胀方法及金相检验探讨了产生各向异性畸变的可能机制.

  11. Laser Engineered Net Shaping (LENS(TM)): A Tool for Direct Fabrication of Metal Parts

    Atwood, C.; Ensz, M.; Greene, D.; Griffith, M.; Harwell, L.; Reckaway, D.; Romero, T.; Schlienger, E.; Smugeresky, J.


    For many years, Sandia National Laboratories has been involved in the development and application of rapid prototyping and dmect fabrication technologies to build prototype parts and patterns for investment casting. Sandia is currently developing a process called Laser Engineered Net Shaping (LENS~) to fabricate filly dense metal parts dwectly from computer-aided design (CAD) solid models. The process is similar to traditional laser-initiated rapid prototyping technologies such as stereolithography and selective laser sintering in that layer additive techniques are used to fabricate physical parts directly from CAD data. By using the coordinated delivery of metal particles into a focused laser beam apart is generated. The laser beam creates a molten pool of metal on a substrate into which powder is injected. Concurrently, the substrate on which the deposition is occurring is moved under the beam/powder interaction zone to fabricate the desired cross-sectiwal geometry. Consecutive layers are additively deposited, thereby producing a three-dmensional part. This process exhibits enormous potential to revolutionize the way in which metal parts, such as complex prototypes, tooling, and small-lot production parts, are produced. The result is a comple~ filly dense, near-net-shape part. Parts have been fabricated from 316 stainless steel, nickel-based alloys, H13 tool steel, and titanium. This talk will provide a general overview of the LENS~ process, discuss potential applications, and display as-processed examples of parts.

  12. Nano-phases and corrosion resistance of C+Mo dual implanted steel


    The corrosion resistance of C+Mo dual-implanted H13 steel wasstudied using multi-sweep cyclic voltammetry. The phase formation conditions for corrosion resistance and its effects were researched. The super-saturation solid station solution of Mo+ and C+ atoms was formed in Mo+C dual implanted steel. Precipitate phase with nanometer size Fe2Mo, FeMo, MoC, Fe5C3 and Fe7C3 were formed in dual implanted layer. The passivation layer consisted of these nanometer phases. The corrosion resistance of the dual implanted layer was better than that of single Mo implantation. Jp of the Mo implanted sample is 0.55 times that of H13 steel. The corrosion resistance of the dual implantation was enhanced when ion dose increased. When the Mo+ ion dose was 6×1017/cm2 in the dual implantation, Jp of the dual implanted sample was only 0.11 times that in H13 steel. What is important is that pitting corrosion properties of dual implanted steel were improved obviously.

  13. Comparison of Wear Resistance Mechanisms of Die Steel Implanted with C and mo Ions

    Cheng, M. F.; Yang, J. H.; Luo, X. D.; Zhang, T. H.

    Mo and C ions extracted from a metal vapor vacuum arc ion source were implanted into the surface of die steel (H13) to compare the wear resistance mechanisms of the implanted samples, respectively. The concentration depth profiles of implanted ions were measured using Rutherford backscattering spectroscopy and calculated by a code called TRIDYN. The structures of the implanted steel were observed by X-ray photoelectron spectroscopy and grazing-angle X-ray diffraction, respectively. It was found that the conventional heat-treated H13 steel could not be further hardened by the subsequent implanted C ions, and the thickness of the implanted layer was not an important factor for the Mo and C ion implantation to improve the wear resistance of the H13 steel. Mo ion implantation could obviously improve the wear resistance of the steel at an extraction voltage of 48 kV and a dose of 5 × 1017cm-2 due to formation of a modification layer of little oxidation with Mo2C in the implanted surface.

  14. Analysis of the effect of ultrasonic vibrations on the performance of micro-electrical discharge machining of A2 tool steel

    Puthumana, Govindan


    The application of ultrasonic vibrations to a workpiece or tool is a novel hybrid approach in micro-electrical discharge machining. The advantages of this method include effective flushing out of debris, higher machining efficiency and lesser short-circuits during machining. This paper presents...... effective at higher machining depths for achieving stable machining conditions. Regression equations were developed for MRR and TWR with capacitance, ultrasonic vibration factor, feed rate and machining time....

  15. Reserch of unilateral clamping lifting tool of great steel tube stake at sea%海上大型基础钢桩单边夹持吊具的研究



    A unilateral clamping suspension tool was researched for tube stake installation of marine fan impeller and it is able to lift great steel tube stake .First of all,it carried out the structural design of the suspension tool and described the its working prin -ciple;Secondly ,the force state of suspension tool clamping was analyzed and the hydraulic and the dead load cam clamping mech -anism were designed and also analyzed the clamping force;Finally,it developed the prototype and carried out hanging tube experi-ments to verify the rationality and reliability of the design of prototype and lay the theoretical and practice foundation for the de -sign of engineering prototype .%针对海上风机叶轮大型基础钢桩的安装作业,进行了一种单边夹持吊具的研究,能够实现大型基础钢桩的海上吊装操作。首先,进行了单边夹持吊具的结构设计并阐述了工作原理;其次,分析了吊具夹紧受力状态,研究了液压缸凸轮与自重凸轮夹紧机构,进行了夹紧力分析;最后,研制了模型样机并进行了吊桩实验,验证了方案设计的合理性与可靠性,为工程样机的设计打下了理论与实践基础。

  16. High Nitrogen Stainless Steel


    Kiev, 1993. 7. High Nitrogen Steels, edited by M. Kikuchi and Y. Mishima , Vol. 36, No. 7, Iron and Steel Institute of Japan Inernational, Tokyo...the Corrosion of Iron and Steels,” High Nitrogen Steels, edited by M. Kikuchi and Y. Mishima , Vol. 36, No. 7, Iron and Steel Institute of Japan

  17. Steel designers' handbook

    Gorenc, Branko; Tinyou, Ron


    The Revised 7th Edition of Steel Designers' Handbook is an invaluable tool for all practising structural, civil and mechanical engineers as well as engineering students at university and TAFE in Australia and New Zealand. It has been prepared in response to changes in the design Standard AS 4100, the structural Design Actions Standards, AS /ANZ 1170, other processing Standards such as welding and coatings, updated research as well as feedback from users. This edition is based on Australian Standard (AS) 4100: 1998 and subsequent amendments. The worked numerical examples in the book have been e

  18. The Influence of Temperature on the Frictional Behavior of Duplex-Coated Die Steel Rubbing Against Forging Brass

    Ebrahimzadeh, I.; Ashrafizadeh, F.


    Improvement of die life under hot forging of brass alloys is considered vital from both economical and technical points of view. One of the best methods for improving die life is duplex coatings. In this research, the influence of temperature on the tribological behavior of duplex-coated die steel rubbing against forging brass was investigated. The wear tests were performed on a pin-on-disk machine from room temperature to 700 °C; the pins were made in H13 hot work tool steel treated by plasma nitriding and by PVD coatings of TiN-TiAlN-CrAlN. The disks were machined from a two-phase brass alloy too. The results revealed that the friction coefficient of this tribosystem went through a maximum at 550 °C and decreased largely at 700 °C. Furthermore, the formation of Cr2O3 caused the reduction of friction coefficient at 700 °C. PVD coatings proved their wear resistance up to 550 °C, well above the working temperature of the brass forging dies.

  19. Large-scale shocks in the starburst galaxy NGC253 Interferometer mapping of a ~600 pc $SiO/H_{13}CO^{+}$ circumnuclear disk

    García-Burillo, S; Fuente, A; Neri, R


    This paper presents the first high-resolution SiO map made in an external galaxy. The nucleus of the nearby barred spiral NGC253 has been observed simultaneously in the v=0, J=2-1 line of SiO and in the J=1-0 line of H13CO+ with the IRAM interferometer, with a resolution of 7.5"x2.6". Emission from SiO and H13CO+ is extended in the nucleus of NGC253. The bulk of the SiO/H13CO+ emission arises from a 600pcx250pc circumnuclear disk (CND) with a double ringed structure. The inner ring, of radius r=60pc, viewed edge-on along PA=51deg, hosts the nuclear starburst; the outer pseudo-ring opens out as a spiral-like arc up to r=300pc. The kinematics of the gaseous disk, characterized by strong non-circular motions, is interpreted in terms of the resonant response of the gas to the barred potential. The inner ring would correspond to the inner Inner Lindblad Resonance(iILR), whereas the outer region is linked to the onset of a trailing spiral wave across the outer ILR (oILR). Most notably, we report the detection of a ...

  20. Observation of 1H-13C and 1H-1H proximities in a paramagnetic solid by NMR at high magnetic field under ultra-fast MAS

    Li, Shenhui; Trébosc, Julien; Lafon, Olivier; Zhou, Lei; Shen, Ming; Pourpoint, Frédérique; Amoureux, Jean-Paul; Deng, Feng


    The assignment of NMR signals in paramagnetic solids is often challenging since: (i) the large paramagnetic shifts often mask the diamagnetic shifts specific to the local chemical environment, and (ii) the hyperfine interactions with unpaired electrons broaden the NMR spectra and decrease the coherence lifetime, thus reducing the efficiency of usual homo- and hetero-nuclear NMR correlation experiments. Here we show that the assignment of 1H and 13C signals in isotopically unmodified paramagnetic compounds with moderate hyperfine interactions can be facilitated by the use of two two-dimensional (2D) experiments: (i) 1H-13C correlations with 1H detection and (ii) 1H-1H double-quantum ↔ single-quantum correlations. These methods are experimentally demonstrated on isotopically unmodified copper (II) complex of L-alanine at high magnetic field (18.8 T) and ultra-fast Magic Angle Spinning (MAS) frequency of 62.5 kHz. Compared to 13C detection, we show that 1H detection leads to a 3-fold enhancement in sensitivity for 1H-13C 2D correlation experiments. By combining 1H-13C and 1H-1H 2D correlation experiments with the analysis of 13C longitudinal relaxation times, we have been able to assign the 1H and 13C signals of each L-alanine ligand.

  1. Machining tools in AISI M2 high-speed steel obtained by spray forming process; Ferramentas de usinagem em aco rapido AISI M2 obtido por conformacao por 'spray'

    Jesus, Edilson Rosa Barbosa de. E-mail:


    The aim of the present work was the obtention of AISI M2 high-speed steel by spray forming technique and the material evaluation when used as machining tool. The obtained material was hot rolled at 50% and 72% reduction ratios, and from which it was manufactured inserts for machining tests. The performance of inserts made of the spray formed material was compared to inserts obtained from conventional and powder metallurgy (MP) processed materials. The spray formed material was chemical, physical, mechanical and microstructural characterised. For further characterisation, the materials were submitted to machining tests for performance evaluation under real work condition. The results of material characterisation highlight the potential of the spray forming technique, in the obtention of materials with good characteristics and properties. Under the current processing, hot rolling and heat treatments condition, the analysis of the results of the machining tests revealed a very similar behaviour among the tested materials. Proceeding a criterious analysis of the machining results tests, it was verified that the performance presented by the powder metallurgy material (MP) was slight superior, followed by conventional obtained material (MConv), which presented a insignificant advantage over the spray formed and hot rolled (72% reduction ratio) material. The worst result was encountered for the spray forming and hot rolled (50% reduction ratio) material that presented the highest wear values. (author)

  2. Friction Stir Spot Welding of Advanced High Strength Steels

    Hovanski, Yuri; Santella, M. L.; Grant, Glenn J.


    Friction stir spot welding was used to join two advanced high-strength steels using polycrystalline cubic boron nitride tooling. Numerous tool designs were employed to study the influence of tool geometry on weld joints produced in both DP780 and a hot-stamp boron steel. Tool designs included conventional, concave shouldered pin tools with several pin configurations; a number of shoulderless designs; and a convex, scrolled shoulder tool. Weld quality was assessed based on lap shear strength, microstructure, microhardness, and bonded area. Mechanical properties were functionally related to bonded area and joint microstructure, demonstrating the necessity to characterize processing windows based on tool geometry.

  3. Fatigue strength tests of layered steel

    Michal Černý


    Full Text Available The work deals with original measurement of fatigue properties of formed layered steel material – damask steel. This is a material that exhibits a fine micro-structure as well as a regular composition of many material layers with complementary properties. The article experimentally verifies high-cycle fatigue properties of layered steel and evaluates them from the point of view of fatigue tests of conventional steel materials and a parallel application of a non-destructive – acoustic emission – testing. Finally, it discusses the influence of production on fatigue strength and the possibilities of using multi-layered steel materials in technological practice. A serious result of this pilot experiment is the fact documented no only by the fractographic observation, but mainly by the AE records that the fatigue service life of this material is high if it its not stressed by tension approximating the yield point Re. However, such stress is not common in practical use of tools made of damask steel and thus under common bending stress an exceptionally long service life of tools made of this type of material is demonstrable. The fact that damask steel behaves like a homogeneous material is mainly confirmed by the records of the AE signal at lower values of stress σa. When stressed by higher amplitudes of tension σa damask responds in AE records similarly to a laminate material that is stressed by bending.

  4. Market challenges for steel

    Lauprecht, W.E.; Bulla, W.


    Country-wise division of generation of high-alloyed steels, stainless steel and alloyed steel in Western Europe/the Western World. Review of expanding markets for alloyed steels on sectors like-oil field pipes, offshore structure gas- and oil transport in pipelines, coal conversion, nuclear energy, condenser tubes, solar energy, car industry, environmental protection and chemistry.

  5. Determining hydrogen-bond interactions in spider silk with 1H-13C HETCOR fast MAS solid-state NMR and DFT proton chemical shift calculations.

    Holland, Gregory P; Mou, Qiushi; Yarger, Jeffery L


    Two-dimensional (2D) (1)H-(13)C heteronuclear correlation (HETCOR) solid-state NMR spectra collected with fast magic angle spinning (MAS) are used in conjunction with density functional theory (DFT) proton chemical shift calculations to determine the hydrogen-bonding strength for ordered β-sheet and disordered 310-helical structures in spider dragline silk. The hydrogen-bond strength is determined to be identical for both structures in spider silk with a 1.83-1.84 Å NH···OC hydrogen-bond distance.

  6. A 1H, 13C and 15N NMR study in solution and in the solid state of six N-substituted pyrazoles and indazoles.

    Claramunt, Rosa M; Santa María, M Dolores; Sanz, Dionisia; Alkorta, Ibon; Elguero, José


    Three N-substituted pyrazoles and three N-substituted indazoles [1-(4-nitrophenyl)-3,5-dimethylpyrazole (1), 1-(2,4-dinitrophenyl)-3,5-dimethylpyrazole (2), 1-tosyl-pyrazole (3), 1-p-chlorobenzoylindazole (4), 1-tosylinda-zole (5) and 2-(2-hydroxy-2-phenylethyl)-indazole (6)] have been studied by NMR spectroscopy in solution (1H, 13C, 15N) and in the solid state (13C, 15N). The chemical shifts have been compared with GIAO/DFT calculated absolute shieldings. Some discrepancies have been analyzed.

  7. Retained Austenite Decomposition and Carbide Formation During Tempering a Hot-Work Tool Steel X38CrMoV5-1 Studied by Dilatometry and Atom Probe Tomography

    Lerchbacher, Christoph; Zinner, Silvia; Leitner, Harald


    The microstructural development of a hot-work tool steel X38CrMoV5-1 during continuous heating to tempering temperature has been investigated with the focus on the decomposition of retained austenite (Stage II) and carbide formation (Stages III and IV). Investigations have been carried out after heating to 673.15 K, 773.15 K, 883.15 K (400 °C, 500 °C, 610 °C) and after a dwell time of 600 seconds at 883.15 K (610 °C). Dilatometry and atom probe tomography were used to identify tempering reactions. A distinctive reaction takes place between 723.15 K and 823.15 K (450 °C and 550 °C) which is determined to be the formation of M3C from transition carbides. Stage II could be evidenced with the atom probe results and indirectly with dilatometry, indicating the formation of new martensite during cooling. Retained austenite decomposition starts with the precipitation of alloy carbides formed from nanometric interlath retained austenite films which are laminary arranged and cause a reduction of the carbon content within the retained austenite. Preceding enrichment of substitutes at the matrix/carbide interface in the early stages of Cr7C3 alloy carbide formation could be visualised on the basis of coarse M3C carbides within the matrix. Atom probe tomography has been found to be very useful to complement dilatational experiments in order to characterise and identify microstructural changes.

  8. Wear behaviour of powder metallurgy tool steel M3/2 reinforced with niobium carbide by pin-on-disk test; Estudio del desgaste de aceros rapidos pulvimetalurgicos M3/2 reforzados con carburo de niobio mediante el ensayo pin-on-disk

    Candela, N.; Lopez, A.; Ruano, O. A.; Jimenez, J. a.


    In this work, composite materials M3/2 high-speed steel reinforced with 5, 10 and 15%, in volume, of niobium carbide have been obtained to improve the wear behaviour. The materials were prepared by powder metallurgy using steel and carbide powders that were mechanically ball milled in a planetary mill, and then hot isostatically pressed. The wear mechanically ball milled in a planetary mill, and then hot isostatically pressed. The wear behaviour was determined by pin-on-disk tests. The materials present a microstructure consisting of grains with a few microns in size and fine MC and M{sub 6}C particles homogeneously dispersed in its interior. In the case of reinforced materials, reinforcing carbides particles are placed mainly at the surface of the prior steel powder particle boundaries. the wear behaviour was evaluated from friction and wear coefficients, and also from weight loss. the addition of niobium carbide improves the wear properties of the tool steel in both martensitic and tempered conditions. A decrease of the weight loss and the wear coefficient is observed with increasing volume fraction of NbC. (Author) 7 refs.

  9. Evaluation of Hole Quality in Hardened Steel with High-Speed Drilling Using Different Cooling Systems

    Lincoln Cardoso Brandão


    Full Text Available This work evaluates the hole quality on AISI H13 hardened steel using high-speed drilling. Specimens were machined with new and worn out drills with 8.6 mm diameter and (TiAlN coating. Two levels of cutting speed and three levels of cooling/lubrication systems (flooded, minimum lubrication quantity, and dry were used. The hole quality is evaluated on surface roughness (Ra parameter, diameter error, circularity, and cylindricity error. A statistical analysis of the results shows that the cooling/lubrication system significantly affects the hole quality for all measured variables. This analysis indicates that dry machining produces the worst results. Higher cutting speeds not only prove beneficial to diameter error and circularity errors, but also show no significant difference on surface roughness and cylindricity errors. The effects of the interaction between the cooling/lubrication systems, tool wear, and cutting speed indicate that only cylindricity error is influenced. Thus, the conclusion is that the best hole quality is produced with a higher cutting speed using flooded or minimum lubrication quantity independent of drill wear.

  10. Microstructural characterization in dissimilar friction stir welding between 304 stainless steel and st37 steel

    Jafarzadegan, M. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Feng, A.H. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Abdollah-zadeh, A., E-mail: [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of); Saeid, T. [Advanced Materials Research Center, Sahand University of Technology, P.O. Box: 51335-1996, Tabriz (Iran, Islamic Republic of); Shen, J. [State Key Laboratory of Advanced Welding Production Technology, School of Materials Science and Eng., Harbin Institute of Technology, P.O. Box: 150001, Harbin (China); Assadi, H. [Department of Materials Eng., Tarbiat Modares University, P.O. Box: 14115-143, Tehran (Iran, Islamic Republic of)


    In the present study, 3 mm-thick plates of 304 stainless steel and st37 steel were welded together by friction stir welding at a welding speed of 50 mm/min and tool rotational speed of 400 and 800 rpm. X-ray diffraction test was carried out to study the phases which might be formed in the welds. Metallographic examinations, and tensile and microhardness tests were used to analyze the microstructure and mechanical properties of the joint. Four different zones were found in the weld area except the base metals. In the stir zone of the 304 stainless steel, a refined grain structure with some features of dynamic recrystallization was evidenced. A thermomechanically-affected zone was characterized on the 304 steel side with features of dynamic recovery. In the other side of the stir zone, the hot deformation of the st37 steel in the austenite region produced small austenite grains and these grains transformed to fine ferrite and pearlite and some products of displacive transformations such as Widmanstatten ferrite and martensite by cooling the material after friction stir welding. The heat-affected zone in the st37 steel side showed partially and fully refined microstructures like fusion welding processes. The recrystallization in the 304 steel and the transformations in the st37 steel enhanced the hardness of the weld area and therefore, improved the tensile properties of the joint. - Highlights: Black-Right-Pointing-Pointer FSW produced sound welds between st37 low carbon steel and 304 stainless steel. Black-Right-Pointing-Pointer The SZ of the st37 steel contained some products of allotropic transformation. Black-Right-Pointing-Pointer The material in the SZ of the 304 steel showed features of dynamic recrystallization. Black-Right-Pointing-Pointer The finer microstructure in the SZ increased the hardness and tensile strength.

  11. 1H, 13C, 15N and 195Pt NMR studies of Au(III) and Pt(II) chloride organometallics with 2-phenylpyridine.

    Pazderski, Leszek; Pawlak, Tomasz; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward


    (1)H, (13)C, (15)N and (195)Pt NMR studies of gold(III) and platinum(II) chloride organometallics with N(1),C(2')-chelated, deprotonated 2-phenylpyridine (2ppy*) of the formulae [Au(2ppy*)Cl(2)], trans(N,N)-[Pt(2ppy*)(2ppy)Cl] and trans(S,N)-[Pt(2ppy*)(DMSO-d(6))Cl] (formed in situ upon dissolving [Pt(2ppy*)(micro-Cl)](2) in DMSO-d(6)) were performed. All signals were unambiguously assigned by HMBC/HSQC methods and the respective (1)H, (13)C and (15)N coordination shifts (i.e. differences between chemical shifts of the same atom in the complex and ligand molecules: Delta(1H)(coord) = delta(1H)(complex) - delta(1H)(ligand), Delta(13C)(coord) = delta(13C)(complex) - delta(13C)(ligand), Delta(15N)(coord) = delta(15N)(complex) - delta(15N)(ligand)), as well as (195)Pt chemical shifts and (1)H-(195)Pt coupling constants discussed in relation to the known molecular structures. Characteristic deshielding of nitrogen-adjacent H(6) protons and metallated C(2') atoms as well as significant shielding of coordinated N(1) nitrogens is discussed in respect to a large set of literature NMR data available for related cyclometallated compounds.

  12. 1H, 13C, and 15N NMR Studies of Au(III and Pd(II Chloride Complexes and Organometallics with 2-Acetylpyridine and 2-Benzoylpyridine

    Daria Niedzielska


    Full Text Available Au(III and Pd(II chloride complexes with N(1,O-chelating 2-acetylpyridine (2apy and N(1- monodentately binding 2-benzoylpyridine (2bz′py-[Pd(2apyCl2], [Au(2bz′pyCl3], trans-[Pd(2bz′py2Cl2], as well as Au(III chloride organometallics with monoanionic forms of 2apy or 2bz′py, deprotonated at the acetyl or benzyl side groups (2apy*, 2bz′py*-[Au(2apy*Cl2], [Au(2bz′py*Cl2], were studied by 1H, 13C, and 15N NMR. 1H, 13C, and 15N coordination shifts (i.e., differences between the respective , , and chemical shifts of the same atom in the complex and ligand molecules: , , were discussed in relation to the molecular structures and coordination modes, as well as to the factors potentially influencing nuclear shielding. Analogous NMR measurements were performed for the new (2bz′pyH[AuCl4] salt.

  13. Effect of composition and processing on the thermal fatigue and toughness of high performance die steels. Year 1 report

    Wallace, J.F.; Wang, Yumin; Schwam, D.


    The goal of this project is to extend the lifetime of dies for die casting by 20%. Since the die contributes about 10% to the cost of die cast parts, such an improvement in lifetime would result in annual savings of over $200 Million dollars. This is based on the estimated annual die production of one Billion dollars in the US. The major tasks of this two year project are: (1) Evaluate NEW DIE STEEL COMPOSITIONS that have been developed for demanding applications and compare them to Premium Grade H-13 die steel. (2) Optimize the AUSTENITIZING TREATMENT of the new composition. Assess the effects of fast, medium and slow COOLING RATES DURING HEAT TREATMENT, on the thermal fatigue resistance and toughness of the die steel. (3) Determine the effect of ELECTRO-DISCHARGE MACHINING (EDM) on the thermal fatigue resistance and impact properties of the steel. (4) Select demanding components and conduct IN-PLANT TESTING by using the new steel. Compare the performance of the new steel with identical components made of Premium Grade H-13. The immersion thermal fatigue specimen developed at CWRU is being used to determine resistance to heat checking, and the Charpy V-notch test for evaluating the toughness. The overall result of this project will be identification of the best steel available on the market and the best processing methods for aluminum die casting dies. This is an interim report for year 1 of the project.

  14. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)


    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  15. Clean Cast Steel Technology, Phase IV

    Charles E. Bates


    The objective of the Clean Cast Steel Technology Program was to improve casting product quality by removing or minimizing oxide defects and to allow the production of higher integrity castings for high speed machining lines. Previous research has concentrated on macro-inclusions that break, chip, or crack machine tool cutters and drills and cause immediate shutdown of the machining lines. The overall goal of the project is to reduce the amount of surface macro-inclusions and improve the machinability of steel castings. Macro-inclusions and improve the machinability of steel castings. Macro-inclusions have been identified by industrial sponsors as a major barrier to improving the quality and marketability of steel castings.

  16. Reinforcing the Steel Sector


    By pushing forward mergers between steel-makers, China gears up to consolidate the large but fragmented industryIn a government effort to consolidate the crowded steel industry and position it for fierce global competition, the state-

  17. A one-dimensional double-chain coordination polymer: [Mn(C12H13NO6S)(C10H8N2)]n.

    Liang, Fu-Pei; Chen, Man-Sheng; Hu, Rui-Xiang; Chen, Zi-Lu


    In the title compound, poly[[(2,2'-bipyridine-kappa(2)N,N')manganese(II)]-micro(3)-N-tosyl-L-glutamato-kappa(4)O,O':O":O"'], [Mn(tsgluo)(bipy)](n), where tsgluo is N-tosyl-L-glutamate (C(12)H(13)NO(6)S) and bipy is 2,2'-bipyridine (C(10)H(8)N(2)), the Mn atoms are octahedrally coordinated by two N atoms of one bipy ligand and by four O atoms of three tsgluo(2-) anions. The gamma-carboxyl group coordinates to the Mn(II) atom in a chelating mode, while the alpha-carboxyl group coordinates in a bidentate-bridging mode. The complex displays a one-dimensional double-chain structure.

  18. Structure and equilibria of Ca 2+-complexes of glucose and sorbitol from multinuclear ( 1H, 13C and 43Ca) NMR measurements supplemented with molecular modelling calculations

    Pallagi, A.; Dudás, Cs.; Csendes, Z.; Forgó, P.; Pálinkó, I.; Sipos, P.


    Ca 2+-complexation of D-glucose and D-sorbitol have been investigated with the aid of multinuclear ( 1H, 13C and 43Ca) NMR spectroscopy and ab initio quantum chemical calculations. Formation constants of the forming 1:1 complexes have been estimated from one-dimensional 13C NMR spectra obtained at constant ionic strength (1 M NaCl). Binding sites were identified from 2D 1H- 43Ca NMR spectra. 2D NMR measurements and ab initio calculations indicated that Ca 2+ ions were bound in a tridentate manner via the glycosidic OH, the ethereal oxygen in the ring and the OH on the terminal carbon for the α- and β-anomers of glucose and for sorbitol simultaneous binding of four hydroxide moieties (C1, C2, C4 and C6) was suggested.

  19. A molecule-like PtAu24(SC6H13)18 nanocluster as an electrocatalyst for hydrogen production

    Kwak, Kyuju; Choi, Woojun; Tang, Qing; Kim, Minseok; Lee, Yongjin; Jiang, De-En; Lee, Dongil


    The theoretically predicted volcano plot for hydrogen production shows the best catalyst as the one that ensures that the hydrogen binding step is thermodynamically neutral. However, the experimental realization of this concept has suffered from the inherent surface heterogeneity of solid catalysts. It is even more challenging for molecular catalysts because of their complex chemical environment. Here, we report that the thermoneutral catalyst can be prepared by simple doping of a platinum atom into a molecule-like gold nanocluster. The catalytic activity of the resulting bimetallic nanocluster, PtAu24(SC6H13)18, for the hydrogen production is found to be significantly higher than reported catalysts. It is even better than the benchmarking platinum catalyst. The molecule-like bimetallic nanocluster represents a class of catalysts that bridge homogeneous and heterogeneous catalysis and may provide a platform for the discovery of finely optimized catalysts.

  20. Stereospecificity of (1) H, (13) C and (15) N shielding constants in the isomers of methylglyoxal bisdimethylhydrazone: problem with configurational assignment based on (1) H chemical shifts.

    Afonin, Andrei V; Pavlov, Dmitry V; Ushakov, Igor A; Keiko, Natalia A


    In the (13) C NMR spectra of methylglyoxal bisdimethylhydrazone, the (13) C-5 signal is shifted to higher frequencies, while the (13) C-6 signal is shifted to lower frequencies on going from the EE to ZE isomer following the trend found previously. Surprisingly, the (1) H-6 chemical shift and (1) J(C-6,H-6) coupling constant are noticeably larger in the ZE isomer than in the EE isomer, although the configuration around the -CH═N- bond does not change. This paradox can be rationalized by the C-H⋯N intramolecular hydrogen bond in the ZE isomer, which is found from the quantum-chemical calculations including Bader's quantum theory of atoms in molecules analysis. This hydrogen bond results in the increase of δ((1) H-6) and (1) J(C-6,H-6) parameters. The effect of the C-H⋯N hydrogen bond on the (1) H shielding and one-bond (13) C-(1) H coupling complicates the configurational assignment of the considered compound because of these spectral parameters. The (1) H, (13) C and (15) N chemical shifts of the 2- and 8-(CH(3) )(2) N groups attached to the -C(CH(3) )═N- and -CH═N- moieties, respectively, reveal pronounced difference. The ab initio calculations show that the 8-(CH(3) )(2) N group conjugate effectively with the π-framework, and the 2-(CH(3) )(2) N group twisted out from the plane of the backbone and loses conjugation. As a result, the degree of charge transfer from the N-2- and N-8- nitrogen lone pairs to the π-framework varies, which affects the (1) H, (13) C and (15) N shieldings. Copyright © 2012 John Wiley & Sons, Ltd.

  1. Water Powered Tools


    Space Spin-Offs, Inc. under a contract with Lewis Research Center and Marshall Space Flight Center produced a new water-powered saw that cuts through concrete and steel plate reducing danger of explosion or electric shock in rescue and other operations. In prototype unit efficient water-powered turbine drives an 8 inch diameter grinding disk at 6,600 rpm. Exhaust water cools disk and workpiece quenching any sparks produced by cutting head. At maximum power, tool easily cuts through quarter inch steel plate. Adapter heads for chain saws, impact wrenches, heavy duty drills, and power hack saws can be fitted.

  2. Friction stir processing on carbon steel

    Tarasov, Sergei Yu., E-mail: [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Melnikov, Alexander G., E-mail: [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Rubtsov, Valery E., E-mail: [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation)


    Friction stir processing of medium carbon steel samples has been carried out using a milling machine and tools made of cemented tungsten carbide. Samples have been machined from 40 and 40X steels. The tools have been made in the shape of 5×5×1.5 mm and 3×3×1.5 mm tetrahedrons. The microstructure of stirred zone has been obtained using the smaller tool and consists of fine recrystallized 2-3 μm grains, whereas the larger tool has produced the 'onion-like' structures comprising hard quenched 'white' 500-600 MPa layers with 300-350 MPa interlayers of bainite needles. The mean values of wear intensity obtained after measuring the wear scar width were 0.02 mm/m and 0.001 mm/m for non-processed and processed samples, respectively.

  3. The steel scrap age.

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M


    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  4. Machine Tool Software


    A NASA-developed software package has played a part in technical education of students who major in Mechanical Engineering Technology at William Rainey Harper College. Professor Hack has been using (APT) Automatically Programmed Tool Software since 1969 in his CAD/CAM Computer Aided Design and Manufacturing curriculum. Professor Hack teaches the use of APT programming languages for control of metal cutting machines. Machine tool instructions are geometry definitions written in APT Language to constitute a "part program." The part program is processed by the machine tool. CAD/CAM students go from writing a program to cutting steel in the course of a semester.

  5. A friction model for cold forging of aluminum, steel and stainless steel provided with conversion coating and solid film lubricant

    Bay, Niels; Eriksen, Morten; Tan, Xincai


    Adopting a simulative tribology test system for cold forging the friction stress for aluminum, steel and stainless steel provided with typical lubricants for cold forging has been determined for varying normal pressure, surface expansion, sliding length and tool/work piece interface temperature...... of normal pressure and tool/work piece interface temperature. The model is verified by process testing measuring friction at varying reduction in cold forward rod extrusion....

  6. Electrical-thermal interaction simulation for resistance spot welding nugget process of mild steel and stainless steel

    王春生; 韩凤武; 陆培德; 赵熹华; 陈勇; 邱冬生


    A three-dimensional finite difference electrical-thermal model for resistance spot welding nugget process of mild steel and stainless steel is introduced. A simulation method of the interaction of electrical and thermal factors is presented. Meanwhile, calculation method of contact resistance and treatment method of heater structure is provided. The influence of the temperature dependent material properties and various cooling boundary conditions on welding process was also taken into account in the model. A method for improving the mild steel and stainless steel joint was analyzed in numerical simulation process. Experimental verification shows that the model prediction agrees well with the practice. The model provides a useful theoretic tool for the analysis of the process of resistance spot welding of mild steel and stainless steel.

  7. Friction Stir Spot Welding of Advanced High Strength Steels

    Hovanski, Yuri; Grant, Glenn J.; Santella, M. L.


    Friction stir spot welding techniques were developed to successfully join several advanced high strength steels. Two distinct tool materials were evaluated to determine the effect of tool materials on the process parameters and joint properties. Welds were characterized primarily via lap shear, microhardness, and optical microscopy. Friction stir spot welds were compared to the resistance spot welds in similar strength alloys by using the AWS standard for resistance spot welding high strength steels. As further comparison, a primitive cost comparison between the two joining processes was developed, which included an evaluation of the future cost prospects of friction stir spot welding in advanced high strength steels.

  8. Determination of electrostatic parameters of a coumarin derivative compound C17H13NO3 by x-ray and density functional theory

    Youcef, Megrouss; Nadia, Benhalima; Rawia, Bahoussi; Nouredine, Boukabcha; Abdelkader, Chouaih; Fodil, Hamzaoui


    This work is devoted to the experimental determination of the electrostatic properties of the molecular 4-methyl-7-(salicylidene amino) coumarin (C17H13NC3) using high resolution x-ray diffraction data. The experimental results are compared with those obtained theoretically from calculation type ab initio. The experimental investigation is carried out using the molecular electron charge density distribution based on the multipolar model of Hansen and Coppens. However the theoretical calculations are conducted by using the molecular orbital B3LYP method and the Hartree-Fock (HF) approximation with the basis set 6-31G (d,p) implemented in the Gaussian program. In addition to the structural analysis, the thermal agitation is also analyzed in terms of rigid blocks to ensure a better precision of the results. Subsequently, the electrostatic atomic and molecular properties such as the net charges, the molecular dipolar moment to highlight the nature of charge transfer existing within the molecule studied are derived. Moreover, the obtained electrostatic potential enables the localization of the electropositive and the electronegative parts of the investigated molecule. The present work reports in detail the obtained electrostatic properties of this biologically important molecule.

  9. Determination of electrostatic parameters of a coumarin derivative compound C17H13NO3 by x-ray and density functional theory

    Youcef Megrouss; Nadia Benhalima; Rawia Bahoussi; Nouredine Boukabcha; Abdelkader Chouaih; Fodil Hamzaoui


    This work is devoted to the experimental determination of the electrostatic properties of the molecular 4-methyl-7-(salicylidene amino) coumarin (C17H13NC3) using high resolution x-ray diffraction data. The experimental results are compared with those obtained theoretically from calculation type ab initio. The experimental investigation is carried out using the molecular electron charge density distribution based on the multipolar model of Hansen and Coppens. However the theoretical calculations are conducted by using the molecular orbital B3LYP method and the Hartree–Fock (HF) ap-proximation with the basis set 6-31G (d,p) implemented in the Gaussian program. In addition to the structural analysis, the thermal agitation is also analyzed in terms of rigid blocks to ensure a better precision of the results. Subsequently, the electrostatic atomic and molecular properties such as the net charges, the molecular dipolar moment to highlight the nature of charge transfer existing within the molecule studied are derived. Moreover, the obtained electrostatic potential enables the localization of the electropositive and the electronegative parts of the investigated molecule. The present work reports in detail the obtained electrostatic properties of this biologically important molecule.

  10. 2D 1H -13C Heteronuclear Shift Correlation Of 2a - Hydroxy Aiantolactone From Pulicaria Undulata C.A. Mey

    A. Rustaiyan


    Full Text Available We have reported recently the isolation and characterization of several sesquiterpene lactones from Pulicaria undulata (1."nThe lactones were isolated from an Et20 - Petrol (1:3 fraction by different chromatographic techniques including HPLC (RP 8, MeOH - H2O, 13:7."nIn this way three eudesmanolides 1 - 3, a guaianolide 4, a nor -guaianolide 5, as well as the pseudoguaianolide 6 and the xanthanolide 7 were isolated. One of the eudesmanolides (2a - hydroxy aiantolactone, 1, was present as the main component."nSuch lactones being known as biologically active substances, we have decided to describe for the first time a detailed interpretation of proton, 1H -NMR, 13C - NMR and 2D lH -13C - heteronuclear shift correlation spectra of 2a - hydroxy aiantolactone. The stereochemistry of C - 2 , C - 7 and C - 8 was determined by the NOESY experiments, H - 7 and H - 8 are in the a configuration and H - 2 is in the b configuration.

  11. A novel hemoglobin variant beta135(H13) Ala > Asp identified in an asymptomatic Korean family by direct sequencing: suggesting a new insight into Hb Beckman mutation.

    Kim, S Y; Kim, G Y J; Jo, S A; Lee, E H; Cho, E H; Hwang, S H; Lee, E Y


    This article describes the clinical observation of a novel hemoglobin (Hb) variant found during the course of routine blood testing on a 61-year-old subject. The Hb variant was observed during HbA1c testing by ion-exchange high-performance liquid chromatography. Alkaline electrophoresis and DNA sequencing confirmed the presence of a new Hb variant, HBB:c.407C > A (p.Ala136Asp). This mutation has been reported to induce Hb Beckman variant in the Globin Gene Server. However, it was different from the only experimental report for Hb Beckman by Rahbar, Lee & Asmeron (p.Ala136Glu; Hb Beckman alpha2 beta2 135(H13) ala-to-glu: a new unstable variant and reduced oxygen affinity. Blood 78, 204a). And our case was asymptomatic with normal lab findings, while Rahbar et al.'s case showed the clinical manifestations of chronic anemia. This would be a report for a novel Hb variant suggesting new insight of Hb Beckman variant. This would be a report of a novel Hb variant suggesting new insights into Hb Beckman variant.

  12. Development of Next Generation Heating System for Scale Free Steel Reheating

    Dr. Arvind C. Thekdi


    The work carried out under this project includes development and design of components, controls, and economic modeling tools that would enable the steel industry to reduce energy intensity through reduction of scale formation during the steel reheating process. Application of scale free reheating offers savings in energy used for production of steel that is lost as scale, and increase in product yield for the global steel industry. The technology can be applied to a new furnace application as well as retrofit design for conversion of existing steel reheating furnaces. The development work has resulted in the knowledge base that will enable the steel industry and steel forging industry us to reheat steel with 75% to 95% reduction in scale formation and associated energy savings during the reheating process. Scale reduction also results in additional energy savings associated with higher yield from reheat furnaces. Energy used for steel production ranges from 9 MM Btu/ton to 16.6 MM Btu/ton or the industry average of approximately 13 MM Btu/ton. Hence, reduction in scale at reheating stage would represent a substantial energy reduction for the steel industry. Potential energy savings for the US steel industry could be in excess of 25 Trillion Btu/year when the technology is applied to all reheating processes. The development work has resulted in new design of reheating process and the required burners and control systems that would allow use of this technology for steel reheating in steel as well as steel forging industries.

  13. Nickel: makes stainless steel strong

    Boland, Maeve A.


    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  14. Modification of AISI M2 high speed tool steels after laser surface melting under different operation conditions; Modificacion de los aceros rapidos de herramientas AISI M2 por fusion superficial con laser bajo diferentes condiciones de operacion

    Arias, J.; Cabeza, M.; Castro, G.; Feijoo, I.; Merino, P.; Pena, G.


    We applied a laser surface melting treatment to AISIM2 high-speed steel hardened and tempered- and studied the resulting surface characteristics (microstructure) and mechanical behavior (hardness and wear performance). The steel was treated using a Nd:YAG continuous-wave laser with different operation conditions. The influence of the laser processing parameters on the single tracks and on melted surface layer obtained by multipass system with 50% overlap were studied. The microstructure for all conditions is formed by MC- and M{sub 2}C-type carbides, martensite and retained austenite; the quantities of this phase depends on the operations conditions. It has been determined that low levels of power density and high speed scanning of the beam leads to greater homogeneity in the microstructure with high hardness values and wear resistance. (Author) 26 refs.

  15. Effect of composition and processing on the thermal fatigue and toughness of high performance die steels. Final report

    Wallace, J.F.; Wang, Y.; Schwam, D.


    The objective of this study was to improve average die life by optimizing die steel composition and the die processing. Four different steels, K,Q,C and Premium Grade H-13 have been investigated for thermal fatigue resistance and toughness. Optimum heat treatment processing has been determined for each steel with respect to austenitizing temperature and tempering conditions. The effect of the quenching rate on the thermal fatigue resistance and toughness of the die steels and the effect of Electro-Discharge Machining (EDM) on the thermal fatigue resistance were also determined. The immersion thermal fatigue specimen developed at CWRU was used to determine the thermal fatigue resistance as characterized by the two parameters of average maximum crack length and total crack area. The Charpy V-notch impact test was used over a -100{degrees}F to 450{degrees}F testing temperature range to evaluate the toughness and the brittle-ductile transition behavior. K steel has been identified as superior in performance compared to Premium Grade H-13. Q and C provide lower toughness and thermal fatigue resistance than H-13. Faster cooling rates provide higher thermal fatigue resistance and toughness. Higher austenitizing temperatures such as 1925{degrees}F compared to 1875{degrees}F provide better thermal fatigue resistance, but lower austenitizing temperatures of 1875{degrees}F provide better toughness. Higher hardness improves thermal fatigue resistance, but reduces toughness. A minimum of Rc 46 hardness is desired for aluminum die casting dies. EDM reduces the thermal fatigue resistance compared to conventional machining operations. When the EDM process of multiple small steps of decreasing energy and post-EDM treatments are employed, the effect can be reduced to a very slight amount. Preliminary evidence of the superior performance of the K steel has been provided by ongoing field testing of inserts in multiple cavity dies.

  16. Ultrahigh Carbon Steel.


    Steels have been utilized to prepare compacted powders of white cast iron (2 to 3%C) which exhibit superplastic be- havior at 650 0C and which are ductile ...strength and ductility than many of these commercially-avail- able steels. In particular, austempered fine-grained UHC steels exhibit good co7,binations of... Ductility of Rapidly Solidified White Cast Irons ", Powd. Metall., 26 (1983), pp. 155-160. (29) L. E. Eiselstein, 0. A. Ruano, J. Wadsworth, and 0. D

  17. Springback analysis of ultra high strength steel

    Tenma, Kenji; Kina, Futoshi; Suzuki, Wataru


    It is an inevitable trend in the automotive industry to apply more and more high strength steels and even ultra-high strength steels. Even though these materials are more difficult to process the development time of forming tools must be reduced. In order to keep the development time under control, simulation tools are used to verify the forming process in advance. At Aoi Machine Industry a project has been executed to accurately simulate springback of ultra-high strength steels in order to reduce the tool tryout time. In the first phase of the project the simulation settings were optimized based on B-Pillar model A made of Dual Phase 980. In the second phase, it was verified with B-Pillar model B whether these simulation settings were usable as general setting. Results showed that with the right settings it is very well possible to accurately simulate springback of ultra-high strength steels. In the third phase the project the stamping of a B-Pillar of Dual Phase 1180 was studied.

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

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


    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......The increasing use of high strength steels in a variety of mechanical engineering applications has illuminated problems associated with galling in sheet metal forming operations. Galling is a tribological phenomenon associated with transfer of material from the steel sheet to the tool surface...

  19. Ultrahigh Carbon Steels

    Sherby, O. D.; Oyama, T.; Kum, D. W.; Walser, B.; Wadsworth, J.


    Recent studies and results on ultrahigh carbon (UHC) steels suggest that major development efforts on these steels are timely and that programs to evaluate prototype structural components should be initiated. These recent results include: the development of economical processing techniques incorporating a divorced eutectoid transformation, the improvement of room temperature strength and ductility by heat treatment, the enhancement of superplastic properties through dilute alloying with silicon, and the attainment of exceptional notch impact strength in laminated UHC steel composites manufactured through solid state bonding. The unique mechanical properties achieved in UHC steels are due to the presence of micron-size fer-rite grains and ultrafine spheroidized carbides.

  20. New structural information on a humic acid from two-dimensional 1H-13C correlation solid-state nuclear magnetic resonance.

    Mao, J D; Xing, B; Schmidt-Rohr, K


    New information on the chemical structure of a peat humic acid has been obtained using a series of two-dimensional 1H-13C heteronuclear correlation solid-state NMR (HETCOR) experiments with different contact times and with spectral editing by dipolar dephasing and 13C transverse relaxation filtering. Carbon-bonded methyl groups (C-CH3) are found to be near both aliphatic and O-alkyl but not aromatic groups. The spectra prove that most OCH3 groups are connected directly with the aromatic rings, as is typical in lignin. As a result, about one-third of the aromatic C-O groups is not phenolic C-OH but C-OCH3. Both protonated and unprotonated anomeric O-C-O carbons are identified in the one- and two-dimensional spectra. COO groups are found predominantly in OCHn-COO environments, but some are also bonded to aromatic rings and aliphatic groups. All models of humic acids in the literature lack at least some of the features observed here. Compositional heterogeneity was studied by introducing 1H spin diffusion into the HETCOR experiment. Comparison with data for a synthetic polymer, polycarbonate, indicates that the separation between O-alkyl and aromatic groups in the humic acid is less than 1.5 nm. However, transverse 13C relaxation filtering under 1H decoupling reveals heterogeneity on a nanometer scale, with the slow-relaxing component being rich in lignin-like aromatic-C-O-CH3 moieties and poor in COO groups.

  1. Solution structures of the prototypical 18 kDa translocator protein ligand, PK 11195, elucidated with 1H/13C NMR spectroscopy and quantum chemistry.

    Lee, Yong-Sok; Siméon, Fabrice G; Briard, Emmanuelle; Pike, Victor W


    Eighteen kilodalton translocator protein (TSPO) is an important target for drug discovery and for clinical molecular imaging of brain and peripheral inflammatory processes. PK 11195 [1a; 1-(2-chlorophenyl)-N-methyl-(1-methylpropyl)-3-isoquinoline carboxamide] is the major prototypical high-affinity ligand for TSPO. Elucidation of the solution structure of 1a is of interest for understanding small-molecule ligand interactions with the lipophilic binding site of TSPO. Dynamic (1)H/(13)C NMR spectroscopy of 1a revealed four quite stable but interconverting rotamers, due to amide bond and 2-chlorophenyl group rotation. These rotamers have been neglected in previous descriptions of the structure of 1a and of the binding of 1a to TSPO. Here, we used quantum chemistry at the level of B3LYP/6-311+G(2d,p) to calculate (13)C and (1)H chemical shifts for the rotamers of 1a and for the very weak TSPO ligand, N-desmethyl-PK 11195 (1b). These data, plus experimental NMR data, were then used to characterize the structures of rotamers of 1a and 1b in organic solution. Energy barriers for both the amide bond and 2'-chlorophenyl group rotation of 1a were determined from dynamic (1)H NMR to be similar (ca.17 to 18 kcal/mol), and they compared well with those calculated at the level of B3LYP/6-31G*. Furthermore, the computed barrier for Z to E rotation is considerably lower in 1a(18.7 kcal/mol) than in 1b (25.4 kcal/mol). NMR (NOE) unequivocally demonstrated that the E rotamer of 1a is the more stable in solution by about 0.4 kcal/mol. These detailed structural findings will aid future TSPO ligand design and support the notion that TSPO prefers to bind ligands as amide E-rotamers.


    V. N. Fedulov


    Full Text Available The technological scheme of the new tool steel 5HVMFS smelting by means of electroslag casting method with the use of different combinations of steel scrap of R6M5 and CH5 steels and dressing the chemical composition directly in the bowl and also filling into metal bowl is developed.

  3. Application of RST in the steel industry

    Raman, R. V.; Maringer, R. E.


    The rapid solidification technology (RST) involves quenching molten metals at rates of perhaps 102 to 1010 degrees C per second. First reported in 1960, RST has experienced rapid growth during the last decade and is now established on the commercial market-place. This has resulted from the simple facts that unusual properties result from RST, that relatively easy techniques are available to produce large quantities of material, and that applications for these materials have been recognized. Ferrous-base materials produced by RST methods include staple fibers of mild and stainless steel for incorporation into concrete and castable refractories, powder metallurgy tool steels, and amorphous strip for power transformers. Research results suggest that RST will have a strong continuing influence on ferrous powder metallurgy, on the direct casting of strip and foil of carbon and stainless steel, and on core materials for motor and transformers.

  4. Modern Steel Framed Schools.

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  5. A sustainability assessment system for Chinese iron and steel firms

    Long, Yunguang; Pan, Jieyi; Farooq, Sami;


    The environmental impact of the Chinese iron and steel industry is huge due to its high consumption of ore, coal and energy, and water and air pollution. It is important not only for China but also for the rest of the world that the Chinese iron and steel industry becomes more sustainable....... A sustainable assessment indicator system is an important tool to support that development. Currently, however, a sustainable assessment system, specifically designed to match the characteristics of Chinese iron and steel firms, is not available. In this paper such a system is proposed and evaluated using data...... from financial and sustainability reports of four leading Chinese iron and steel firms. The proposed sustainable assessment system is envisaged to help Chinese iron and steel firms to objectively investigate their sustainability performance, provide clear and effective information to decision makers...

  6. The Synchrotron Radiation for Steel Research

    Piyada Suwanpinij


    Full Text Available The synchrotron X-ray radiation is a great tool in materials characterization with several advantageous features. The high intensity allows clear interaction signals and high energy of X-ray yields higher sampling volume. The samples do not need extra preparation and the microstructure is therefore not affected. With the tunability of the X-ray energy, a large range of elements and features in the samples can be investigated by different techniques, which is a significant difference between a stand-alone X-ray tube and synchrotron X-ray. Moreover, any experimental equipment can be installed through which the synchrotron beam travels. This facilitates the so-called in situ characterization such as during heat treatment, hot deformation, chemical reaction or welding. Although steel which possesses rather high density requires very high energy X-ray for large interaction volume, lower energy is still effective for the investigation of local structure of nanoconstituents. This work picks up a couple examples employing synchrotron X-ray for the characterization of high strength steels. The first case is the quantification of precipitates in high strength low alloyed (HSLA steel by X-ray absorption spectroscopy. The other case is the in situ X-ray diffraction for phase fraction and carbon partitioning in multiphase steels such as transformation induced plasticity (TRIP steel.




    Full Text Available This paper presents experimental research concerning the behavior on cutting by turning of steels for magnets NdFeB based. In this context, cutting by rough turning of steels magnet neodymium and boron ferrite based were performed. Turning processing with the values of the cutting parameters recommended by European Union and Sandvik Coromant company rules, taking into account the chemical composition of the processed material and cutting tool were performed. The tables have been drawn up with different values of the cutting parameters. By comparing these data it can be concluded that steels for permanent magnets, NdFeB based have acceptable behavior, the process by rough turning. A full assessment of the optimization of the cutting by turning process of steels for permanent magnet, NdFeB base will result from subsequent experimental research that will take into account the wear of cutting tools and quality (roughness of processed surface.

  8. Suitability assessment of replacement of conventional hot-working steels with maraging steel. Pt. I. Mechanical properties of maraging steel after precipitation hardening treatment

    Grum, J.; Zupancic, M. [Ljubljana Univ. (Slovenia). Fakulteta za Strojnistvo


    The paper deals with the results of measurement of mechanical properties of maraging steel Thyssen 1.2799 after precipitation annealing with a wide spectrum of temperature/time conditions. The purpose of the investigation conducted on the material for die-casting tools was to find out how the tool life could be extended depending on the heat-treatment conditions and the microstructure of the steel. Thus the influence of temperature/time conditions of precipitation annealing on tensile strength, hardness, and impact toughness of the steel was studied. The Charpy impact toughness test was carried out at a temperature of 200 C, which is, according to our assessment, an average operating temperature of the observed tool surface in die casting of aluminium alloys. Measurements of the mechanical properties were accomplished on three test pieces under each combination of annealing conditions. Special attention was paid to the correlation of the mechanical properties measured under individual precipitation annealing conditions. (orig.)

  9. 工具式围堰在桥梁墩柱维修中的应用%Operation Method of the Tool-typed Recycling Double Wall Steel Cofferdam in Wate-pier Reinforcement Engineering in the Spring Tide of Poor Water

    刘昂; 吴中鑫; 朱慈祥


    In this paper,in the engineering background of detection and reinforcement project of the No.14~18 Pier of a bridge,the construction method of the Tool-Typed Double Wall Steel Cofferdam in the bridge of low clearance flyovers which is removable and recyclable in the spring tide of poor wa-ter is introduced.In the method,the factors,the spring tide of poor water,low clearance flyovers, and details of design and fabrication of the steel cofferdams are considered.An application example shows that the method can reduce construction time,cost,energy conservation and environmental protection..%以某桥梁15~18号桥墩检测加固项目为工程背景,介绍了某桥梁高潮差低净空下的工具式可拆卸循环利用双壁钢围堰使用方法,该工具式可拆卸循环利用双壁钢围堰的施工考虑了涨落潮变化、桥下净空较小等环境因素,以及围堰及辅助措施的设计、制作安装。应用证明,该方法具有减少施工工期、降低成本、节能环保等特点。

  10. Fractography analysis of tool samples used for cold forging

    Dahl, K.V.


    Three fractured tool dies used for industrial cold forging have been investigated using light optical microscopy and scanning electron microscopy. Two of the specimens were produced using the traditional Böhler P/M steel grade s790, while the lastspecimen was a third generation P/M steel produced...... using new technology developed by Böhler. All three steels have the same nominal composition of alloying elements. The failure in both types of material occurs as a crack formation at a notch inside ofthe tool. Generally the cold forging dies constructed in third generation steels have a longer lifetime...

  11. Clean Production of Steel and Refractories in China's Steel Industry

    SU Tiansen


    The paper describes the importance of clean production of steel and the relationships amongst sustaining development of steel industry, environment protection and the role of refractories in the clean production of steel. The main achievements and main shortcomings in the clean production of China' s steel industry have been reviewed together with the introduction of the policy supporting system and the future development of clean production in China' s steel industry.

  12. Steel: Price and Policy Issues


    Inland Steel. He had also acquired a major Mexican producer, the integrated steel works on the Pacific coast at Lazaro Cardenas . But his major coup...Steel-Producing Countries Launch Talks on Banning Subsidies at OECD Meeting” (Dec. 20, 2002). 76 Nancy E. Kelly, “Steel Talks to Kick Off in Paris, Six

  13. Friction Stir Welding of Shipbuilding Steel with Primer

    José Azevedo


    Full Text Available Abstract Friction Stir Welding has proven its merits for welding of aluminium alloys and is focused in expanding its material database to steel and titanium and also to assess new joint configurations. The use of welded structures in shipbuilding industry has a long tradition and continuously seeks for innovation in terms of materials and processes maintaining, or even, reducing costs. Several studies have been performed in the past years on FSW of steel. However, just recently were reported defect-free welds, free of martensite with stable parameters in steel without Primer. FSW of steel with primer has not been addressed. This work aims to fulfil a knowledge gap related to the use of friction stir for welding shipbuilding steel by analysing the effect of welding parameters on the metallurgical characteristics and mechanical properties of welds obtained with an innovative FSW tool in joining steel plates with a primer. Welds were performed in 4mm thick GL-A36 steel plates painted with a zinc based primer followed by a detailed microscopic, chemical and mechanical analysis. The results that matching fatigue properties are obtained using this technique, in FSW of shipbuilding steel with Primer.

  14. Suitability assessment of replacement of conventional hot-working steels with maraging steel. Pt. II. Microstructure of maraging steel after precipitation hardening treatment

    Grum, J.; Zupancic, M. [Ljubljana Univ. (Slovenia). Fakulteta za Strojnistvo


    A study of the properties of maraging steel Thyssen 1.2799 in the production of die-casting tools for aluminium alloys has been undertaken. Beside the study of the mechanical properties described in Part I of the paper, analyses of the microstructure by means of optical microscopy and scanning electron microscopy were made, too. The precipitates having a size of the order of a few 10 nm and more could be identified. Relating of the mechanical properties to the microstructure analyses supported by a micro chemical analysis, the suitability of the maraging steel concerned for the production of die-casting tools for aluminium alloys was proved. (orig.)

  15. Quantification of indium in steel using PIXE

    Oliver, A.; Miranda, J.; Rickards, J.; Cheang, J.C.


    The quantitative analysis of steel endodontics tools was carried out using low-energy protons (/le/ 700 keV). A computer program for a thick-target analysis which includes enhancement due to secondary fluorescence was used. In this experiment the L-lines of indium are enhanced due to the proximity of other elements' K-lines to the indium absorption edge. The results show that the ionization cross section expression employed to evaluate this magnitude is important. (orig.).

  16. Springback characteristics of steel sheets for warm U-draw bending

    Seo, Dae Gyo; Chang, Sung Ho; Lee, Sang Moo


    The purpose of this study is to investigate the characteristics of springback for various process conditions of the U-draw bending operation. The process variables are the forming temperature and the tool geometry, including punch profile radius (Rp) and die profile radius (Rd). In order to control springback, the use of a warm forming method is applied. For the warm draw-bending, five steps of temperature ranges, from room temperature to 200°C, were adopted. Two kinds of steel sheets, cold rolled carbon steel (SCP1, for general purposes in the automobile industries) and TRIP (transformation-induced plasticity) steel, were adopted. TRIP steel was the newly developed high-strength steel sheet. The results indicated that elevated temperature and the geometry of tools in the two kinds of steel sheet affected the springback.

  17. Glass Stronger than Steel

    Yarris, Lynn


    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  18. Life after Steel

    Mangan, Katherine


    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  19. Enhanced boronizing kinetics of alloy steel assisted by surface mechanical attrition treatment

    Yang, Haopeng, E-mail:; Wu, Xiaochun, E-mail:; Yang, Zhe; Pu, Shengjun; Wang, Hongbin


    Highlights: • Nanostructured surface layer is fabricated on H13 steel assisted by SMAT. • The boronizing kinetics of SMAT sample can be enhanced remarkably. • Borided layer can delay fatigue cracks initiation and impede their propagation. -- Abstract: A nanostructured surface layer was fabricated on AISI H13 steel by means of surface mechanical attrition treatment (SMAT). Boronizing behaviors of the SMAT samples were systematically investigated in comparison with their coarse-grained counterparts. The boron diffusion depth of the SMAT sample with pack boriding treatment at 600 °C for 2 h was about 8 μm, which was much deeper than that of the coarse-grained sample. A much thicker borided layer on the SMAT sample can be synthesized by a duplex boronizing treatment at 600 °C followed by at a higher temperature. The borided layer was composed with monophase of Fe{sub 2}B and the growth of it exhibited a (0 0 2) preferred orientation. Moreover, the activation energy of boron diffusion for the SMAT sample is 140.3 kJ/mol, which is much lower than 209.4 kJ/mol for the coarse-grained counterpart. The results indicate that the boronizing kinetics can be significantly enhanced in the SMAT sample with a duplex boronizing treatment. Furthermore, the thermal fatigue tests show that the borided layer with excellent oxidation resistance and mechanical strength at elevated temperatures could effectively delay the thermal fatigue cracks initiation and impede their propagation. Therefore, the thermal fatigue property of H13 steel with a duplex boronizing treatment can be improved remarkably.

  20. Study of the solidification of M2 high speed steel Laser Cladding coatings

    Candel Bou, Juan Jose; Franconetti Rodríguez, Patricia; Amigó Borrás, Vicente


    [EN] High speed steel laser cladding coatings are complex because cracks appear and the hardness is lower than expected. In this paper AISI M2 tool steel coatings on medium carbon AISI 1045 steel substrate have been manufactured and after laser cladding (LC) processing it has been applied a tempering heat treatment to reduce the amount of retained austenite and to precipitate secondary carbides. The study of metallurgical transformations by scanning electron microscopy (SEM) and backscattered...


    A. L. Valko


    Full Text Available Techniques metallographic researches of structure and definition of size of grain of tool steels are offered. The structure of the fast-cutting steel received by a method electroslag remelting from a waste of tool manufacture is investigated.

  2. Articles comprising ferritic stainless steels

    Rakowski, James M.


    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  3. Research on High-Speed Drilling Performances of Austenitic Stainless Steels

    J.W.Zhong; Y.P.Ma; F.H.Sun; M.Chen


    Due to specific properties arising from their structure (high ductility, high toughness,strong tenacious and low heat conductivity), the stainless steels have poor machinability. The drilling of the stainless steels becomes the machining difficulty for their serious work-hardening and abrasion of tools. In this paper, the austenitic stainless steel is used as the work-piece to perform the contrastive experiments with the TiN coated and TiAlN-coated high-speed steel drills. The cutting force, torque, cutting temperature, and the abrasion of drills and tool life are tested and analyzed in the process of high-speed drilling. Experiment results show the effect of drilling speed on cutting force, cutting temperature, and drill wear. TiAlN-coated drills demonstrate better performances in high speed drilling. The research results will be of great benefit in the selection of drills and in the control of tool wear in high speed drilling of stainless steels.

  4. Manufacturing of complex high strength components out of high nitrogen steels at industrial level

    Hannes NONEDER; Marion MERKLEIN


    High performance components,e.g.,fasteners,nowadays are usually made out of cold forged and heat treated steels like steel 1.5525 (20MnB4).To overcome the problems of heat treatment,e.g.,low surface quality,new workpiece materials for cold forging should be found to achieve the needlessness of heat treatment after cold forging.One possible material is given by high nitrogen steels like steel 1.3815 (X8CrMnN19-19).Due to the high strain hardening of these materials the process and tool design for an industrial batch process are challenging and should be conducted by FE-simulation.The numerical results show that,high strength tool materials,like PM-steels or cemented carbides,in most cases,are inevitable.Additionally to the selection of suitable tool materials,the tool layout should be developed further to achieve a high loadability of the tools.The FE-models,used for process and tool design,are validated with respect to the materials' flow and occurring forming force to assure a proper design process.Also the comparison of strength of components made out of steel 1.5525 in quenched and tempered conditions and steel 1.3815 in strain hardened condition is done.The results show that the component made of steel 1.3815 has a significantly higher strength than the component made of steel 1.5525.This shows that by the use of high nitrogen steels a high performance component can be manufactured by cold forging.

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

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


    The increasing use of high strength steels in a variety of mechanical engineering applications has illuminated problems associated with galling in sheet metal forming operations. Galling is a tribological phenomenon associated with transfer of material from the steel sheet to the tool surface dur...

  6. Clean steels for fusion

    Gelles, D.S.


    Fusion energy production has an inherent advantage over fission: a fuel supply with reduced long term radioactivity. One of the leading candidate materials for structural applications in a fusion reactor is a tungsten stabilized 9% chromium Martensitic steel. This alloy class is being considered because it offers the opportunity to maintain that advantage in the reactor structure as well as provide good high temperature strength and radiation induced swelling and embrittlement resistance. However, calculations indicate that to obtain acceptable radioactivity levels within 500 years after service, clean steel will be required because the niobium impurity levels must be kept below about 2 appm and nickel, molybdenum, nitrogen, copper, and aluminum must be intentionally restricted. International efforts are addressing the problems of clean steel production. Recently, a 5,000 kg heat was vacuum induction melted in Japan using high purity commercial raw materials giving niobium levels less than 0.7 appm. This paper reviews the need for reduced long term radioactivity, defines the advantageous properties of the tungsten stabilized Martensitic steel class, and describes the international efforts to produce acceptable clean steels.

  7. Microstructure, state of internal stress and corrosion resistance of the short-time laser heat-treated nitrogen high-alloyed tool steel X30CrMoN151; Mikrostruktur, Eigenspannungszustand und Korrosionsbestaendigkeit des kurzzeitlaserwaermebehandelten hochstickstofflegierten Werkzeugstahls X30CrMoN151

    Bohne, C. (ed.)


    This study compares the crystalline structure, state of internal stress and chemical properties of the high-alloyed nitrogen tool steel X30CrMoN15 1 and conventional cold work steel X39CrMo17 1. Transformation points A{sub c}1b and A{sub c}1e were calculated from residual austenite analysis and the c{sub m}/a{sub m} martensite ratios for various heating rates. This was used to generate a TTA (time-temperature-austenitisation) graph for X30CrMoN15 1 for the first time. Transmission electron microscopy and small-angle neutron scattering show that precipitates in nitrogen high-alloyed steel X30CrMoN15 1 can be eliminated completely by short-time laser heat treatment. The corrosion tests show that in contrast to X39CrMo17 1 X30CrMoN15 1 reacts more sensitively to parameter changes during short-time heat treatment in oxidising acid at pH 5-6. [German] Im Rahmen der Arbeit werden die Gefuegeausbildung, Eigenspannungen und chemische Eigenschaften des hochstickstofflegierten Werkzeugstahls X30CrMoN15 1 und des konventionellen Kaltarbeitsstahls X39CrMo17 1 verglichen. Aus den Restaustenitanalysen und den c{sub m}/a{sub m}-Verhaeltnissen des Martensits konnten die Umwandlungspunkte A{sub c1b} und A{sub c1e} fuer verschiedene Aufheizraten bestimmt und daraus ein bisher nicht bekanntes ZTA-Schaubild fuer den X30CrMoN15 1 erstellt werden. Transmissionselektronenmikroskopie und Neutronenkleinwinkelstreuung zeigen, dass sich die Ausscheidungen im hochstickstofflegierten Stahl X30CrMoN14 1 durch die Kurzzeitlaserwaermebehandlung vollstaendig aufloesen koennen. Die Korrosionsversuche zeigen, dass im Gegensatz zum X39CrMo17 1 der X30CrMoN15 1 in oxidierender Saeure bei pH 5-6 empfindlicher auf Parameteraenderungen bei der Kurzzeitwaermebehandlung reagiert. (orig.)

  8. Thermochemical surface engineering of steels

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  9. Continuous steel production and apparatus

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng


    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  10. Fatigue damage of steel components

    Fæster, Søren; Zhang, Xiaodan; Huang, Xiaoxu


    Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials......Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials...

  11. A-3 steel work completed


    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  12. Thermomechanical processing and mechanical properties of hypereutectoid steels and cast irons

    Lesuer, D.R.; Syn, C.K.; Sherby, O.D. (eds.)


    Recent advances in metallurgy of hypereutectoid steels and cast irons show that unique properties, such ultrahigh hardness and strength, and superplasticity, are achievable. This book focuses on the mechanical properties of hypereutectoid steels and cast irons as influenced by thermomechanical processing and microstructure. Some topics covered are: (1) Hot workability of hypereutectoid tool steels; (2) Thermomechanical processing of austempered ductile iron: An overview; (3) Mechanical behavior of ultrahigh strength, ultrahigh carbon steel wire and rod; and (4) Tensile elongation behavior of fine-grained Fe-C alloys at elevated temperatures.

  13. The Effect of Different Non-Metallic Inclusions on the Machinability of Steels.

    Ånmark, Niclas; Karasev, Andrey; Jönsson, Pär Göran


    Considerable research has been conducted over recent decades on the role of non‑metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, etc.) are discussed and summarized. Finally, some methods for modification of non-metallic inclusions in the liquid steel are considered to obtain a desired balance between mechanical properties and machinability of various steel grades.

  14. The Effect of Different Non-Metallic Inclusions on the Machinability of Steels

    Niclas Ånmark


    Full Text Available Considerable research has been conducted over recent decades on the role of non‑metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, etc. are discussed and summarized. Finally, some methods for modification of non-metallic inclusions in the liquid steel are considered to obtain a desired balance between mechanical properties and machinability of various steel grades.

  15. Joints in steel buildings

    Gabriel F. Valencia Clement


    Full Text Available Masonry and steel components used in constructing buildings are in a constant state of motion. Volumetric changes are produced by temperature variation and deformation resulting from static or dynamic loading and in some materials, such as masonry, due to moisture content. This article addresses means of determining when expansion and seismic joints are required and how to proportion and design appropriate joints, specifically in steel buildings. It does not cover the study of expansion joints in concrete structures, in masonry construction or in non-structural (architectural elements.

  16. Relationship Between pH and Electrochemical Corrosion Behavior of Thermal-Sprayed Ni-Al-Coated Q235 Steel in Simulated Soil Solutions

    Wei, Wei; Wu, Xin-qiang; Ke, Wei; Xu, Song; Feng, Bing; Hu, Bo-tao


    Electrochemical corrosion behavior of a thermal-sprayed Ni-Al-coated Q235 steel was investigated in the simulated soil solutions at different pH values using measurements of potentiodynamic polarization curves and electrochemical impedance spectroscopy as well as surface analyses including x-ray diffraction analysis, scanning electron microscope equipped with an energy-dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. The results showed that the corrosion resistance of the Ni-Al-coated Q235 steel was dependent on the pH of the test solution. From pH = 3.53 to pH = 4.79, the corrosion resistance of the coated steel increased rapidly. In the pH range from 4.79 to 12.26, the corrosion resistance exhibited no significant change. At pH 13.25, the corrosion resistance of the sample was found to decrease. The calculated corrosion rate of Ni-Al-coated Q235 steel was lower than that of the uncoated Q235 steel and galvanized steel in all the test solutions. Over a wide range of pH values, the Ni-Al-coated Q235 steel exhibited extremely good corrosion resistance. The experimental data together with the potential-pH diagrams provided a basis for a detailed discussion of the related corrosion mechanisms of the coated steel.

  17. Clean cast steel technology. Final report

    Bates, C.E.; Griffin, J.A.


    This report documents the results obtained from the Clean Cast Steel Technology Program financially supported by the DOE Metal Casting Competitiveness Research Program and industry. The primary objective of this program is to develop technology for delivering steel free of oxide macroinclusions to mold cavities. The overall objective is to improve the quality of cast steel by developing and demonstrating the technology for substantially reducing surface and sub-surface oxide inclusions. Two approaches are discussed here. A total of 23 castings were produced by submerge pouring along with sixty conventionally poured castings. The submerged poured castings contained, on average, 96% fewer observable surface inclusions (11.9 vs 0.4) compared to the conventionally poured cast parts. The variation in the population of surface inclusions also decreased by 88% from 5.5 to 0.7. The machinability of the casting was also improved by submerged pouring. The submerge poured castings required fewer cutting tool changes and less operator intervention during machining. Subsequent to these trials, the foundry has decided to purchase more shrouds for continued experimentation on other problem castings where submerge pouring is possible. An examination of melting and pouring practices in four foundries has been carried out. Three of the four foundries showed significant improvement in casting quality by manipulating the melting practice. These melting practice variables can be grouped into two separate categories. The first category is the pouring and filling practice. The second category concerns the concentration of oxidizable elements contained in the steel. Silicon, manganese, and aluminum concentrations were important factors in all four foundries. Clean heats can consistently be produced through improved melting practice and reducing exposure of the steel to atmospheric oxygen during pouring and filling.

  18. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam


    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  19. Study of the effect of solidification on graphite flakes microstructure and mechanical properties of an ASTM a-48 gray cast iron using steel molds

    Ganwarich Pluphrach


    The analysis of heat conduction is a widely used technique for control of metallurgical process and solidified eutecticalloy investigation. The objectives of this research are studies about the effect of solidification on graphite flakes microstructureand mechanical properties of an ASTM A-48 gray cast iron using SKD 11 tool steel, S45C medium carbon steel andSS400 hot-rolled steel molds. These three steel molds are important for heat conduction and different from other works. Thisanalysis in...

  20. Precipitates in electrical steels

    Jenkins, Keith [Development and Market Research, Cogent Power Limited, Corporation Road, Newport, South Wales NP19 OXT (United Kingdom)], E-mail:; Lindenmo, Magnus [Development and Market Research, Cogent Power Limited, Corporation Road, Newport, South Wales NP19 OXT (United Kingdom)


    Precipitates heavily influence the magnetic properties of electrical steels, either as a key controlled requirement as part of the manufacturing process or as an unwanted harmful residual in the final product. In this current work copper-manganese sulphides precipitates are the primary inhibitor species in the conventional grain-oriented (CGO) steels examined and grain boundary pinning is effective at a mean precipitate size of 30-70 nm. The growth of CuMnS has been studied and the results show that a precipitate size above {approx}100 nm allows the onset of secondary recrystallisation in the heating conditions applied. The effect of precipitates on the magnetic properties of both grain-oriented and non-oriented steels in their final product form is then examined. Examples of grain-oriented material still containing large numbers of precipitates clearly show the detrimental effects with increases in total power loss of 40% or more. Loss deterioration by about 20% is also seen in samples of high silicon non-oriented material in which titanium carbo-nitride precipitates have been observed. In this case the precipitates are believed to have formed during cooling after final annealing. Finally a grain-oriented steel with a large number of very small precipitates, which do not seem to have any harmful effect on the magnetic properties, is demonstrated.

  1. Japan steel mill perspective

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)


    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  2. Special steel production on common carbon steel production line

    Pi, Huachun; Han, Jingtao; Hu, Haiping; Bian, Ruisheng; Kang, Jianjun; Xu, Manlin


    The equipment and technology of small bar tandem rolling line of Shijiazhuang Iron & Steel Co. in China has reached the 90's international advanced level in the 20th century, but products on the line are mostly of common carbon steel. Currently there are few steel plants in China to produce 45 steel bars for cold drawing, which is a kind of shortage product. Development of 45 steel for cold drawing has a wide market outlook in China. In this paper, continuous cooling transformation (CCT) curve of 45 steel for cold drawing used for rolling was set out first. According to the CCT curve, we determined some key temperature points such as Ac3 temperature and Ac1 temperature during the cooling procedure and discussed the precipitation microstructure at different cooling rate. Then by studying thermal treatment process of 45 steel bars for cold drawing, the influence of cooling time on microstructure was analyzed and the optimum cooling speed has been found. All results concluded from the above studies are the basis of regulating controlled cooling process of 45 steel bars for cold drawing. Finally, the feasible production process of 45 steel bars for cold drawing on common carbon steel production line combined with the field condition was recommended.

  3. History of ultrahigh carbon steels

    Wadsworth, J.; Sherby, O.D.


    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  4. Microstructure and Mechanical Properties of a Dissimilar Friction Stir Weld between Austenitic Stainless Steel and Low Carbon Steel

    M.Jafarzadegan; A.Abdollah-zadeh; A.H.Feng; T.Saeid; J.Shen; H.Assadi


    Dissimilar fusion welding of austenitic stainless steels to carbon steels has some metallurgical and technical problems.It was suggested that the solid-state nature of friction stir welding (FSW) can overcome these problems and produce a sound weld with reliable mechanical properties.In this study,plates of 304 stainless steel and st37 steel were welded together by FSW at tool rotational speed of 600 r/min and welding speed of 50 mm/min.In the stir zone (SZ) of 304 stainless steel,the results showed a refined grain structure with some features of metadynamic recrystallization.In the SZ of st37 steel,the hot deformation of material in the austenite region produced small austenite grains.These grains transformed to fine ferrite and pearlite by cooling the material after FSW.The production of fine grains increased the hardness and tensile strength in the SZ of both sides with respect to their base metals (BMs).

  5. Benchmarking research of steel companies in Europe

    M. Antošová


    Full Text Available In present time steelworks are at a stage of permanent changes that are marked with still stronger competition pressure. Therefore managers must solve questions of how to decrease production costs, how to overcome competition and how to survive in the world market. Still more attention should be paid to the modern managerial methods of market research and comparison with competition. Benchmarking research is one of the effective tools for such research. The goal of this contribution is to compare chosen steelworks and to indicate new directions for their development with the possibility of increasing the productivity of steel production.

  6. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.


    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  7. Coated 4340 Steel


    alternative coatings qualified to MIL-PRE-23377 Class N and an electroplated zinc - nickel alloy passivated with a trivalent chromium solution which is...effect of a non-chromate primer and zinc - nickel plating with non-chromate passivation as alternatives to the chromate primer and cadmium plating with...NAWCADPAX/TR-2013/252 COATED 4340 STEEL by E. U. Lee C. Lei M. Stanley B. Pregger C. Matzdorf 26 August 2013

  8. Ferrium M54 Steel


    Examination ................................................................................................. 2 Zinc - Nickel Alloy Plating...resistance measurements using scans from 100 mV below to 100mV above at a scan rate of 0.167 mV/s. ZINC - NICKEL ALLOY PLATING The Zn-14% Ni alloy...release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Bare and Zn-14% Ni alloy coated Ferrium M54 steels were studied to


    Y.Z. Lan; S. Zhang; J.K. Wang; R. W. Smith


    Steel slag is a byproduct produced in large amounts in the steel-making process. It is an important resource that can be effectively utilized. An experiment was described in which steel slag was tested as an adsorbent for the removal of phosphorus from waste water. Phosphorus removal depended on the amount of steel slag added, the pH value, the contact time, and the initial concentration. Under laboratory conditions when the added slag was 7.5g/L, the contact time 2h, and the pH value was equivalent to 6.5, over 99% of the phosphorus was removed; the experimental data on steel slag adsorption of phosphorus in the water fitted the Freundlich isotherm model. Steel slag was found to be very effective in adsorbing phosphorus.

  10. Heat Treatment and Properties of Iron and Steel


    or bronze plating, or by the application of cer- tain paints. 5.6. Surface Hardening It is frequently desirable to harden only the surface of...chromium Hot work H—(H 1 to H 19 incl. chromium base, H 20 to H 39 incl. tungsten base, H 40 to H 59 incl. molybdenum base) !T— Tungsten base M...Molybdenum base L—Low alloy F—Carbon tungsten Mold steels P The AISI identification and type classifica- tion of tool steels is given in table 3

  11. The investment location decisions in the steel industry

    M. M. Abrudan


    Full Text Available The global dimension of the economy in general and of the steel industry in particular makes the decision regarding the location of new production facilities a challenge for managers. This paper tries to provide tools that make the decision taking process easier. Is assumed that certain tax levy rates are important to this process and they are compared and analyzed. Finally, based on this analysis this paper tries to prioritize some countries in terms of their economic attractiveness in order to identify the most suitable country for placing a steel factory.



    The objective this work was to evaluate the chemical waste provoked by the wood on the sheets of steel used in the making of the mountains and cut tools. It was certain the correlationbetween the chemical waste and the extractive soluble in cold water, hot water and in the sequencetoluene and ethanol content. Two types of steel and twenty-seven species different from wood wereused. The corrosive agent, constituted of 50 g of fresh sawdust (moist) mixed to 50 ml of distilledwater, it was prepa...

  13. Characterization of micro machined surface from TRIP/TWIP steels

    Smaga M.


    Full Text Available In this contribution micro machining induced changes in surface morphology, including phase transformation from fcc-austenite into hcp- and bcc-martensite as well as defined surface topography of TRIP/TWIP steel was characterized by scanning electron microscopy using electron backscatter diffraction (EBSD technique. For this, applying micro milling and micro grinding processes with tool diameter of 45 µm, structures were machined into flat specimen surfaces of X30MnAl17–1 steel in defined areas previously characterized by EBSD.


    Z.Z.Yi; X.Zhang; T.H.Zhang; Z.S.Xiao


    The Ti+C+N film was co-deposited on H13 steel by Filtered Vacuum Arc PlasmaDeposition (FVAPD) operated with a modified cathode. The co-deposited layer waseffective for the improvement of surface hardness and corrosion resistance. The nano-hardness value of the co-deposited film is 1.3 times more than that of undepositedsample. The corrosion behavior measurement shows that the corrosion resistance foracid corrosion and pitting corrosion was improved greatly. It is owing to the formationof the new ternary ceramic phase TiCo.7 No.3 in the co-deposited layer. The mechanismof property improvement is discussed.

  15. PCBN刀具断续切削高强度钢的实验研究%The experimental study of interrupted cutting of high strength steel with PCBN tools

    朱坤杰; 黄树涛; 周丽; 许立福


    通过整体PCBN刀具硬态切削淬硬钢58SiMn实验,研究了切削速度和进给量对切削力及表面粗糙度的影响.实验结果表明:切削力和表面粗糙度值都随进给量增加而增大;在较低切削速度时切削力随切削速度提高而减小,当切削速度达到一定程度时出现拐点,继续提高切削速度切削力逐渐增大.在实验条件下,切削速度低于569 m/min时刀片以磨损为主;当速度为768 m/min时,以崩刃为主.%The influence of cutting speed and feed rate on cutting force and surface roughness was researched by the experiment of hard machining of 58SiMn with PCBN tools. According to the experimental results, the cutting force and surface roughness increase with the increasing of cutting speed and feed rate; The cutting force decreases with the increasing of cutting speed when the cutting speed is lower, while cutting force increases gradually with the increasing of cutting speed when cutting speed reachs a certain extent. In the experiment, when the cutting speed is lower than 569 m/min, the blade is wear; when the cutting speed is 768 m/min, the blade is tipping.

  16. Mechanics in Steels through Microscopy

    Tirumalasetty, G. K.


    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP steels, highlighting the importance of microstructure - mechanical properties - applications relationships. In Chapter 2 the material properties and material processing are described into more detai...

  17. Output Model of Steel Plant

    ZHANG Long-qiang; TIAN Nai-yuan; ZHANG Jin; XU An-jun


    Based on the requirement of compactivity, continuity, and high efficiency, and taking full advantage of cushion capability of flexible parts such as external refining in new generation steel plant, an output model of steel plant was established in terms of matching between BOF and caster. Using this model, the BOF nominal capacity is selected, the caster output and equipment amount are computed, and then the steel plant output is computed.

  18. Tough Year Ahead for Steel



    @@ The steel industry, a top beneficiary of the country's sizzling economic growth, is this year likely to see only a meager profit or even report losses, according to a report by the National Development and Reform Commission. Mounting demand for steel in real estate construction and auto making during the past years resulted in an investment craze into the sector, and has caused a glut on the market. Average steel prices fell by a third last year, though domestic steel makers still managed to post a profit of 127.4 billion yuan (US$15.9 billion) on aggregate.

  19. High strength, tough alloy steel

    Thomas, Gareth; Rao, Bangaru V. N.


    A high strength, tough alloy steel is formed by heating the steel to a temperature in the austenite range ( C.) to form a homogeneous austenite phase and then cooling the steel to form a microstructure of uniformly dispersed dislocated martensite separated by continuous thin boundary films of stabilized retained austenite. The steel includes 0.2-0.35 weight % carbon, at least 1% and preferably 3-4.5% chromium, and at least one other substitutional alloying element, preferably manganese or nickel. The austenite film is stable to subsequent heat treatment as by tempering (below C.) and reforms to a stable film after austenite grain refinement.

  20. Hydrogen Embrittlement of Gun Steel


    8217s HY80 and HY130 steels were checked for the critical hydrogen concentrations which were determined to be 6 ppm for HY8O steel 8 and 3 ppm for HY130...JOTC FILE COPY AD-A188 972 AD 1 TECHNICAL REPORT ARCCB-TR-87030 HYDROGEN EMBRITTLEMENT OF GUN STEEL F’ GERALD L. SPFNCER DTIC DEC 1 5 1987 NOVEMBER...PtEtIOC COVERED HYDROGEN EMBRITTLEHENT OF GUN STEEL Final OG EOTNME 6. PERFORMINGORO EOTNME 7. A*JTNOR(s) S. CONTRACT OR GRANT NUMBER(&) Gerald L


    HUYing-ning; WANGCheng-yong; WUXue-qi; QINZhe; ZENGBao-ping


    Tool wear and breakage of the micro-milling tool is an important problem for high speed machining of hardened steel die and mould. Dry milling of S136 hardened steel is carried out using TiA1N coated carbide micro-end mill (Ф2 mm). The effect of cutting speed, feed per tooth and radial depth of cut on cutting force is analyzed. Cutting parameters adapting to dry machining and strategy optimized for higher rate of material removal with lower cutting force are attained. Results of SEM observation show that the main failure patterns of micro-end mill are breakage of tool tip, wear and drop-off of surface coating, micro-chipping, and breakage of flank.

  2. Investigation of Surface Damage in Forming of High Strength and Galvanized Steel Sheets

    Zhongqi Yu; Yingke Hou; Haomin Jiang; Xinping Chen; Weigang Zhang


    Powdering/exfoliating of coatings and scratching are the main forms of surface damage in the forming of galvanized steels and high strength steels (HSS), which result in increased die maintenance cost and scrap rate.In this study, a special rectangular box was developed to investigate the behavior and characteristics of surface damage in sheet metal forming (SMF) processes.U-channel forming tests were conducted to study the effect of tool hardness on surface damage in the forming of high strength steels and galvanized steels (hot-dip galvanized and galvannealed steels).Experimental results indicate that sheet deformation mode influences the severity of surface damage in SMF and surface damage occurs easily at the regions where sheet specimen deforms under the action of compressive stress.Die corner is the position where surface damage initiates.For HSS sheet, surface damage is of major interest due to high forming pressure.The HSS and hot-dip galvanized steels show improved ability of damage-resistance with increased hardness of the forming tool.However, for galvannealed steel it is not the forming tool with the highest hardness value that performs best.

  3. Milled Die Steel Surface Roughness Correlation with Steel Sheet Friction

    Berglund, J.; Brown, C.A.; Rosén, B.-G.


    This work investigates correlations between the surface topography ofmilled steel dies and friction with steel sheet. Several die surfaces were prepared by milling. Friction was measured in bending under tension testing. Linear regression coefficients (R2) between the friction and texture...

  4. Nickel-free manganese bearing stainless steel in alkaline media-Electrochemistry and surface chemistry

    Elsener, B., E-mail: belsener@unica.i [Dipartimento di Chimica Inorganica ed Analitica, Universita di Cagliari, SS 554 bivio per Sestu, I-09042 Monserrato (Italy); ETH Zurich, Institute for Building Materials, ETH Hoenggerberg, CH-8093 Zurich (Switzerland); Addari, D. [Dipartimento di Chimica Inorganica ed Analitica, Universita di Cagliari, SS 554 bivio per Sestu, I-09042 Monserrato (Italy); Coray, S. [ETH Zurich, Institute for Building Materials, ETH Hoenggerberg, CH-8093 Zurich (Switzerland); Rossi, A., E-mail: rossi@unica.i [Dipartimento di Chimica Inorganica ed Analitica, Universita di Cagliari, SS 554 bivio per Sestu, I-09042 Monserrato (Italy)


    Research highlights: {yields} New nickel-free manganese bearing 18Cr18Mn2Mo stainless steel in alkaline media. {yields} XPS analysis shows Mo(VI) enrichment up to 6% in the passive film upon ageing. {yields} No pitting corrosion in alkaline media (pH 13) up to 4 M NaCl (14 wt%). {yields} Promising alternative stainless steel for reinforcement in concrete. - Abstract: The use of austenitic nickel-containing stainless steels as concrete reinforcement offers excellent corrosion protection for concrete structures in harsh chloride bearing environments but is often limited due to the very high costs of these materials. Manganese bearing nickel-free stainless steels can be a cost-effective alternative for corrosion resistant reinforcements. Little, however, is known about the electrochemistry and even less on surface chemistry of these materials in alkaline media simulating concrete pore solutions. In this work a combined electrochemical (ocp = open circuit potential) and XPS (X-ray photoelectron spectroscopy) surface analytical investigation on the austenitic manganese bearing DIN 1.4456 (X8CrMnMoN18-18-2) stainless steel immersed into 0.1 M NaOH and more complex alkaline concrete pore solutions was performed. The results show that the passive film composition changes with immersion time, being progressively enriched in chromium oxy-hydroxide becoming similar to the conventional nickel-containing stainless steels. The composition of the metal interface beneath the passive film is strongly depleted in manganese and enriched in iron; chromium has nearly the nominal composition. The results are discussed regarding the film growth mechanism (ageing) of the new nickel-free stainless steel in alkaline solutions compared to traditional austenitic steels. Combining the results from pitting potential measurements with the composition of the passive film and the underlying metal interface, it can be concluded that the resistance against localized corrosion of the new nickel

  5. Simulation tools

    Jenni, F


    In the last two decades, simulation tools made a significant contribution to the great progress in development of power electronics. Time to market was shortened and development costs were reduced drastically. Falling costs, as well as improved speed and precision, opened new fields of application. Today, continuous and switched circuits can be mixed. A comfortable number of powerful simulation tools is available. The users have to choose the best suitable for their application. Here a simple rule applies: The best available simulation tool is the tool the user is already used to (provided, it can solve the task). Abilities, speed, user friendliness and other features are continuously being improved—even though they are already powerful and comfortable. This paper aims at giving the reader an insight into the simulation of power electronics. Starting with a short description of the fundamentals of a simulation tool as well as properties of tools, several tools are presented. Starting with simplified models ...

  6. Reliability-based condition assessment of steel containment and liners

    Ellingwood, B.; Bhattacharya, B.; Zheng, R. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Civil Engineering


    Steel containments and liners in nuclear power plants may be exposed to aggressive environments that may cause their strength and stiffness to decrease during the plant service life. Among the factors recognized as having the potential to cause structural deterioration are uniform, pitting or crevice corrosion; fatigue, including crack initiation and propagation to fracture; elevated temperature; and irradiation. The evaluation of steel containments and liners for continued service must provide assurance that they are able to withstand future extreme loads during the service period with a level of reliability that is sufficient for public safety. Rational methodologies to provide such assurances can be developed using modern structural reliability analysis principles that take uncertainties in loading, strength, and degradation resulting from environmental factors into account. The research described in this report is in support of the Steel Containments and Liners Program being conducted for the US Nuclear Regulatory Commission by the Oak Ridge National Laboratory. The research demonstrates the feasibility of using reliability analysis as a tool for performing condition assessments and service life predictions of steel containments and liners. Mathematical models that describe time-dependent changes in steel due to aggressive environmental factors are identified, and statistical data supporting the use of these models in time-dependent reliability analysis are summarized. The analysis of steel containment fragility is described, and simple illustrations of the impact on reliability of structural degradation are provided. The role of nondestructive evaluation in time-dependent reliability analysis, both in terms of defect detection and sizing, is examined. A Markov model provides a tool for accounting for time-dependent changes in damage condition of a structural component or system. 151 refs.

  7. The industrial ecology of steel

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.


    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  8. Mechanics in Steels through Microscopy

    Tirumalasetty, G.K.


    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP s

  9. Mechanics in Steels through Microscopy

    Tirumalasetty, G.K.


    The goal of the study consolidated in this thesis is to understand the mechanics in steels using microscopy. In particular, the mechanical response of Transformation Induced Plasticity (TRIP) steels is correlated with their microstructures. Chapter 1 introduces the current state of the art of TRIP


    corrosion inhibitor for carbon steel in 3% ac]neon.s' NaCl solution (pH 6) ... compared to stainless steels (Buchweishaija & Hagen 1997). Organic compounds are ... resistant dust for break and clutch linings, wood binders and mould (Gedam.

  11. Hydrogen Embrittlement of Structural Steels

    Somerday, Brian P.; San Marchi, Christopher W


    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines; however, it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittlement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a well-established failure mode for steel hydrogen containment structures subjected to pressure cycling. This pressure cycling represents one of the key differences in operating conditions between current hydrogen pipelines and those anticipated in a hydrogen delivery infrastructure. Applying structural integrity models in design codes coupled with measurement of relevant material properties allows quantification of the reliability/integrity of steel hydrogen pipelines subjected to pressure cycling. Furthermore, application of these structural integrity models is aided by the development of physics-based predictive models, which provide important insights such as the effects of microstructure on hydrogen-assisted fatigue crack growth. Successful implementation of these structural integrity and physics-based models enhances confidence in the design codes and enables decisions about materials selection and operating conditions for reliable and efficient steel hydrogen pipelines.

  12. Great Challenge in Steel Export

    Charlsea Liu


    @@ In 2008, the export of China steel products experienoeu, a splendid period f fast growing, and then disappointedly followed by fast depression. Until lest December, China in 2008 exported steel products of 59.21 million tons, less than the same term in 2007 by 3.48 million tons, declining about 5.6%.

  13. (1)H, (13)C, (15)N backbone and side-chain resonance assignment of Nostoc sp. C139A variant of the heme-nitric oxide/oxygen binding (H-NOX) domain.

    Alexandropoulos, Ioannis I; Argyriou, Aikaterini I; Marousis, Kostas D; Topouzis, Stavros; Papapetropoulos, Andreas; Spyroulias, Georgios A


    The H-NOX (Heme-nitric oxide/oxygen binding) domain is conserved across eukaryotes and bacteria. In human soluble guanylyl cyclase (sGC) the H-NOX domain functions as a sensor for the gaseous signaling agent nitric oxide (NO). sGC contains the heme-binding H-NOX domain at its N-terminus, which regulates the catalytic site contained within the C-terminal end of the enzyme catalyzing the conversion of GTP (guanosine 5'-triphosphate) to GMP (guanylyl monophosphate). Here, we present the backbone and side-chain assignments of the (1)H, (13)C and (15)N resonances of the 183-residue H-NOX domain from Nostoc sp. through solution NMR.

  14. Study of E/Z isomerization of (arylamino)methylidenefuran-2(3H)-ones by (1) H, (13) C, (15) N spectroscopy and DFT calculations in different solvents.

    Osipov, Alexander K; Anis'kov, Alexander A; Grinev, Vyacheslav S; Yegorova, Alevtina Yu


    The structure and configuration of the series of previously unknown arylaminomethylidenefuran-2(3H)-ones have been determined in solution by (1) H, (13) C, (15) N nuclear magnetic resonance spectroscopy including two-dimensional experiments such as (1) H─(1) H COSY, dqCOSY, (1) H─(13) C HSQC, (1) H─(13) C HMBC. It was found that synthesized substances exist as an equilibrium mixture of E- and Z-enamines in solution. It was established on the basis of density functional theory calculations that the exchange between the two push-pull enamines is a simple rotation around an exocyclic partial double bond that depends on the effect of the solvents. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  15. Steels from materials science to structural engineering

    Sha, Wei


    Steels and computer-based modelling are fast growing fields in materials science as well as structural engineering, demonstrated by the large amount of recent literature. Steels: From Materials Science to Structural Engineering combines steels research and model development, including the application of modelling techniques in steels.  The latest research includes structural engineering modelling, and novel, prototype alloy steels such as heat-resistant steel, nitride-strengthened ferritic/martensitic steel and low nickel maraging steel.  Researchers studying steels will find the topics vital to their work.  Materials experts will be able to learn about steels used in structural engineering as well as modelling and apply this increasingly important technique in their steel materials research and development. 

  16. Microstructure and Properties of Superplastic Welding between 4OCr and CrWMn Steels


    Superplastic welding of tool steel and structural steel was investigated. The welding between 40Cr and CrWMn steels was carried out under the conditions of temperature 750~780°C, strain rate 2×10-4 s-1, compressive stress 50~90 MPa for 3~5 min. The joints show similar strength to that of 40Cr steel and the good metallurgical joining is formed. The structural change occurring during superplastic welding was analyzed by metallography and distribution of carbon content in the vicinity of the welding joint was also determined. The mechanism of superplastic welding for steels is proposed to be the disappearance of original bond interfaces caused by atomic diffusion and the grain sliding.

  17. Computational algorithms to simulate the steel continuous casting

    Ramírez-López, A.; Soto-Cortés, G.; Palomar-Pardavé, M.; Romero-Romo, M. A.; Aguilar-López, R.


    Computational simulation is a very powerful tool to analyze industrial processes to reduce operating risks and improve profits from equipment. The present work describes the development of some computational algorithms based on the numerical method to create a simulator for the continuous casting process, which is the most popular method to produce steel products for metallurgical industries. The kinematics of industrial processing was computationally reproduced using subroutines logically programmed. The cast steel by each strand was calculated using an iterative method nested in the main loop. The process was repeated at each time step (Δ t) to calculate the casting time, simultaneously, the steel billets produced were counted and stored. The subroutines were used for creating a computational representation of a continuous casting plant (CCP) and displaying the simulation of the steel displacement through the CCP. These algorithms have been developed to create a simulator using the programming language C++. Algorithms for computer animation of the continuous casting process were created using a graphical user interface (GUI). Finally, the simulator functionality was shown and validated by comparing with the industrial information of the steel production of three casters.

  18. Nanoprecipitation in bearing steels

    Barrow, A.T.W. [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom); Rivera-Diaz-del-Castillo, P.E.J., E-mail: [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)


    {theta}-phase is the main hardening species in bearing steels and appears in both martensitically and bainitically hardened microstructures. This work presents a survey of the microstrucural features accompanying nanoprecipitation in bearing steels. Nanoprecipitate structures formed in 1C-1.5Cr wt.% with additions of Cr, Mn, Mo, Si and Ni are studied. The work is combined with thermodynamic calculations and neural networks to predict the expected matrix composition, and whether this will transform martensitically or bainitically. Martensite tetragonality, composition and the amount of retained austenite are related to hardness and the type of nanoprecipitate structures in martensitic grades. The {theta}-phase volume fraction, the duration of the bainite to austenite transformation and the amount of retained austenite are related to hardness and a detailed quantitative description of the precipitate nanostructures. Such description includes compositional studies using energy-dispersive spectroscopy, which shows that nanoprecipitate formation takes place under paraequilibrium. Special attention is devoted to a novel two-step bainite tempering process which shows maximum hardness; we prove that this is the most effective process for incorporating solute into the precipitates, which are finer than those resulting from one-step banitic transformation processes.

  19. Influence of the steel scrap classes on the liquid steel output molten in electric steel processes

    K. Janiszewski


    Full Text Available Purpose: This is why we have analysed in the paper, using statistical analysing methods, the influence of use in the electric arc furnace charges of steel scrap of different qualities on the index of liquid steel output from a melt.Design/methodology/approach: The used research methodology consists in analytical simulation of variations in mass of liquid steel obtained from melts differing in steel scrap content in the metallic charge and statistical analyses of industrial results acquired from the corresponding process documentation (so called melt cards.Findings: Basing on the analytical and statistical analyses carried out we have determine resulting variations in the liquid steel per melt ratios depending on the content of steel scrap in the metallic charge.Research limitations/implications: The research results obtained can be utilized in each steelmaking facility, which employs the Electric Steelmaking process, in order to “design” the metallic charge compositions, having in view the quality and economic aspects.Practical implications: The research results presented in the paper can be used for steel production of high purity steels.Originality/value: The results presented in this paper are directed to the steelmakers employing the Electric Steelmaking process and constitute the authors’ original study.

  20. An Investigation of Vibration Reducing on a Machine Tool


    In order to reduce the vibration on a machine tool, more orthogonal experiment schemes have been designed, which are based on the steel balls vibration reducing principle. After experiments the optimal reducing vibration scheme was determined. This kind of vibration reducing scheme is used in steel balls vibration absorber, which can be used to reduce vibration magnitudes of a machine tools under the working conditions, whereby improving machining precision. The suggested experiment method is of useful reference in reducing vibrations on other machine tools too.

  1. Tool wear mechanism in turning of novel wear-resisting aluminum bronze

    倪东惠; 夏伟; 张大童; 郭国文; 邵明


    Tool wear and wear mechanism during the turning of a wear-resisting aluminum bronze have been stud-ied. Tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novelhigh strength, wear resisting aluminum bronze without coolant and lubricant. Adhesion of workpiece materials wasfound on tool's surface. Under the turning condition used in this study major wear mechanisms for turning aluminumbronze using M2 high-speed steel tool are diffusion wear, adhesive wear and plastic deformation and shear on thecrater. Partial melting of high-speed steel on the rake plays a role in the tool wear also. Major wear mechanisms forturning aluminum bronze using YW1 cemented carbide tool are diffusion wear, attrition wear and sliding wear. Tocontrol the machining temperature is essential to reduce tool wear.

  2. Improving the toughness of ultrahigh strength steel

    Soto, Koji


    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  3. 49 CFR 192.55 - Steel pipe.


    ... 49 Transportation 3 2010-10-01 2010-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for use...

  4. Magnetic sensing for microstructural assessment of power station steels: Magnetic Barkhausen noise and minor loop measurements

    Wilson, J. W.; Karimian, N.; Yin, W.; Liu, J.; Davis, C. L.; Peyton, A. J.


    There are currently no techniques available to monitor the microstructural condition of power station steel components in-service (at elevated temperatures). Electromagnetic (EM) inspection methods have the potential to provide a solution to this problem. Tests have been carried out on power generation steel (P9 and T22) samples with different microstructural states using major and minor B-H loop measurements and correlations established between EM properties and material properties such as Vickers hardness. These correlations will be used to develop a field deployable tool for the quantification of degradation in power station steels.

  5. Use of technical analysis indicators at trading shares of steel companies

    J. Zuzik


    Full Text Available When trading on capital markets, used are multitude of methods. The intention set out in the present paper is to analyse probability of profit of the businessman using selected technical analysis indicators whilst trading with shares of the globally largest steel companies. Selected for analysing were 21 steel companies, and selected as the technical analysis tool was the relative strength index (RSI indicator. Analysed have been the period of one year commencing in May 2012 and ending in May 2013, based on daily closing prices of the shares of steel companies.

  6. Environmental Performance of Companies in the Iron and Steel Industry. Accounting Aspects

    ABDELKARIM Abdelali


    Full Text Available Iron and steel industry is a sector of great importance in the development of a country's economy due to the close relationship that it has with many other industries. Iron and steel industry is an industry that uses large amounts of material and consumes a lot of energy. In this context, achieving environmental performance and its management is a major issue. Accounting provides a number of tools to realize this. The paper aims to show how the accounts can become a means of measuring and managing environmental performance of companies in the iron and steel industry.

  7. The Effect of Different Non-Metallic Inclusions on the Machinability of Steel

    Niclas Ånmark; Andrey Karasev; Pär Göran Jönsson


    Considerable research has been conducted over recent decades on the role of non-metallic inclusions and their link to the machinability of different steels. The present work reviews the mechanisms of steel fractures during different mechanical machining operations and the behavior of various non-metallic inclusions in a cutting zone. More specifically, the effects of composition, size, number and morphology of inclusions on machinability factors (such as cutting tool wear, power consumption, ...

  8. Evaluation of Friction Stir Processing of HY-80 Steel Under Wet and Dry Conditions

    Young, Garth William II


    This thesis describes the microstructural and mechanical property changes associated with Friction Stir Processing (FSP) of HY-80 steel under dry and underwater conditions. HY-80 is a low-carbon alloy steel that is used in a quenched and tempered condition and is highly susceptible to hydrogen assisted cracking associated with conventional fusion welding. FSW/P (400 RPM/ 2 IPM) was conducted using a polycrystalline cubic boron nitride tool having a pin length of 6.35 mm. Two sets ...

  9. Dissimilar Friction Stir Welding Between UNS S31603 Austenitic Stainless Steel and UNS S32750 Superduplex Stainless Steel

    Theodoro, Maria Claudia; Pereira, Victor Ferrinho; Mei, Paulo Roberto; Ramirez, Antonio Jose


    In order to verify the viability of dissimilar UNS S31603 austenitic and UNS S32750 superduplex stainless steels joined by friction stir welding, 6-mm-thick plates were welded using a PCBN-WRe tool. The welded joints were performed in position control mode at rotational speeds of 100 to 300 rpm and a feed rate of 100 mm/min. The joints performed with 150 and 200 rpm showed good appearance and no defects. The metallographic analysis of both joints showed no internal defects and that the material flow pattern is visible only in the stirred zone (SZ) of the superduplex steel. On the SZ top, these patterns are made of regions of different phases (ferrite and austenite), and on the bottom and central part of the SZ, these patterns are formed by alternated regions of different grain sizes. The ferrite grains in the superduplex steel are larger than those in the austenitic ones along the SZ and thermo-mechanically affected zone, explained by the difference between austenite and ferrite recrystallization kinetics. The amount of ferrite islands present on the austenitic steel base metal decreased near the SZ interface, caused by the dissolving of the ferrite in austenitic matrix. No other phases were found in both joints. The best weld parameters were found to be 200 rpm rotation speed, 100 mm/min feed rate, and tool position control.

  10. Micromilling experiments on hardened tool steel and Titanium

    Bissacco, Giuliano

    This document is an organized collection of the final settings, decisions, variations and relevant notes regarding the experimental work carried on at Pinol A/S by Giuliano Bissacco within the Ph.D. project Surface Generation and Optimization in Micromilling. The document is divided into sections...

  11. A study on the die steel surface modification by electron beam

    Wu Ai Min; Zou Jian Xin; Hao Sheng Zhi; Dong Chuang; Zhang Ai Ming; Xu Tao


    A new surface modification technology-high current pulsed electron beam treatment method was applied to the surface of die steel to improve its properties. It has been shown that as a result of the HCPEB treatment, the most pronounced changes of the structure-phase state occur in the near-surface layers quenched from the liquid state, where the crystallization front velocity reaches its maximum. In these layers partial or complete dissolving of second phases and formation of over saturated solid solutions and ordered nano-sized structures may take place. This makes it possible to improve substantially the electrochemical and strength properties of the surface layer. The authors found that the thickness of remelt layer is about 10 mu m, and the sectional microhardness increased accompanied by the enhancement of the wear resistance of the material. After modification, the relative wear resistance of D2 steel have increased 5.63 times and that of H13 steel increased 11.76 times

  12. Cold-formed steel design

    Yu, Wei-Wen


    The definitive text in the field, thoroughly updated and expanded Hailed by professionals around the world as the definitive text on the subject, Cold-Formed Steel Design is an indispensable resource for all who design for and work with cold-formed steel. No other book provides such exhaustive coverage of both the theory and practice of cold-formed steel construction. Updated and expanded to reflect all the important developments that have occurred in the field over the past decade, this Fourth Edition of the classic text provides you with more of the detailed, up-to-the-minute techni

  13. Friction Stir Spot Welding (FSSW) of Advanced High Strength Steel (AHSS)

    Santella, M. L.; Hovanski, Yuri; Pan, Tsung-Yu


    Friction stir spot welding (FSSW) is applied to join advanced high strength steels (AHSS): galvannealed dual phase 780 MPa steel (DP780GA), transformation induced plasticity 780 MPa steel (TRIP780), and hot-stamped boron steel (HSBS). A low-cost Si3N4 ceramic tool was developed and used for making welds in this study instead of polycrystalline cubic boron nitride (PCBN) material used in earlier studies. FSSW has the advantages of solid-state, low-temperature process, and the ability of joining dissimilar grade of steels and thicknesses. Two different tool shoulder geometries, concave with smooth surface and convex with spiral pattern, were used in the study. Welds were made by a 2-step displacement control process with weld time of 4, 6, and 10 seconds. Static tensile lap-shear strength achieved 16.4 kN for DP780GA-HSBS and 13.2kN for TRIP780-HSBS, above the spot weld strength requirements by AWS. Nugget pull-out was the failure mode of the joint. The joining mechanism was illustrated from the cross-section micrographs. Microhardness measurement showed hardening in the upper sheet steel (DP780GA or TRIP780) in the weld, but softening of HSBS in the heat-affect zone (HAZ). The study demonstrated the feasibility of making high-strength AHSS spot welds with low-cost tools.

  14. The study of high speed fine turning of austenitic stainless steel

    W.S. Lin


    Full Text Available Purpose: The purpose of this research paper is focused on the surface roughness variation in high speed fine turning of the austenitic stainless steel.Design/methodology/approach: A series of experimental tests have been done to evaluate the possibility of high speed fine turning of the austenitic stainless steel from the surface roughness variation and machining stability.Findings: It was found that, the smaller the feed rate, the smaller the surface roughness value. But when the feed rate smaller than the critical feed rate, the chatter will occurs and the surface roughness of the work piece would be deteriorated.The higher the cutting speed is, the higher the cutting temperature of cutting tool is. The cutting tool will be soften and the surface roughness of the workpiece will be deteriorated.Research limitations/implications: The tool chattering would caused poor surface roughness in high speed fine turning for feed rate smaller than 0.02 mm/rev. The chatter suppression method must be considered when high speed fine turning of austenitic stainless steel.Originality/value: Most of the stainless steel machining proceeds at low cutting speed because the austenitic stainless steel is a hard machining material. The research result of this paper indicated that high speed fine turning of austenitic stainless steel is possible.

  15. Friction Stir Spot Welding of DP780 and Hot-Stamp Boron Steels

    Santella, Michael L.; Frederick, Alan; Hovanski, Yuri; Grant, Glenn J.


    Friction stir spot welds were made in two high-strength steels: DP780, and a hot-stamp-boron steel with tensile strength of 1500 MPa. The spot welds were made at either 800 or 1600 rpm using either of two polycrystalline boron nitride tools. One stir tool, BN77, had the relatively common pin-tool shape. The second tool, BN46, had a convex rather than a concave shoulder profile and a much wider and shorter pin. The tools were plunged to preprogrammed depths either at a continuous rate (1-step schedule) or in two segments consisting of a relatively high rate followed by a slower rate. In all cases, the welds were completed in 4s. The range of lap-shear values were compared to values required for resistance spot welds on the same steels. The minimum value of 10.3 kN was exceeded for friction stir spot welding of DP780 using a 2-step schedule and either the BN77- or the BN46-type stir tool. The respective minimum value of 12 kN was also exceeded for the HSB steel using the 2-step process and the BN46 stir tool.

  16. Adiabatic Shear Localization for Steels Based on Johnson-Cook Model and Second- and Fourth-Order Gradient Plasticity Models

    WANG Xue-bin


    To consider the effects of the interactions and interplay among microstructures, gradient-dependent models of second- and fourth-order are included in the widely used phenomenological Johnson-Cook model where the effects of strain-hardening, strain rate sensitivity, and thermal-softening are successfully described. The various parameters for 1006 steel, 4340 steel and S-7 tool steel are assigned. The distributions and evolutions of the local plastic shear strain and deformation in adiabatic shear band (ASB) are predicted. The calculated results of the second- and fourth-order gradient plasticity models are compared. S-7 tool steel possesses the steepest profile of local plastic shear strain in ASB, whereas 1006 steel has the least profile. The peak local plastic shear strain in ASB for S-7 tool steel is slightly higher than that for 4340 steel and is higher than that for 1006 steel. The extent of the nonlinear distribution of the local plastic shear deformation in ASB is more apparent for the S-7 tool steel, whereas it is the least apparent for 1006 steel. In fourth-order gradient plasticity model, the profile of the local plastic shear strain in the middle of ASB has a pronounced plateau whose width decreases with increasing average plastic shear strain, leading to a shrink of the portion of linear distribution of the profile of the local plastic shear deformation. When compared with the second-order gradient plasticity model, the fourth-order gradient plasticity model shows a lower peak local plastic shear strain in ASB and a higher magnitude of plastic shear deformation at the top or base of ASB, which is due to wider ASB. The present numerical results of the second- and fourth-order gradient plasticity models are consistent with the previous numerical and experimental results at least qualitatively.

  17. 2169 steel waveform experiments.

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.


    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mmthick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  18. Feasibility of Underwater Friction Stir Welding of HY-80 Steel


    control procedures. A single tool of polycrystalline cubic boron nitride (PCBN) in a Tungsten -Rhenium binder was used to conduct three bead-on-plate FSW... Tungsten -Rhenium binder was used to conduct three bead-on-plate FSW traverses, approximately 40 inches in length on 0.25 inch HY-80 steel. The...the processing of nickel aluminum bronze propellers used on Navy ships and submarines. Friction stir welding is accomplished by using a cylindrical

  19. Feasibility of underwater friction stir welding of HY-80 steel

    Stewart, William Chad


    Approved for public release; distribution is unlimited. The purpose of this thesis is to determine the feasibility of underwater friction stir welding (FSW) of high-strength; quench and temper low carbon steels that are susceptible to hydrogen-assisted cracking (HAC). The specific benefits of underwater FSW would be weld repairs of ship and submarine control surfaces and hulls without the need for drydocking and extensive environmental control procedures. A single tool of polycrystallin...

  20. Corrosion of Steels in Steel Reinforced Concrete in Cassava Juice

    Oluwadare, G. O.; Agbaje, O.

    The corrosion of two types of construction steels, ST60Mn and RST37-2♦, in a low cyanide concentration environment (cassava juice) and embedded in concrete had been studied. The ST60 Mn was found to be more corrosion resistant in both ordinary water and the cassava juice environment. The cyanide in cassava juice does not attack the steel but it provides an environment of lower pH around the steel in the concrete which leads to breakdown of the passivating film provided by hydroxyl ions from cement. Other factors such as the curing time of the concrete also affect the corrosion rates of the steel in the concrete. The corrosion rate of the steel directly exposed to cassava juice i.e., steel not embedded in concrete is about twice that in concrete. Long exposure of concrete structure to cassava processing effluent might result in deterioration of such structures. Careful attention should therefore be paid to disposal of cassava processing effluents, especially in a country like Nigeria where such processing is now on the increase.

  1. Performance evaluation of vegetable-based oils in drilling austenitic stainless steel

    Belluco, Walter; De Chiffre, Leonardo


    The efficiency of six cutting oils was evaluated in drilling AISI 316L austenitic stainless steel using conventional HSS-Co tools by measurements of tool life, tool wear, cutting forces and chip formation. Seven tools were tested with each fluid to catastrophic failure. Cutting forces and chip...... in a measurement capability comparable to that obtained using tool life as a performance criterion. As a consequence, it is suggested that drilling thrust can be used to assess the performance of cutting fluids in drilling stainless steel, resulting in considerable time savings and cost reduction with respect...... breaking were recorded for each bore, and tool wear was measured at constant intervals. A commercial mineral-based oil was taken as reference product, and five vegetable-based cutting fluids at different levels of additivation were tested. All measured parameters were in agreement, confirming...

  2. Image analysis of corrosion pit initiation on ASTM type A240 stainless steel and ASTM type A 1008 carbon steel

    Nine, H. M. Zulker

    The adversity of metallic corrosion is of growing concern to industrial engineers and scientists. Corrosion attacks metal surface and causes structural as well as direct and indirect economic losses. Multiple corrosion monitoring tools are available although those are time-consuming and costly. Due to the availability of image capturing devices in today's world, image based corrosion control technique is a unique innovation. By setting up stainless steel SS 304 and low carbon steel QD 1008 panels in distilled water, half-saturated sodium chloride and saturated sodium chloride solutions and subsequent RGB image analysis in Matlab, in this research, a simple and cost-effective corrosion measurement tool has identified and investigated. Additionally, the open circuit potential and electrochemical impedance spectroscopy results have been compared with RGB analysis to gratify the corrosion. Additionally, to understand the importance of ambiguity in crisis communication, the communication process between Union Carbide and Indian Government regarding the Bhopal incident in 1984 was analyzed.

  3. Steels for cryogenic power engineering

    Ermakov, B.S.; Nikolaich A.Y.; Oparin, V.A.


    The authors investigated steels containing 0.9% C and 30% Mnwhich were additionally alloyed with 2, 4, 6, 8, 10, and 11% Al. Phase analysis on a diffractometer established that steels containing up to 10% Al have a single-phase austenitic structure and do not undergo any transformations whatsoever in plastic deformation and when cooled to 4 K. The magnetic permeability in an external magnetic field with intensity 620 kA/m and the mechanical properties of the investigated steels are presented in a table. These properties improve when their aluminum content increases to 10%; further alloying with aluminum causes some impairment of the plastic and ductile properties which is connected with the formation of alpha-phase in the structure of the steels.

  4. Weld bonding of stainless steel

    Santos, I. O.; Zhang, Wenqi; Goncalves, V.M.


    This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot...


    Debanshu Bhattacharya


    Full Text Available Two major drivers for the use of newer steels in the automotive industry are fuel efficiency and increased safety performance. Fuel efficiency is mainly a function of weight of steel parts, which in turn, is controlled by gauge and design. Safety is determined by the energy absorbing capacity of the steel used to make the part. All of these factors are incentives for the U.S. automakers to use both Highly Formable and Advanced High Strength Steels (AHSS to replace the conventional steels used to manufacture automotive parts in the past. AHSS is a general term used to describe various families of steels. The most common AHSS is the dual-phase steel that consists of a ferrite-martensite microstructure. These steels are characterized by high strength, good ductility, low tensile to yield strength ratio and high bake hardenability. Another class of AHSS is the complex-phase or multi-phase steel which has a complex microstructure consisting of various phase constituents and a high yield to tensile strength ratio. Transformation Induced Plasticity (TRIP steels is another class of AHSS steels finding interest among the U.S. automakers. These steels consist of a ferrite-bainite microstructure with significant amount of retained austenite phase and show the highest combination of strength and elongation, so far, among the AHSS in use. High level of energy absorbing capacity combined with a sustained level of high n value up to the limit of uniform elongation as well as high bake hardenability make these steels particularly attractive for safety critical parts and parts needing complex forming. A relatively new class of AHSS is the Quenching and Partitioning (Q&P steels. These steels seem to offer higher ductility than the dual-phase steels of similar strengths or similar ductility as the TRIP steels at higher strengths. Finally, martensitic steels with very high strengths are also in use for certain parts. The most recent initiative in the area of AHSS

  6. Hydrogen embrittlement of structural steels.

    Somerday, Brian P.


    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline

  7. Streamlining Iron and Steel Production


    Eliminating unproductive iron and steel facilities is vital to environmental protection and sustainable development of this industry The Chinese Government is once again shutting down unproductive plants in tune with its green policy and the march toward sustainable development.This time it’s the iron and steel industry to feel the brunt of the Chinese Government’s stringent measures. The deafening buzz of factory floors have

  8. Rapid Cycle Casting of Steel


    such as macrosegregation, hot tears, and blowholes are also difficult to control. Rheocasting l on the other hand, is a recent development which...viscosity. Advantages of the rheocasting process are: * Reduced attack of die or mold because of the reduced tempera- ture (by 1000 C for steel) and...4W W ’ V6W 4 1.2 THE SD PROCESS Many metals, including steel, can be cast at still lower tempera- soliifiction(2) tures than rheocasting by

  9. Analysis of plasma nitrided steels

    Salik, J.; Ferrante, J.; Honecy, F.; Hoffman, R., Jr.


    The analysis of plasma nitrided steels can be divided to two main categories - structural and chemical. Structural analysis can provide information not only on the hardening mechanisms but also on the fundamental processes involved. Chemical analysis can be used to study the kinetics for the nitriding process and its mechanisms. In this paper preliminary results obtained by several techniques of both categories are presented and the applicability of those techniques to the analysis of plasma-nitrided steels is discussed.

  10. Optimization of Process Parameters of Tool Wear in Turning Operation

    Manik Barman


    Full Text Available Tool Wear is of great apprehension in machining industries since itaffects the surface quality, dimensional accuracy and production cost of the materials / components. In the present study twenty seven experiments were conducted as per 3 parameter 3 level full factorial design for turning operation of a mild steel specimen with high speed steel (HSS cutting tool. An experimental investigation on cutting tool wear and a mathematical model for tool wear estimation is reported in this paper where the model was simulated by computer programming and it has been found that this model is capable of estimating the wear rate of cutting tool and it provides an optimum set of process parameters for minimum tool wear.

  11. Efficient machining of ultra precise steel moulds with freeform surfaces

    Bulla, B.; Robertson, D. J.; Dambon, O.; Klocke, F.


    Ultra precision diamond turning of hardened steel to produce optical quality surfaces can be realized by applying an ultrasonic assisted process. With this technology optical moulds used typically for injection moulding can be machined directly from steel without the requirement to overcoat the mould with a diamond machinable material such as Nickel Phosphor. This has both the advantage of increasing the mould tool lifetime and also reducing manufacture costs by dispensing with the relatively expensive plating process. This publication will present results we have obtained for generating free form moulds in hardened steel by means of ultrasonic assisted diamond turning with a vibration frequency of 80 kHz. To provide a baseline with which to characterize the system performance we perform plane cutting experiments on different steel alloys with different compositions. The baseline machining results provides us information on the surface roughness and on tool wear caused during machining and we relate these to material composition. Moving on to freeform surfaces, we will present a theoretical background to define the machine program parameters for generating free forms by applying slow slide servo machining techniques. A solution for optimal part generation is introduced which forms the basis for the freeform machining experiments. The entire process chain, from the raw material through to ultra precision machining is presented, with emphasis on maintaining surface alignment when moving a component from CNC pre-machining to final machining using ultrasonic assisted diamond turning. The free form moulds are qualified on the basis of the surface roughness measurements and a form error map comparing the machined surface with the originally defined surface. These experiments demonstrate the feasibility of efficient free form machining applying ultrasonic assisted diamond turning of hardened steel.

  12. Brazing diamond grits onto a steel substrate using copper alloys as the filler metals

    Chen, S.-M.; Lin, S.-T.


    Surface-set diamond tools were fabricated by an active metal brazing process, using bronze (Cu-8.9Sn) powder and 316L stainless steel powder mixed to various ratios as the braze filler metals. The diamond grits were brazed onto a steel substrate at 1050 °C for 30 min in a dry hydrogen atmosphere. After brazing practice, an intermediate layer rich in chromium formed between the braze filler metal and diamond. A braze filler metal composed of 70 wt % bronze powder and 30 wt % stainless steel powder was found to be optimum in that the diamond grits were strongly impregnated in the filler metal by both mechanical and chemical types of holding. The diamond tools thus fabricated performed better than conventional nickel-plated diamond tools. In service, the braze filler metal wore at almost the same rate as the diamond grits, and no pullout of diamond grits or peeling of the filler metal layer took place.

  13. Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR.

    Hiroshi Teramura

    Full Text Available A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D 1H-13 C hetero-nuclear single quantum coherence (HSQC nuclear magnetic resonance (NMR spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16 peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13 peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45-0.59 g/g-dry biomass. Starch-derived components showed positive correlations (r = 0.71 to 0.96 with glucose, 5-hydroxymethylfurfural (5-HMF, and formate concentrations in the liquid hydrolysates, and negative correlations (r = -0.95 to -0.97 with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate.

  14. Synthesis and Crystal Structure of 1D Chain Zn( Ⅱ ) Coordination Polymer [Zn(C16H13O3)2(4, 4′-bipy) (H2O)]n Constructed by Ketoprofen Ligand%一维链状酮洛芬锌配位聚合物[Zn(C16H13O3)2(4,4′-bipy)(H2O)]n的合成与晶体结构



    The ID chain Zn ( Ⅱ ) coordination polymer with Ketoprofen ligand were synthesized and characterized by elemental analysis, X-ray single crystal diffraction. The complex [Zn(C16H13O3)2(4, 4'-bipy) (H2O)], (4,4'-bipy = 4, 4'-bipyridine) belonged to monoclinic orthorhombic system, the space group was C 2/c, a=28.452(6)A, b=6.1719( 12)A, c=22.984(5)A α=90.00A,β=118.46(3)A, y= 90.00°. Each zinc atom had a trigonal bipyramid coordination environment, defined by two 0 atoms from two different ketoprofen ligands and two N atoms from two 4, 4'-bipy ligands and one water molecule. The adjacent Zn (Ⅱ) atoms were bridged by 4, 4'-bipy ligands, and formed a one-dimensional linetype chain structure. The distance of adjacent Zn'Zn was 11.5322(23)A.%以酮洛芬为配体合成了一维链状锌的配位聚合物,并通过元素分析和单晶X射线衍射仪对该配位聚合物的结构进行了表征.配位聚合物[Zn(C16H13O3)2(4,4′-bipy)( H2O)],(其中4,4′-bipy为4,4′-联吡啶)属于单斜晶系,空间群为C2/c,a=28.452(6)(A),b=6.1719(12)(A),c=22.984(5)(A),α=90.00(A),β=118.46(3)(A),γ=90.00°.每个锌原子分别与两个酮洛芬配体的两个羧基氧原子、两个4,4′-联吡啶分子的两氮原子和一个水分子配位,具有五配位的三角双锥构型.4,4′-联吡啶配体桥联了相邻的两个锌原子形成了一维线型链结构,相邻两个锌原子之间的距离是11.5322(23)(A).

  15. Steel mill products analysis using qualities methods

    B. Gajdzik


    Full Text Available The article presents the subject matter of steel mill product analysis using quality tools. The subject of quality control were bolts and a ball bushing. The Pareto chart and fault mode and effect analysis (FMEA were used to assess faultiness of the products. The faultiness analysis in case of the bolt enabled us to detect the following defects: failure to keep the dimensional tolerance, dents and imprints, improper roughness, lack of pre-machining, non-compatibility of the electroplating and faults on the surface. Analysis of the ball bushing has also revealed defects such as: failure to keep the dimensional tolerance, dents and imprints, improper surface roughness, lack of surface premachining as well as sharp edges and splitting of the material.

  16. The Bendability of Ultra High strength Steels

    Hazra, S. K.; Efthymiadis, P.; Alamoudi, A.; Kumar, R. L. V.; Shollock, B.; Dashwood, R.


    Automotive manufacturers have been reducing the weight of their vehicles to meet increasingly stringent environmental legislation that reflects public demand. A strategy is to use higher strength materials for parts with reduced cross-sections. However, such materials are less formable than traditional grades. The frequent result is increased processing and piece costs. 3D roll forming is a novel and flexible process: it is estimated that a quarter of the structure of a vehicle can be made with a single set of tooling. Unlike stamping, this process requires material with low work hardening rates. In this paper, we present results of ultra high strength steels that have low elongation in a tension but display high formability in bending through the suppression of the necking response.

  17. Ion implantation of superhard ceramic cutting tools

    Chou, Y. Kevin; Liu, Jie


    Despite numerous reports of tool life increase by ion implantation in machining operations, ion implantation applications of cutting tools remain limited, especially for ceramic tools. Mechanisms of tool-life improvement by implantation are not clearly established due to complexity of both implantation and tool-wear processes. In an attempt to improve performance of cubic boron nitride (CBN) tools for hard machining by ion implantation, a literature survey of ion-implanted cutting tools was carried out with a focus on mechanisms of tool-wear reduction by ion implantation. Implantation and machining experiments were then conducted to investigate implantation effects on CBN tools in hard machining. A batch of CBN tools was implanted with nitrogen ions at 150 keV and 2.5×1017 ions/cm2 and further used to cut 61 HRc AISI 52100 steel at different conditions. Results show that ion implantation has strong effects on partsurface finish, moderate effect on cutting forces, but an insignificant impact on tool wear. Friction coefficients, estimated from measured cutting forces, are possibly reduced by ion implantation, which may improve surface finish. However, surprisingly, 2-D orthogonal cutting to evaluate tribological loading in hard machining showed no difference on contact stresses and friction coefficients between implanted and nonimplanted CBN tools.

  18. Relationship between Material Properties and Local Formability of DP980 Steels

    Choi, Kyoo Sil; Soulami, Ayoub; Li, Dongsheng; Sun, Xin; Khaleel, Mohammad A.; Xu, Le; Barlat, Frederic


    A noticeable degree of inconsistent forming behaviors has been observed for the 1st generation advanced high strength steels (AHSS) in production, and they appear to be associated with the inherent microstructural-level inhomogeneities for various AHSS. This indicates that the basic material property requirements and screening methods currently used for the mild steels and high strength low alloys (HSLA) are no longer sufficient for qualifying today’s AHSS. In order to establish more relevant material acceptance criteria for AHSS, the fundamental understandings on key mechanical properties and microstructural features influencing the local formability of AHSS need to be developed. For this purpose, in this study, DP980 was selected as model steels and eight different types of DP980 sheet steels were acquired from various steel suppliers. Various experiments were then performed on the eight different DP980 steels such as chemical composition analysis, static tensile test, hole expansion test, channel forming test. Scanning electron microscope (SEM) pictures of the DP980 steels were also obtained, and image processing tools were then adopted to those SEM pictures in order to quantify their various microstructural features. The results show that all DP980 steels show large discrepancy in their performance and that the tensile properties and hole expansion properties of these steels do not correlate with their local formability. According to the results up to date, it is not possible to correlate the microstructural features alone to the macroscopically measured deformation behaviors. In addition to image analysis, other experiments (i.e., nano-indentation test) are also planned to quantify the individual phase properties of the various DP steels.


    Zhengjun Tang


    Full Text Available The silos are widely used in bulk material in many fields such as agriculture, mining, chemical, electric power storage, etc. Thin metal cylindrical silo shells are vulnerable to buckling failure caused by the compressive wall friction force. In this paper, the structural analysis of two types of steel silo with cylindrical-wall bearing and profile-steel bearing is implemented by Abaqus finite element analysis. The results indicate that under the same loading conditions, steel silos with profile-steel bearing and cylindrical-Wall bearing have similar values in Mises stress, but the steel silo with profile-steel bearing has a smaller radial displacement and a better capability of buckling resistance. Meanwhile, the total steel volumes reduced 8.0% comparing to the steel silo with cylindrical-wall bearing. Therefore, steel soil with profile-steel bearing not only has a less steel volumes but also a good stability.

  20. Review on Cold-Formed Steel Connections

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian


    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  1. Some peculiarities of corrosion of wheel steel

    Alexander SHRAMKO


    Full Text Available Corrosion mechanism and rate of different chemical composition and structural condition of wheel steel were investigated. It was shown that “white layers”, variation in grain size and banding of wheel steel structure results in corrosion rate. Microstructure of steel from different elements of railway wheels after operation with corrosion was investigated. Wheel steel with addition of vanadium corroded more quickly than steel without vanadium. Non-metallic inclusions are the centre of corrosion nucleation and their influence on corrosion depends on type of inclusion. Mechanism of corrosion of wheel steel corrosion was discussed.

  2. Correlation between vibration amplitude and tool wear in turning: Numerical and experimental analysis

    Prasad, Balla Srinivasa; Babu, M. Prakash

    In this paper, a correlation between vibration amplitude and tool wear when in dry turning of AISI 4140 steel using uncoated carbide insert DNMA 432 is analyzed via experiments and finite element simulations...

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

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


    focus on tribological issues are galling and pick-up formation as well as tool life in roll forming of stainless duplex steel sheets. The roll forming process is exemplified by production of an s-shaped profile used in interlock carcass production for flexible pipes used in off-shore oil extraction...... are relatively low and surface expansion is more or less non-existent, long roll forming production runs imply large sliding/contact lengths due to relative movement between steel strip and rolls. This requires an efficient tribological system to prevent pick-up formation on the forming tools. The present work...

  4. Enabling ultra high precision on hard steels using surface defect machining


    This paper is an extension to an idea coined during the 13th EUSPEN Conference (P6.23) named "surface defect machining" (SDM). The objective of this work was to demonstrate how a conventional CNC turret lathe can be used to obtain ultra high precision machined surface finish on hard steels without recourse to a sophisticated ultra precision machine tool. An AISI 4340 hard steel (69 HRC) workpiece was machined using a CBN cutting tool with and without SDM. Post-machining measurements by a Form...

  5. Optimization and testing results of Zr-bearing ferritic steels

    Tan, Lizhen [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Yang, Ying [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tyburska-Puschel, Beata [Univ. of Wisconsin, Madison, WI (United States); Sridharan, K. [Univ. of Wisconsin, Madison, WI (United States)


    The mission of the Nuclear Energy Enabling Technologies (NEET) program is to develop crosscutting technologies for nuclear energy applications. Advanced structural materials with superior performance at elevated temperatures are always desired for nuclear reactors, which can improve reactor economics, safety margins, and design flexibility. They benefit not only new reactors, including advanced light water reactors (LWRs) and fast reactors such as sodium-cooled fast reactor (SFR) that is primarily designed for management of high-level wastes, but also life extension of the existing fleet when component exchange is needed. Developing and utilizing the modern materials science tools (experimental, theoretical, and computational tools) is an important path to more efficient alloy development and process optimization. Ferritic-martensitic (FM) steels are important structural materials for nuclear reactors due to their advantages over other applicable materials like austenitic stainless steels, notably their resistance to void swelling, low thermal expansion coefficients, and higher thermal conductivity. However, traditional FM steels exhibit a noticeable yield strength reduction at elevated temperatures above ~500°C, which limits their applications in advanced nuclear reactors which target operating temperatures at 650°C or higher. Although oxide-dispersion-strengthened (ODS) ferritic steels have shown excellent high-temperature performance, their extremely high cost, limited size and fabricability of products, as well as the great difficulty with welding and joining, have limited or precluded their commercial applications. Zirconium has shown many benefits to Fe-base alloys such as grain refinement, improved phase stability, and reduced radiation-induced segregation. The ultimate goal of this project is, with the aid of computational modeling tools, to accelerate the development of a new generation of Zr-bearing ferritic alloys to be fabricated using conventional

  6. Kinetics of borided gear steels

    Ibrahim Gunes


    In this study, the case properties and diffusion kinetics of GS18NiMoCr36 (GS18), GS22NiMoCr56 (GS22) and GS32NiCrMo6.4 (GS32) gear steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The boride layer was characterized by optical microscopy, X-ray diffraction technique and microVickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. The thickness of the boride layer increases by increasing boriding time and temperature for all steels. The hardness of the boride compounds formed on the surface of the steels GS18, GS22 and GS32 ranged from 1624 to 1905 HV0,05, 1702 to 1948 HV0,05, and 1745 to 2034 HV0,05 respectively, whereas Vickers hardness values of the untreated steels GS18, GS22 and GS32 were 335 HV0,05, 358 HV0,05 and 411 HV0,05, respectively. The activation energies (Q) of borided steels were 228.644 kJ/mol for GS18, 280.609 kJ/mol for GS22 and 294.359 kJ/mol for GS32. The growth kinetics of the boride layers forming on the GS18, GS22 and GS32 steels and the thickness of boride layers were also investigated.

  7. The microstructure of chromium-tungsten steels

    Klueh, R. L.; Maziasz, P. J.


    Chromium-tungsten steels are being developed to replace the Cr-Mo steels for fusion-reactor applications. Eight experimental steels were produced and examined by optical and electron microscopy. Chromium concentrations of 2.25, 5, 9 and 12 pct were used. Steels with these chromium compositions and with 2 pct W and 0.25 pct V were produced. To determine the effect of tungsten and vanadium, three other 2.25Cr steels were produced as follows: an alloy with 2 pct W and 0 pct V and alloys with 0 and 1 pct W and 0.25 pct V. A 9Cr steel containing 2 pct W, 0.25 pct V, and 0.07 pct Ta also was studied. For all alloys, carbon was maintained at 0.1 pct. Two pct tungsten was required in the 2.25Cr steels to produce 100 pct bainite (no polygonal ferrite). The 5Cr and 9Cr steels were 100 pct martensite, but the 12Cr steel contained about 25 pct delta-ferrite. Precipitate morphology and precipitate types varied, depending on the chromium content. For the 2.25Cr steels, M3C and M7C3 were the primary precipitates; for the 9Cr and 12Cr steels, M23C6 was the primary precipitate. The 5Cr steel contained M7C3 and M23C6. All of the steels with vanadium also contained MC.

  8. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    Vojtěch Kundrát


    Full Text Available Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42 substrates using a multi-structured molybdenum (Mo – tungsten (W interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  9. Correlation of FEA Prediction And Experiments On Dual-Phase Steel Automotive Rails

    Du, C.; Chen, X. M.; Lim, T.; Chang, T.; Xiao, P.; Liu, S.-D.


    The North American Auto/Steel Partnership (A/SP) High-Strength Steel Forming Project Team has been studying the impact of advanced high-strength steels on stamping of structural components. Tooling was built to evaluate the effect of different grades of dual-phase steels on rail type stampings. The formed panels were laser scanned and the amount of springback was measured against the design intention. FEA simulation of the forming process was carried out to validate the numerical modeling techniques in the large and complex dual-phase steel stampings. The materials used in the study were Dual-Phase (DP) Steels DP600, DP780 and DP980. The FEA solver used was LS-Dyna version 971. The simulation results were correlated with the measurement data under various forming conditions including forming methods, trimming, binder and pad pressures. Reasonably good correlations were obtained across different grades of steels in terms of flange opening angles, wall opening angles, twist angles and dimensional deviations.

  10. A novel Mo-W interlayer approach for CVD diamond deposition on steel

    Kundrát, Vojtěch; Sullivan, John; Ye, Haitao, E-mail: [School of Engineering and Applied Science, Aston University, Birmingham, B4 7ET (United Kingdom); Zhang, Xiaoling; Cooke, Kevin; Sun, Hailin [Miba Coating Group: Teer Coatings Ltd, West-Stone-House, West-Stone, Berry-Hill-Industrial-Estate, WR9 9AS, Droitwich (United Kingdom)


    Steel is the most widely used material in engineering for its cost/performance ratio and coatings are routinely applied on its surface to further improve its properties. Diamond coated steel parts are an option for many demanding industrial applications through prolonging the lifetime of steel parts, enhancement of tool performance as well as the reduction of wear rates. Direct deposition of diamond on steel using conventional chemical vapour deposition (CVD) processes is known to give poor results due to the preferential formation of amorphous carbon on iron, nickel and other elements as well as stresses induced from the significant difference in the thermal expansion coefficients of those materials. This article reports a novel approach of deposition of nanocrystalline diamond coatings on high-speed steel (M42) substrates using a multi-structured molybdenum (Mo) – tungsten (W) interlayer to form steel/Mo/Mo-W/W/diamond sandwich structures which overcome the adhesion problem related to direct magnetron sputtering deposition of pure tungsten. Surface, interface and tribology properties were evaluated to understand the role of such an interlayer structure. The multi-structured Mo-W interlayer has been proven to improve the adhesion between diamond films and steel substrates by acting as an effective diffusion barrier during the CVD diamond deposition.

  11. Quenching Simulation of PM Coated Tools

    AxelHoftert; WernerTheisen; ChristophBroeckmann


    HIP cladding is a powder metallurgical coating technique used in the production of wear parts and tools. In many cases the composite components consist of carbide-free hot-work steel as base material and wear resistant carbide-rich PM cold-work steel as coating material. To ensure operativeness a heat tleatment matched to the substrate and coating material is required. Dissimilar phase tlansformation behaviour and different thermal expansion coefficients of layer and substrate entail inner stresses affecting the tlansformation kinetics in tam. In order to get a deeper insight into these effects Finite Element simulation tools are used. On the one hand, the tlansient heat conduction problem of the quenching process has to be solved. Non-linear boundary conditions and phase transformation of both, substrate and layer are considered. On the other hand, the mechanical response is calculated. The overall aim of the investigation is an improvement of common heat treatment techniques used for HIP cladded wear parts.

  12. Quenching Simulation of PM Coated Tools

    Axel H(o)fter; Werner Theisen; Christoph Broeckmann


    HIP cladding is a powder metallurgical coating technique used in the production of wear parts and tools. In many cases the composite components consist of carbide-free hot-work steel as base material and wear resistant carbide-rich PM cold-work steel as coating material. To ensure operativeness a heat treatment matched to the substrate and coating material is required. Dissimilar phase transformation behaviour and different thermal expansion coefficients of layer and substrate entail inner stresses affecting the transformation kinetics in turn. In order to get a deeper insight into these effects Finite Element simulation tools are used. On the one hand, the transient heat conduction problem of the quenching process has to be solved. Non-linear boundary conditions and phase transformation of both, substrate and layer are considered. On the other hand, the mechanical response is calculated. The overall aim of the investigation is an improvement of common heat treatment techniques used for HIP cladded wear parts.

  13. Management Tools


    Manugistics, Inc. (formerly AVYX, Inc.) has introduced a new programming language for IBM and IBM compatible computers called TREES-pls. It is a resource management tool originating from the space shuttle, that can be used in such applications as scheduling, resource allocation project control, information management, and artificial intelligence. Manugistics, Inc. was looking for a flexible tool that can be applied to many problems with minimal adaptation. Among the non-government markets are aerospace, other manufacturing, transportation, health care, food and beverage and professional services.

  14. Towards Responsible Steel: Preliminary Insights

    Suzanne Benn


    Full Text Available This paper examines the structures and processes underpinning the attempt of the Australian steel industry to establish a certification scheme for Responsible Steel. We take it as a case example of how collective action and collaboration along a supply chain has the potential to be a win-win situation for the environment and for the competitiveness of an industry sector. The paper identifies the drivers that have prompted key stakeholders from all major sectors of the Australian steel product life cycle from mining through steel manufacturing, processing, product fabrication, use and re-use, and recycling to collaborate in the establishment of the Steel Stewardship Forum (SSF, the structure established to lead the development of the certification scheme. The development of this initiative is indicative of the wider shift to sustainability-related certification schemes as a means of garnering legitimacy and market advantage and provides detailed insights into both the drivers for and the challenges associated with such initiatives. Findings from the paper contribute to our understanding of the shift to sustainable supply chains as it is interpreted through institutional and institutional entrepreneurship theory.

  15. Measurement of absolute concentrations of individual compounds in metabolite mixtures by gradient-selective time-zero 1H-13C HSQC with two concentration references and fast maximum likelihood reconstruction analysis.

    Hu, Kaifeng; Ellinger, James J; Chylla, Roger A; Markley, John L


    Time-zero 2D (13)C HSQC (HSQC(0)) spectroscopy offers advantages over traditional 2D NMR for quantitative analysis of solutions containing a mixture of compounds because the signal intensities are directly proportional to the concentrations of the constituents. The HSQC(0) spectrum is derived from a series of spectra collected with increasing repetition times within the basic HSQC block by extrapolating the repetition time to zero. Here we present an alternative approach to data collection, gradient-selective time-zero (1)H-(13)C HSQC(0) in combination with fast maximum likelihood reconstruction (FMLR) data analysis and the use of two concentration references for absolute concentration determination. Gradient-selective data acquisition results in cleaner spectra, and NMR data can be acquired in both constant-time and non-constant-time mode. Semiautomatic data analysis is supported by the FMLR approach, which is used to deconvolute the spectra and extract peak volumes. The peak volumes obtained from this analysis are converted to absolute concentrations by reference to the peak volumes of two internal reference compounds of known concentration: DSS (4,4-dimethyl-4-silapentane-1-sulfonic acid) at the low concentration limit (which also serves as chemical shift reference) and MES (2-(N-morpholino)ethanesulfonic acid) at the high concentration limit. The linear relationship between peak volumes and concentration is better defined with two references than with one, and the measured absolute concentrations of individual compounds in the mixture are more accurate. We compare results from semiautomated gsHSQC(0) with those obtained by the original manual phase-cycled HSQC(0) approach. The new approach is suitable for automatic metabolite profiling by simultaneous quantification of multiple metabolites in a complex mixture.

  16. Elasto-Magnetic Sensor-Based Local Cross-Sectional Damage Detection for Steel Cables

    Kim, Ju Won; Nam, Min Jun; Park, Seung Hee [Sungkyunkwan University, Suwon (Korea, Republic of); Lee, Jong Jae [Sejong University, Seoul (Korea, Republic of)


    The Elasto-magnetic sensor is applied to detect the local cross-sectional loss of steel cables in this study while it was originally developed for measuring the tensile force in the previous works. To verify the feasibility of the proposed damage detection technique, steel bars which have 4-different diameters were fabricated and the output voltage value was measured at each diameter by the E/M sensor. Optimal input voltage and working point are chosen so that the linearity and resolution of results can ensure through repeated experiments, and then the E/M sensor was measured the output voltage values at the damage points of steel bar specimen that was applied the 4 types of damage condition based on the selected optimal experimental condition. This proposed approach can be an effective tool for steel cable health monitoring.

  17. Multilevel Optimal Design of Prestressed Lightweight Concrete-Steel Platform Structures

    王立成; 宋玉普; 康海贵; 王兴国


    The concrete-steel platform structure is rather complicated because it involves such materials as concrete, reinforcingbars, steel, and so on. If the traditional dimension optimization method is employed, the optimal design of the platform willmeet many handicaps, even it cannot be implemented at all. The multilevel optimal design approach is an efficient tool forthe solution of large-scale engineering structures. In this paper, this approach is applied to the optimal design of a concrete-steel platform, which is formulated as a system level optimal design problem and a set of uncoupled substructure level opti-mal design problems. The process of optimization is a process of iteration between system level and substructure level untilthe objective function converges. An illustrative example indicates that this method is effective in the optimal design of con-crete-steel platforms.

  18. Influence of surface texture on the galling characteristics of lean duplex and austenitic stainless steels

    Wadman, Boel; Eriksen, J.; Olsson, M.;


    of sheet materials and lubricants. The strip reduction test, a severe sheet forming tribology test was used to simulate the conditions during ironing. This investigation shows that the risk of galling is highly dependent on the surface texture of the duplex steel. Trials were also performed......Two simulative test methods were used to study galling in sheet forming of two types of stainless steel sheet: austenitic (EN 1.4301) and lean duplex LDX 2101 (EN 1.4162) in different surface conditions. The pin-on-disc test was used to analyse the galling resistance of different combinations...... in an industrial tool used for high volume production of pump components, to compare forming of LDX 2101 and austenitic stainless steel with equal thickness. The forming forces, the geometry and the strains in the sheet material were compared for the same component. It was found that LDX steels can be formed...

  19. Computer aided design of free-machinability prehardened mold steel for plastic

    HE Yan-lin; LI Lin; GAO Wen; WANG Qing-liang; WU Xiao-chun


    In order to improve the machinability but not to impair other properties of the prehardened mold steel for plastic, the composition was designed by application of Thermo-Calc software package to regulate the type of nonmetallic inclusion formed in the steel. The regulated non-metallic inclusion type was also observed by SEM and EDX. Then the maehinability assessment of the steel with designed composition under different conditions was studied by the measurement of tool wear amount and cutting force. The results show that the composition of free cutting elements adding to mold steel for plastic can be optimized to obtain proper type of non-metallic inclusion in the aid of Thermo-Calc, compared with the large volume fraction of soft inclusion which is needed for promoting ductile fracture at low cutting speeds, the proper type of inclusion at high cutting speeds is glassy oxide inclusion. All those can be obtained in the present work.

  20. On qualification of TOFD technique for austenitic stainless steel welds inspection

    Martinez-Ona, R. [Tecnatom, San Sebastian de los Reyes (Spain); Viggianiello, S.; Bleuze, A. [Metalscan, Saint-Remy (France)


    Time of Flight Diffraction (TOFD) technique is gaining ground as a solid method for detection and sizing of defects. It has been reported that TOFD technique provides good results on the inspection of fine grain steels. However, there are few results regarding the application and performance of this technique on austenitic stainless steels. A big challenge of these inspections is the coarse grain structure that produces low signal to noise ratio and may mask the diffraction signals. Appropriate transducer design, selection of technique parameters and analysis tools could overcome the actual difficulties. In this paper, the main design aspects and parameters of the TOFD technique for austenitic steels are presented. It follows the description of qualification tests carried out to validate the technique for inspecting stainless steels welds. To conclude, discussion of results from actual inspections is shown. (orig.)