The evolution of microstructure in the drawing process of commercially pure aluminum wire （CPAW） does not only depend on the nature of materials, but also on the stress profile. In this study, the effect of stress p...The evolution of microstructure in the drawing process of commercially pure aluminum wire （CPAW） does not only depend on the nature of materials, but also on the stress profile. In this study, the effect of stress profile on the texture evolution of the CPAW was systematically investigated by combining the numerical simulation and the microstructure observation. The results show that the tensile stress at the wire center promotes the formation of 〈111〉 texture, whereas the shear stress nearby the rim makes little contribution to the texture formation. Therefore, the 〈111 〉 texture at the wire center is stronger than that in the surface layer, which also results in a higher microhardness at the center of the CPAW under axial loading.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.展开更多
The microstructures and mechanical properties of Ti–47 at%Ni–3 at%Fe shape memory alloy wire under the condition of severe cold-drawing at room temperature and different postdeformation annealing processes were inte...The microstructures and mechanical properties of Ti–47 at%Ni–3 at%Fe shape memory alloy wire under the condition of severe cold-drawing at room temperature and different postdeformation annealing processes were intensively investigated using transmission electron microscope(TEM),X-ray diffraction(XRD),Vickers microhardness tester and electron tensile tester.It is indicated that the structure of the alloy evolves into a predominant amorphous structure with a trace of nanocrystalline B2 phase after the cold-drawing of 76%areal reduction.Postdeformation annealing process exerted significant influence on the microstructure and mechanical properties.Crystallization occurs when the cold-drawn wire was annealed at 300℃ for 30 min.The ultimate tensile strength and ductility as well as the superelasticity of the wire are improved significantly by cold-drawing plus postdeformation annealing.展开更多
Based on experimental data, the mathematical model of rolling force parameters of 3-roll mills was studied. The structure ofthe model was theoretically set up and the coefficients were determined by static analysis of...Based on experimental data, the mathematical model of rolling force parameters of 3-roll mills was studied. The structure ofthe model was theoretically set up and the coefficients were determined by static analysis of the data. The torque in continuous rollingwas measured, and the characteristics and efficiency of 3-roll mills are investigated.展开更多
The microstructures and crystallization behavior of Ti-47 at% Ni-3 at% Fe shape memory alloy wire under the condition of severe cold drawing at room temperature and different post-deformation annealing processes were ...The microstructures and crystallization behavior of Ti-47 at% Ni-3 at% Fe shape memory alloy wire under the condition of severe cold drawing at room temperature and different post-deformation annealing processes were intensively investigated using transmission electron microscope（TEM） and differential scanning calorimetry（DSC）. It is indicated that the amorphous phase is dominant in the Ti50Ni47Fe3 wire after the cold drawing of 78 % areal reduction. The critical temperature for recrystalization is determined at about 300 °C. The average grain size grows from 7 up to 125 nm when annealing temperature rises from300 to 500 °C. Post-deformation annealing process exerts significant influence on the crystallization temperature which climbs up with the increase of annealing temperature.展开更多
It was shown by the study of TEM that the fine lamellar pearlite becomes a ductile phase dur- ing cold drawing.There exist many ledges to emit dislocations at Fe_3C/Fe interface.It is one of the reasons that high dens...It was shown by the study of TEM that the fine lamellar pearlite becomes a ductile phase dur- ing cold drawing.There exist many ledges to emit dislocations at Fe_3C/Fe interface.It is one of the reasons that high density of dislocations emerges at the Fe_3C/Fe interface. Furthermore,there are some evidences to support that dislocation cuts through Fe_3C.There- fore,it is necessary to consider the contribution of cementite being sheared strengthening.展开更多
Cold heading carbon steels for 8.8 grade fasteners are mostly produced by pouring reel or spooler plant.Currently,with improvement of cold heading equipment,the 10.9 grade fasteners produced by cold heading have repla...Cold heading carbon steels for 8.8 grade fasteners are mostly produced by pouring reel or spooler plant.Currently,with improvement of cold heading equipment,the 10.9 grade fasteners produced by cold heading have replaced most of hot forged fasteners gradually.As well known,wire rod coil has been used to produce alloy steels.The properties and microstructures of medium carbon alloy steels,such as B7,ML40Cr and SCM435,produced by wire rod coils under hot rolled condition and after spheroidization,have been investigated.In this paper,the effect of microstructure of hot rolled steel wire rods on cold heading annealing process was studied.The results show that the hardness of wire rod coil products is generally lower than that of bar products by 5 ～ 10 HRB and the ferrite fraction in wire rod coil products is higher.After spheroidization treatment,the hardness value and spheroidization grade of wire rod coil products are relatively low.alloy steels of wire rod coils can be directly drawn slightly and the annealing time can be reduced at the same time.This practice is much helpful for energy conservation.展开更多
Commercial grade-70 tire cord steel was microalloyed with V and N to explore the possibility of substitu- ting V for C and the effect of V and N on cementite dissolution during cold drawing process. Tensile strength, ...Commercial grade-70 tire cord steel was microalloyed with V and N to explore the possibility of substitu- ting V for C and the effect of V and N on cementite dissolution during cold drawing process. Tensile strength, elon- gation and torsion laps of cold-drawn wires were determined. Microstructures of secondary phases were studied by transmission electron microscopy （TEM） and energy dispersive spectroscopy （EDS）. Saturation magnetization was measured by using a vibrating sample magnetometer （VSM） to evaluate cementite dissolution during cold drawing process. Experimental results showed that with the increase of V content, tensile strength increased, elongation slightly decreased, and the torsion laps of the cold-drawn wires decreased. Results also showed that with the increase of N content, a peak （increasing first and then decreasing） appeared in the tensile strength graph, and an increase of elongation and a decrease of torsion laps of the cold-drawn wires occured. N is soluble in ferrite when its content is low. The increase in the content of N to 82 × 10^-6 will result in the precipitation of the V-containing secondary pha- ses. Also, cementite tended to be stable during cold drawing process with the increase of V and N contents. Grade-80 tire cord steel can be replaced by grade 70 tire cord steel microalloyed with 0. 086 mass% V.展开更多
By using transmission electron microscopy, the microstructures of drawn industrial single crystal copper wires produced by Ohno Continuous Casting(OCC) process were analyzed. The results show that the typical microstr...By using transmission electron microscopy, the microstructures of drawn industrial single crystal copper wires produced by Ohno Continuous Casting(OCC) process were analyzed. The results show that the typical microstructures in the wires mainly include extended planar dislocation boundaries, a small fraction of twins and some dislocation cells sharing boundaries parallel to drawn direction. Besides the typical microstructures, 9R structure configurations were observed in the wires. The formation of 9R polytypes may be caused by the coupled emission of Shockley dislocations from a boundary.展开更多
基金financially supported by the State Grid Corporation of China (No. 52110416001z)the National Natural Science Foundation of China (No. 51331007)
文摘The evolution of microstructure in the drawing process of commercially pure aluminum wire （CPAW） does not only depend on the nature of materials, but also on the stress profile. In this study, the effect of stress profile on the texture evolution of the CPAW was systematically investigated by combining the numerical simulation and the microstructure observation. The results show that the tensile stress at the wire center promotes the formation of 〈111〉 texture, whereas the shear stress nearby the rim makes little contribution to the texture formation. Therefore, the 〈111 〉 texture at the wire center is stronger than that in the surface layer, which also results in a higher microhardness at the center of the CPAW under axial loading.2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.
基金supported by the National Natural Science Foundation of China (No. 50921003)Industry, Education and Research Projects of the China Aviation Industrial (No.cxy2012BH04)
文摘The microstructures and mechanical properties of Ti–47 at%Ni–3 at%Fe shape memory alloy wire under the condition of severe cold-drawing at room temperature and different postdeformation annealing processes were intensively investigated using transmission electron microscope(TEM),X-ray diffraction(XRD),Vickers microhardness tester and electron tensile tester.It is indicated that the structure of the alloy evolves into a predominant amorphous structure with a trace of nanocrystalline B2 phase after the cold-drawing of 76%areal reduction.Postdeformation annealing process exerted significant influence on the microstructure and mechanical properties.Crystallization occurs when the cold-drawn wire was annealed at 300℃ for 30 min.The ultimate tensile strength and ductility as well as the superelasticity of the wire are improved significantly by cold-drawing plus postdeformation annealing.
文摘Based on experimental data, the mathematical model of rolling force parameters of 3-roll mills was studied. The structure ofthe model was theoretically set up and the coefficients were determined by static analysis of the data. The torque in continuous rollingwas measured, and the characteristics and efficiency of 3-roll mills are investigated.
基金financially the National Natural Science Foundation of China (Nos. 50835002 and 51105102)the Industry, Education and Research Projects of the China Aviation Industrial (No. cxy2012BH04)
文摘The microstructures and crystallization behavior of Ti-47 at% Ni-3 at% Fe shape memory alloy wire under the condition of severe cold drawing at room temperature and different post-deformation annealing processes were intensively investigated using transmission electron microscope（TEM） and differential scanning calorimetry（DSC）. It is indicated that the amorphous phase is dominant in the Ti50Ni47Fe3 wire after the cold drawing of 78 % areal reduction. The critical temperature for recrystalization is determined at about 300 °C. The average grain size grows from 7 up to 125 nm when annealing temperature rises from300 to 500 °C. Post-deformation annealing process exerts significant influence on the crystallization temperature which climbs up with the increase of annealing temperature.
文摘It was shown by the study of TEM that the fine lamellar pearlite becomes a ductile phase dur- ing cold drawing.There exist many ledges to emit dislocations at Fe_3C/Fe interface.It is one of the reasons that high density of dislocations emerges at the Fe_3C/Fe interface. Furthermore,there are some evidences to support that dislocation cuts through Fe_3C.There- fore,it is necessary to consider the contribution of cementite being sheared strengthening.
文摘Cold heading carbon steels for 8.8 grade fasteners are mostly produced by pouring reel or spooler plant.Currently,with improvement of cold heading equipment,the 10.9 grade fasteners produced by cold heading have replaced most of hot forged fasteners gradually.As well known,wire rod coil has been used to produce alloy steels.The properties and microstructures of medium carbon alloy steels,such as B7,ML40Cr and SCM435,produced by wire rod coils under hot rolled condition and after spheroidization,have been investigated.In this paper,the effect of microstructure of hot rolled steel wire rods on cold heading annealing process was studied.The results show that the hardness of wire rod coil products is generally lower than that of bar products by 5 ～ 10 HRB and the ferrite fraction in wire rod coil products is higher.After spheroidization treatment,the hardness value and spheroidization grade of wire rod coil products are relatively low.alloy steels of wire rod coils can be directly drawn slightly and the annealing time can be reduced at the same time.This practice is much helpful for energy conservation.
基金Sponsored by Natural Science Foundation of Hubei Province of China(2014CFB801)
文摘Commercial grade-70 tire cord steel was microalloyed with V and N to explore the possibility of substitu- ting V for C and the effect of V and N on cementite dissolution during cold drawing process. Tensile strength, elon- gation and torsion laps of cold-drawn wires were determined. Microstructures of secondary phases were studied by transmission electron microscopy （TEM） and energy dispersive spectroscopy （EDS）. Saturation magnetization was measured by using a vibrating sample magnetometer （VSM） to evaluate cementite dissolution during cold drawing process. Experimental results showed that with the increase of V content, tensile strength increased, elongation slightly decreased, and the torsion laps of the cold-drawn wires decreased. Results also showed that with the increase of N content, a peak （increasing first and then decreasing） appeared in the tensile strength graph, and an increase of elongation and a decrease of torsion laps of the cold-drawn wires occured. N is soluble in ferrite when its content is low. The increase in the content of N to 82 × 10^-6 will result in the precipitation of the V-containing secondary pha- ses. Also, cementite tended to be stable during cold drawing process with the increase of V and N contents. Grade-80 tire cord steel can be replaced by grade 70 tire cord steel microalloyed with 0. 086 mass% V.
基金Project(50771076) supported by the National Natural Science Foundation of ChinaProject(07JK274) supported by the Education Department of Shaanxi Province, China
文摘By using transmission electron microscopy, the microstructures of drawn industrial single crystal copper wires produced by Ohno Continuous Casting(OCC) process were analyzed. The results show that the typical microstructures in the wires mainly include extended planar dislocation boundaries, a small fraction of twins and some dislocation cells sharing boundaries parallel to drawn direction. Besides the typical microstructures, 9R structure configurations were observed in the wires. The formation of 9R polytypes may be caused by the coupled emission of Shockley dislocations from a boundary.
