The variety,inner quality and surface quality of low-alloy spring steel wire rod for domestic automobile is summarized in detail.And according to commercial low-alloy spring steel wire rod variety, product quality lev...The variety,inner quality and surface quality of low-alloy spring steel wire rod for domestic automobile is summarized in detail.And according to commercial low-alloy spring steel wire rod variety, product quality level and its actual application situation on automobile supplied by present industrially developed country metallurgy enterprises,it is pointed that the variety of low-alloy spring steel wire rod for domestic automobile can't satisfy the requirements of automobile industry development,compare with overseas advanced technology,product quality has the following gaps:the first is that steel purity is low,the control level of non-metallic inclusions is not steady,there is often large grain difficult deforming non-deformation inclusions existing,the control level of steel purity has big difference,the level of large steel factory is high,but its steady has a large gap compare with foreign advanced level,not to mention small steel factory which research and development powder is low.The second is surface complete decarburization can' t be avoided completely.The third is that surface defects are more.The fourth is that composition segregation and structure segregation are not steady,steel wire can't be drawn normally when the segregation is serious. In all,the segregation of 55SiCrA is superior to 60Si2MnA obviously.The industrialization of domestic high level low-alloy spring steel wire rod can't seek quick success and instant benefits,independent innovation perseveringly must be adopted,the success may be reached after master core technologies and adopt the science way of step by step.展开更多
Low carbon steel wires were prepared by two processes,serial drawing(SD)and reverse-direction drawing(RD).Effects of the two processes on microstructure and mechanical properties in steel wires were investigated by fi...Low carbon steel wires were prepared by two processes,serial drawing(SD)and reverse-direction drawing(RD).Effects of the two processes on microstructure and mechanical properties in steel wires were investigated by field emissio scanning electron microscopy,electron backscatter diffraction(EBSD),X-ray diffraction and transmission electron microscopy(TEM).Residual compressive stress and more low-angle grain boundaries were introduced into the steel wire by the RD.As a result,the RD wires exhibited a greater tensile strength when drawing strain s<1.18.The SD encouraged grain refinement and texture formation in the wire.The SD wires exhibited a smaller average width of the elongated ferrite grain and a higher intensity of(110)fiber texture at all drawing strains.Therefore,the SD wires showed a bit greater tensile strength and 20%greater torsion performance than the RD wires at c=2.51.TEM and EBSD analysis indicated that dislocation tangle was formed easily in RD wires,and it transformed into twist boundary.This twist boundary impeded the grain refinement in the RD wires,and there were still non-fibrous grains in the RD wires even after heavy drawing.展开更多
文摘The variety,inner quality and surface quality of low-alloy spring steel wire rod for domestic automobile is summarized in detail.And according to commercial low-alloy spring steel wire rod variety, product quality level and its actual application situation on automobile supplied by present industrially developed country metallurgy enterprises,it is pointed that the variety of low-alloy spring steel wire rod for domestic automobile can't satisfy the requirements of automobile industry development,compare with overseas advanced technology,product quality has the following gaps:the first is that steel purity is low,the control level of non-metallic inclusions is not steady,there is often large grain difficult deforming non-deformation inclusions existing,the control level of steel purity has big difference,the level of large steel factory is high,but its steady has a large gap compare with foreign advanced level,not to mention small steel factory which research and development powder is low.The second is surface complete decarburization can' t be avoided completely.The third is that surface defects are more.The fourth is that composition segregation and structure segregation are not steady,steel wire can't be drawn normally when the segregation is serious. In all,the segregation of 55SiCrA is superior to 60Si2MnA obviously.The industrialization of domestic high level low-alloy spring steel wire rod can't seek quick success and instant benefits,independent innovation perseveringly must be adopted,the success may be reached after master core technologies and adopt the science way of step by step.
基金This work is supported by the National Natural Science Foundation of China(Grant No.51371050)Special Talent Program of Jiangsu Province(2015-XCL-004)+2 种基金the Industry・University Strategic Research Fund of Jiangsu Province(BY2016076-08)The study is also partly supported by the Science and Technology Advancement Program of Jiangsu Province(Grant No.BA2017112)L.C.Zhou appreciates the support provided by Fundamental Research Funds for the Central Universities and the Scientific Research Foundation of the Graduate School of Southeast University(YBJJ1674).
文摘Low carbon steel wires were prepared by two processes,serial drawing(SD)and reverse-direction drawing(RD).Effects of the two processes on microstructure and mechanical properties in steel wires were investigated by field emissio scanning electron microscopy,electron backscatter diffraction(EBSD),X-ray diffraction and transmission electron microscopy(TEM).Residual compressive stress and more low-angle grain boundaries were introduced into the steel wire by the RD.As a result,the RD wires exhibited a greater tensile strength when drawing strain s<1.18.The SD encouraged grain refinement and texture formation in the wire.The SD wires exhibited a smaller average width of the elongated ferrite grain and a higher intensity of(110)fiber texture at all drawing strains.Therefore,the SD wires showed a bit greater tensile strength and 20%greater torsion performance than the RD wires at c=2.51.TEM and EBSD analysis indicated that dislocation tangle was formed easily in RD wires,and it transformed into twist boundary.This twist boundary impeded the grain refinement in the RD wires,and there were still non-fibrous grains in the RD wires even after heavy drawing.
