真空退火对冷拔34CrMo4钢薄壁管残余应力、组织和性能的影响  

Effect of vacuum annealing on residual stress,microstructure and properties of cold⁃drawn 34CrMo4 steel thin⁃walled pipe

作　　者：候平 王京成 王泽 钱金京 Hou Ping;Wang Jingcheng;Wang Ze;Qian Jinjing(School of Materials Engineering,Jiangsu University of Technology,Changzhou Jiangsu 213001,China;Jiangsu Hongyi Seiko Co.,Ltd.,Changzhou Jiangsu 213102,China)

机构地区：[1]江苏理工学院材料工程学院,江苏常州213001 [2]江苏宏亿精工股份有限公司,江苏常州213102

出　　处：《金属热处理》2024年第6期85-91,共7页Heat Treatment of Metals

基　　金：2022年产学研合作项目(KYH22264)。

摘　　要：通过冷拔工艺制备出0.9 mm壁厚的34CrMo4无缝钢管,利用X射线应力测定仪、扫描电镜(SEM)、电子背散射衍射(EBSD)技术、万能拉伸试验机等,研究在真空退火过程中冷拔34CrMo4薄壁无缝钢管残余应力和组织性能的变化。结果表明,真空退火能有效降低试验钢在冷拔后存留的残余应力,试验钢强度下降,塑性升高,冷拔区域的组织得到回复,但仍保持冷拔变形时的流线型组织形貌。冷拔导致组织内小角度晶界密度升高,经过真空退火,小角度晶界逐渐被大角度晶界所代替。650℃真空退火时,试验钢有效铁素体晶粒尺寸为3.62μm,残余应力为-13.1 MPa,抗拉强度为693 MPa,伸长率为26.1%,在降低残余应力的同时获得了良好的强塑性匹配。34CrMo4 seamless steel pipe with wall thickness of 0.9 mm was prepared by cold drawing process,and the changes of residual stress,microstructure and properties of the cold⁃drawn pipe during vacuum annealing were studied by X⁃ray stress tester,scanning electron microscope(SEM),electron backscatter diffraction(EBSD)technology and universal tensile testing machine.The results show that the vacuum annealing can effectively reduce the residual stress of the tested steel after cold drawing,where the strength decreases,the plasticity increases,and the structure of the cold drawing zone recovers,but the streamline microstructure of the cold drawing deformation is still maintained.The cold drawing leads to increase in the density of small angle grain boundaries,while after vacuum annealing,small angle grain boundaries are gradually replaced by large angle grain boundaries.When vacuum annealed at 650℃,the effective ferrite grain size of the tested steel is 3.62μm,the residual stress is-13.1 MPa,the tensile strength is 693 MPa,the elongation is 26.1%,which reduces the residual stress while obtains a good strength plasticity matching.

关 键 词：真空退火 薄壁钢 残余应力 显微组织 力学性能 

分 类 号：TG356.52[金属学及工艺—金属压力加工]