喷丸处理55Si2MnMoV弹簧钢的疲劳性能和破坏行为  

Fatigue properties and fracture behavior of shot peened 55Si2MnMoV spring steel

作　　者：贾金柯 李行 张继旺[1] Jia Jinke;Li Xing;Zhang Jiwang(National Key Laboratory of Rail Transit Vehicle System,Southwest Jiaotong University,Chengdu Sichuan 610031,China)

机构地区：[1]西南交通大学轨道交通运载系统全国重点实验室,四川成都610031

出　　处：《金属热处理》2024年第12期237-242,共6页Heat Treatment of Metals

摘　　要：对55Si2MnMoV弹簧钢进行喷丸和喷丸抛光处理,利用激光共聚焦显微镜、显微硬度计、X射线残余应力分析仪对其表面粗糙度、硬度和残余应力进行表征,并对其进行疲劳试验,绘制S-N曲线和观察疲劳断口形貌,研究了喷丸处理55Si2MnMoV弹簧钢的疲劳性能。结果表明,喷丸处理提高了弹簧钢试样的疲劳性能,相比未喷丸试样,喷丸和喷丸抛光试样的疲劳强度都提升了16.7%;喷丸抛光试样的表面粗糙度比喷丸试样低,但疲劳强度与喷丸试样相同;喷丸并未改变试样的疲劳断裂机制,所有试样均为表面裂纹萌生的断裂模式。喷丸试样强化层中的残余压应力是疲劳强度提升的主要因素。Shot peening and shot peening-polishing treatments were applied to the 55Si2MnMoV spring steel.The surface roughness,hardness,and residual stress were characterized by using laser confocal microscopy,microhardness tester and X-ray residual stress analyzer.Fatigue tests were conducted to plot S-N curves and observe fatigue fracture morphology,thereby investigating the fatigue property of the 55Si2MnMoV spring steel subjected to shot peening.The results indicate that shot peening improves the fatigue property of the spring steel specimens.Compared to the untreated specimen,the fatigue strength of the both shot peened and shot peened-polished specimens is increased by 16.7%.Although the surface roughness of the shot peened-polished specimens is lower than that of the shot peened specimens,their fatigue strength remain the same.Shot peening treatments do not change the fatigue fracture mechanism,as all the specimens exhibit a fracture mode initiated by surface cracks.The residual compressive stress in the hardened layer of the shot peened specimens is the primary factor contributing to the enhanced fatigue strength.

关 键 词：喷丸处理 55Si2MnMoV弹簧钢 表面粗糙度 残余应力 疲劳强度 

分 类 号：TG113.25[金属学及工艺—物理冶金]