喷丸及磨削对8Cr4Mo4V钢残余应力及位错密度分布的影响  

Effect of Shot Peening and Grinding on Residual Stress and Dislocation Density Distribution in 8Cr4Mo4V Steel

作　　者：张兴洪 李正辉 周丽娜 刘永宝 黄丽 刘璐莹 何俊龙 马欣新[2] ZHANG Xinghong;LI Zhenghui;ZHOU Lina;LIU Yongbao;HUANG Li;LIU Luying;HE Junlong;MA Xinxin(China Aviation Development Harbin Bearing Company Limited,Harbin 150025,China;School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China)

机构地区：[1]中国航发哈尔滨轴承有限公司,黑龙江哈尔滨150025 [2]哈尔滨工业大学材料科学与工程学院,黑龙江哈尔滨150001

出　　处：《热加工工艺》2024年第24期145-149,共5页Hot Working Technology

基　　金：国家科技重大专项项目(2017-VII-0003-0096)。

摘　　要：喷丸作为8Cr4Mo4V钢的机械强化工艺,可在材料表层形成近300μm的残余压应力层,有利于提高材料的接触疲劳性能。由于喷丸后材料的近表层粗糙度较大,同时存在开裂的碳化物,需进行磨削处理。磨削工艺引入的附加应力,对于喷丸后的应力分布存在较大的影响。通过SEM、XRD、残余应力测试等方法,探究了喷丸加磨削工艺对于8Cr4Mo4V钢表层组织结构与残余应力分布的影响。结果表明:随着喷丸强度的提高,残余应力的分布加深,应力影响层的深度最高达到320μm左右。由于喷丸后材料表面的高应力和高密度位错,马氏体衍射峰产生峰位左偏、半高宽增加、强度降低的现象。基于采用WH理论计算位错密度的方法,给出了表层位错密度分布与残余应力分布的关系。As a mechanical strengthening process of 8Cr4Mo4V steel,shot peening can form a residual compressive stress layer of nearly 300μm on the surface of the material,which is beneficial to improve the contact fatigue performance of the material.Due to the large roughness of the near-surface layer of the material after shot peening and the existence of cracked carbides,the grinding treatment is required.The additional stress introduced by the grinding process has a great influence on the stress distribution after shot peening.The influence of shot peening and grinding process on the surface structure and residual stress distribution of 8Cr4Mo4V steel was explored by SEM,XRD,residual stress test and other methods.The results show that with the increase of the peening strength,the distribution of the residual stress deepens,and the highest depth of the stress-affected layer reaches about 320μm.Due to the high stress and high density of dislocations on the surface of the material after shot peening,the martensitic diffraction peaks have a left-shifted peak position,an increase in the full width at half maximum,and a decrease in strength.Based on the method of calculating the dislocation density with the WH theory,the relationship between the dislocation density distribution and residual stress distribution in the surface layer is given.

关 键 词：喷丸 残余应力 位错密度 磨削 

分 类 号：TG142.72[一般工业技术—材料科学与工程]