预应力时效性对磨削强化表面应力的影响  

Effect of Pre-stress Time-Characteristics on Grinding Strengthened Surface Stress

作　　者：牛艺静 孙聪[1] 庞刚 修世超[1] NIU Yi-jing;SUN Cong;PANG Gang;XIU Shi-chao(School of Mechanical Engineering&Automation,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学机械工程与自动化学院,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2020年第4期546-550,共5页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(51775101);中央高校基本科研业务费专项资金资助项目(N180306003).

摘　　要：为了获得不同预应力卸载时间的磨削硬化层残余应力值及马氏体含量,进行了预应力淬硬磨削实验.对预应力磨削进行仿真,得到了工件表层的温度变化情况及预应力卸载时间对表面机械热应力的影响.结合实验数据和仿真模拟,讨论了预应力时效性对相变和相变应力的影响.结果表明:在7s内,预应力具有一定的时效性;随着卸载时间的增加,晶体内部晶界伸长,马氏体含量有所增加,加工表面残余压应力增加.In order to obtain the residual stress value and martensite content of the hardened layer with different pre-stress unloading times,a pre-stress hardening grinding experiment was carried out.The pre-stress grinding was simulated to obtain the temperature change of the surface layer of the workpiece and the influence of the pre-stress unloading time on the surface’s mechanical thermal stress.Combining the experimental data and simulation,the effects of pre-stress time-characteristics on phase transformation and phase transformation stress were discussed.The results showed that the pre-stress has certain time-characteristics in 7 seconds.With the increase of unloading time,the grain boundary of the crystal is elongated,the content of martensite increases,and the residual compressive stress of the machined surface increases.

关 键 词：预应力磨削 卸载时间 相变 残余应力 有限元仿真 

分 类 号：TH164[机械工程—机械制造及自动化]