超声振动时效可行性分析及实验研究

Feasibility Analysis and Experiment Research of Ultrasonic Vibratory Stress Relief

经过冷、热加工的金属零件表面和内部会存在残余应力,目前消除残余应力的振动时效技术主要是频率低于200Hz的低频振动,而对高频振动时效(大于1000Hz而小于15kHz)和超声振动时效(15kHz以上)的研究很少。对于固有频率较高的小型工件进行有效的时效处理成为目前亟待解决的问题之一。利用压力机对小型杆件施加集中荷载来模拟残余应力的形成,通过对超声振动激振应力计算和实验杆件中残余应力的计算,并从超声振动时效原理上进行实验的可行性分析。最后进行实验分析,即利用残余曲率计算出残余应力并进行时效效果分析,结果表明超声振动时效对小型工件的残余应力的消除有很明显的效果。为以后的超声振动时效研究奠定了理论及实验基础。

The surface and inside of metal parts will exist residual stress after the hot working or pressure processing.The present study about vibration stress relief（VSR）mainly is the frequency of less than 200Hz frequency vibration but rarely for high frequency vibration stress relief（more than 1000Hz and less than 15kHz）and ultrasonic vibration stress relief（15kHz above）.The VSR processing for the workpieces with high natural frequency becomes one of the presently existing problems to be solved.It uses the process of the concentrated load from the press machine applying to a small rod to simulate the formation of residual stress and calculate the ultrasonic vibration stress and the rod residual stress in the experiment,then carry on experimental feasibility analysis of the experiment according to ultrasonic vibration stress relief principle.Finally,it carries on the experimental analysis that uses residual curvature to calculate residual stress and stress relief effect analysis.The results show that it has obvious effect that ultrasonic vibration stress relief eliminates the residual stress of small workpieces.It lays a theoretical and experimental basis for the following ultrasonic vibration stress relief study.