磁弹性法无损测试转向架残余应力分布的试验研究

Test and Research on Nondestructive Measurement of Residual Stress Distribution in Bogies with the Magnetic Elastic Method

利用磁弹性法研究了转向架构架焊接残余应力的分布和焊后热处理对焊接残余应力消除的影响,讨论了适合生产实际的焊后热处理条件。结果表明,焊缝区存在着高焊接残余拉应力,且纵向应力远大于横向应力,丁字形焊缝区产生应力极大值;焊后热处理能显著降低焊接残余应力,并且焊后热处理温度越高,消除效果越好,选择630℃、2.5 h进行焊后热处理时,残余应力平均消除率可达到56.6%。

The magnetic elastic method is used to study the distribution of welding residual stress in bogie frames and the effect of heat treatment after welding on the elimination of welding residual stresses.The conditions of heat treatment after welding that is appropriate to the practical production are discussed.The result shows that there is high welding residual pull stress in the weld area,the longitudinal stress is much bigger than the lateral stress,and the maximal value exists in the intercepted weld area;The heat treatment after welding can reduce the welding residual stresses obviously,and the higher temperature of the heat treatment after welding,the better effect of elimination will be obtained.If the 630 ℃,2.5 h is chosen in the heat treatment after welding,the average elimination rate of residual stresses can reach 56.6%.