结构钢残余应力的电磁法测量优化研究

Optimization study of electromagnetic measurement of residual stress in structural steel

采用万能试验机、金相显微镜、X射线衍射仪及电磁应力仪,研究了电磁法测残余应力灵敏系数与层深之间的关系,对相应工件不同层深残余应力进行测量,并提出了使用线性拟合法取得更合适的灵敏系数,最后使用X射线衍射法进行了验证。结果表明:灵敏系数随着层深增加,先增大后减小;工件近表层残余应力分布与深层有着显著区别,在0.6 mm以上更深层处的残余应力差异较小;使用线性拟合法取得的灵敏系数更加契合实际灵敏系数,能一定程度上减小电磁法测量误差。

The relationship between the sensitivity coefficient of residual stress and the layer depth in electromagnetic meth⁃od was studied using universal testing machine,metallographic microscope,X⁃ray diffractometer and electromagnetic stress meter.The corresponding residual stress in different layer depth in workpiece was measured.A more appropriate sensitivity coefficient was obtained by using the linear fitting method.Finally,the X⁃ray diffractometer was used for verification.The results showed that the sensitivity coefficient first increased and then decreased with the increase of layer depth.The distri⁃bution of residual stress in the near surface layer was significantly different from that in the deep layer.The sensitivity coef⁃ficient obtained by the linear fitting method was more suitable for the actual sensitivity coefficient,which could reduce the measurement error to a certain extent in the electromagnetic method.