电磁复合处理降低焊接残余应力增益效应的初步研究

Enhancement Effect of Reducing Welding Residual Stress by Composite Electromagnetic Treatment

通过外加磁场和通过脉冲电流改善材料的力学性能是两种新型的处理方法,研究表明这两种方法对材料残余应力有一定作用。在这两种处理方法研究的基础上,提出同时耦合脉冲磁场和脉冲电流的复合处理方式,并发现该处理方法在降低残余应力上有不同于磁处理及电处理的增益效应。试验采用16Mn平板焊接试样,通过X射线应力测定仪测量同一位置沿焊缝和垂直焊缝两个方向处理前后的残余应力的大小,并进行比较。试验结果表明,磁处理后残余应力下降10%左右,电处理后应力上升大约20%,而相同参数下同时耦合脉冲磁场、脉冲电流进行复合处理后,应力下降超过50%。对于其中出现的增益效应,初步分析是由于与残余应力相关的位错结构在脉冲磁场与电流复合作用下发生较大迁移,导致了应力的松弛。

Reducing residual stress through an electromagnetic method is presented and the enhancement effect is found,which is obviously different from magnetic field treatment or pulsed current treatment.The studied samples are welded with 16Mn plates and residual stress in different area is investigated.Stress variations caused by magnetic field treatment,pulsed current treatment and electromagnetic treatment are compared.Experiment results show that after magnetic treatment the stress decreases by 10%,after electrical treatment the stress increases by 20%,while after electromagnetic treatment the stress decreases by more than 50%.There is an enhancement effect on residual stress relief in electromagnetic treatment due to great migration of dislocation structure related to the residual stress.