磁处理降低钢中残余应力的微观机理模型

目的是定量研究一种新颖的降低材料内应力的非热方法、低频交变磁处理法的效果及其微观机理。在试验研究了该方法降低试样内残余应力的程度、特点和工艺参数的影响后 ,通过透射电镜分析 ,着重观察了磁处理时材料内部的位错运动规律。结果表明 ,低频交变磁处理用于降低材料的内应力是有效的 ,其主要应力降低原因是磁处理过程引起的位错均匀化。在实验结果和理论分析的基础上 ,提出了磁处理时材料内应力松弛的物理模型 ,合理地解释了低频交变磁处理方法降低残余应力的机理

Micro-mechanism model of residual stress relaxation in steels by magnetic treatment

Low frequency alternating magnetic field treatment is an innovative non thermal method to process welded samples with internal residual stresses. This paper investigates the stress relaxation mechanism and the correlation between the magnetic treatment parameters and the magnitude of stress relaxation. The microstructure changes of the material during magnetic treatment is observed by TEM and related to the dislocation behavior in the material. The experimental results indicate that low frequency alternating magnetic field treatment is an effective method for reducing residual stresses in steels. The main reason for the stress reduction is the even distribution of the dislocations by the magnetic treatment. A physical model for the residual stress relaxation by magnetic treatment is proposed based on the experimental results and microstructure observations that explains the micro mechanisms.