磁处理降低焊接残余应力中磁场方向的影响

为了解磁处理可降低铁磁性材料残余应力的内在机理和作用规律,通过实验研究了焊接试板在经不同磁场方向的磁场处理前后的残余应力分布,发现焊板平面内垂直于焊缝方向磁场处理后,焊缝区附近的残余应力有明显的降低;沿板厚方向磁场处理后,焊缝区附近残余应力也有所下降;而磁场方向沿焊缝方向进行处理,残余应力降低不明显。这说明磁场方向垂直于最大主应力方向时最有利于残余应力的降低。该文还初步分析了磁处理降低焊接残余应力时,磁场方向影响其效果的机理。

Effect of magnetic field direction during magnetic treatment to reduce residual welding stresses

Pulsed magnetic fields can reduce internal stresses in ferromagnetic materials.To find the knowledge about the mechanism and correlations between the magnetic treatment parameters and the magnitude of the stress relaxation,this paper investigates how the direction of the magnetic field affects the magnetic treatment.The residual welding stress distributions were studied before and after magnetic treatment to show that when the magnetic field is perpendicular to the welding direction,the residual stresses in the welds and in the HAZ(heat affected zone) are reduced 30@%.While the magnetic field is oriented along the plate thickness,the residual stresses in the welds and in the HAZ are reduced 250%.The effect on the residual stresses of decreases of the magnetic treatment along the weld direction was not obvious.In addition,the mechanism for the directional effect of magnetic treatment is explained based on the experimental results and a theoretical analysis.