厚板焊接时的残余应力与应变特征

Characteristics of welding residual stresscs and strains of thick plate

本文采用热弹塑性有限元方法对厚板的表面堆焊.多次焊补和多层焊进行了实例分析计算.结果表明,在表面焊道下面并且离开焊缝中心线若干距离的地方,出现相当高的三向拉伸应力和大的塑性应变积累.该区有可能引起冷裂纹以及引起断裂韧性的降低,应当引起注意.

In this paper, welding residual stresses and strains are analvsed for three types of weld on thick plate: the surface weld, the multi-repair weld and the multi-pass weld. A thermal clastic-plastic analysis technique is used under conditions of plane deformation.The results show that the triaxial residual stresses and plastic strains can accumulate to relatively high values just below the surface and at a short distance away from the weld area. As a consequence cold cracking may occur, causing the fracture toughness to deerease. More attention should be paid to this area in the manufacturing of thick walled structures.