低合金钢与不锈钢异质金属平板堆焊数值模拟

Numerical Simulation on Dissimilar Metal Overlay-welding of Low Alloy Steel with Stainless Steel

核电设备由于其复杂的服役环境,不同位置对材料提出不同要求,因此大量使用了异质金属堆焊。本文为研究异质金属堆焊接头温度场和焊接残余应力的分布规律,基于有限元分析软件ABAQUS,开发了用于模拟平板堆焊接头温度场、应力场的热-弹-塑性有限元计算方法。计算结果表明,所开发的基于高斯面热源的移动热源模型很好地拟合了实际生产时的熔池形态;同时由于材料性能的差异,在界面上存在明显的残余应力不连续的现象;在多道焊条件下后焊焊道对先焊焊道有一定的退火作用,可以适度降低先焊焊道时形成的残余应力。

Dissimilar metal overlay-welding has been widely used in nuclear facilities for the complicated working environment and different positions to material demands. In order to study the temperature field and welding residual stress distribution induced by overlay-welding, based on ABAQUS software, a thermal-elastic-plastic finite element method was developed and used for the temperature field and the stress field of the simulated overlay-welding joints. The results show that the developed moving heat source based on Gauss surface heat source can capture the features of weld pool well. In the interface between the base metal and the weld metal, the residual stress distribution presents a discontinuous feature,because of the difference of material performance. In addition, under complex weld passes conditions, the subsequent weld pass has a certain annealing effect for the previous weld pass, which can reduce residual stress produced by the previous weld pass properly.