不锈钢焊接凝固裂纹应力应变场数值模拟结果分析

Simulated Stress strain Distributions for Weld Metal Solidification Cracking in Stainless Steel

对不锈钢凝固裂纹的驱动力即熔池尾部应变场进行了模拟。首先 ,通过单元再生方案 ,消除了焊接构件中熔池变形对熔池尾部应力应变场的影响。其次 ,通过加大材料的线膨胀系数 ,考虑了凝固收缩对熔池尾部应力应变场的影响 ,最终得到了各种条件下的焊接应力 -应变场。此外 ,本文将机械应变随时间变化的关系曲线处理成机械应变随温度变化的关系曲线 ,从而获得了凝固裂纹驱动力 ,为凝固裂纹的预测奠定了基础。

This paper has simulated the driving force of solidification crack of stainless steels, namely the,stress strain field in the trail of molten weld pool. Firstly, the effect of the deformation in the molten weld pool was eliminated after the element rebirth method was adopted. Secondly, the influence of solidification shrinkage was considered by increasing thermal expansion coefficients of the steels at elevated temperature. Finally, the stress strain distributions of different conditions have been got and analyzed. Furthermore, the driving force curves of the solidification crack of the steels have been obtained by converting strain position curves into strain temperature ones which found a basis for predicting welding solidification crack.