应用数值模拟技术建立了SS400钢中厚板焊接有限元模型, 采用生死单元技术结合体生热率热源模型, 在不同热输入下对其焊接热循环过程进行模拟计算, 根据模拟得到的特征温度值进而得到不同热输入下热影响区宽度的变化规律, 并将模拟结果与试验结果进行对比验证。结果表明: 过热区宽度受热输入变化的影响较小, 但不完全重结晶区宽度随热输入的增加几乎成线性增长; 焊接热循环曲线模拟值与试验值的误差小于4.5%, 热影响区宽度模拟值与试验值基本吻合, 证明了建模及加载的准确性。

The finite element model for the welding process of SS400 medium steel plate was established by using the numerical simulation technique. The body heat source model combined with birth-death model was adopted for the simulation of weld thermal cycle process under different heat-input conditions. According to the simulated characteristic temperature, the change law of heat affected zone(HAZ) width was obtained. The simulated and experimental results were compared. The results show that the influence of heat-input on the width of overheated zone was little; the width of incomplete recrystallization zone increased linearly with the increase of heat-input. The error between the simulated values and test values of thermal circling curves was below 4.5%. The simulated width for the welding HAZ was accorded with test value, which proved the accuracy of modeling and loading.