焊接工艺参数对Q345钢平板焊接残余应力的影响

为研究焊接工艺参数对Q345钢平板焊接残余应力的影响,对采用药芯焊丝半自动焊接后的8 mm厚平板焊缝结构进行仿真模拟,在经验数值范围内设置不同的焊接工艺参数值,分析平板在横向和厚度方向的焊接残余应力分布情况。研究结果表明:横向的最大焊接残余应力分布在热影响区,且随着焊接速度的增大和焊接层间温度的降低而降低；沿厚度方向的最大焊接残余应力为115.92 MPa,位于平板中间层,随着焊接速度的增大而先减小后增大；平板焊接在横向的残余应力远大于厚度方向的应力。根据焊接残余应力的变化情况,运用二元回归分析法对横向和厚度方向的最大焊接残余应力进行函数拟合与检验,并开展多因素拟合模型的分析,得到焊接速度和焊接层间温度对焊接残余应力的综合影响规律。通过研究残余应力的变化趋势可选定焊接残余应力最小时的工艺参数范围,实现焊接工艺参数优化。

Effect of welding parameters on residual stress of Q345 steel plate welding

In order to study the effect of welding parameters on residual stress of Q345 steel plate, the simulation has been performed on the welding seam structure of 8 mm thick plate after the flux-cored wire semi-automatic welding. The different welding parameters are set within the range of empirical values to analyze the residual stress distribution of the plate in the transverse and thickness directions. The results show that the maximum transverse residual stress is located in the heat affected zone and tends to decrease with increasing welding speed and decreasing welding interpass temperature. The maximum residual stress along the thickness direction is 115.92 MPa, which is located in the middle layer of the flat plate and tends to increase with increasing welding speed. The residual stress in the transverse direction is much larger than that in the thickness direction. According to the distrubution of welding residual stress, the functions of the maximum welding residual stress in the transverse and thickness directions are fitted and verified by the binary regression analysis method. Based on the multi-factor fitting model, the comprehensive influence law of welding speed and welding interpass temperature on welding residual stress is obtained. By studying the variation trend of residual stress, the range of process parameters with minimum welding residual stress can be selected to optimize the welding parameters, which guides the selection of welding parameters for Q345 steel plate welding.