金属堆焊成型层间应力分析及工艺优化

Stress Analysis Between Layers and Process Optimization in Metal Surfacing

基于焊接有限元分析基本理论,采用Visual-weld调用Sysweld求解器对单道多层堆积熔焊进行了数值模拟计算和分析,得到了焊接件温度场、应力和变形场的变化规律,重点研究了焊接速度、焊接路径对焊接件残余应力的影响,并对优化的焊接工艺进行加工实验验证。结果表明,各层交接处及起弧和收弧处应力集中,为焊接危险区,熔焊区后层对前层有应力释放作用。金属堆焊速度越快,熔焊区纵向残余应力越大,横向残余应力越小;往返式堆积路径降低了焊缝稳定区和基板的残余应力,焊接变形小,改善了堆焊断弧处弧坑缺陷。

Based on the basic theories of finite element analysis in welding, single pass surfacing welding was simulated and analyzed by Visual-weld and Sysweld soitware. The change regulations of welding temperature field, stress and deformation field were obtained. The influence of welding speed and path on welding residual stressed was studied. The optimized welding process was verified by machining experiments. The results show that stress concentration appears in the junctions of each layers and starting and breaking arc points. These places are dangerous areas. The stress on the previous layer is released with the next layer. Longitudinal residual stress in weld zone increases and the transverse residual stress reduces with the increase of welding speed. The residual stress in the weld zone and the substrate reduces and the welding deformation is small with the return welding path. Crater defects at breaking arc points are improved by this method.