相变对管道环焊缝残余应力的影响

利用ADINA程序计算了管道环焊缝接头未考虑相变和考虑相变两种情况下的残余应力,有限元分析中考虑了材料热物理性能参数和力学性能参数的温度相关性.结果表明,考虑相变应力比未考虑相变应力,其外表面的轴向压应力值增加,内表面的拉应力值降低;外表面的环向应力出现压应力,内表面的拉应力值降低,最大拉应力的峰值区偏向近缝区.这说明相变应力对管道接头焊缝和近缝区有较大的影响.计算结果与实测结果基本一致,对焊接接头的金相组织分析也验证了计算结果.

Phase Transformation Effects on Residual Stresses during Girth Welding of Pipes

The comparisons of residual stresses between with phase transformation and without phase transformation were calculated using ADINA during girth welding of pipes. The temperature-dependent of thermal-elastoplasticity and mechanical properties were taken into account. The results show that phase transformation has great effects on residual stresses at the welding and surrounding. Combined with the experimental and the metallographic analysis, this paper present that the phase transformation stress caused by the volume expansion in phase transformation is one main factor resulting in the lower residual stresses.