AP1000核电站主管道自动焊接头残余应力分析

Analysis on residual stress of automatic welding joints of main pipeline in AP1000 nuclear power plant

采用X射线衍射法对AP1000核电站主管道自动焊接头进行应力演变及焊后残余应力测试。分析讨论管道内壁及外壁的环向及轴向残余应力分布。结果表明:管道内壁近缝处环向残余应力值先增大后减小并逐渐稳定,而远缝处残余应力则保持缓慢上升并逐渐稳定。焊后状态下,管道外壁轴向残余应力随着远离焊缝,先减小后增大至母材水平,而环向残余应力则先上升后下降。

Using X-ray diffraction method, stress evolution and residual stress test after welding were conducted on automatic welding joints of main pipeline in AP1000 nuclear power plant. The distributions of the hoop and axial residual stress of pipe wall and outer wall were analyzed and discussed. The results showed that, the hoop residual stress values of pipe wall near joints increased first and then decreased,and gradually remained stable. While residual stress ones far from joints slowly rised and gradually remained stable. After welding,axial residual stress values of outer wall with far away from joints,decreased first and then increased to the level of parent metal,while the hoop residual stress fell after rising first.