工艺参数对压力容器异种钢接头残余应力的影响及优化分析

Study and optimization analysis on the influence of welding residual stress in dissimilar metal joints of pressure vessel based on the process parameters

为明晰焊接过程产生的残余应力对核电压力容器管道疲劳裂纹扩展和结构断裂失效的影响,优化焊接工艺,从而减小残余应力,借助了Ansys和Isight软件,以核电压水堆一主回路焊接接头焊缝区域为研究目标,利用“生死单元法”进行多层多道焊条件下温度场的模拟,同时利用DOE方法探究焊接结构参数与焊接产生的残余应力间关联关系,得出压力管道异种金属焊接接头残余应力分布规律,明晰了主要工艺参数对结构残余应力的影响机制。结果表明,环向残余应力是压力容器管道焊缝结构发生破坏的直接因素,减小焊接残余应力应增大焊接处的坡口角度和接头内外径差值。

In order to research the influence of residual stress on fatigue crack growth and structural fracture failure of nuclear power pressure vessel and optimize welding process to reduce residual stress. With the help of Ansys and Isight,this paper object at the welding area of the primary circuit of nuclear voltage water reactor,simulate the temperature field and residual stress field of multi-layer and multi-channel welding process by using of the “birth and death element method”. At the same time,the DOE method was used to explore the relationship between welding structure parameters and welding residual stress. The welding residual stress field of pressure pipe joint was obtained. On this basis,the influence of residual stress on the mechanical properties of welded joint was analyzed and to reduce the welding residual stress,the curvature of the weld and the diameter of the joint should be added.