X80钢管道焊接致氢富集及热处理数值模拟

Numerical simulation of hydrogen enrichment induced by welding and heat treatment for X80 steel pipe

为了探究焊后热处理对焊接残余应力及氢扩散的影响,采用Abaqus软件建立含六层环焊缝的X80钢管道模型,进行温度场、应力场和氢扩散耦合分析。结果表明,焊接产生的残余应力主要集中在焊缝区和热影响区,Mises等效应力峰值为580 MPa,已接近管材的屈服强度。管道材料内氢浓度沿着径向和轴向分布不同,但均与静水应力的分布规律相似。输氢管道焊后热处理的效果明显,可显著降低焊接残余应力、静水应力,从而降低氢富集浓度,减少焊缝处可能的氢脆现象发生。

In order to explore the influence of post-welding heat treatment on welding residual stress and hydrogen diffusion,a model of X80 girth weld pipe with six layers was established by using Abaqus software,and the coupling analysis of temperature field,stress field and hydrogen diffusion was carried out.The results show that the residual stress generated by welding is mainly concentrated in the weld zone and the heat-affected zone.The peak value of the Mises equivalent stress is 580 MPa,which is closing to the yield strength of the pipe.The distribution of hydrogen concentration in the pipeline metal is different along the radial and axial directions,while the distribution of hydrogen concentration and hydrostatic stress are similar.The post-welding heat treatment of the hydrogen pipeline has an obvious effect on reducing the welding residual stress and hydrostatic stress,thereby reducing the hydrogen enrichment concentration and avoiding probability of occurrence of hydrogen embrittlement at the weld.