X80管线钢焊接接头氢分布的数值模拟

利用ABAQUS有限元软件,建立了三维有限元模型,对X80管线钢焊接接头的氢扩散行为进行了模拟. 通过对不同焊接条件下温度场、应力场、氢扩散的三场耦合模拟,研究了焊接工艺参数对焊接接头中氢扩散及分布的影响. 结果表明,焊接热影响区残余应力水平最高,是整个接头的应力集中部位,也是焊接接头中的富氢地带. 适当地提高预热温度和焊接热输入,均有利于焊接接头中氢的扩散逸出,降低氢在焊接热影响区的聚集程度,从而降低氢致裂纹的敏感性.

Numerical simulation of hydrogen distribution in welded joint of X80 pipeline steel

Three-dimensional model was established to simulate the transient hydrogen diffusion for X80 pipeline steel welded joint using ABAQUS finite element software. Based on the coupled thermo-mechanical-diffusion analyses under various welding conditions, the effects of welding parameters on the hydrogen diffusion behavior and distribution pattern were investigated. Simulation results indicate that the heat-affected zone with stress concentration was the part with both high-level residual stress and high hydrogen concentration in the welded joint. Increasing preheating temperature and heat input was favorable for hydrogen to diffuse out from the weld zone and effective in reducing hydrogen concentration in the heat-affected zone, which would reduce the susceptibility to hydrogen induced cracking.