管线钢在役焊接多道焊的数值模拟

管线钢在役焊接是在高压流动管线不停输的条件下进行焊接作业的，由于介质流动带压的特性，必然对焊接作业的安全性和焊后管道的使用性造成影响。采用SYSWELD焊接模拟软件对在役焊接进行数值模拟，考虑了材料热物理性能随温度变化和在役条件对散热的影响，获得了三维多道焊焊接接头的应力分布情况。结果表明：在役焊接接头残余应力分布规律与常规焊接基本保持一致，但数值上有所不同，计算结果对油气管线的在役焊接修复具有指导意义。

Numerical Modeling of the Multi-pass Welding of In-service Welding onto the Pipeline Steel

In-service welding of the pipeline steel is performed under the condition that the deliver of the high pressure pipeline doesn't stop,and will affect the safety of the welding and the service performance after the welding of the pipeline,because of the character of the medium with pressure.The paper simulated the process of in-service welding with SYSWELD,considering the change of physical property along temperature and the effect of the welding condition on radiating,and gets the stress distribution of the joint in 3-D multi-pass welding.The results show that the rule of the stress distribution of the joint while in-service welding is same as the normal welding,but numeric value is different,the calculated results can direct the in-service welding.