管道在役焊接接头残余应力的研究

Study on Residual Stress of In-service Welding onto Pipeline Steel

采用SYSWELD焊接模拟软件对X70级管道在役焊接接头应力进行模拟,并将在役焊接残余应力与常规焊接进行对比。结果表明:在役焊接接头残余应力分布规律与常规焊接保持一致,符合管道焊接接头"内凸外凹"的变形机理,但在数值上差别较大。近缝区在役焊接残余应力大于常规焊接,随远离焊接中心,在役焊接应力曲线转变速度较快,且在役焊接和常规焊接环向残余应力拉压应力转变位置不同。

Basing on SYSWELD software,stress of in-service welding joint of X70 pipeline steel has been simulated,and residual stress of in-service was compared with routine welding.Results show that distribution regularity of residual stress of in-service keeps coherent with routine welding,which measures up deformation mechanism of welding,but numeric value is different.Residual stress of in-service welding is larger than routine welding near the joint zone,as far away from weld center line,stress curve of in-service welding changes faster,as well as transition position of hoop tensile compressive stress is different.