焊接残余应力对20G管道焊接接头组织性能的影响

Effect of welding residual stress on microstructure and properties of 20G pipe welded joints

通过X射线衍射法研究管线用20G焊接残余应力的分布和焊后热处理对焊缝残余应力的影响,择优选取了焊后热处理条件。结果发现,在焊缝区存在较高的焊接残余应力。焊后热处理可以显著降低焊接残余应力,其中以620℃加热温度、1 h保温时间的处理工艺为宜。此外,热处理细化了焊缝区域晶粒,降低了焊缝区域硬度,改善了焊接接头抗H2S腐蚀的能力。

Distribution of residual welding stress and effect of post-weld heat treatment on residual welding stress relaxation in 20G pipelines welded joints was studied by X-ray diffraction method and the post-weld heat treatment conditions was selected.The result showed that there is a high weld residual stresses in welding zone.Post weld heat treatment can significantly reduce residual stresses.the process which the heating temperature is 620 ℃,holding time is 1 h is better.In addition,the heat treatment refines the grain of the weld zone,reduces the hardness of the weld region in order to improve the ability of welded joints anti-H2S corrosion.