X60钢级HFW焊管焊缝冲击韧性异常原因分析

摘要

通过对某X60钢级HFW焊管进行拉伸试验、压扁试验及-20℃低温冲击试验，发现该焊管焊缝的冲击韧性异常低。采用金相显微分析、扫描电镜分析及能谱分析法对焊缝冲击韧性异常的原因进行了分析。结果表明，焊缝源区存在大量的灰斑，是造成焊缝冲击韧性较低的主要原因，母材组织中存在一定的带状组织也会降低焊缝的冲击韧性，另外，如果焊后热处理工艺不当，就不能起到改善焊缝冲击韧性的作用。%The tensile test, flattening test and -20 ℃ low temperature Charpy impact test on one X60 HFW pipe weld were carried out. It found that the impact toughness abnormal low. The cause of the low impact toughness was analyzed by the metallographic analysis, SEM and energy spectrum analysis. The results showed that, the existence of a large number of gray spot in weld source area is the main cause of low impact toughness, and the banded structure of base metal also can reduce the impact toughness of weld. In addition, improper heat treatment after welding will not improve weld impact toughness.