X65管线钢焊缝金属裂纹分析

Crack Analysis of Weld Metal in X65 Pipe Line Steel

X65管线钢在焊接过程中,内侧焊缝金属出现横向和纵向沿熔合线方向的裂纹,横向裂纹贯穿焊缝金属横截面。用扫描电镜分析断口,发现裂纹处的焊缝金属与母材有较严重的化学成分偏析,内侧焊缝金属的熔合线基本垂直于母材。分析结果表明:局部成分偏析、工艺参数不适宜是造成焊缝裂纹的主要原因。

The longitudinal cracks along bond line and the transverse cracks which cut across the weld metal cross section inside weld metal were formed, while X65 pipe line steel was welding. It was founded that the chemical compositions of the weld metal and base plate about the crack are very inhomogeneous and the bond lines inside weld metal are about perpendicular to the base plate, while the fault planes were analysed with scanning electron microscope. The results analysed show that the cracks in weld metal were created because of the inhomogeneous chemical compositions and unreasonable welding parameters.