焊接钛管焊缝开裂原因分析

Cause Analysis on Weld Cracking of the Welded Titanium Pipes

某焊接钛管在冷轧时于焊缝处开裂,通过化学成分分析、金相检验、断口形貌分析以及能谱分析等方法对其开裂原因进行了分析。结果表明:由于钛管在焊接时存在不规范操作,使得钛管焊缝处混入杂质元素,并与空气中的氧元素发生反应生成氧化物或碳氧化合物;这些化合物成为焊缝中的大颗粒夹杂物,从而导致钛管焊缝在冷轧时局部区域发生开裂。

The welded titanium pipe cracked when cold-rolling, and means of chemical compositions analysis, microstructure analysis, fracture morphology observation and energy spectrum analysis were performed to analyze the cracking cause. The results show that the non-standard operations in the welding process made the impurity elements interfuse in the weld which reacted with the oxygen in the air and formed oxycarbide. These oxycarbide became large inclusions in the weld and resulted in local cracking of the welded titanium pipe when cold-rolling.