某公司制氢装置集气管在服役过程中发生开裂。通过化学成分分析、金相检验、断口分析和应力计算等方法对集气管开裂的原因进行了分析。结果表明：集气管超温运行使富铬碳化物在晶界处析出，集气管组织敏化，且管壁所受应力远高于其许用应力，导致管壁优先在应力集中区域开裂，并表现为沿晶开裂。

The gas collecting tube of hydrogen production plant of a company cracked in service. The causes of cracking on gas collecting tube were analyzed by means of chemical composition analysis, metallographic examination, fracture analysis and stress calculation. The results show that the over temperature operation of gas collecting tube resulted in the precipitation of chromium rich carbides at the grain boundary and the sensitization of gas collecting tube tissue, and the stress on the wall of the tube was much higher than the allowable stress, which led to the cracking of the tube wall in the stress concentration area preferentially and presented intergranular cracking.