某69111半奥氏体不锈钢高压气瓶点火时发生漏气，从钢瓶宏观形貌、化学成分、显微组织、硬度等方面分析了气瓶失效的原因。结果表明: 失效不是材料质量问题造成的；气瓶开裂部位断口平整，无明显塑性变形，气瓶外表面的腐蚀物及断面可检出大量氯元素，说明气瓶开裂为应力腐蚀开裂。

A high pressure vessel made of 69111 semi austenitic stainless steel leaked at the time of ignition. The failure reasons for the steel vessel were analyzed through macro morphology, chemical composition, microstructure and hardness. The results show that the failure was not caused by the quality of material. The fracture in the position of cracking was smooth, and there was no obvious plastic deformation. A lot of chlorine was found in the outside corrosion product and on the fracture of the steel vessel. Above phenomena illustrate that the failure reasons for the steel vessel was because of stress corrosion cracking.