某发动机在进行台架循环负荷试验过程中出现漏油现象,拆机检查后发现气缸盖上有裂纹.通过断口分析、金相检验及化学成分分析等方法对气缸盖开裂的原因进行了分析.结果表明：气缸盖为脆性开裂,根本原因是缸盖固溶处理温度过高产生了过烧.建议加强气缸盖固溶处理温度的控制,防止过烧产生,保证产品质量.

There was oil leaked from a engine during the bench cycle load test,the cracks were found on the cylinder head by disassembling examination.By means of fracture analysis,metallographic examination,chemical composition analysis and so on,the cracking reasons were analyzed.The results showed that the brittle cracking occurred in cylinder head caused by over-burning,because of the high solution treatment temperature.It was suggested that the solution treatment temperature should be controlled to prevent over-burning and ensure product quality.