某公司生产的厨房用角阀在安装使用约4个月后，部分发生开裂。通过断口宏微观分析、化学成分分析、硬度测试、金相检验、氨熏试验等手段，对角阀开裂的原因进行了分析。结果表明：角阀失效属于应力腐蚀开裂，角阀装配应力过大是导致其发生应力腐蚀开裂的主要原因。

Some brass angular valves used for kitchens produced by a factory cracked after use for about 4 months. Means, such as macroscopic and microscopic fracture analysis, chemical composition analysis, hardness testing, metallographic inspection, and ammonia test, were used to investigate cracking reasons of the brass angular valves. The results show that:the failure of angular valves resulted from the stress corrosion; the stress corrosion cracking was mainly caused by too big assembling stress of angular valves.