某公司在检漏工序中发现其生产的空调制冷用TU2铜管存在泄漏现象, 泄漏比例约为20%, 泄漏位置随机分布。采用断口分析、金相检验及氧含量测定等方法, 对TU2铜管的泄漏原因进行了分析。结果表明: 由于泄漏铜管中存在颗粒状沿晶分布的(α＋Cu2O)共晶体, 在高温长时间H2保护的焊接环境中产生氢脆, 形成沿晶微裂纹, 继而在试压过程的压力作用下发生泄漏。

Leakage was found for air conditioner refrigeration TU2 copper tubes produced by a company during leakage detection process. The ratio of leakage was up to 20% and the leakage locations distributed in random. Means such as fracture analysis, metallographic examination and oxygen content determination were used to analyze leakage reasons of the TU2 copper tubes. The results show that there was (α＋Cu2O) eutectic distributing along the grain boundary of the leakage tubes, which caused hydrogen embrittlement with forming micro-cracks along the grain boundary in high temperature H2 atmosphere. So leakage occurred to the TU2 copper tubes under pressure of the leakage detection process.