Reasons Analysis on Leakage of TU2 Copper Tubes

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.