深冷温度下的纯铜管断裂失效分析

Fracture Failure Analysis of the Pure Copper Pipes Used for Cryogenic Purposes

纯铜是一种深冷温度下应用的优异结构材料，但在特定条件下产生了应力腐蚀开裂。分析认为，其原因是弯管加工和运行过程中产生了拉伸应力叠加，以及CH4＋C2H4液体馏份中微量腐蚀介质的联合作用。有效的防止措施是采用450～500℃退火处理以消除弯管过程中产生的残余拉应力。

Pure copper is a superior structural material for cryogenic purposes. But it has been found that in the case of special conditions, pure copper can also suffer stress corrosion cracking. The SCC may be due to the superimposition of tensile stresses that take place during bending operation and working process of pure copper pipes, and the faint corrosion environment in CH4+C2H4 liquid fraction.It is possible to remove the stresses in pure copper pipes by annealing at temperature of 450~ 500℃, so that the pure copper pipes will not tend towards stress corrosion cracking