奥氏体不锈钢换热器应力腐蚀开裂的失效分析

Failure Analysis of Stress Corrosion Cracking of Austenitic Stainless Steel Heat Exchanger

某化工企业于2018年9月投用了一台硫化氢水冷换热器,正常使用半年后,至2019年3月车间检修时,将换热器外隔热层打开并观察其使用情况,发现壳程外部法兰焊缝处存在明显裂纹。检验人员遂对该裂纹产生原因进行了一系列的研究分析,最终确定该裂纹为奥氏体不锈钢氯化物应力腐蚀开裂所致,并针对此种情况提出了相应的防护意见,避免了类似损伤模式的再次发生。

A hydrogen sulfide water-cooled heat exchanger was put into operation in a chemical enterprise in September 2018.After six months of normal use,the heat exchanger outer insulation layer was opened and observed during the workshop maintenance in March 2019.It was found that there were visible cracks in the outer flange weld of shell side.The inspectors then carried out a series of research and analysis on the causes of the crack,and finally determined that the crack was caused by stress corrosion cracking of austenitic stainless steel chloride.In view of this situation,corresponding protective suggestions were put forward to avoid the recurrence of similar damage modes.