摘要
某天然气管线材料为304不锈钢,使用中发现其距焊缝约5 mm处发生腐蚀和泄漏。对发生泄漏的管线进行了宏观检验、化学成分析和金相检验。结果表明:泄漏管线的化学成分不合格,即含碳量偏高而铬和镍的含量偏低,焊缝热影响区析出了Cr_(23)C_(6)碳化物,因而发生了应力腐蚀和晶间腐蚀,导致其开裂而泄漏。
A natural gas pipe-line,which made of 304 stainless steel,exhibited corrosion and leakage at about 5 mm from the weld in service.The failed pip-line was tested for macroscopic appearance,chemical composition and microstructure.The results indicated that pipe-line exhibiting leakage contained unqualified chemical composition,that is,higher carbon and lower chromium and nickel relative to the standard values,and that Cr_(23)C_(6)carbides were precipitated in the heat affected zone of weld and,therefore,stress corrosion and intergranular corrosion occurred,resulting in its leakage due to cracking.
作者
郭海霞
蔡海琛
吴凤烨
张聪毅
GUO Haixia;CAI Haichen;WU Fengye;ZHANG Congyi(Luoyang Ship Material Research Institute,Luoyang 471023,Henan China)
出处
《热处理》
CAS
2022年第3期57-60,共4页
Heat Treatment
关键词
天然气管线
304不锈钢
腐蚀
natural gas pipeline
304 stainless steel
corrosion
