摘要
某核电厂SEC系统不锈钢仪表管在服役近2年后发生了穿孔泄漏。针对异常泄漏的不锈钢仪表管,通过对管道内外部宏/微观检查、金相检验、硬度检测、点蚀浸泡试验等试验分析,以确定该不锈钢仪表管的失效性质及原因。结果表明,SEC不锈钢仪表管泄漏是由于插套焊间隙内发生点蚀穿孔所致,其主要原因由于插套焊间隙易导致海水滞留和氯离子富集,为点蚀的发生、发展提供了有利的环境条件;且泄漏管件材料中因成分或组织等因素造成其耐点蚀性能有所下降。
Corrosion perforation was occurred in the stainless steel tube of SEC system after 2 years of service in a nuclear power plant. The failure analysis of the stainless steel tube was made by macroexamination, chemical composition analysis, metallographic test,hardness test, pitting corrosion test, etc.The results showed that the leakage of SEC stainless steel tube was due to the pitting perforation in the gap. The main reason was that the gap was easy to lead to the accumulation of water and chloride ion, which provides favorable environmental conditions for the occurrence and development of pitting corrosion. And the corrosion resistance of the material of the leakage pipe was decreased due tothe effect of composition and microstructure.
出处
《全面腐蚀控制》
2016年第1期53-56,共4页
Total Corrosion Control
关键词
SEC系统
不锈钢管
泄漏
点蚀
SEC system
stainless steel pipe
leakage
pitting corrosion
