奥氏体不锈钢外表面氯离子应力腐蚀开裂与防治

Chloride Ion Stress Corrosion Cracking and Prevention on the Outer Surface of Austenitic Stainless Steel

某化工厂树脂加氢装置反应器的出口承压TP321不锈钢管道发生泄漏事故,通过宏观检验、扫描电镜分析、能谱分析及金相检验等检测手段结合现场调研,对失效管道的失效部位渗漏的原因进行了综合分析,得出管道泄漏原因是不锈钢管道在外保温棉中氯离子在液态水和空气环境中发生应力腐蚀。最后,通过制定有效隔离措施,使不锈钢管道其他类似部位安全隐患在运行状态下大大减少。

A leakage accident occurred in the outlet pressure TP321 stainless steel pipe of the resin hydrogenation unit reactor in a chemical plant.Through the means of macroscopic inspection,scanning electron microscope analysis,energy spectroscopy analysis and metallographic examination combined with field investigation,the causes of leakage in the failed parts of the failed pipe were comprehensively analyzed.It is concluded that the leakage of stainless steel pipe is caused by stress corrosion of chloride ions in the outer insulation cotton in liquid water and air.Finally,through the development of effective isolation measures,other similar parts of the stainless steel pipeline safety hazards are greatly reduced under operating conditions.