炼化装置奥氏体不锈钢连多硫酸应力腐蚀开裂分析

ON STRESS CORROSION CRACKING OF AUSTENITIC STAINLESS STEEL WITH POLYSULPHURIC ACID IN REFINING AND CHEMICAL UNITS

奥氏体不锈钢的连多硫酸应力腐蚀开裂是炼化装置停工检修期间经常遇到的一种腐蚀失效类型。近年来随着炼化装置不断进行材质升级,奥氏体不锈钢的应用越来越广泛,奥氏体不锈钢发生连多硫酸应力腐蚀开裂的失效案例也越发多见。文章总结分析了连多硫酸应力腐蚀开裂的发生条件、腐蚀特征、发展过程及影响因素,探讨了炼化装置应对连多硫酸应力腐蚀开裂的可行防护措施,并对连多硫酸应力腐蚀开裂相关研究尚无确定结论的几个问题进行了分析阐述。

Stress corrosion cracking(SCC)of austenitic stainless steel is a kind of corrosion failure frequently occurring during shutdown and maintenance of refining and chemical units.In recent years,with the continuous material upgrading of refining and chemical units,austenitic stainless steel is increasingly applied and the failure cases of stress corrosion cracking of austenitic stainless steel are more and more common.This paper summarized and analyzed the occurrence conditions,corrosion characteristics,development process and influencing factors of stress corrosion cracking of polysulphuric acid.It discussed the feasible protective measures against stress corrosion cracking of polysulphuric acid in refining and chemical units.The paper also analyzed and expounded several problems related to stress corrosion cracking of polysulphuric acid.