湿硫化氢环境膨胀节开裂失效分析

Failure Analysis of Expansion Joint under Wet Hydrogen Sulfide Environment

通过对失效的321奥氏体不锈钢膨胀节的化学成分、力学性能、磁性、金相、断口形貌和能谱等分析,判断该膨胀节失效原因为湿硫化氢环境下的氢致开裂和应力导向氢致开裂。膨胀节材料在冷成型过程中,由于加工硬化产生了大量的形变马氏体是失效的根本因素。分析了该膨胀节的腐蚀环境因素、应力因素和材料因素,提出了预防和改进措施。

Based on the analysis of chemical composition, mechanical properties, magnetic properties, microstructure, fracture morphology and energy spectrum of the disabled 321 anstenite stainless steel expansion joint, the results show that the failure of the expansion joint is hydrogen induced cracking and stress oriented hydrogen induced cracking under wet hydrogen sulfide environment. A large number of deformed martensite produced by work hardening in the cold forming process of the expansion joint was the basic factor of failure. The factors of corrosion condition, stress and material were analyzed and the corresponding prevention and improvement measures were put forward.