新型含铝奥氏体不锈钢在含硫化氢环境中的腐蚀行为

Corrosion behavior of a new alumina-forming austenitic stainless steel in environments containing hydrogen sulfide

奥氏体不锈钢由于具有优异的抗氯化物点蚀和应力腐蚀性能,成为油气田环境中最常用的结构材料之一。然而,关于奥氏体不锈钢在Cl--H_(2)S共同存在的腐蚀环境下的腐蚀行为的相关研究还不充分,特别是有关Al、Mo等合金化元素对钝化保护膜的形成行为及耐蚀性能的影响规律尚不清楚。因此,结合奥氏体不锈钢在复杂油气田环境下的应用前景,研究选用创新设计的新型含铝奥氏体不锈钢,通过电化学方法对其在Cl--H_(2)S耦合环境条件下的的耐腐蚀性能展开全面评估,采用XPS、SEM、TEM等显微分析手段观察其腐蚀行为,揭示其耐腐蚀机制和耦合腐蚀介质作用规律。结果表明,新型含铝奥氏体不锈钢尽管在复杂腐蚀条件下未能形成富Al的钝化保护膜层,但由于适量Mo的加入,明显提高了抗点蚀性能,因此具有良好的耐H_(2)S腐蚀性能。

As one of the most commonly used structural material in petroleum mining industrials,austenitic stainless steels exhibit excellent resistance to chloride pitting corrosion and stress corrosion in complex oil and gas combining environments.However,the current research on the environments which Cl--H_(2)S coexists is relatively inadequate.In addition,the effects of Al and Mo alloying elements on the formation of passivation protective film and corrosion resistance mechanism are still unclear.Therefore,in attempt to promote the application of austenitic stainless steels,the corrosion performance of a new designed alumina-forming austenitic stainless steel in Cl-and H_(2)S environments was evaluated by electrochemical tests.Furthermore,the corrosion behavior of the steel was observed by means of XPS,SEM and TEM,and the corrosion resistance mechanism and the interaction regulations in H_(2)S containing environments were revealed.The results show that due to the addition of an appropriate amount of Mo,the pitting corrosion resistance of the alumina-forming austenitic stainless steel without forming of an Al-rich passivation film was improved,resulting in good resistance to hydrogen sulfide corrosion.