超级13Cr油套管钢的点蚀行为研究

摘要

石油管材的点蚀穿孔是管材失效的主要原因,采用电化学测试和化学浸泡的方法,研究了超级13Cr油套管钢的点蚀行为,旨在为超级13Cr钢的研究开发提供依据.结果表明,Cl-和温度是影响超级13Cr钢点蚀发生的主要原因,材料的点蚀敏感性均随Cl-浓度和温度的升高而增加;电化学和化学浸泡两种方法测定的临界点蚀温度(CPT)分别为40.5℃和37.5℃,相差3℃.当温度低于CPT时,13Cr钢处于破钝和再钝化的平衡状态,材料表面形成少、小而浅的点蚀坑;当温度高于CPT时,13Cr钢表面则形成多、大而深的点蚀坑,点蚀全面发生.%The pitting corrosion is the main reason for the failure of petroleum tubular goods.In this article,by the electrochemical test and chemical immersion method,it studied the pitting corrosion behavior of super 13Cr casing and tubing steel to provide the basis for research and development.The results showed that Cl-and temperature are the main influence factors for pitting corrosion of super 13Cr,with Cl-concentration and temperature increasing,the pitting corrosion sensitivity increases.The critical pitting temperature is respectively 40.5 ℃ and 37.5 ℃,by the electrochemical test and chemical immersion method,the difference is 3 ℃.When the temperature is below the CPT,13Cr steel is in equilibrium state of breaking inactivation and repassivation,few,small and shallow pitting dents form on material surface; when the temperature is above CPT,many,big and deep dents appear,so the pitting entirely happen.