摘要
目的研究超级13Cr钢在高CO_2分压条件下的腐蚀行为并评价其耐腐蚀能力,为存在类似工况的气田选材提供参考。方法模拟东方气田腐蚀环境(141℃,CO_2分压27.9 MPa),通过高温高压腐蚀挂片实验和电化学实验对超级13Cr开展腐蚀行为研究。结果在东方气田高CO_2分压腐蚀环境下,挂片腐蚀试验表明,超级13Cr的腐蚀形式为全面腐蚀,其均匀腐蚀速率为3×10-3 mm/a;电化学分析表明,13Cr不锈钢的自腐蚀电位(-0.785 V)和点蚀电位(-0.301 V)较超级13Cr不锈钢的(-0.580 V,-0.139V)有明显负移,而自腐蚀电流密度和维钝电流密度明显更大。结论高CO_2分压条件下,超级13Cr可满足气田油套管使用要求,超级13Cr不锈钢的耐蚀性能和抗点蚀敏感性均强于13Cr不锈钢。
Objective To analyze the corrosion behavior of super 13Cr and evaluate its anti-corrosion ability in high CO2 level condition. The result can support material selection work for similar gas fields. Methods High temperature/pressure corro- sion coupon test and electrochemical test were conducted in simulated Dong Fang gas field high CO2 level environment （141 ℃, CO2 27.9 MPa）. Results The corrosion coupon test result indicated that the corrosion type of super 13Cr was general corrosion with a corrosion rate of 3x10-3 mnVa. The electrochemical test showed that the corrosion potential and pitting potential of 13Cr （-0.785 V, -0.301 V） had an obvious negative shift compared to super 13Cr （-0.580 V, -0.139 V）. The corrosion current density and passivation current density of 13Cr were obviously higher than super 13Cr. Conclusion Super 13Cr could be applied to high CO2 level environment as tubing or casing. Super 13Cr was better than 13Cr in anti-corrosion and anti-pitting properties.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2016年第5期72-78,共7页
Surface Technology
关键词
高CO2分压
超级13Cr
油套管
东方气田
腐蚀行为
high CO2 partial pressure
super 13Cr
tubing and casing
Dong Fang gas field
corrosion behavior
