基于点蚀的316L不锈钢在酸性气田环境中的适应性评价  

Adaptability Evaluation of 316L Stainless Steel Based on Pitting Corrosion in Acid Gas Field

作　　者：鲍明昱 任呈强[1] 郑云萍[2] 杜磊 鲜宁 姜放 郭小阳[2] BAO Mingyu REN Chengqiang ZHENG Yunping DU Lei XIAN Ning JIANG Fang GUO Xiaoyang(School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500 State Key Laboratory of Oil ＆ Gas Reservoir Geology and Exploration, Southwest Petroleum University, Chengdu 610500 China Petroleum Engineering Co. , Ltd. Southwest Company, Chengdu 610041)

机构地区：[1]西南石油大学材料科学与工程学院,成都610500 [2]西南石油大学油气藏地质及开发工程国家重点实验室,成都610500 [3]中国石油集团工程设计有限责任公司西南分公司,成都610041

出　　处：《材料导报》2016年第17期10-15,35,共7页Materials Reports

基　　金：国家自然科学基金(51374180)

摘　　要：国内外酸性气田的开发使腐蚀环境越来越苛刻,为满足气液混输的工艺要求,发展了耐蚀合金/碳钢的双金属复合管技术。316L不锈钢被广泛用于双金属管的内衬,在含H_2S和CO_2环境中腐蚀速率很低,然而在高含Cl-的溶液中,316L不锈钢容易出现点蚀而诱发集输管线失效,为此,就316L不锈钢在酸性气田集输环境中的点蚀进行评述。讨论了影响316L不锈钢点蚀的材质因素,Mn和Fe的硫化物及Mg、Al、Ca的氧化物等两种夹杂物均能促进钝化膜的溶解而引起点蚀;分析了316L不锈钢点蚀的H_2S、CO_2、温度、Cl-浓度和pH值等环境的适应性条件,发现H_2S环境比CO_2环境更容易发生点蚀,H_2S和CO_2对点蚀发生存在协同机制,温度升高、Cl-浓度增加和酸性介质均会增加316L不锈钢点蚀的敏感性。为进一步优化选材原则,需重点加强环境因素的协同机制、环境适应性的边界条件、点蚀发展的动力学以及新的标准研究。The corrosion conditions become more and more severe due to the rapid development of acid gas field.In order to meet the requirements of gas-liquid mixed transportation technology,bimetal-lined pipe composed of anti-corrosion alloy and carbon steel has been manufactured.316 Lstainless steel has been widely used for the liner of the bimetal-lined pipe because of the low corrosion rate in the H2S and CO2 environments.However,316 Lstainless steel has potential failure risk,which is attributed to the pitting corrosion in the solution containing Cl-.Therefore,the pitting corrosion of 316 Lstainless steel in acid gas field is commented.The material factors affecting the pitting corrosion of 316 Lstainless steel are discussed.Both the sulfide of manganese,iron and the oxide of magnesium,aluminum,calcium can promote the local dissolution of the passive film and further cause pitting corrosion.The environmental adaptability conditions of pitting corrosion to 316 Lstainless steel are analyzed including H2S,CO2,temperature,Cl-concentration and pH value.It is discovered that pitting corrosion is more likely to occur in H2S environment,rather than in CO2 environment.And there is a synergistic effect for pitting corrosion between H2S and CO2.In addition,the pitting sensitivity of 316 Lstainless steel increases by rising temperature,increasing chloride concentration and acid medium.The interrelationship mechanism of environmental factors,the boundary conditions of environmental adaptability,the kinetics of the development stage of pitting corrosion and the new standards of experiment and engineering should be strengthened in the future.

关 键 词：316L不锈钢 气液混输 点蚀 双金属复合管 边界条件 

分 类 号：TG172[金属学及工艺—金属表面处理] TE832[金属学及工艺—金属学]