摘要
新疆油田的火驱尾气中含有O_2、H_2S和CO_2三种腐蚀性气体。以35CrMo钢为实验材料,基于新疆油田火驱尾气的现场工况,设计正交实验条件;采用失重法测试35CrMo钢的腐蚀速率;结合SEM等手段对典型工况的腐蚀产物进行测试分析。结果表明:35CrMo钢在实验条件下发生均匀腐蚀,气质组成对腐蚀速率的影响最大,其次是温度和总压;产物形态以粒状为主,在含氧条件下有片状产物,较高温度和含氧条件下产物膜厚度较大,产物中有Fe、C、O、S四种元素,并含有Cr元素,既有Fe的硫化物,也有Fe和Cr的氧化物; O_2除了参与吸氧反应,还会氧化Fe^(2+)等,也会与H_2S发生交互作用生成单质S,与CO_2交互作用抑制FeCO_3生成。该研究结果为金属材料在O_2、H_2S和CO_2混合体系中的腐蚀机理和防护研究提供了理论基础。
The fire drive off-gas in Xinjiang oilfield contains three types of corrosive gases,namely O2,H2S and CO2.35CrMo steel is selected as experimental material.Orthogonal experiment is designed based on field working conditions and the corrosion rate is studied by weight loss method.Aimed at typical conditions,corrosion product films are studied by SEM and the like.The findings reveal that general corrosion occurs on the 35CrMo steel under experimental conditions and the composition of gases exerts the greatest impact on corrosion rate,followed by temperature and total pressure in turn.Corrosion product is mainly granular,mixed with platelet when O2 is contained.As partial pressure of O2 and temperature increasing,corrosion rate become much higher,product film becomes thicker.There are four elements of Fe,C,O,S in corrosion product mainly,Cr was detected as well.Corrosion product consisted of sulfide of Fe and oxide of Fe and Cr.The reason is that besides precipitating in oxygen absorption reaction,O2 also oxidizes some product such as Fe^2+.Moreover,O2 interacts with H2S,generating S,and with CO2,restraining formation of FeCO3.The findings provides research on corrosion mechanism and protection of metallic materials with theoretical basis under O2,H2S and CO2 mixed system.
出处
《天然气与石油》
2018年第6期92-98,共7页
Natural Gas and Oil
基金
国家自然科学基金"天然气集输管道弯头磨损腐蚀机理研究"(51474183)
