高硫高酸值原油温度对1Cr5Mo钢耐蚀性能的影响

Effect of high sulfur and high acid value crude oil temperature on corrosion resistance of 1Cr5Mo steel

采用高温高压釜实验研究了高硫高酸值原油温度对1Cr5Mo钢腐蚀速率的影响。利用扫描电镜和能谱技术观察并测试了腐蚀产物膜的微观形貌和产物膜的化学组成。利用电化学测试方法测试了带膜试样腐蚀电化学行为。结果表明,原油温度低于473 K时,1Cr5Mo钢主要腐蚀机理为环烷酸腐蚀,腐蚀速率增加缓慢;原油温度高于473 K时,1Cr5Mo钢主要腐蚀机理为环烷酸腐蚀、硫腐蚀,腐蚀速率迅速增加。当原油温度不大于513 K时,随原油温度增加,腐蚀产物膜渐趋完整,1Cr5Mo钢自腐蚀电流密度不断下降;当原油温度达到553 K时,产物膜变成疏松絮状结构,自腐蚀电流显著增加。

Effect of high sulfur and high acid value crude oil temperature on corrosion rate of 1 Cr5 Mo steel was studied by high temperature and pressure autoclave. The microstructure of corrosion product and chemical composition of corrosion film were measured and analyzed by scanning electron microscopy （SEM） , energy dispersive spectrometer （EDS）. The corrosive electrochemical behaviour was examined by electrochemical method. The results show that the 1 Cr5Mo steel is corroded by naphthenic acid when crude oil temperature is lower than 473 K, and the cossion rate increases slowly with increasing temperature. The 1Cr5Mo steel is corroded by naphthenic acid and active sulfur with a rapid increase in corrosion rate when crude oil temperature is higher than 473 K. When the oil temperature is higher than 513 K, the whole corrosion film is formed, the self-corrosion current density of the 1Cr5 Mo decreases. However, when the oil temperature is 553 K, the product film becomes loose and flocculent structure, and self-corrosion current density increases remarkably.