饱和H2S／CO2溶液中Cl-对2Crl3钢腐蚀行为的影响

摘要

采用失重法和电化学方法研究了饱和H2S／CO2溶液中Cl对2Crl3钢腐蚀行为的作用，并用SEM、EDS和XRD对钢上的腐蚀产物的形貌、组成与成分进行了分析。结果表明，随着Cl-含量的增加，2Crl3钢在饱和H2S／CO2溶液中的腐蚀失重速率也增加，且在Cl-含量为20g／L时达到最大值。在2Crl3钢上所形成的腐蚀产物以四方硫铁矿型FeS为主，并有少量的Fe1-xS。2Crl3钢活性溶解的腐蚀电化学过程主要受阴极扩散过程控制，而Cl-的存在不改变2Crl3钢腐蚀的活性溶解状态以及电化学反应历程与机制，仅影响了其腐蚀倾向和速率大小。%The influence of Cl- on corrosion behavior of 2Crl3 steel in H2 S/CO2 saturated solutions was investigated by weight loss method and electrochemical measurement technology. Morphology, elements and composition of corrosion products on the surface of 2Crl3 steel specimens were analyzed by means of SEM, EDS and XRD. The results showed that the increase of CI- content aggravated the corrosion rate of 2Crl3 steel in H2S/COz saturated solutions, which would reach the maximum value at concentration of Cl- 20 g/L. Corrosion products of 2Crl3 steel specimens consisted mainly of quartet pyrite FeS and a small amount of Fel xS. The electrochemical process of 2Crl3 steel active dissolution corrosion was controlled by cathode diffusion process. The existence of Cl- in H2 S/CO2 saturated solutions did not change the active dissolution situation of 2Crl3 steel corrosion and the electrochemical reaction mechanism, only could have an impact on the corrosion tendency and the value of corrosion rate.