对X60管线钢在硫酸盐还原菌(SRB)和CO2共存环境中进行浸泡实验,对浸泡不同时间后的腐蚀形态及膜层的组成进行观察和分析,并对膜层覆盖的X60钢的腐蚀电化学参数特征进行分析.结果表明,SRB吸附形成的微生物膜覆盖程度加大导致X60钢电位正移,腐蚀产物FeS和FeCO3含量增加导致X60钢电位负移.X60钢表面膜层中腐蚀产物含量较低时,仅有一个与电极电位有关的时间常数,当膜层中腐蚀产物的含量高时,增加了与腐蚀产物膜有关的时间常数.在浸泡初期,随微生物膜覆盖程度增加,X60钢的电荷传递电阻增大;随腐蚀产物含量增加,电荷传递电阻先下降后增大.随浸泡时间的延长,X60钢双电层电容和膜层电容均增大.
The corrosion morphology, the corrosion film composition, and corrosion electrochemical characteristics of X60 steel soaking in CO2 and sulfate reducing bacteria (SRB) coexistence environment for different times were investigated respectively. Results showed that the potential of X60 steel increased with the increase of biofilm covering extent, and then decreased with the increase of the content of corrosion product FeS and FeCO3. According to the analytical results of EIS, only a time constant related to electrode potential existed when the content of corrosion product in the film forming on the surface of X60 steel was low, and then an additional time constant related to the corrosion film appeared with the increase of the content of corrosion product in the film. The transferring resistance increased with the increase of the covering extend of biofilm ir, the early soaking stage. And then the transferring resistance first decreased, and then increased with the increase of the content of corrosion product. With the increase of soaking time, both electrical double-layer capacitance and film capacitance increased.