目的 探究电气化铁路动态直流干扰和硫酸盐还原菌(SRB)及其协同作用对X80钢腐蚀行为的影响。方法 通过构建动态杂散电流室内模拟试验装置，对浸泡在灭菌和接菌(SRB)NS4溶液中的X80钢施加周期性阴极保护和方形脉冲动态杂散电流干扰。采用MPN计数法和活/死细胞染色方法分析了X80钢表面SRB的数量和活性，通过SEM、EDS、XPS和CLSM等表面分析技术，结合失重测试对灭菌和接菌环境下X80钢的腐蚀产物、腐蚀速率及腐蚀后形貌进行了表征。结果 动态直流干扰对溶液中SRB的生长未产生明显影响，但对SRB及生物膜在试样表面的附着产生较大影响。阴极保护会抑制SRB在X80钢表面的附着，通过抑制SRB的呼吸作用降低金属表面SRB活性，从而降低X80钢的微生物腐蚀。阳极干扰电流促进SRB在X80钢表面的附着，金属表面生物膜内的SRB活性增强。X80钢在灭菌环境下–400、0、500 mV试样的腐蚀速率分别为0.086 35、0.219 2、0.458 3 mm/a，分别为自然腐蚀速率的0.97、2.46、5.15倍。接菌环境下X80钢的腐蚀速率反而下降，但X80钢表面的最大点蚀坑深度明显增大。结论 在动态直流干扰下，X80钢的腐蚀速率大幅增加，单次短时直流干扰的累积对X80钢产生了十分严重的破坏。同时动态直流干扰通过促进X80钢表面SRB的活性，从而加速其微生物腐蚀，SRB生物膜在一定程度上减缓了X80钢的动态直流干扰腐蚀，但其与动态直流干扰共同作用加剧了X80钢表面的点蚀。

In order to explore the influence of dynamic DC interference and sulfate reducing bacteria (SRB) and their synergistic effect on the corrosion behavior of X80 steel in electrified railway, the dynamic stray current was applied to X80 steel soaked in SRB by building the indoor simulation experimental device of dynamic stray current. MPN counting method, living / dead cell staining, SEM, EDS, XPS, CLSM and other surface analysis techniques were used to study the effect of dynamic DC interference on the physiological activity of SRB and the corrosion behavior of X80 steel under the combined action of dynamic DC interference and SRB. The results show that the dynamic DC interference has no obvious effect on the growth of SRB in solution. But it has a great influence on the adhesion of SRB and biofilm on the surface of X80 steel. Cathode protection inhibit the adhesion of SRB on the surface of X80 steel and reduce the SRB activity on the metal surface by inhibiting the respiration of SRB, so as to reduce the microbial corrosion of X80 steel. The anodic interference current promote the adhesion of SRB on the surface of X80 steel, and enhance the SRB activity in the biofilm on the metal surface. The corrosion rates of ?400 mV, 0 mV and 500 mV samples of X80 steel in sterilized environment are 0.086 35 mm/a, 0.219 2 mm/a and 0.458 3 mm/a respectively, which are 0.97, 2.46 and 5.15 times of natural corrosion rates. Under dynamic DC interference, the corrosion rate of X80 steel increases greatly. Although the single DC stray current interference time is short, but it has a very serious damage to X80 steel with the accumulation of time. The biofilm formed by SRB can slow down the dynamic DC stray current corrosion of X80 steel to a certain extent, but the combined action of SRB and dynamic DC aggravates the pitting corrosion on the surface of X80 steel.