SRB对X100钢在鹰潭土壤模拟溶液中腐蚀行为的影响

Effect of SRB on Corrosion Behavior of X100 Steel in Simulated Solution of Yingtan Soil

采用失重法、线性极化曲线和阻抗谱电化学技术,结合扫描电子显微镜和能谱分析仪研究了X100钢在有/无SRB的鹰潭土壤模拟溶液中的腐蚀行为。结果表明:X100钢在无菌与有菌时的腐蚀速率随时间延长均为:减小→增大→减小,腐蚀速率有菌时小于无菌,SRB的存在减缓了X100钢的腐蚀;腐蚀速率的控制主要由腐蚀产物膜的均匀性与致密性决定,无菌介质中,腐蚀产物膜不致密、不均匀,保护性较差,在有菌介质中,钢表面形成致密均匀的结合膜,致密的膜对传质有一定的阻碍作用,从而减轻了X100钢的腐蚀;无菌时腐蚀产物主要为Fe2O3,Fe3O4,α-FeO(OH),有菌时腐蚀产物为Fe3O4,FeS。

The corrosion behavior of X100 steel was studied in simulated solution of Yingtan soil with and without sulfate-reducing bacteria （SRB） by means of mass-loss measurement,linear polarization curves and electrochemical impedance spectroscopy （EIS） techniques,combined with scanning electron microscopy（SEM） and spectroscopy analyzer（EDS）.The results show that the corrosion rate with and without SRB with time is：decrease→increase→decrease,the corrosion rate with SRB is less than without SRB,SRB inhibit the corrosion of X100 steel;Corrosion rate is controlled by uniformity and compactness of corrosion product films,Corrosion product film is loose,uneven and less protective in the solution without SRB.In the solution with SRB,however,a compact and homogeneous bonding film is formed on the steel surface,which could suppress the mass transfer so that to mitigate the steel corrosion.Corrosion products are Fe2O3,Fe3O4 and α-FeO（OH） in the solution without SRB,while corrosion products are Fe3 O4 and FeS in the solution with SRB.