土壤中SRB及Cl-对1Cr18Ni9Ti不锈钢腐蚀的相互影响

利用交流阻抗测试技术、扫描电镜及表面能谱、失重法、微生物分析等方法 ,研究了在不同Cl-含量的土壤中 ,硫酸盐还原菌对 1Cr18Ni9Ti不锈钢腐蚀的影响规律 .13 6d的试验结果表明 ,不同Cl-含量土壤中SRB菌量在2 3 0 0 0～ 3 5 0 0 0 (个 /克土 )之间 ,Cl-的加入并没有显著影响SRB的生长 ,随着Cl-的加入土壤中SRB的菌量有增大的趋势 ;随着土壤中Cl-含量的增大 ,不锈钢腐蚀电位负偏移 ,而且在接菌土壤中的腐蚀电位比在灭菌土壤中负移幅度更大 ;不锈钢在灭菌土壤中没有发生点蚀现象 ,而在接菌土壤中发生了严重的点蚀 ,最大点蚀深度随着土壤中Cl-含量的增加而增大 ,这说明在土壤中SRB及Cl-的共同作用下 ,增大了不锈钢的点蚀敏感性 .不锈钢在灭菌土壤中的阻抗图谱表现为一个半径很大的容抗弧 ,而在接菌土壤中的阻抗图表现为两个时间常数的双容抗弧

EFFECTS OF SRB ON CORROSION OF 1Cr18Ni9Ti STAINLESS STEEL IN SOILS OF Cl-

The effects of sulfate reducing bacterial (SRB) on corrosion of 1Cr18Ni9Ti stainless steel in different Cl -content soils with and without SRB have been studied, Using bacterial analysis,weight loss,electrochemical impedance spectroscopy(EIS),scanning electron microscopy (SEM) and EDAX.The results showed that corrosion rate in different Cl - content soils with SRB are larger than those in soils without SRB.Corrosion pitting of 1Cr18Ni9Ti stainless steel occurred in soils with SRB,and corrosion pitting depth of 1Cr18Ni9Ti stainless steel increases with the increasing of Cl -content of soils with SRB.The results indicate that corrosion rate of 1Cr18Ni9Ti stainless steel increases in soils with SRB.For no pits of 1Cr18Ni9Ti in soils without SRB,the sluyters diagram of EIS are composed of single capacitive loops.For the pits propagation of 1Cr18Ni9Ti in soils with SRB,the sluyters diagram of EIS are composed of two capacitive loops.