含水量对X70钢在大港滨海盐渍土壤中腐蚀行为的影响

采用极化曲线、电化学交流阻抗等技术对X70钢在含水量20%～34%(质量分数)的大港滨海盐渍土中的腐蚀行为进行研究.结果表明:土壤含水量对X70钢腐蚀行为影响显著;水质量分数为25%时X70钢发生局部腐蚀,水质量分数高于30%时发生均匀腐蚀;随着土壤中含水量的增加,腐蚀电流密度先增后减,在水质量分数为25%时腐蚀速率达到最大;含水量较低时,X70钢在大港滨海盐渍土中腐蚀的电化学阻抗谱会出现低频感抗弧,随着含水量的增加,低频感抗弧消失,表现为单一的容抗弧.

Influences of water content on the corrosion behavior of X70 steel in Dagang saline-alkaline soil

The corrosion behavior of X70 steel in Dagang saline-alkaline soil with 20%-34% water content was studied by polarization curve measurement and electrochemical impedance spectroscopy(EIS).It is shown that the corrosion behavior of X70 steel is strongly dependent on the water content in soil.Local corrosion occurred at the water content of 25%,and general corrosion took place when the water content was more than 30%.With increasing water content,the corrosion current density increased to a maximum at the water content of 25% and then decreased.The low-frequency inductance loop emerged at the water content of 20%.It disappeared with increasing water content and a single capacitive impedance loop was observed.