1,3-二甲基硫脲对冷轧钢在柠檬酸溶液中的缓蚀性能

Corrosion inhibition of 1,3-dimethylthiourea on cold rolled steel in citric acid solution

通过失重法、动电位极化曲线、电化学阻抗谱(EIS)、扫描电子显微镜(SEM)和接触角测试研究了1,3-二甲基硫脲(DMTU)在1.0 mol·L^(-1)柠檬酸(H_(3)C_(6)H_(5)O_(7))溶液中对冷轧钢(CRS)的缓蚀性能。实验数据表明,在40℃时,DMTU的最大缓蚀率高达94.74%,且随温度的升高亦能保持优良的缓蚀性能。DMTU在CRS表面的吸附符合Langmuir吸附等温式。DMTU属于以阴极抑制为主的混合型缓蚀剂,添加DMTU后电荷转移电阻显著增大,缓蚀作用增强。且通过SEM与接触角对CRS进行表面分析,加入DMTU缓蚀后,粗糙程度明显减小和接触角增大,DMTU能够有效吸附在CRS表面,达到缓蚀效果。

The corrosion inhibition of 1,3-dimethylthiourea(DMTU)on cold rolled steel(CRS)in 1.O mol·L^(-1)citric acid(H_(3)C_(6)H_(5)O_(7))solution was studied by weight loss method,potentiodynamic polarization curves,electrochemical impedance spectroscopy(EIS),scanning electron microscopy(SEM)and contact angle measurements.The experimental data show that the maximum inhibition efficiency of DMTU is as high as 94.74%at 40℃,and the DMTU can maintain the excellent inhibition performance even with the increase of temperature.The adsorption of DMTU on CRS surface conforms to Langmuir adsorption isotherm.DMTU is a hybrid inhibitor,but mainly retards the cathodic reaction.The charge transfer resistance increases significantly,and the inhibition effect is enhanced after DMTU is added.The surface of CRS is analyzed by scanning electron microscopy(SEM)and contact measurements.After DMTU corrosion inhibition was added,the roughness is decreased significantly,while the contact angle increased.