2-巯基嘧啶对冷轧钢在柠檬酸中的缓蚀性能

Corrosion Inhibition of 2-mercaptopyrimidine for Cold Rolled Steel in Citric Acid Solution

采用失重法、动电位极化曲线和电化学阻抗谱(EIS)研究了2-巯基嘧啶(MP)对冷轧钢在0.2 mol/L柠檬酸(H_3C_6H_5O_7)溶液中的缓蚀性能。结果表明,MP具有优良的缓蚀作用,缓蚀率随缓蚀剂浓度及温度的升高而增大。MP在钢表面的吸附符合Langmuir吸附等温式,且为伴随熵增加的吸热过程。MP的电化学作用机理为"几何覆盖效应"的混合抑制型缓蚀剂,EIS谱呈单时间常数的弥散容抗弧,电荷转移电阻随MP浓度的增加而增大。

The inhibition of 2-mercaptopyrimidine（MP） on the corrosion of cold rolled steel in 0.2 mol/L citric acid（H3C6H5O7） was studied by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy（EIS） methods. The results show that MP acts as a good inhibitor, and the inhibition efficiency increases with the increase of inhibitor concentration and temperature. The adsorption of MP on the steel surface follows Langmuir isotherm, and is an endothermic process accompanied with the increase of entropy. MP acts as a mixed-type inhibitor, and the inhibition effect may be ascribed to geometry blocking-effect. EIS spectra exhibits the depressed capacitive loop with only one time constant, and the charge transfer resistance increases with the concentration of MP.