常温低浓度乙酸中硫脲对冷轧钢的缓蚀作用

Corrosion Inhibition of Thiourea on Cold Rolled Steel in Low Concentration Acetic Acid Solution at Normal Temperature

采用极化曲线法及电化学阻抗谱法研究了在30℃、0.05mol/L乙酸(HAc)溶液中硫脲(TU)对冷轧钢的缓蚀作用。结果表明,在常温低浓度乙酸溶液中TU对冷轧钢具有较好的缓蚀效果,且缓蚀率随着TU浓度(5～30mg/L)的升高而增大,但TU浓度高于30mg/L时缓蚀率有下降趋势。极化曲线表明硫脲在乙酸溶液中为混合型缓蚀剂,在5～50mg/L浓度范围内,缓蚀作用存在极值现象。

The inhibition effects of thiourea（TU） on the corrosion of a cold rolled steel（CRS） in 0. 05 mol/L HAc were investigated by polarization curves and electrochemical impedance spectroscopy（EIS）. The results show that TU is a good inhibitor in low concentration acetic acid solution at normal temperature, and the inhibition efficiency increases with the increase of the concentration of TU, but when the concentration of TU is higher than 30 mg/L, the inhibition efficiency would be decreased with the increase of the concentration of TU. Polarization curves show that TU acts as a mixed-type inhibitor in acetic acid.