中性红在盐酸溶液中对冷轧钢的缓蚀作用

Corrosion inhibition of neutral red for cold rolled steel in hydrochloric acid solution

用失重法和动电位极化曲线法研究了酸碱指示剂中性红对冷轧钢在1.0～8.0mol/LHCl溶液中的缓蚀作用。结果表明:中性红对冷轧钢在1.0mol/LHCl溶液中具有良好的缓蚀作用,为混合抑制型缓蚀剂,且在钢表面的吸附符合校正的Langmuir吸附等温式,缓蚀率随缓蚀剂浓度的增加而增大,但随温度和盐酸浓度的增加而减小。通过吸附理论求出了相应的吸附热力学(吸附自由能ΔG°,吸附热ΔH°,吸附熵ΔS°)和动力学参数(腐蚀速度常数k,腐蚀动力学常数B),并根据这些参数讨论了缓蚀作用机理。

The inhibition effect of acid indicator of neutral red on the corrosion of cold rolled steel （CRS） in 1.0 -8.0 mol/L HClsolution at 20- 50℃ has been studied by weight loss and potentiodynamic polarization methods. The results show that neutral red is a good inhibitor in 1.0 mol/L HClfor CRS, and the adsorption of neutral red on the CRS surface follows the amended Langmuir adsorption isotherm equation. Inhibition efficiency increases with the increase of inhibitor concentration,while decreases with the temperature and HCI concentration. Polarization curves show that neutral red is a mixed - type inhibitor in hydrochloric acid. Three adsorption thermodynamic parameters （ adsorption free energy △G°, adsorption heat △H°, adsorption entropy △S°） and two kinetic parameters （corrosion rate constant k, kinetic reaction constant B） are also calculated. Based on the parameters, the inhibitive mechanism is discussed in detail.