木质素磺酸钠对3.5%NaCl溶液中AZ31镁合金的缓蚀作用

Inhibiting Effect of Sodium Lignosulphonate on the Corrosion of AZ31 Magnesium Alloy in NaCl Solution

摘要:

采用失重法，极化曲线，电化学阻抗谱和扫描电子显微镜研究木质素磺酸钠(SLS)在质量分数为3.5%NaCl溶液中对AZ31镁合金的缓蚀作用。结果表明：在298K时SLS可有效抑制AZ31在NaCl介质中的腐蚀。当SLS为4.0g?L-1时，缓蚀率可达到最大。提高浓度后，其缓蚀率会下降。SLS是阴极型缓蚀剂，并且SLS在AZ31表面的吸附符合langmuir吸附模型。由吸附自由能G0及Arrhenius活化能Ea知，SLS在AZ31镁合金表面是化学吸附。

Abstract:

The inhibition effects of sodium lignosulphonate (SLS) have been studied by means of weight loss method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The results showed that sodium lignosulphonate (SLS) could inhibit effectively the corrosion for AZ31 magnesium alloy in 3.5% NaCl solution, and that the consisting of 4.0 g/L SLS is of an inhibition efficiency higher to 75.4%. SLS is an anion inhibitor and the adsorption of SLS on the AZ31 magnesium alloy surface obeys to the Langmuir adsorption isotherm which due to the adsorption free energy ?G0 and the Arrhenius active energy Ea.