Abstract

The corrosion rate of mild steel in hydrochloric acid and in sulphuric acid was determined by potentiodynamic polarization and electrochemical impedance spectroscopy in 0.5 M concentrations of HCl and of H₂SO₄ using 4-hydroxy n-[2-methoxy naphthalene methylidene] benzohydrazide (HNBH) as an inhibitor The inhibition efficiency of HNBH for the corrosion mitigation of mild steel was studied by varying the concentration of the inhibitor and temperature. It was found that the inhibition efficiency of HNBH increased with increase in the inhibitor concentration in both media. The maximum of 80% inhibition efficiency at the optimum inhibitor concentration of 2.5 × 10^–4 M was achieved. However, with an increase in temperature, the inhibition efficiency decreased. The corrosion inhibition by HNBH took place through physisorption. The adsorption isotherm fitting with the experimental data was identified to find out the mechanism of inhibition. The results indicated that HNBH functions as mixed type inhibitor and follows the Langmuir adsorption isotherm. The surface of the specimen was analyzed using scanning electron microscopy.

中文翻译：

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4-羟基n-[2-甲氧基萘亚甲基]苯甲酰肼作为低碳钢在酸性介质中的缓蚀剂的电化学研究

摘要

低碳钢在盐酸和硫酸中的腐蚀速率是通过动电位极化和电化学阻抗谱在 0.5 M 浓度的 HCl 和 H ₂ SO ₄中使用 4-羟基n- [2-甲氧基亚萘基]苯甲酰肼 (HNBH ) 作为缓蚀剂 通过改变缓蚀剂的浓度和温度，研究了 HNBH 对低碳钢缓蚀的缓蚀效率。发现HNBH的抑制效率随着两种培养基中抑制剂浓度的增加而增加。^{最佳抑制剂浓度为 2.5 × 10 –4}时抑制效率最高为 80%达到了 M。然而，随着温度的升高，抑制效率降低。HNBH 的缓蚀作用是通过物理吸附发生的。确定与实验数据拟合的吸附等温线，找出抑制机理。结果表明，HNBH作为混合型抑制剂，遵循朗缪尔吸附等温线。使用扫描电子显微镜分析样品的表面。