吐温-80对一种冷轧钢在氨基磺酸溶液中的缓蚀性能及机理研究

Corrosion Inhibition Performance and Mechanism of Tween-80 on a Cold Rolled Steel in NH_(2)SO_(3)H Solution

通过失重法、动电位极化曲线法、原子力显微镜(AFM)和X射线光电子能谱(XPS)以及缓蚀溶液体系电导率和表面张力等研究了吐温-80在氨基磺酸溶液中的缓蚀机理。结果表明:在氨基磺酸溶液中吐温-80对冷轧钢具有良好的缓蚀效果。30℃时,在0.10 mol/L氨基磺酸溶液中吐温-80的缓蚀率可高达94.33%;在冷轧钢表面,标准吸附Gibbs自由能(ΔG)为-29.94~-33.79 kJ/mol,说明吐温-80是以化学吸附为主的混合吸附,且其吸附服从Langmuir吸附等温式;吐温-80是混合抑制型缓蚀剂;在添加吐温-80后的溶液表面张力急剧降低;缓蚀后的电导率上升且趋于平缓,略低于浸泡前;AFM观察表明在添加吐温-80后能有效的抑制NH_(2)SO_(3)H对冷轧钢的腐蚀;XPS结果证实吐温-80能在钢片表面形成一层吸附膜层从而达到缓蚀的效果。

The corrosion inhibition performance of Tween-80 for a cold rolled steel in amino sulfonic acid solution was studied by mass loss method,potentiodynamic polarization measurement,atomic force microscopy(AFM)and X-ray photoelectron spectroscopy(XPS),as well as measuring the conductivity and surface tension of corrosion inhibitor containing solutions.The results showed that Tween-80 had a good corrosion inhibition effect on cold-rolled steel in amino sulfonic acid solution.The corrosion inhibition efficiency of Tween-80 in 0.10 mol/L amino sulfonic acid solution at 30℃ can reach as high as 94.33%.The standard adsorption Gibbs free energy(ΔG)is-29.94~-33.79 kJ/mol for the inhibitor adsorption on the surface of cold-rolled steel,it indicates that Tween-80 is a mixed adsorption dominated by chemisorption,and it follows the Langmuir adsorption isotherm equation.Therefore,Tween-80 is a mixed inhibitory corrosion inhibitor.After adding Tween-80,the surface tension of the solution decreases sharply.With the progress of corrosion inhibition of the steel,the conductivity of the solution increases,then gradually decreases and tends to be flat,which finally slightly lower than the conductivity before the steel immersion in the solution.AFM and XPS results confirmed that Tween-80 can effectively suppress the corrosion,while form an adsorption film on the surface of steel to achieve corrosion inhibition effect.