山梨酸钾与Zn2+在NaCl溶液中对Q235钢的缓蚀协同作用

采用失重法、电化学法、X射线光电子能谱(XPS)和扫描电子显微镜(SEM)研究了0.5 mol/L NaCl溶液中,山梨酸钾(PS)与Zn²⁺对Q235钢的缓蚀协同效应。 失重实验结果表明,在0.5 mol/L NaCl溶液中,PS对Q235钢具有一定的缓蚀效果,缓蚀效率随PS质量浓度的增加而增大,当添加PS的质量浓度为25.0 g/L时,最大缓蚀效率仅为38.37%,而PS与Zn²⁺复配后存在显著的缓蚀协同作用,缓蚀效率高达91.03%。 动电势极化结果表明,PS与Zn²⁺混合物可同时抑制Q235钢的阴、阳极反应,属于阳极型缓蚀剂。 阻抗谱表明,该混合物可在电极表面形成致密的保护膜。 XPS分析证明保护膜是由PS、铁的氧化物/氢氧化物和Zn(OH)₂沉淀组成。

Synergistic Inhibition Effect of Potassium Sorbate and Zn2+ Ions on Corrosion of Q235 Steel in NaCl Solution

The synergistic inhibition effect of potassium sorbate (PS) and Zn²⁺ ions on the corrosion of Q235 steel in 0.5 mol/L NaCl solution was studied by weight loss method, electrochemical method, X-ray photoelectron spectroscopy (XPS) and scanning electronic microscopy (SEM). The results of weight loss measurement show that potassium sorbate has some inhibition of corrosion of Q235 steel in 0.5 mol/L NaCl solution, the inhibition efficiency increases with the increase of concentration. When the added PS concentration is 25.0 g/L, the maximum inhibition efficiency is 38.37%. The combination of PS and Zn²⁺ ions has a significantly synergistic inhibition effect, the corrosion inhibition efficiency is as high as 91.03%. Potentiodynamic polarization shows that the mixture of PS and Zn²⁺ ions can simultaneously inhibit the cathodic, anodic corrosion reactions of Q235 steel, belonging to an anodic-type corrosion inhibitors. Impedance spectroscopy shows that the mixture can form a dense corrosion inhibitor film on the electrode surface. XPS analysis confirms that the corrosion inhibitor film consists of potassium sorbate, iron oxide/hydroxide and Zn(OH)₂ precipitate.