Al（OH）3和Cl一对稀土铝热浸镀层腐蚀行为的影响

以自制热浸镀稀土铝为研究对象，采用失重法、极化曲线、SEM和电化学阻抗测试研究了淡水中存在的A1（OH）3对镀层腐蚀行为的影响；同时，通过极化曲线考察了饱和A1（oH）3溶液中C1一浓度对镀层腐蚀的影响。结果表明：A1（OH）3能够抑制镀层破损钝化膜的修复，促进阳极活化，诱导镀层点蚀反应的发生，使腐蚀加剧；随Cl一浓度...

Effect of Aluminum Hydroxide and Cl~- Ion on Corrosion Behavior of Hot Dipped Rare Earth-Aluminum Coating

The corrosion behavior of hot dipped rare earth-aluminum（RE-A1） coating in fresh water with or without Al（OH）₃ was investigated using weight loss test,scanning electron microscopic analysis as well as measurement of polarization curve and electrochemical impedance spectra. At the same time,the effect of Cl^- concentration in saturated Al（OH）₃ solution on corrosion behavior of hot dipped RE - Al coating was examined by measuring polarization curve.Results show that Al（OH）₃ in fresh water can retard the repair of damaged passivation film,accelerate anodic reaction and induce pitting corrosion,resulting in severe corrosion of the RE - Al coating. The corrosion current of the coating initially rose but later declined with increasing concentration of Cl^-.The maximum current density was obtained at Cl^- concentration of 4%, corresponding to the worst corrosion resistance of the hot - dipped RE-Al coating.