中文摘要：

采用电沉积技术在20号钢表面制备了Fe—Ni合金层，考察了镀液中Fe^2＋浓度对合金镀层沉积速度、镀层成分、相结构、镀层显微硬度和耐蚀性的影响规律，并探讨了耐蚀机理．实验结果表明：电镀Fe—Ni合金可获得纳米晶结构，随镀液中Fe^2＋浓度增加，镀层中含铁量增大；镀层显微硬度的变化与Fe原子在Ni晶格中有序固溶程度有关；Fe—Ni合金镀层的耐蚀性均优于20号钢，当镀液Fe^2＋浓度为0．01mol·L^-1时，获得镀层具有最佳的耐蚀性．随镀层中铁含量增加，具有钝化特性的高含Ni的Fe—Ni相含量减少，耐蚀性下降，但该相纳米结构显著细化，加速钝化可提高耐蚀性，这一对矛盾导致镀层耐蚀性与铁含量间没有明显的变化规律．高孔隙率也是耐蚀性下降的原因之一．

英文摘要：

An Fe-Ni alloy coating on 20 steel was prepared by electrodeposition technology. The effects of Fe^2＋ concentration in the bath on the deposition rate, chemical composition, phase structure, micro-hardness and corrosion resistance of the coating were investigated, and the corrosion mechanism was analyzed. Experimental results show that the Fe-Ni alloy coating is nano-crystaIline, and the iron content in the coating increases with increasing Fe^2＋ concentration in the bath. The change in micro-hardness of the Fe-Ni coating is related to the ordered solid solution degree of Fe atoms in the Ni lattice. The corrosion resistance of the Fe-Ni alloy coating is superior to 20 steel, and it is the best when the Fe^2＋ concentration is 0.01 mol· L^-1. With the increase of iron content in the coating, the content of Fe-Ni alloy phase, which has passivation properties and high nickel ratio, and the corrosion resistance decrease. But the nanostructure of Fe-Ni alloy phase is significant refined, and it accelerates the passivity, and thus the corrosion resistance is improved. Due to the contradiction the relationship between corrosion resistance and coating iron content is not obvious. High porosity is one of the reasons for the low corrosion resistance of the Ni-Fe alloy coating.