一、引言在低浓度硝酸钠溶液中电解加工铁基合金时,一般来说,其效率曲线在钝化区效率很低,截止电流io较大,在超钝化区曲线斜率较大。因此,使处于不同电流密度或者说不同极间间隙的工件表面具有不同的金属去除速率,以使得在加工过程中,工件表面各点与阴极之间接近于均匀间隙,而得到良好的尺寸复制精度。但这种低浓度电解液即使在较高电流密度下,其电流效率也比较低, I. INTRODUCTION In the electrolysis of iron-based alloys in low concentration sodium nitrate solution, the efficiency curve is generally low in the passivation zone with large off-current io and large slope in the hyperpassivation zone. Therefore, at different current density or different gap between the workpiece surface with different metal removal rate, so that during processing, the workpiece surface and the cathode close to the gap between the uniform and good dimensional replication accuracy . However, this low concentration of electrolyte even at higher current densities, the current efficiency is relatively low,