Studies of Chromium alloy plating on steel

使用多种二价铬镀液研究了铬和Cr-Zn合金以及Cr-Fe-Ni合金的电沉积。用钛阴极电解还原Cr_2（SO_4）_3水溶液制备二价铬镀液。在0.8kmol m^CrSO_4 <-3>- 0.008kmol m^ZnSO_4 <-3>- 2.0kmol m^<-3>KCl-0.3kmol m^<-3>HCOOH（pH2.4）体系中，通过电沉积获得荧光粉。存款含有锌和铬锌合金相。在阴极电位为-1.0 ~-1.1VvsSHE条件下，用0.1- <-3>0.4kmolm_2CrSO_4 - 0.1kmolm_2FeSO_4 - <-3>0.1kmolm_2NiSO_4 <-3>- 1.0kmolm_2KCl<-3>-0.3kmolm_2HCOOH<-3>（pH 2.4）溶液获得了光亮的Cr-Fe-Ni合金镀层。存款中的铬含量随着镀液中铬浓度的增加和阴极电位的降低而增加。在沉积30 min时，二价铬镀液中Cr-Fe-Ni沉积的平均电流效率为15%~ 25%，高于传统三价铬镀液中的平均电流效率。

The electrodeposition of chromium and Cr-Zn alloy and Cr-Fe-Ni alloy was examined using a variety of divalent chromium baths. Divalent chromium baths were prepared by electrolytic reduction of aqueous Cr_2(SO_4)_3 solution using a titanium cathode. Lustrous deposits were obtained by electrodeposition using aqueous 0.8 kmol m^<-3> CrSO_4 -0.008 kmol m^<-3> ZnSO_4 -2.0 kmol m^<-3> KCl-0.3 kmol m^<-3> HCOOH (pH 2.4). The deposit contained Zn and Cr-Zn alloy phases. Lustrous Cr-Fe-Ni alloy deposits were obtained at cathode potentials from -1.0 to -1.1 V vs SHE,using aqueous 0.1-0.4 kmol m^<-3> CrSO_4 -0.1 kmol m^<-3> FeSO_4 -0.1 kmol m^<-3> NiSO_4 -1.0 kmol m^<-3> KCl -0.3 kmol m^<-3> HCOOH (pH 2.4). The chromium content in the deposit increased with an increase in the chromium concentration of a plating bath and with a decrease in the cathode potential. For 30 min of deposition, the average current efficiency for Cr-Fe-Ni deposition from divalent chromium baths was 15% to 25%, which was higher than that from conventional trivalent chromium baths.