Studies of Chromium alloy plating on steel

点击翻译按钮获取中文摘要

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.