Corrosion behavior of electrolytic CoRe alloys under exposure in an alkaline media

Corrosion behavior of electrolytic binary and ternary alloys in the 1 M KOH solution de­posited from citrate-pyrophosphate electrolytes was studied. Based on the performed impe­dance measurements, the formation of a dense oxide layer, which blocks the access of the electrolyte to the metal through cracks and pores, is shown. Equivalent schemes have been selected and substantiated, and the parameters of the corrosion process have been calculated for 9 days of the samples exposure in the corrosive solution. Using chemical mapping, it is shown that the corrosion product is predominantly cobalt oxide. A ternary alloy is charac­terized by a higher initial corrosion resistance of 6 kW×cm–2 and a significant polarization resistance after slowing down and stabilization of the corrosion process – 37 kW×cm–2.