The Influence of Chromium Carbide on Corrosion Resistance of Plasma NiCrBSi Coating

Studies have been carried out to evaluate the effect of chromium carbide on the corrosion resistance of coatings obtained by plasma heating of mixtures of NiCrBSi alloy powder and OK 84.78 coating on the surface of St3 steel. It has been established that an increase in the content of chromium carbide in the initial composition of the coating leads to an increase in the microhardness of the modification coatings, but at the same time, the likelihood of cracks and pores also increases. An increase in the content of chromium carbide in the composition of the coating affects the mechanism of formation of the grain structure of the surface layer. Studies of coating corrosion in 3% NaCl solution showed that, with an increase in the chromium content in the coating composition, the corrosion potential decreases, while corrosion current density increases with an increase in carbon content.