Metallurgical Processes During Plasma Remelting of a Metallized Coating of the Fe–C–Cr–Ti–Al System

Abstract

Various methods are used for working surface treatment in order to prolong the life of machine components subjected to different forms of wear. Deposition of coatings from the Fe–C–Cr–Ti–Al system is used extensively for protection from abrasive wear, although their lamellar and porous structure facilitates a reduction in wear resistance. Metallurgical processes are considered in this work in coatings prepared by arc metallizing of cored wire of the Fe–C–Cr–Ti–Al system and their effect on coating properties. ADM-10 activated arc metallization equipment is used to apply coatings. Remelting of sprayed coatings is performed in a universal unit for plasma treatment. It is carried out with direct current polarity using argon as a protective and plasma-forming gas. Results are provided for a study of the structure, microhardness and chemical composition of metallized coatings before and after remelting. Coating plasma treatment leads to remelting and a marked change in structure and microhardness. Coating microhardness increases considerably compared with the originally deposited coating. More uniform distribution is noted throughout the coating thickness that is due to a uniform coating structure, absence of oxide interlayers, porosity, and discontinuities, and also uniform chemical element distribution. It is established that oxidation of aluminum and titanium during sprayed coating plasma remelting facilitates the formation of a martensitic structure with strengthening by fine chromium carbide.