Vorona T. Raising wear resistance of gas-thermal steel coatings via electric contact processing using carbon-containing fillers.

Structural-phase transformations in sprayed coatings from steel of ferrite and martensite grades arising under electrocontact processing which initiates deformational ? ? ? (gamma ? alpha) transitions in the material of coatings and thus increase their hardness and wear resistance have been studied. The electrocontact processing activates the diffusion of carbon modifiers into coating accompanied by formation of atom-molecule bonds with its components and so enables obtaining a nanosized cell substructure on the basis of carbon modifiers, which not only can increase the coating wear resistance but also serve as a solid lubricant. A method and processing schemes for formation of wear-resistant coatings from steels of ferrite and martensite grades via combination of techniques for gas flame/electric arc spraying with and without modifiers have been developed. It was established that in order to produce high-hardness coatings, it is necessary to spray wire martensite steel by flame spraying whereas wire ferrite steels - by electric arc spraying. The increase in microhardness of coating from martensite steel after electrocontact processing is conditioned by the presence of higher contents of carbon and chromium carbide inclusions as compared to ferrite steel. The smooth decrease in microhardness through thickness and at the "coating-base" interface upon the coating processing provides a strong coating-to-base adhesion and minimizes the probability of coating detachment.