Formation of a thermally sustainable polygonization substructure with enhanced properties in electric arc coatings

Abstract

The paper studies the possibility of forming electric arc steel sprayed coating from wires of grades 65G and Sv-08G2C with a partially thermally stabilized polygonal substructure due to additional deformation and heat treatment. It has been established that additional deformation by pressing 25% and 30% of electric arc steel coating from wire 65G and 20% and 30% of coatings from wire Sv-08G2S provides an opportunity to increase the duration of exposure of heat treatment for 15 ... 20 minutes without significant reduction of hardness due to the formation of partially stabilized substructure. The method of X-ray diffraction analysis has calculated the average size of sub-grains, the angle of divergence between them and the number of nanostructured elements in sprayed coatings. It has been shown that the average size of subgrains of electric arc coatings decreases with deformation and stabilization of the substructure by 40 ... 45% in comparison with coatings after spraying. Also, when carrying out the heat treatment and additional deformation, an increase in the number of nanostructured elements from 18% to 32 ... 35% is ensured and the average angle of subgrains divergence increases. The influence of surface plastic deformation by shot blasting processing on the possibility of forming a stable polygonization substructure in the coatings of 65G wire has been investigated. Shot blasting provides stabilization of the polygonal substructure during heat treatment to the duration of exposure 40 minutes. Experimental investigations of the influence of heat treatment, surface plastic deformation and combined deformation-heat treatment on the bond strength and wear resistance of the electric arc steel coatings from wire 65G have been carried out. t has been established that carrying out heat treatment of 65G wire coatings provides an increase in the bond strength by 30% compared to the coatings after deposition by reducing internal stresses. Heat treatment of additionally deformed coatings provides a significant increase in bond strength compared to heat treated coatings without deformation. It is shown that heat treatment provides an increase in the wear resistance of coatings from 65G by 45% compared with the state after spraying.