Use of steel gas thermal coatings to increase wear resistance of parts

Abstract

The process of gas-thermal spraying of coatings made of wire materials has been studied by determining rational regimes to increase the wear resistance of surfaces of vehicle parts. It is determined that the main factors influencing the wear resistance of steel gas-thermal coatings are the cooling rate of steel and the concentration of alloying elements. It is shown that in order to obtain wear-resistant sprayed coatings from alloyed structural steels it is necessary to achieve certain conditions of coating formation, namely: heating and spraying temperature of wire, cooling rate of molten particles, and their oxidation state. One of the most probable reasons for increasing wear resistance is the saturation of the melt droplets with alloying elements (primarily chromium) and impurities of introduction (carbon, nitrogen) in the process of melting the wire in the flame. The relatively low flight speed of molten steel particles and the high concentration of propane-containing carbon in the combustion products contribute to the deep saturation of the melt droplets with carbon. It is likely that these circumstances are associated with the process of increasing the wear resistance of coatings obtained by gas-flame and electric arc spraying. An additional factor that increases the wear resistance of the sprayed coating may be the saturation of the melt droplets with carbon in the process of melting and spraying using propane flames. Studies have suggested that both for the method of gas-flame spraying and for the method of electric arc spraying, there are modes and steels for spraying, which can increase the wear resistance of the coating. On the basis of the conducted researches technologies of strengthening and restoration of details of vehicles by drawing wear-proof coverings are offered.