FEATURES OF THE FORMATION OF GAS THERMAL COATINGS IN THE RESTORATION OF THE WORKING SURFACES OF SHIP EQUIPMENT PARTS

Abstract

Introduction. One of the promising directions in solving the problem of increasing the durability of parts of ship machines and mechanisms, prone to intensive wear and tear during operation, is gas-thermal and, in particular, gas-flame spraying (GFS) of coatings in the process of restorative repair. The effectiveness of the GFS process and the properties of coatings are largely determined by the nature of the process of movement and heating of powder particles in the gas jet. By controlling the speed and temperature of the particles by changing the operating mode of the spraying devices, it is possible to apply coatings with the desired properties. The purpose of the article is to establish and study the technological factors affecting the formation of gas-flame coating during the restoration and strengthening of parts of ship machines and mechanisms. The results. The conducted research at the stage of gas-flame coating formation made it possible to establish the main technological parameters that significantly affect the quality of the process and to investigate the multiphase system of physical and chemical interaction of coating formation parameters. Conclusions. The main technological parameters affecting the formation of the gasflame coating (the speed of the sprayed particles, the spraying distance, the speed of gas movement, the spread of the flame front, etc.) are determined. The relationship between the dynamic and thermophysical parameters of the formation process was studied. From the analysis of experimental studies, a regression equation was obtained for determining the maximum values of the flight speed of particles with a size of 40...63 microns. To determine the optimal spraying distance, the temperature distribution of the section, the length of the flame torch and the temperature of the particles were determined experimentally.