Investigation of the Strength of Diffusion Coatings on Cast Iron Friction Pairs in Contact with Hard Abrasive Soil Particles

Abstract

Abstract Replacing steel parts with cast iron is a promising task for agricultural engineering. However, high-strength cast iron VCh 60, widely used in mechanical engineering and studied in this work, is inferior in abrasive resistance to steel parts that have undergone chemical-thermal and subsequent heat treatment. This disadvantage was eliminated by the formation of high-hard diffusion coatings with vanadium or chromium, by the method of saturation of their powders. But these coatings, despite their hardness, are brittle and lie on a softer base of cast iron. This paper estimates the minimum thickness of the above-mentioned coatings that can withstand the specified level of contact load without destruction when solid non-crushed soil particles or particles of other origin enter the interface. Based on the conducted research, the empirical dependences of the minimum thickness of the coating that can withstand a given level of load without destruction are derived from the size of the resulting imprint of the Vickers pyramid pressed into the surface. The graphs are convenient to use when designing gears and worm gears with a given contact load in the engagement, the part of the space located above the critical line 6 in the figures shown in the work is a safe area of coating thicknesses at the identified contact pressure.