HARDENING HEAT TREATMENT OF WEAR-RESISTANT CARBIDE PARTS MADE BY CASTING ACCORDING TO GASIFIED MODELS
Abstract
This article presents the theoretical and practical basics of manufacturing cast parts of tillage and agricultural machinery and mechanisms by casting gasified models. Technology has been developed for producing polystyrene foam models of various types of products and manufacturing cast parts of machines with a wear-resistant carbide coating of the sormite type. A technique for applying wear-resistant carbide coatings to the working surfaces of foam modelsparts when casting according to gasified models has also been developed. A method for forming the casting of parts with a carbide coating up to three mm thick has been created. The quality of the casting of parts and the thickness of the applied wear-resistant carbide coatings have been checked. The macro-and microstructures of carbide coatings obtained by casting on expanded polystyrene gasified models have been studied. The thickness of the carbide coating on specially prepared grinds cut from the casting of parts with a coating thickness of 2,0-2,5-3,0 mm has also been studied. The thickness of the coating was determined using an optical metallographic microscope MIM-8M and Neophot-21 with various magnifications from x 100 to x1000. At the same time, the microstructure and phase composition of the hard alloy was studied. The hardness, microhardness, and depth of the carbide coating were determined on samples and parts obtained by casting on a polystyrene foam gasified model, on the working surface of which a powdered hard alloy of the sormite type was applied. Optimal modes of heat treatment with double phase recrystallization for these cast parts of machines and mechanisms have been developed. It is proved that heat treatment with double phase recrystallization of such products increases abrasive wear resistance and durability 2-3 times higher than serial products. The present developed technology has been tested and implemented in one of the largest giant enterprises of "Uzbekistan Metallurgical Combine" JSC with the best economic effect.