МОДИФІКУВАННЯ РОБОЧИХ ПОВЕРХОНЬ СТАЛЕВИХ ДЕТАЛЕЙ З ФОРМУВАННЯМ ВИСОКОВУГЛЕЦЕВИХ СТРУКТУР

Abstract

The urgent task is to create on the surface of steel parts layers that are capable of long time to work reliably under conditions of friction and wear. The tool for increasing the wear resistance of the surface layers of steel parts is chosen to modify the working surfaces by their carbonization. In this case, the hardness of the metal is controlled by the change in the carbon concentration in the surface layers, the content of the alloying elements by thermal and chemical-thermal processing techniques. In the work comparative studies of the efficiency of various technologies of carburization of working surfaces of steel parts and formation of the properties of wear resistance, formation of burrs and gripping according. It has been proposed to carry out comparative studies according to the criteria of performance, cost, and applicability for dimensional parts. The analysis revealed the existence of a number of methods that use the diffusion phenomenon to form wear-resistant high-carbon coatings with metal matrix and carbide reinforcing inclusions or cemented layers with different structural components on the surfaces of steel parts, which are known as “quenching structures”, differing in different technical and economic efficiency. Particular attention is also paid to the method of forming composite high-carbon coating in the mode of self-propagating high-temperature synthesis (SHS). As a result of the carried out researches it is shown that there is a significant shortage of the overwhelming majority of the considered methods of carburizing of working surfaces of parts from low or medium carbon varieties of steel - high cost of production due to low productivity and complexity of implementation. These drawbacks stimulate the development of new high-performance methods of forming on steel details corresponding coatings of considerable depth and low cost.