ПОДВІЙНА ХІМІКО-ТЕРМІЧНА ОБРОБКА ЗУБЧАСТОГО КОЛЕСА ІЗ СТАЛІ ВКС-5

Abstract

The process of the double chemical-thermal treatment (DCTT) a gear made of heat-resistant steel VKS-5 is quite common and makes it possible to obtain secondary hardness. Double or combined chemical-thermal treatment is designed to increase the contact durability of steels by nitriding final finished parts that these were carburizing, hardened and ground. Comparison of the process of double chemical-thermal treatment with traditional methods of chemical-thermal treatment(CTT) carburizing and nitriding. Object of the study is a gear wheel treated with the DCTO method, after it was compared the hardness of the wheel past the DCTO using gas nitriding and liquid, with other similar CTT processes such as nitriding and carburizing and nitrocarburizing the results were a graph of hardness and the depth of the strengthened layer for each of the processes. Discussion of the developed technology for the preparation of double chemical-thermal treatment and the results of studies on the use of dispensing methods for obtaining DCTO. Efficiency is justified by metallographic studies of the developed technology. Also, metallographic studies have shown the need to control the surface layer the E-phase is formed due to which it is possible to substantially increase the hardness of the surface while preserving the structure of the entire material without cracking thereby providing increased contact durability. We also consider the possibility of using ion-plasma equipment, which allows to significantly increase the speed of the process, control the thickness of the layer of surface phases and also makes it possible to additionally apply the method of surface deformation to create compressive stresses on the surface. This technology allows to obtain a surface combining the advantages of nitriding and carburizing, excluding useing harmful substances affecting a health and ecology, and also economically more beneficial than nitrocarburizing. DCTT can be used to increase the contact endurance of the gear wheels in a large module, and eliminating the need for further machinary treatment of the surface layer after DCTT.