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Постійне посилання на розділhttps://repository.kpi.kharkov.ua/handle/KhPI-Press/35393
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Документ The choice of the optimal temperature and time parameters of gas nitriding of steel(ЧП "Технологический Центр", 2016) Al-Rekaby, Dhafer Wadee; Kostyk, Viktoriia; Kostyk, Kateryna; Glotka, Alexandr; Chechel, MykolaMathematical modeling of the gas nitriding process allows solving the problems of control of process parameters, prediction of outcomes and development of various treatment conditions, which is quite an urgent issue today. The research was aimed at selecting the optimum temperature and time parameters of gas nitriding of 38Сr2MoAl steel. Optical and electron microscopy showed that the diffusion layer after gas nitriding in the ammonia environment is the nitrided case and the region of internal nitriding. The experimental data showed that the diffusion layer depth varies from 40 to 650 µm in the range of gas nitriding temperatures of 500-560 °С and time of 20-80 hours, while the surface hardness varies within 6.5-10 GPa. The mathematical models in the form of quadratic polynomials, describing the dependence of the depth of the nitrided case and the surface hardness on the temperature and time of gas nitriding were obtained. The mathematical description of the changes in the depth of the nitrided case and surface hardness depending on the changes in the treatment temperature and time, which allows determining the specific conditions of the gas nitriding (temperature and time) based on the desired depth of the diffusion layer or the surface hardness of 38Сr2MoAl steel was constructed.Документ Modeling of the case depth and surface hardness of steel during ion nitriding(ЧП "Технологический Центр", 2016) Khalaf, Mohanad Muzahem; Kostyk, V.; Demin, D.; Kostyk, KaterynaModeling of the ion nitriding process allows solving many problems of operations management, forecasting of results and development of new treatment regimes, which is an urgent issue today. The goal of the paper was modeling of the case depth and surface hardness of 38Cr2MoAl А steel during ion nitriding. The experimental data showed that the case depth varies from 20 to 620 µm in the ion nitriding temperature range of 500-560 °С and duration of 1-12 hours, with the surface hardness varying from 8 to 12 GPa. The mathematical models in the form of quadratic polynomials, describing the dependence of the nitrided case depth and surface hardness on the temperature and duration of thermochemical treatment were obtained. The graph-analytical description of variations in the nitrided case depth and surface hardness depending on variations in temperature and duration of treatment, which allows determining the specific conditions of ion nitriding 38Cr2MoAl steel is constructed.