Shevchenko S. Technological support of wear resistance of machine parts by methods of chemical-thermal and diamond-abrasive processing.

The thesis is devoted to solving an important scientific and technical problem of increasing the wear resistance of machine parts by processing by complex ionic nitriding (CIN) and hardening electro-erosion diamond grinding (EDG). It is proposed to evaluate the formation of a hardened layer in the course of the technological process, taking into account the energy impact on the workpiece. The modeling of the penetration depth of nitrogen in the surface layer is carried out considering the holding time of the workpiece in the furnace at the hardening temperature in the technology of complex ion nitriding. A formula is obtained for determining the depth of the hardened layer taking into accountthe energy coefficient. It is proposed, after hardening grinding with the occurrence of cracks, to carry out the final processing consideringthe depth of the cracks formed after each pass. The physical processes occurring in the surface layer of the metal during CIN are investigated, the optimal sequences of technological operations are recommended, depending on the size of the parts. The parameters of the quality of the surface layer at EDG are studied and recommendations for strengthening the surface layer of parts are proposed. To select the technological parameters of the finishing and hardening technology at the design stage, considering the carbon content in steel for the formation of the specified characteristics of the surface layer in the EDG process, a technological scheme is assigned.