Abstract
This paper presents the results of an experimental study on the effect of electrolyte-plasma hardening (EPH) on the microstructure, microhardness, and abrasive wear resistance of widely used structural steels – grades 45 and 65G. The treatment was carried out in an aqueous solution of sodium carbonate under a voltage of 300-320 V for a duration of 2-3 seconds. The EPH method provided ultra-high heating and cooling rates due to direct contact with the electrolyte, which contributed to the formation of a thin hardened layer with a martensitic structure and carbide inclusions.Microstructural analysis revealed the presence of three characteristic zones: a hardened surface layer, a heat-affected zone, and an unchanged core matrix. The surface microhardness after EPH increased by 1.6-1.8 times compared to the initial state, while abrasive wear resistance improved by 1.3-1.6 times. It was also noted that extending the treatment duration positively influenced the surface layer’s plasticity, with only a slight reduction in hardness.The obtained results confirm the high efficiency of EPH as a resource- and energy-saving method of local surface hardening, capable of significantly extending the service life of components operating under frictional and abrasive conditions. The method is recommended for integration into the technological processes of the mechanical engineering, transportation, and agricultural industries.