Structural-phase state of the surface layer of low-carbon steel after electrolytic-plasma modification

Abstract

An alternative technology of strengthening by electrolytic-plasma modification of low-carbon alloy steel for the wedge columns binding for stop valves has been developed. The processing of steel 20X samples was carried out on an experimental installation, the optimal processing modes were determined experimentally. Simulation of the treated surface makes it possible to assume that during the electrolytic-plasma heating of parts, along with quenching, chemical modification of the metal surface layers occurs. The volt-temperature characteristic with the superposition of real time on the proposed processing clearly shows a significant reduction in the time for hardening, relative to traditional hardening methods of similar steel. Also, energy consumption and, accordingly, the cost of the part and the product as a whole are significantly reduced. Electrolyte-plasma modification promotes the transformation of coarse-grained pearlite-ferrite microstructure into quenched martensite. An increase in hardness relative to the initial state indicates an increase in physical and mechanical properties after electrolyte-plasma treatment. The advantage of the method of electrolytic-plasma treatment consists in low energy consumption at high quenching rates, the possibility of local surface treatment; there are prerequisites for creating a semi-industrial installation for an alternative electrolyte-plasma hardening.