Investigation on the effect of technological parameters of electrolyte-plasma cementation method on phase structure and mechanical properties of structural steel 20X

Abstract

This article presents the results of a study on the effect of electrolyte-plasma cementation on the phase composition of the surface-modified layer and the mechanical properties of 20X steel using different solutions. It has been determined that electrolyte-plasma cementation followed by quenching in solutions containing (a) 10% calcined soda (Na₂CO₃), 10% urea (CH₄N₂O), 10% glycerin (C₃H₈O₃) and 70% distilled water and (b) 10% calcined soda (Na₂CO₃), 20% urea (CH₄N₂O) and 70% distilled water, results in the formation of a modified structure on the surface of 20X steel. This structure mainly consists of the α-Fe phase, along with separate particles of reinforcing phases, Fe₃C and Fe₃C₇ carbides and martensitic αx-Fe phase. The plasma of the electrolyte was used to heat the samples. Then these samples were partially immersed in the electrolyte and held at a temperature of 950 ℃ for 5 min, followed by quenching. As a result of this process, it was found that 20X steel exhibits higher hardness. After the electrolyte plasma cementation, it was observed that the friction coefficient of the modified surface of the steel samples significantly decreased. Additionally, the wear volume was reduced by more than 6.5 times compared to the initial state. The average microhardness after the electrolyte-plasma cementation is 660 HV, which is nearly four times higher than that of the initial material.