Effect of electrolytic plasma hardening on the strength properties of steel

Abstract

This study investigates the effect of electrolytic plasma surface hardening on the structural, mechanical, tribological, and corrosion properties of steel grade 2 used for railway applications. The treatment was performed in an aqueous electrolyte containing 10% carbamide and 20% sodium carbonate under conditions of rapid heating and self-quenching. The phase composition of the surface layer was analyzed by X-ray diffraction, while mechanical properties, wear resistance, and corrosion behavior were evaluated using standard testing methods. The results show that the treatment leads to the formation of a multiphase surface layer consisting of α-Fe, iron carbides, and oxide phases. As a result, a significant improvement in mechanical properties was observed, including an increase in strength and a substantial rise in surface microhardness. The wear resistance of the treated samples increased by 3.5–3.7 times compared to the initial state. At the same time, electrochemical tests revealed an increase in corrosion current density, indicating higher surface activity, while the overall corrosion rate decreased, suggesting the formation of partially protective surface layers. The obtained results demonstrate that electrolytic plasma surface hardening is an effective method for improving the performance of steel grade 2, although the balance between enhanced wear resistance and corrosion behavior requires further optimization.