Electrolyte-plasma surface hardening of 65G and 20GL low-alloy steels

Abstract

This work is devoted to formation of modified surface layers in 65G and 20GL steels which using for the manufacture of railway transport parts, as well as the study of influence of the parameters of electrolyteplasma surface hardening method on the changes in structural-phase states, improving of wear-resistance. The process of electrolyte-plasma surface hardening of 65G and 20GL steels samples conducted in the electrolyte from water solution of 20 % sodium carbonate, in the mode ~850 °C — 2 seconds, ~1200 °C — 3 seconds. It is established that in the initial state 20GL steel has ferrite-pearlite structure, and the 65G steel consists of pearlite and cement structure. After application of electrolyte-plasma surface hardening is observed the formation of carbides particles and martensite phase components in the structure of 20GL and 65G steels. It is determined that after electrolyte-plasma surface hardening with heating time — 2 s, the abrasive wearresistance of 65G and 20GL steels increased to 1,3 times and 1,2 times, respectively, and the microhardness is increased to 1,6 times and 1,3 times, respectively