G213 Plasma nitriding for steels under atmospheric pressure using pulsed-arc thermal plasma

Abstract

Plasma nitriding for hardening steel surface is achieved by spraying thermal pulsed-arc plasma jet under atmospheric-pressure N_2/H_2 mixture. The quality of nitriding is found to depend on the H_2 flow rate, which has an optimal value. We propose a simple mechanism of this dependence. Moreover, the amount of H_2 necessary for best nitriding can be decreased to 1/20 by changing the way of H_2 addition.