Pulsed non-self-sustained glow discharge with a large-area hollow cathode for nitriding of iron-based alloys

摘要

The paper reports on a study of a pulsed non-self-sustained glow discharge with a hollow cathode area of 2.3 m~2 and pulse current of up to 370 A. The ignition and operation of the discharge at low pressures (0.4-1 Pa) was sustained through electron injection from the plasma of an arc discharge based on a cold hollow cathode. The current-voltage characteristics of the pulsed glow discharge were measured. Specimens of 12 Cr18Ni10Ti, Cr12, and 40Cr steels were nitrided in the glow discharge plasma with double thermal shields at a temperature of 520 °C and pressure of 0.9 Pa for 4 h. The nitrided layer thickness for 40Cr, Cr12, and 12Cr18Ni10Ti steels was 240, 90, and 50 μm, respectively.