MODIFICATION OF HIGH-SPEED STEELS BY NITROGEN COMPRESSION PLASMA FLOW: STRUCTURE, ELEMENT COMPOSITION, TRIBOLOGICAL PROPERTIES

The influence of the nitrogen compression plasma flow impact on the phase and element composition, tribological properties of AISI M2 and AISI T1 high-speed steels was investigated in this work. The bank capacitor initial voltage, the number of pulses and nitrogen pressure in the vacuum chamber varied during experiments providing the change of energy deposited in the surface layer within the limits of 5–13 J/cm2 per pulse. It was found that treatment resulted in carbides partial dissolution and austenite formation in the surface layer. The modified layer thickness amounted to 24 μm while the nitrogen penetration depth did not exceed 400 nm. Treatment by the compression plasma flow mainly led to the decrease of hardness and the friction coefficient of high-speed steels