Ion nitriding using active screen method

Abstract

Austenitic steel grade 304 according to AISI was tested after ion nitriding in the temperature range 325 - 400 °C and time range 2 - 4 h, and after two different variants of sample arrangement in a glow discharge chamber. The first variant – the samples intended for nitriding were placed on the cathode, the second variant – the samples placed on the cathode were shielded with an active screen. In order to evaluate the effectiveness of the nitriding process variants, investigations of the diffusion depth of the obtained surface layers, surface hardness tests and tribological wear tests were carried out. It was found that using active screens increases the rate of diffusion of nitrogen into nitrided austenitic steel 304, thus increasing the thickness of the resulting surface layers.

Keywords

• austenitic steel
• ion nitriding
• diffusion
• microhardness
• abrasion
• active screen method