Structural, mechanical, and tribological properties of AISI 304 and AISI 316L steels submitted to nitrogen—carbon glow discharge

摘要

Glow discharge (GD) nitrocarburizing, at low-carbon content and different working temperatures, was performed on AISI 316L and AISI 304 stainless steels. Structural compositions were studied by X-ray diffraction. Instrumented indentation and conventional Vickers method allowed hardness profiles to be determined. Tribological behavior was studied by means of reciprocating sliding and nanoscratch tests. After nitrocarburizing, both steels showed similar embedded nitride and carbide formations. The layer formed by GD in nitrogen–carbon atmosphere is thicker than those consisting solely of nitrogen particularly for AISI 316L. At working temperatures higher than 400 °C, roughness increased and wear was limited to asperity compaction. Wear mechanisms were similar in both steels. However, wear was reduced by up to a factor of 5 in treated steels. No difference in elastic surface recovery was observed after nitrocarburizing in either steel.