Effect of Sub-Zero Treatment on the Wear Resistance of P/M Tool Steels

Abstract

Sub-zero treatment of tool steels is included within the cycle of conventional heat treatment. This kind of heat treatment has been reported to improve wear resistance of tools. The improvement is attributed to precipitation of fine carbide particles, but is depending on a number of the other factors as well. This paper follows the previous works, in which the effect of sub-zero treatment on the mechanical and structural properties of P/M tool steels was evaluated. Two types of P/M cold work tool steels were used in the research: Vanadis 6 and high speed steel Vanadis 30. They were austenitized, nitrogen gas quenched and tempered. The 4 hours long sub-zero period of dwell at -196°C was also incorporated between quenching and tempering. Wear evaluation was carried out using a pin-on-disk method.The observed values of wear resistance have been collated with the values of hardness and the bending strength. The results of the work are supplemented by a detailed analysis of the carbide particles of both monitored conditions.

Shallow Cryogenic Treatment (SCT) Effects on the Mechanical Properties of High Cr Cast Iron: Low-Carbon Cast Steel Bimetallic Casting

“…25 Effect of sub-zero treatment on the wear resistance of powder metal (P/M) tool steels has been investigated by Sobotova and colleagues, significant results have been achieved on wear resistance of P/M tool steels. 26 Xiao-Hui Lu and colleagues investigated the effects of subzero celsius treatment of retained austenite in bearing steel and results showed that the activation energy of retained austenite decomposition slightly increased through subzero celsius treatment and tempering. 27 Effect of heat treatment on the bimetallic plates has been investigated by O ¨zdemir 28 and also by Hao Li and colleagues; 29 both investigations presented significant results in terms of hardness, toughness, and good interface.…”