Sliding wear behaviour of conventional and cryotreated PM Cr-V (Vanadis 6) ledeburitic tool steel

Abstract

Cryogenic treatment is a widely accepted method for extending the tool life of tool steels. This study focuses on investigating the tribological properties of PM Cr-V cold work tool steel subjected to conventional and cryogenic treatments. The aim of the study is to compare the reciprocal sliding wear performance of Cr-V cold work tool steel under different treatment conditions. The Cr-V tool steel specimens were cryotreated at temperatures of −75 °C, −140 °C, or −196 °C, followed by double tempering at 170 °C or 530 °C for 2 h. Cryotreated specimens exhibited a 10% increase in hardness compared to conventionally treated specimens after tempering at 170 °C. However, specimens cryotreated and tempered at 530 °C showed a 7% drop in hardness. Reciprocating sliding wear tests were conducted at room temperature using an Al2O3 ball as the counter-body to simulate abrasive wear. The results indicate that the friction coefficient is primarily influenced by the applied load and sliding velocity rather than the material treatment. Cryogenic treatment at 170 °C improved the wear performance by approximately 24% compared to conventionally treated specimens, while cryotreated specimens tempered at 530 °C did not exhibit any improvement in wear performance compared to conventionally treated specimens.