Optimization of wear-, fracture- and corrosion performance of Vanadis 6 steel through cryogenic treatment and tempering

Vanadis 6 cold work tool steel was vacuum austenitized, room temperature quenched, differently cryogenically treated (-75, -140 and -196 °C for different durations) and double tempered, at temperatures of either 170 or 530 °C. Galling resistance was assessed by pin-on-disc testing of differently treated specimens against CuSn bronze, at wide ranges of sliding velocities and loads. The obtained results show that cryogenic treatments combined with low temperature tempering improves anti-galling performance of the steel. The best tribological properties were obtained when high-temperature tempering was combined with cryogenic treatment at -196 °C, due to the maximum extent of microstructural alteration generated by this kind of treatment. The improvement in wear performance is accompanied with slight but undisputable increase in corrosion resistance of the steel, at almost no affected toughness as compared with the state after conventional heat treatment. In conclusion, the obtained results imply an opportunity to simultaneously improve wear performance, corrosion resistance and toughness of the examined steel, by choosing a proper combination of cryogenic treatment and tempering.