The aim of this work was to determine the impact of various heat treatments on the KIc/HRc ratio and subsequently on the wear properties of coated high-speed steel under dynamic impact loading. Metallurgy cold work tool steel, which was used as a substrate material, was vacuum heat treated under six different conditions with the aim to modify hardness and fracture toughness. It was shown that use of cryogenic treatment can increase fracture toughness from 10 and up to 67% at the same hardness. Regarding the static load, the most important feature of substrates is its hardness, which at work hardness of 63-64 HRc already provides good static load capacity of coated substrate. Increased fracture toughness achieved by cryogenic treatment can at very high and/or very low harness of the substrate have negative impact on the dynamic wear properties of coated surfaces. On the other hand, in the case of vacuum heat treatment that ensures adequate working hardness of 63-64 HRC, cryogenic treatment improves impact wear resistance of coated surfaces. It is equal to the wear resistance of the coating applied on a substrate with a maximum hardness, but having more than 50% higher fracture toughness.
COBISS.SI-ID: 1088426