Abrasive wear performance of AlCrN-coated hot work tool steel at elevated temperatures under three-body regime

High temperature abrasive wear performance of X32CrMoV33 hot work tool steel with and without an Al0.61Cr0.39N coating was investigated under three body abrasion conditions. The Al0.61Cr0.39N coating has a remarkable impact on the wear resistance of the X32CrMoV33 hot work tool steel. Extensive oxidation co-occurring with abrasive wear at 750 °C leads to substantial material loss in the latter. The poor adherence and limited ductility of Fe3O4 promote the failure of the thick oxide scale on the tool steel sample impairing its resistance to abrasion at elevated temperatures. The material loss of the AlCrN-coated tool steel, however, is nearly two orders of magnitude smaller. This is attributed to the adhesive and highly plastic Cr2O3 film that forms on the coating and sustains the abrasion. The much reduced oxidation in the coated sample suppresses the synergy between oxidation and wear, and improves the resistance to abrasive wear. Much higher hardness of the AlCrN coating with respect to the substrate is also believed to be instrumental.