• • NM500 steel exhibits a fine lath martensitic microstructure with a grain size of 7.08 μm, yielding high hardness and a low-temperature wear rate of 1.29×10−6 mm3/(N·m) at −50 to 0 °C; this indicates that the alloy is optimally suited for cryogenic abrasive environments, such as cold-climate mining or LNG handling equipment, where material loss is minimized.
• • At 100, 200, 300, and 600 °C, wear rates escalate to 18×10−6, 22.7×10−6, 46.7×10−6, and 128×10−6 mm3/(N·m), respectively, representing a 14- to 99-fold increase over the cryogenic regime; this sharp degradation underscores that continuous high-temperature service above 300 °C is economically unviable without surface engineering or alloy modification.
• • The friction coefficient drops to a minimum of 0.3 at elevated temperatures, a 50% reduction compared to low-temperature values, due to the formation of continuous oxide films; however, at 600 °C, oxide film delamination and reduced texture strength cause a transition to oxidative wear as the dominant mechanism, accelerating material loss and necessitating protective coatings or alloying additions for high-temperature applications.
• • The wear mechanism shifts from abrasive wear at −50 to 0 °C, to mixed abrasive-fatigue-oxidative wear at 100–200 °C, and finally to oxidative wear with minor abrasive wear at 300–600 °C; this temperature-dependent transition provides a predictive framework for selecting NM500 in industrial tribosystems, where operating temperature must be matched to the dominant wear mode to avoid premature failure.