STUDY OF WEAR RESISTANCE OF METAL ALLOY 100Cr6 AS A RESULT OF VARIOUS HEAT TREATMENT MODES

Abstract

This study investigates the abrasive wear resistance of 100Cr6 (AISI 52100) bearing steel under three distinct heat treatment conditions: spheroidising annealing (as-delivered), normalising at 880°C, and oil quenching from 840°C followed by low-temperature tempering at 160°C. Cylindrical specimens were subjected to abrasive wear testing using a silicon carbide disc (P80 grit) under a constant load of 450 g over test durations of 25 and 60 min. Wear resistance was evaluated by the mass loss method, and microstructural characterisation was performed by optical metallography at 800x magnification. The results demonstrate that the as-delivered condition, characterised by a ferritic matrix with globular carbides and a hardness of 10 HRC, exhibits the highest mass loss and lowest wear resistance (E = 7417 m g^-1). Normalising produces a ferrite-pearlite matrix with a hardness of 18 HRC and improves wear resistance approximately four-fold (E = 29499 m g^-1). The quenched and tempered condition yields a tempered martensite matrix with finely dispersed carbides (< 0.5 μm) and a hardness of 61, 63 HRC, achieving the highest wear resistance (E = 67568 m g^-1) - approximately nine times greater than the as-delivered state. The findings confirm that optimised heat treatment is decisive in maximising the tribological performance of 100Cr6 steel for bearing applications.