The Effects of Austenitizing Conditions on the Microstructure and Wear Resistance of a Centrifugally Cast High-Speed Steel Roll

The influences of austenitizing conditions on the microstructure and wear resistance of a centrifugally cast high-speed steel roll were investigated through thermodynamic calculation, microstructural analysis, and high-temperature wear tests. When the austenitizing temperature was between 1323 K and 1423 K (1050 A degrees C and 1150 A degrees C), coarse eutectic M2C plates were decomposed into a mixture of MC and M6C particles. However, at 1473 K (1200 A degrees C), the M2C plates were first replaced by both new austenite grains and MC particles without M6C particles, and then remaining M2C particles were dissolved during the growth of MC particles. The wear resistance of the HSS roll was improved with increasing austenitizing temperature up to 1473 K (1200 A degrees C) because the coarse eutectic M2C plates, which are vulnerable to crack propagation, changed to disconnected hard M6C and MC particles.