Structure and Phase Transformations upon Carburisation of High-Speed Steel

Diffusion effects of alloying elements on the structure and phase transformation during thermo-chemical treatment in AISI M2 high-speed steel additionally alloyed with vanadium, titanium and niobium have been investigated. The results of metallographic, X-ray diffraction, and electron microprobe analyses of the steels after casting, annealing, hot plastic deformation, carburising, quenching and tempering are discussed. The redistribution of alloying elements between the metallic matrix and carbide phases upon high-temperature treatment due to diffusion was shown to result in the structure and phase transformations in the steels studied.