Investigation on hot deformation behavior of AISI T1 high-speed steel

The hot deformation behavior of AISI T1 (18W–4Cr–1V) high-speed steel has been investigated in the temperature range 950–1150°C at strain rates of 0.001–10 s−1 and true strains of 0–0.6. The results show that the activation energy for deformation, Q, decreases with the increase of strain below 1000°C, and it changes slightly with the strain above 1000°C. Metallography shows that there are fine carbide particles precipitated in the grains, and that these lead to dispersion hardening and an increase in the value of Q. There are fewer of these particles above 1000°C than below it. The Zener–Hollomon parameter and the hyperbolic sine function are used to predict the flow stress as influenced by temperature and strain rate for different strain levels.