Research on hot deformation behaviour of as-cast W12Cr4V5Co5 steel

Abstract

Hot working response of as-cast W12Cr4V5Co5 steel was investigated by isothermal compression testing in the temperature range of 1000-1150°C and strain rate range of 0.01-10 s −1 . Experimental results showed that the flow stress and microstructure evolution were susceptible to the hot deformation parameters. Work hardening first occurred at a small strain, followed by softening, and finally, an approximate dynamic equilibrium was achieved between work hardening and softening. The activation energy of deformation was calculated to be 557.33 kJ mol −1 , and constitutive equations compensated with strain were proposed to describe the flow stress as a function of deformation parameters. Microstructure analysis indicated that the average grain size decreased with the increase in strain rate and the decrease in deformation temperature. Additionally, the simulation of hot deformation via Deform-3D software revealed the sample's inhomogeneous deformation during hot compression. This study may provide guidance for hot working of as-cast W12Cr4V5Co5 steel.