Dynamic recrystallisation and constitutive equation in hot deformed AISI H10 tool steel

ABSTRACT

The compression deformation behavior of AISI H10 (DIN 32CrMoV12-28) hot work tool steel was investigated at temperatures ranging from 900°C to 1200°C and strain rates from 0.01 to 1 s⁻¹. True stress-strain curves showed that a decrease in strain rate or increase in deformation temperature can promote the occurrence of DRX. It was found that the characteristic strains and stresses decrease with an increase in temperature or decrease in strain rate. The σc/σp ratio takes an average of 0.94; and the ϵc/ϵp ratio lies in range of 0.48-0.65 (average of 0.53). This suggests that DRV in H10 is not extensive and DRX starts at strains about half of the peak strain. However, the extensive softening by DRX keeps σp close to σc. Using the hyperbolic-sine constitutive equation, the deformation activation energy was calculated to be about 435.76 kJ mol⁻¹.

KEYWORDS:

• 32CrMoV12-28
• flow curve modelling
• thermomechanical processing
• elevated temperature deformation
• hot deformation
• constitutive analysis

Disclosure statement

No potential conflict of interest was reported by the author(s).