Hot deformation characteristics and kinetics analysis for Nickel-based
corrosion resistant alloy
Abstract
The hot deformation characteristics of Nickel-based corrosion resistant
alloy was studied in the temperature range of
1050~1200oC and the strain rate range of
0.001~0.1s-1 by employing hot compression tests. The
results show that the peak stress increases with decreasing temperature
and increasing strain rate, and the activation energy is about
409kJ/mol. Basing on the Avrami equation through using the critical
strain (εc) and the strain for 50% DRX (ε0.5), a kinetic model for
dynamic recrystallization (DRX) was established, where the model
parameters could be obtained using the modified Zener-Hollomon parameter
(Z*). Applying the model, the predicted value of the steady state strain
(εss) and the strain for maximum softening rate (εm) agree well with the
experimental results. Accordingly, the relationship between ε m and ε
0.5 is established, which is mainly dependent on the Avrami exponent
(n). When n <3.25, εm becomes less than ε0.5 and the
difference in between decreases with increasing the strain rate or
decreasing the deformation temperature. Finally, through observing DRX
microstructure under different deformation conditions, a power law
relation between DRX grain size (Ddrx) and Z*, with an exponent of
-0.36, was found.