Analysis of elevated temperature flow and work hardening behaviour of service-exposed 2.25Cr-1Mo steel using Voce equation

The Voce equation was used to model the tensile flow and work-hardening behaviour of a service-exposed 2.25Cr-1Mo steel. The applicability of Voce parameters obtained from the fit to experimental true stress-true strain datasets for estimating the validity of the fit was examined. The Voce equation was found to model the stress-strain curve closely. The Voce parameter nv was correlated to the underlying dislocation activities. It was found that the values of Voce parameters at various temperatures and strain rates can be used to infer the operating recovery mechanism during stage III hardening. A low absolute value of nv is indicative of recovery by cross-slip, whereas the high temperature transition to climb or sub-boundary migration driven recovery is accompanied by an increase in the value of nv