Constitutive modeling for hot deformation behavior of T24 ferritic steel

Hot compression tests of T24 ferritic steel were carried out using Gleeble-3500 thermo mechanical simulator in the temperature range of 1323–1473 K with the strain rate of 0.01–10 s−1 and the height reduction of 60%. The flow behavior of T24 ferritic steel was characterized based on analysis of the true stress–strain curves. Constitutive equations incorporating the effects of temperature, strain rate and strain have been developed to model the hot deformation behavior of T24 ferritic steel. Material constants α, n, ln A and activation energy Q in the constitutive equations were calculated as a function of strain. The flow stress values of T24 ferritic steel predicted by the proposed constitutive equations show a good agreement with experimental results, which indicated that the developed constitutive equations could give an accurate and precise prediction for the flow stress of T24 ferritic steel.

► The hot deformation behavior of T24 ferritic steel was investigated over a practical range of temperatures and strain rates.
► Constitutive equations to describe the relationship between flow stress and temperature, strain rate, strain were proposed.
► The influence of strain was incorporated by considering the effect of strain on material constants.
► The developed constitutive equations can accurately predict the flow stress of T24 ferritic steel.