Deformation Window and the Optimum Process Parameter Determination of a Bainite Steel Based on Processing Maps, Activation Energy Maps, and Dynamic Recrystallization Conditions

Abstract

The stress–strain curves of a bainite steel have been measured with hot compression experiments at temperatures of 1173, 1273, 1373, 1473 K and strain rates of 0.01, 0.1, 1, 10 s⁻¹ on a thermo-mechanical simulator (Gleeble-1500). The processing maps, activation energy maps, and the overlap regions of dynamic recrystallization zones and flow stability domains have been obtained by utilizing the stress–strain data experimented. The feasible process windows have been determined according to a new criterion that these windows are in the overlap regions where the activation energy isoline is the sparsest with its variation no more than 1%. Moreover, the optimum temperature and strain rate for a given strain have been ascertained by the largest power dissipation efficiency within the feasible process windows.