Prediction of tensile properties of intercritically annealed Al-containing 0.19C–4.5Mn (wt%) TRIP steels

•A model was proposed to predict tensile properties of intercritically annealed medium Mn TRIP steels.•Phase fraction and martensite transformation kinetics were calculated and used as input parameters to the model.•Martensite transformation kinetics under tensile deformation were predicted from austenite chemical composition.•Predicted evolution of tensile properties with annealing temperature showed good correlation with experimental results.•Maximum UTS×UE values and greatest retained austenite fractions were obtained at the temperature of cementite precipitation.

Tensile properties were predicted for intercritically annealed 4.5 wt% Mn steels with varying Al additions up to 1.3 wt%. Intercritically annealed phase fractions and retained austenite chemical compositions were obtained using a retained austenite prediction model assuming ortho-equilibrium alloy partitioning. The martensite transformation kinetics during tensile deformation were also estimated from the predicted retained austenite chemical compositions. Predicted phase fractions and martensite transformation kinetics were incorporated in a composite model for multi-component systems. Predicted tensile strength and uniform elongation values were compared to the experimental data obtained from the steels annealed at temperatures ranging from 550 to 725 °C for 1 h followed by water quenching.

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