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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