Effect of Q&P and Q&T Treatments on the Stability of Austenite and Mechanical Properties of Steel 0.2% C – 8.5% Mn – 3.0% Al

The effect of quenching-partitioning (Q&P) and quenching-tempering (Q&T) treatments on the stability of austenite and mechanical properties of cold-rolled medium-manganese TRIP steel (0.2% C – 8.5% Mn – 3.0% Al – Fe) is studied. It is shown that the Q&T treatment provides an ultimate tensile strength σ r = 1160 MPa and an elongation δ = 53%; the value of σ r × δ = 61 GPa · %, which is lower than after the Q&P treatment (σ r = 910 MPa, δ = 47% and σ r × δ = 43 GPa · %). The elevated mechanical properties of the steel after the Q&T treatment are explained by the higher content of austenite in the structure and the more manifested TRIP effect during the deformation process.