Enhancement of the mechanical properties of a Nb-microalloyed advanced high-strength steel treated by quenching–partitioning–tempering process

There is an urgent requirement for better combination of high strength and adequate toughness of steels to meet the demand of industrial applications. The present study shows that an Fe–0.2C–1.5Mn–1.5Si–0.05Nb–0.13Mo steel subjected to quenching–partitioning–tempering (Q–P–T) process based upon modifying the recently developed Q&P treatment by Speer et al. exhibits high-tensile strength (1500 MPa) and relatively high elongation (15%), therefore, Q–P–T steels have become a novel group of advanced high-strength steels. The origin of such excellent mechanical properties was revealed by characterization of microstructure.