Effects of quenching-partitioning-tempering treatment on microstructure and mechanical performance of Nb-V-Ti microalloyed ultra-high strength steel

Microstructure evolution and mechanical performances of the Nb–V–Ti microalloyed ultra-high strength steel subjected to quenching–partitioning–tempering (Q–P–T) treatment are investigated by SEM, TEM, XRD examination and mechanical tests. After Q-P treatment, the microstructure consists of multiple phases, including lath martensite, retained austenite and small amount of twin martensite. Moreover, three types of carbides have been identified,...