Bainite microstructures have become increasingly attractive for the development of advanced high-strength steel owing to their balanced strength-plasticity properties.In this study, the final microstructure and mechan...Bainite microstructures have become increasingly attractive for the development of advanced high-strength steel owing to their balanced strength-plasticity properties.In this study, the final microstructure and mechanical properties of a quenching and partitioning(QP) steel sample after two distinct QP processes were analyzed.The results reveal that martensite transformation after quenching resulted in a lathed morphology with higher yield strength and hole expansion ratio.In contrast, bainite transformation after quenching resulted in the formation of a blocky microstructure composed of bainitic ferrite retained austenite and nanoscale precipitates during the subsequent phase transformation at a higher temperature.This kind of final microstructure is beneficial to the elongation of QP steel but detrimental to the hole expansion ratio.展开更多
文摘Bainite microstructures have become increasingly attractive for the development of advanced high-strength steel owing to their balanced strength-plasticity properties.In this study, the final microstructure and mechanical properties of a quenching and partitioning(QP) steel sample after two distinct QP processes were analyzed.The results reveal that martensite transformation after quenching resulted in a lathed morphology with higher yield strength and hole expansion ratio.In contrast, bainite transformation after quenching resulted in the formation of a blocky microstructure composed of bainitic ferrite retained austenite and nanoscale precipitates during the subsequent phase transformation at a higher temperature.This kind of final microstructure is beneficial to the elongation of QP steel but detrimental to the hole expansion ratio.
