A simple heat treatment of austenitization followed by austempering was proposed to obtain ferritic–bainitic/martensitic dual-phase (DP) microstructure with ~ 18% bainite and ~ 30% martensite in low-carbon steel, which provides a promising way for processing of low-cost high-performance advanced high-strength steels (AHSSs) with improved strength–ductility trade-off, tensile toughness, and fracture behavior. The processed bainite-aided DP steel exhibited high yield stress and high ultimate tensile strength while maintaining high total elongation to failure, which were beyond the expected trends for conventional steels, ferritic–martensitic DP steels, and ferritic–bainitic DP steels. The continuous yielding behavior (with the disappearance of the yield point phenomenon) and more ductile fracture surface appearance were also remarkable. Accordingly, besides grain refinement by cold rolling and intercritical annealing, the present work proposed an alternative way for processing high-performance DP steels.

提出了奥氏体化后奥氏体回火的简单热处理，以获得铁素体-贝氏体/马氏体双相 (DP) 微观结构，在低碳钢中具有 ~ 18% 贝氏体和 ~ 30% 马氏体，这为低碳钢的加工提供了一种有前途的途径-成本高性能的先进高强度钢 (AHSS)，具有改进的强度-延展性权衡、拉伸韧性和断裂行为。加工后的贝氏体辅助 DP 钢表现出高屈服应力和高极限抗拉强度，同时保持高总断裂伸长率，这超出了常规钢、铁素体-马氏体 DP 钢和铁素体-贝氏体 DP 钢的预期趋势。连续屈服行为（随着屈服点现象的消失）和更具韧性的断裂表面外观也很显着。因此，