Effect of caliber rolling temperature on the deformation behavior and mechanical properties of dual-phase medium Mn steel

• Published in: Materials chemistry and physics 2024-06, Vol.319, p.129328, Article 129328
• Main Authors: Tong, HaoChuan, Liu, Baoxi, Chen, Cuixin, Chen, Haifeng, Xiao, Zhixia, Ji, Puguang, Feng, Jianhang, Yin, Fuxing
• Format: Article
• Language: English
• Subjects: Austenite stability; Caliber rolling; Dual-phase medium manganese steel; Fracture characteristics; Mechanical property
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2024.129328

Dual-phase medium manganese steel (MMS) was caliber rolled at 800, 900 and 1000 °C, respectively, in order to clarify the deformation behavior and mechanical properties of warm deformed MMS. Herein, the microstructure evolution, tensile behavior and fracture characteristics exhibit obvious dependence on the caliber rolling temperature. The warm rolled steel contains martensite and austenite phases with heterogeneous grains including coarse fiber grains (CFG) and ultrafine equiaxed grains (UFG), which shows different microstructural stability. With the increase of rolling temperature, dynamic recrystallization (DRX) is more obvious, corresponding with the increasing percent of UFG, as well as the decreasing percent of CFG and martensite volume fraction. Meanwhile, high deformation temperature also leads to high austenite stability and the decreasing Transformation Induced Plasticity (TRIP) effect. The strength, strain hardening behavior and total elongation are gradually increased with the decrease of rolling temperature, which is attributed to severe strain partitioning and unique laminated structure in the caliber rolled MMS with low rolling temperature. Moreover, the warm rolled MMS reveals obvious ductile-ductile transition behavior in the temperature range from 25 °C to −60 °C. In addition, the low caliber rolling temperature also results into high impact energy, which is attributed to the high volume fraction of CFG. •Dual-phase medium manganese steel is rolled by caliber rolling at 800/900/1000 °C.•Delamination of martensite and austenite.•The lower rolling temperature, the higher ultimate strength and total elongation.•The impact energy is increased with the decrease of rolling temperature.