The effect of Ti-Mo additions on microstructural evolution and superplastic deformation behavior of cold–rolled medium Mn steels

• Published in: Materials characterization 2023-09, Vol.203, p.113051, Article 113051
• Main Authors: Zhang, H.T., Li, H.Y., Yan, H.L., Tang, S., Beladi, H., Hodgson, P.D., Cai, M.H.
• Format: Article
• Language: English
• Subjects: Grain boundary sliding; Medium Mn steel; Microstructural evolution; Superplastic deformation behavior; Ti–Mo microalloying
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2023.113051

This study investigated the effect of Ti-Mo alloying on the microstructural evolution and superplastic deformation behavior of Fe–5.6Mn–1.1Al–0.2C steels. The steels were subjected to cold–rolling and intercritical deformation at a strain rate of 10−2 s−1 and temperatures between 655 and 775 °C. The results showed that Ti-Mo added steel exhibits a significant improvement in the strength due to the high density of nano–sized (Ti, Mo)C particles and optimized superplastic elongation of approximately 1000% at 745 °C. The superplastic flow behavior showed a strong temperature dependence under three typical temperature regions. This can be mainly attributed to the decreased interaction between precipitation and DRX with increasing deformation temperature. The grain boundary sliding (GBS) accommodation process varied with the deformation temperature due to the difference in precipitation nature of the (Ti, Mo)C particles. •The Ti-Mo added steel exhibited an optimized superplastic elongation of ∼1000% at 745 °C.•The influence of Ti-Mo addition on microstructural evolution and high–temperature tensile behavior was investigated.•The interactions between precipitation, dynamic recrystallization and superplastic deformation were identified.•The accommodation process for grain boundary sliding was verified to vary with deformation temperature.