Making Medium Mn Steel by Sustainable Ferromanganese Pre-alloy

Driving toward net-zero CO2 emissions in the steel industry, a more sustainable approach should be adopted in both iron-making and steel-making processes. While the sustainability of iron making is supported by the prospering hydrogen-based direct reduction technology [1], research on the sustainability of alloying ingredients used in steel making has been limited.

In this study, we utilized a “green” ferromanganese pre-alloy (FeMn) produced by a novel “HAlMan” process, which ensures lower energy consumption [2], as the Mn alloying ingredient in medium Mn steel production. The chemical composition of the designed steel using HAlMan FeMn (hereafter referred to as “HAlMan steel”) is Fe-0.2C-10.2Mn-2.8Al-1Si (in wt. %). To demonstrate the feasibility of the HAlMan steel, we also produced another medium Mn steel with similar composition using electrolytic Mn (hereafter referred to as “EMn steel”). Both steels underwent an identical thermomechanical process. Comparability between the HAlMan steel and EMn steel was demonstrated by a thorough microstructure characterization and mechanical testing.

In summary, the HAlMan steel showcases a similar grade of medium Mn steel performance as conventional EMn steel while utilizing a more sustainable alloying ingredient. This research effort aims to reduce the overall energy consumption of steel making without compromising steel performance, contributing to a more sustainable future in the steel industry.

References

[1] D. Raabe Chemical reviews, 2023, 123, pp.2436-2608.

[2] J. Safarian Conference of Metallurgists. Cham: Springer Nature Switzerland, 2023, pp.749-756.