Evidence of Martensitic Transformation in Fe-Mn-Al Steel Similar to Maraging Steel

• Published in: Metallurgical and materials transactions. A, Physical metallurgy and materials science Physical metallurgy and materials science, 2021-01, Vol.52 (1), p.26-33
• Main Authors: Kenedy, Gurumayum Robert, Lin, Yi-Jyun, Cheng, Wei-Chun
• Format: Article
• Language: English
• Subjects: Air cooling; Aluminum base alloys; Austenite; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cooling; Cooling rate; Ferritic stainless steels; High temperature; Iron; Low temperature; Manganese; Maraging steels; Martensite; Martensitic stainless steels; Martensitic transformations; Materials Science; Metallic Materials; Nanotechnology; Phase transitions; Quenching; Steel; Structural Materials; Surfaces and Interfaces; Temperature; Ternary alloys; Thin Films; TRIP steels
• ISSN: 1073-5623; 1543-1940
• DOI: 10.1007/s11661-020-06054-y

The Fe-Mn-Al steels claim a low density, and some fall into the category of transformation-induced plasticity (TRIP) steel. In Fe-Mn-Al TRIP steel development, phase transformations play an important role. Herein, the martensitic transformation of an Fe-16.7 Mn-3.4 Al ternary alloy (wt pct) was experimentally discovered, whose equilibrium phases are a single phase of austenite at 1373 K and dual phases of ferrite and austenite at low temperature. Ferritic lath martensite forms in the prior austenite grains after cooling from 1373 K under various cooling rates via quenching, air cooling, and furnace cooling. The formation mechanism of the ferritic lath martensite is different from that of traditional ferritic lath martensite in steel and quite similar to that in maraging steel. A slight strain energy coupled with a small temperature gradient can lead to the formation of ferritic lath martensite in the Fe-Mn-Al alloy after cooling from high temperature. It is also found that micro-twins exist in the ferritic lath martensite.