Microstructure, mechanical properties and deformation mechanism of Fe-18Mn-8Al-1C lightweight steel

doi:10.13251/j.issn.0254-6051.2025.03.029

Abstract

Abstract: Fe-18Mn-8Al-1C lightweight steel was annealed at 950 ℃ for 1 h and tensile deformation with different tensile strain (ε=5%, 15%, 25%, 35%) was conducted. The microstructure, mechanical properties and deformation mechanism of the Fe-18Mn-8Al-1C lightweight steel were investigated by means of optical microscope, electron backscattered diffraction, electron channeling contrast imaging and transmission electron microscope. The results show that an excellent combination of high strength and adequate total elongation is obtained of the tested steel annealed at 950 ℃. A typical deformation mode, i.e., planer glide, is observed in the tested steel. The deformation mode can be concluded as: dislocation gliding in single/multiple slipping system →Taylor lattices →microband. The strain hardening ability can be significantly enhanced as a result of the increase in the geometrically necessary dislocation, while the effect of microband induced plasticity can be activated by the development of microband, leading to a simultaneous enhancement in the strength and elongation of the tested steel.

Key words: Fe-Mn-Al-C lightweight steel, microstructure, mechanical properties, deformation mechanism, microband induced plasticity, Taylor lattice

CLC Number:

TG156.21

Ma Ruoxi, Yin Yubin, Deng Chao, Li Ziyu, Zhang Zhelin, Ding Hua. Microstructure, mechanical properties and deformation mechanism of Fe-18Mn-8Al-1C lightweight steel[J]. Heat Treatment of Metals, 2025, 50(3): 183-188.

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