Enhanced High‐Temperature Strength of a Low‐Density Dispersion‐Strengthened Fe–Mn–Al–C Steel

Abstract

A novel low‐density dispersion‐strengthened Fe–18%Mn–8%Al–0.8%C (wt%) steel exhibiting superior high‐temperature strength at 700–900 °C, is developed. The finely dispersed ferritic grains that form near the grain boundaries of the austenite phase provide significant strengthening by pinning the dislocations and enable high microstructural stability by restricting the dynamic recovery/recrystallization. The high Mn content provides remarkable solid solution strengthening to this steel, while the high aluminum content prominently lowers the density to enhance the specific strength. This newly developed steel with low alloying and manufacturing costs has great potentials for structural applications at elevated temperatures.

Tailoring Strength and Ductility of an Fe–Mn–Al–C Low‐Density Duplex Steel by Controlling the Cooling Path after Hot Rolling

“…[1] The austenitic lowdensity steels usually take advantage of the precipitation of κ-carbides, and thus high contents of aluminum and carbon are generally required. [2][3][4][5][6] In general, the low-density ferritic steels have a lower strength, [7] but the duplex low-density steels exhibit an excellent strength-ductility match. [8][9][10][11][12] Herein, the high work hardening capability of duplex low-density steels could be regulated by deformation-induced martensitic transformation of retained austenite.…”