Strengthening Mechanisms in Low Density Fe–26Mn–xAl–1C Steels

Abstract

The authors elucidate here the structure‐mechanical property relationship in Fe–26Mn–xAl–1C steels with different concentration of Al in conjunction with the quantitative assessment of different strengthening mechanisms. Nano‐sized κ carbides contribute significantly to the increase in yield strength of the steel, being ≈1.78 times of the effect of solution hardening by Al.

Effect of Al Additions and Cooling Rate on the Microstructure and Mechanical Properties of Austenite FeMnAlC Steels

“…According to the mechanical properties results shown in Figure 4 , the increasing of Al addition and decreasing of cooling rate promote the precipitation of κ-carbides, which improve the strength and slightly reduce the plasticity, but significantly reduce the impact toughness. It has been reported in many studies that the solid solution of Al improves the strength of FeMnAlC steel [ 29 , 31 ], 1% Al addition in solid solution can increase the strength by 9.3 MPa, κ-carbides significantly improve the strength of steel. Song found that κ-carbides began to precipitate and long-range order aged at 600 °C for 15 min, which has a strong strengthening effect, and like traditional carbide strengthening, such as NbC, TiC, VC, etc., the strengthening potential reaches 100–350 MPa.…”

Microstructure and mechanical properties of an Fe–Mn–Al–C lightweight steel after dynamic plastic deformation processing and subsequent aging

“…where α is a constant related to the material properties and has a value of 0.24, M is the orientation factor which is equal to 3.06 for FCC materials, G is the shear modulus of austenite which is taken as 70.7 GPa and b is the modulus of the Burgers vector of austenite having a value of 0.26 nm [41,43,55]. According to Eq.…”

“…where 𝛾𝛾 𝐴𝐴𝐴𝐴𝐴𝐴 is the average antiphase boundary energy which is 0.2 J/m 2 , r is the mean nanoprecipitate radius, f is the volume fraction of the precipitates, ε is the constrained lattice parameter mismatch which is 0.574%, χ and m are constants having values of 2 and 0.85, respectively, and ΔG is the shear modulus mismatch which is 23.7 GPa [41,43,55].…”

“…The DPD processing produces a reduction in the grain size and therefore it strengthens the material. The contribution of the refined grain size to the strength is described directly by the Hall-Petch relationship which gives [41,43,55]:…”

The Effect of Nb/Mo on the Microstructures and Mechanical Properties of Fe–Mn–Al–Ni–C Austenitic Steels

“…[1][2][3][4][5] To further develop the potential properties and promising applications of the steels, several investigators have recently evaluated the addition of Ni in Fe-Mn-Al-C lightweight steels. [6][7][8][9][10][11] They found the formation of B2 phase, an NiAl-type intermetallic compound having ordered body-centered cubic crystal structure, in the steels led to an improvement in work hardening ability and corresponding more attractive strength and ductility matching. [12][13][14][15][16][17] It was also shown that the size, distribution, and morphology of B2 phase had a remarkable impact on the mechanical properties.…”