Role of Nb Addition on Microstructural Stability and Deformation Behaviors of FeMnAlC Lightweight Steels at 400 °C

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

“…For example, the addition of 0.1 wt% Nb to a Fe-20Mn-8Al-1.0C austenitic steel led to an increase in yield strength by nearly 60 MPa attributed to the precipitation strengthening of NbC carbides and grain boundary strengthening. [29] Our previous study showed that the coaddition of 0.04Nb-0.3Mo in Fe-Mn-Al-C steels can effectively increase the strength as well. [42] Nevertheless, a review of these data shows that no reports are available to date on the effect of the addition of Nb, Mo, or coaddition of Nb-Mo on microstructures, including volume fraction of different B2 morphology, amount of κ (L 0 1 2 ordered (Fe,Mn) 3 AlC carbide) and grain sizes, and mechanical properties of Ni-containing Fe-Mn-Al-C steels.…”

“…[20] The B2 band-free Fe-16Mn-8Al-5Ni-1C steel possessed a better formability without any degradation of yield strength compared to the B2 banded Fe-15Mn-10Al-5Ni-0.8C steel, despite a much lower volume fraction of B2 in the former than the latter. [15] Furthermore, adding microalloying elements, such as Nb, [26][27][28][29] V, [30][31][32] Ti, [33][34][35] Si [36,37] and Mo, [38][39][40][41] is another effective strategy to improve the mechanical properties of Fe-Mn-Al-C lightweight steels. For example, the addition of 0.1 wt% Nb to a Fe-20Mn-8Al-1.0C austenitic steel led to an increase in yield strength by nearly 60 MPa attributed to the precipitation strengthening of NbC carbides and grain boundary strengthening.…”

“…Furthermore, adding microalloying elements, such as Nb, [ 26–29 ] V, [ 30–32 ] Ti, [ 33–35 ] Si [ 36,37 ] and Mo, [ 38–41 ] is another effective strategy to improve the mechanical properties of Fe–Mn–Al–C lightweight steels. For example, the addition of 0.1 wt% Nb to a Fe–20Mn–8Al–1.0C austenitic steel led to an increase in yield strength by nearly 60 MPa attributed to the precipitation strengthening of NbC carbides and grain boundary strengthening.…”

“…For example, the addition of 0.1 wt% Nb to a Fe–20Mn–8Al–1.0C austenitic steel led to an increase in yield strength by nearly 60 MPa attributed to the precipitation strengthening of NbC carbides and grain boundary strengthening. [ 29 ] Our previous study showed that the coaddition of 0.04Nb–0.3Mo in Fe–Mn–Al–C steels can effectively increase the strength as well. [ 42 ]…”

High Temperature Deformation Behavior and Microstructure Evolution of Low-Density Steel Fe30Mn11Al1C Micro-Alloyed with Nb and V

“…Very importantly, the addition of Al also induces dynamic precipitation of κ-carbide in the face centered cubic (FCC) structure by the spinodal decomposition of austenite during cooling and aging process, which deteriorates the ductility and toughness [ 7 , 22 , 23 , 24 ]. In order to overcome this drawback, Nb was proposed to addition to the austenitic Fe-Mn-Al-C steel because Nb has a strong affinity with C to form a very stable NbC phase during heat treatment process [ 25 ], which suppresses the precipitation of coarse κ-carbides [ 26 ] and retards the grain growth of austenite significantly due to the existence of stable nanosized NbC during the high temperature deformation process [ 27 ]. However, the effects of Nb on high temperature deformation behaviors and microstructural evolutions are seldom reported in the austenitic low-density steel.…”