Fe−Mn−Al precipitation-hardening austenitic alloys

Conclusions

• 1. To obtain an austenitic structure and good physicochemical properties Fe−Mn−Al alloys should contain 8–10% Al, 25–30% Mn, and ∼1% C. An increase of the aluminum content and decrease of the manganese and carbon content results in α-phase in the structure, which impairs the magnetic and plastic characteristics of the alloys.

• 2. After quenching from 1150°C and aging 16 h at 550°C the alloys of the optimal composition have the following mechanical properties: σ_b=90–95 kg/mm²; σ_0.2=80–85 kg/mm²; δ=10–20%; ψ=15–30%.

• 3. Alloys of the optimal composition have a density of 6.7–6.8 g/cm³ and a substantially higher strength than the widely used Cr−Ni steel 10Kh2N24 or the Mn−Al steel 45G17Yu3.

• 4. Alloys with 8–10% Al have the same oxidation resistance as stainless steel 1Kh17N2.