Cobalt-Free Maraging Alloys

The maraging alloys series containing copper but cobalt free have been investigated. It was found that during solid solution treatment, the temperature for the second phase Fe₂Mo dissolving completely could not lower than 950℃, and for the alloys containing 6% Mo or less,the recrystallization treatment temperature for high temperature reversed auste-nite was 950℃.For the alloys containing more than 6% Mo, the recrystallization treatment temperature raised with increasing Mo%.Under opi-tical microscopy the morphology after recrystallization was rectangular block shape while it was fine packet shape before recrystallization.
After solid solution and recrystallization treatments at 950℃ and aging at 540℃ for 3 h, the general mechanical properties of Fe-Nil5-Mo6-Cu4-Ti alloy were as follow:
σ_b=1893.3MPa, σ_0.2=1784.5MPa.δ₅=9.5%, (ψ)=46%,H_RC=52.5.