On the Properties of Semihard Magnetic Alloys “Recalloy” in the Fe–Nb System

Magnetic properties, electrical resistivity, hardness and microstructure have been studied on Fe–Nb alloys “Recalloy” containing less than 4%Nb. The alloys are water-quenched from various temperatures over the α-γ transformation point, cold-drawn by more than 50% reduction, and then reheated at 400–1000°C for less than 5 h. The magnetic properties of these alloys depend remarkably on the reduction rate, reheating temperature and time. An Fe-3.1%Nb alloy reheated at 650°C for 30 min after water-quenching from 1050°C and subsequent cold-drawing by 97.2% reduction exhibits very superior properties as follows: magnetic induction at 8 kA/m B8=1.74 T, residual induction Br=1.62 T, coercive force Hc=1.62 kA/m, squareness ratio Br⁄B8=0.93 and squareness \sqrt(BH)max⁄BrHc=0.90. The electrical resistivity and Vickers hardness of this alloy are 0.126 μΩm and 353, respectively.