On magnetic properties of Fe-Si-Mn alloy sheet

Fe-Si-Mn alloys composed of 3.5-7,5%, 0-3.5%Mn and 90-96.5%Fe were melted in argon and hot-rolled. Measurements of their magnetic properties and electrical resistivity indicate that the addition of manganese to higher silicon-iron alloys improves in permeability and coercive force of the alloys. Maximum permeability as high as 83000 is obtained when the alloy of 6.70%Si, 0.55%Mn and 92.75%Fe is quenched into oil from 400° after annealing at 1200° for 5 hr. The alloy exhibits the coercive force of 0.06 Oe for the maximum induction of 10 kG. The electrical resistivity of the alloy is 86 μΩ-cm, with the Vickers hardness of 355.