| 摘要 |
A ferromagnetic material with a low relative hysteresis factor for use in transformer cores is made from a nickel base alloy of composition 68.5-81.5% Ni, 0-15% Cu and 11.5-23.5% Fe + Mo and/or Cr, the Mo and/or Cr content being 0-10%, which is first annealed at 700 DEG to 1100 DEG C., e.g. for 1-10 hours, in a reducing atmosphere such as hydrogen or in a vacuum, and then tempered at between 400 DEG and 600 DEG C., e.g. for 20 minutes-10 hours in hydrogen. The tempering may be effected by definite cooling from 600 DEG to 400 DEG C., e.g. at rate of 125 DEG C./hour, directly after the anneal. Specification 717,823 is referred to. |
