The effect of isothermal storage temperature and cooling rate on thermal processing on the maximum magnetic penetration in amorphous bands of magnetically soft [Formula: see text] alloys was studied. The dependence of maximum magnetic penetration on the isothermal storage temperature is determined using diffusion processes which occur during thermal processing at the certain isothermal storage temperatures. It is clear that increase of cooling rate directly impacts on the magnetic properties. Magnetic properties have been approached after thermal treatment of the surface when the surface is amorphous and at a certain optical thickness during formation of the amorphous-crystalline layer due to the increasing cooling speed.

We consider the possibility to use an amorphous Fe–Ni–Si–B material in the core of contactors, which are widely used in connecting and disconnecting electric circuits, instead of the crystalline material of 3% electric steel. Alloys containing Fe–Ni–Si–B have been treated with the use of mechanical, thermomechanical, and magnetic fields, and the material for practical applications has been obtained. The processing modes were chosen so that a change in the performance of ferromagnetic (below the Curie temperature) alloys during the annealing could be controlled. The obtained specimens were annealed in oil at 360 ∘C in a magnetic field of 200 A/m for 200 min. The temperature mode was chosen so that the stress relaxation could occur during the annealing, and the structural changes in the material could be observed.