Temperatures and Atmospheres
A controlled atmosphere, suited to the type of material being annealed, is necessary to prevent contamination and consequent impairment of magnetic properties. Temperatures for commercial annealing should be closely controlled and no higher than required to obtain the necessary magnetic performance of the final product.
In certain critical applications, somewhat higher tem- peratures or modified atmospheres may yield slightly better magnetic properties. However, such practice is not generally recommended because the temperature, time and atmosphere must be controlled more carefully. This is necessary not only to obtain consistent results, but also to avoid deterioration of surface insulations and an increased tendency for adhesion, or sticking, of laminations. Special annealing requirements should be discussed with AK Steel specialists to obtain specific recommendations for the conditions