5. Magnetic performance with low sensitivity to external disturbances

The magnetic properties of materials are generally guaranteed by manufacturers under optimum conditions, both in terms of material condition (stress relaxation, reductive annealing to avoid oxidation, optimized microstructure) and measurement conditions (20 to 25°C, low humidity, "young" material that has not been allowed to age by carbon diffusion at low temperature, absence of stress). However, in many cases, the magnetic performance of materials is significantly affected, and rarely in the right direction, by :

• thermomechanical processing (annealing, cutting, machining, blue staining) for electrical and electronic consumers;

• external disturbances that affect the application in a foreseeable way: superimposed DC field, harmonic components, random high-intensity electrical disturbance, accidental high temperature,...