Influence of the applied elastic tensile and compressive stress on the hysteresis curves of Fe-3%Si non-oriented steel

The influence of applied elastic tensile stress up to 120 MPa and compressive stress up to 35 MPa on the magnetic hysteresis curves of non-oriented Fe-3%Si steel is studied. In two tensile stress ranges the hysteresis loop changed monotonously - low stress below 10 MPa facilitated the magnetization process, while above 15 MPa tension deteriorated magnetic properties. This difference in behavior corresponds to two different mechanisms - 1) favoring by tensile stress magnetic easy axes closest to the filed direction and 2) appearance of large demagnetizing fields at grain boundaries and the sample surface. Compression continuously deteriorated magnetic properties and made the hysteresis loop constricted above a few MPa. The effective field as a product of two functions - of the magnetization and of the stress gave excellent agreement with experimental curves for both tensile stress ranges and for compression. The sensitivity of magnetization to compression was approximately five times larger than to tension. The complex hysteresis loop behavior under tension and compression was explained on the basis of our previous results on stressed grain-oriented steel of the same composition, in which the magnetic domains were also studied.