The effects of substructure on the high density core loss properties of commercial grain-oriented 3% SiFe

Commercially-produced grain-oriented 3% SiFe is batch annealed in coil form thereby generating single crystal grains with slight amounts of misorientation as measured from grain edge to grain interior. When heat flattened, lattice bending occurs along with the generation of a dislocation substructure, the quantity and arrangement of which depend on deformation rate, amount of deformation and stress relief annealing temperature. The 60 Hz core losses at 1.5 and 1.7T were found to be very sensitive to the latter two parameters. Core losses were modeled as a function of dislocation substructure. A strong linear correlation between supplemental losses, which are associated with 90° domain wall motion, and dislocation density was found without regard to dislocation arrangement. A weaker correlation was found between the interaction of 180° domain walls and dislocation density, perhaps indicating that dislocation arrangement is important here.