An extended description of the behaviour of steel sheet under rotational flux conditions

The behaviour of steel sheet under the condition of pure rotational flux is described by the permeability tensor, which is the product of the phase difference matrix alpha and the anisotropy matrix mu. The matrix cu considers the phase difference between the flux density B and the magnetic field strength H. The physical meaning of the matrix mu is the magnetic anisotropy of a steel sheet due to rolling processes and grain orientation. The fundamental harmonics of B and H are linked to the permeability tensor as follows: B = alpha mu H. The components of this tensor are obtained from measurements under rotational flux conditions, using the time dependent signals of two orthogonal induction coils wound around the sheet which pick up the magnetic flux, and two Rogowski-Chattock coils which measure the magnetic field strength on the surface of the sheet. The deviation of the texture axis of the steel sheet from the measuring direction and the angle of mismatch of the field sensors is described by the nondiagonal elements of the tensor.