ON THE VARIATION OF REVERSIBLE PERMEABILITY WITH INTENSITY OF REMANENT MAGNETIZATION

The variation of reversible permeability (μ) with the intensity of remanent magnetization (Mr) is studied in three magnetically semihard materials having comparable values of Hc (20-30 Oe) and M s (≅16 kG), but widely different M-H loop shapes. Mr was altered by the transient exposure of wire specimens to mechanical vibrations, excursions of temperature, and a wide range of field conditions. At low-to-moderate values of Mr, μ showed greater dependence on the magnetization path than on the magnitude of Mr. Both the value of μ and its path sensitivity were found to decrease at high values of M r. Modest transient heating of a two-phase high carbon steel strongly influenced both μ and Mr. No such effects were observed in the other materials.