SEMIPROCESSED NONORIENTED MAGNETIC STEEL SHEET HAVING EXCELLENT MAGNETIC CHARACTERISTICS AND METHOD FOR MAKING THE SAME

摘要

The present invention relates to a semiprocessed nonoriented magnetic steel sheet which is used in iron cores of motors and transformers, finished to a final product by rolling having a reduction rate of 2 to 18% after final annealing by a manufacturer, and assures desired magnetic characteristics due to coarsening of crystal grains during strain-relief annealing after processing by a user. The excellent magnetic characteristics can be achieved by increasing lubrication during second cold rolling so as to satisfy the equation: e c .ltoreq. e s .ltoreq. 1.18e c wherein e s represents a strain value at the surface layer of the steel sheet and e c represents a strain value at the central layer.