METHOD FOR PREVENTING EDGE CRACK IN COLD ROLLING OF SILICON STEEL SHEET

PURPOSE:To prevent edge crack and improve the yield by cold tandem rolling a silicon steel sheet, the silicon of which content is limited under specified conditions. CONSTITUTION:At the time of rolling the silicon steel sheet whose silicon content is >=1.5wt.% with a cold tandem mill, edge grinding treatment that the allowance for grinding is >=0.5mm in the width direction from the edges of sheet is executed just after trimming. At the time of tandem rolling after that, one ends of the work rolls of a 1st stand are made claviform, upper and lower work rolls are arranged so that their axial directions are reverse to each other and they are made to be movable in the axial directions of the work rolls. One ends of the work rolls of stands after a 2nd stand is tapered down, upper and lower work rolls are arranged so that their axial directions are reverse to each other and they are made to be movable in the axial directions of the work rolls. The temps. of the edges of sheet on the inlet sides of the stands after the 2nd stand shall be >=80 deg.C.