JPS5619901A - Slab with dog bone end - Google Patents

Abstract

PURPOSE:To prevent a decrease of the product yield, by forming both ends of the slab before being fed to the broadside rolling work, into the specified dog bone shape for the purpose of reducing breadth and making the slab breadth after the roughing pass to be approximately uniform. CONSTITUTION:The deformed slab S with previously specified breadth as shown in the figure A is naturally fitted to the width set in the edging roll (e) of the roughing mill. That is, at this point of time, the excessive correction of breadth is not performed. Accordingly, the end 1 keeps the previously formed dog bone shape as it is; and with the progress of broadside rolling work from the end 1 to the middle part 2, the dog bone zone is gradually increased as far as the middle part 2, and hereafter, the dog bone 3 in uniform condition is continuously formed. As a result, the dog bone 3 formed over whole slab S becomes uniform over all length as shown in the figure C, and this slab S can be rolled with almost uniform pressure in the flat rolling pass shown in the figure D. Accordingly, both ends of the product possess the almost same breadth as in the middle zone (figure E), so that the cutting work for both ends becomes unnecessary.