JPS57206505A - Cross rolling method in rolling of thick plate - Google Patents

Abstract

PURPOSE:To improve cross rolling accuracy in rolling of thick plates by determining the volume of a slab after drawing out from a heating furnace, calculating the target thickness at the end of the cross rolling and subjecting the slab to cross rolling. CONSTITUTION:With the actual weight of a slab S prior to loading into a heating furance defined as W, the density taking the steel compsn. of the slab S into consideration as rho, and the coefft. of scale loss of the heating furnace as alpha, the volume V of the slag after drawing out from the heating furnace is determined by the equation v=w/rhoxalpha. The target thickness T at the end of the cross rolling is calculated by the equation T=V/(AXB) from said volume V of the slab, the width A of the slab allowing for the rate of deformation measured with a side guide or a width gage or the like prior to starting of rolling and the target plate width B taking the rate of defomation during the cross rolling into consideration. The rolling reduction of rolling mills is set at this target thickness T, and the slab Sl is subjected to the cross rolling.