CONTROLLER FOR COOLING HOT-ROLLED STEEL SHEET

摘要

PURPOSE:To obtain the cooling controller with improved precision in the temps. of the upper and lower faces of a hot steel sheet and cooling temp. in the cooling process by controlling the amt. of cooling water to be sprayed from the nozzles arranged on the upper and lower faces to minimize the camber of the sheet obtained from the stress and strain value obtained by a stress and strain arithmetic means. CONSTITUTION:The relation between the amt. of cooling water to be sprayed from the nozzles 7c provided on the upper and lower faces and the heat conductivity of a hot steel sheet 1 is obtained based on the previously given physical properties of the sheet 1. The temp. distribution in the thickness direction of the sheet 1 is calculated by a temp. distribution calculating means from the heat transfer rate at the actual cooling water amt. by the calculation from the relation between the cooling water amt. obtained by the actual temp. of the sheet 1 at the inlet of a cooler 7 detected by a temp. detecting means and the heat conductivity of the sheet 1. The amt. of cooling water to be sprayed from the nozzles 7c arranged on the upper and lower faces is controlled by the cooling water control means so that the camber of the sheet 1 shown by the correction value obtained by a stress and strain correction value calculating means and obtained by the stress and strain arithmetic means is minimized.