Accelerated cooling method of steel after plate to minimize vertical temperature deviation in thickness direction

摘要

The present invention relates to accelerated cooling of post-steel plates useful for line pipes, hull structural, architectural structures, and the like; And an object of the present invention is to provide an accelerated cooling method that minimizes the vertical temperature deviation in the thickness direction during manufacturing of the steel sheet of 60 Kg / mm 2 or less.;The present invention relates to a method for accelerated cooling after hot rolling a heated slab to a steel backing plate, wherein the upper and lower portions of the steel strip are cooled at a predetermined upper and lower initial flow rate (W_top) (W_bot) The upper and lower flow rate values BTFR, that is, BTFR = a.times. (. DELTA.T) + b (.DELTA.T) are calculated by using the upper and lower temperature deviations .DELTA.T;(B = 1, 0.800 BTFR 1. 200, a: the flow compensation gradient for the temperature deviation, 0.001 A 0.01, b: the initial flow rate setting value b = 1), and then the BTFR is calculated as the upper initial flow rate W_top ), And an accelerated cooling method for a steel plate after the steel plate is accelerated and cooled by applying the upper flow rate value W_top = W_top (initial set upper flow rate) BTFR to the steel plate in the thickness direction is minimized.