COOLING METHOD FOR ROLLING STOCK IN CONTINUOUS HOT ROLLING OF STEEL BAR, WIRE ROD

摘要

PURPOSE:To shorten length of nonwater cooled part and inadequately cooled part at rolling stock top end and to improve yield of product, by controlling respectively and independently flow rates of cooling water supplied to plural cooling pipes provided parallelly along a pass line of rolling stock. CONSTITUTION:Billet extracted from a heating furnace 20 is continuously hot rolled to rolled stock such as steel bar, wire rod by rolling mills 1-16. Cooling zones 24, 25 having cooling zones 34, 35 between tandem rolling mills 22, 23 and behind the tandem finish rolling mill 23 respectively are arranged, and the zones 34, 35 have plural cooling pipes 36 provided parallelly along the pass line 33 of rolling stock. Rolling stock is cooled by supplying cooling water to the pipes while being transferred in the pipes 36. At this time, flow rates of cooling water supplied to respective pipes 36 are controlled by controller contg. a process control computer 29 to, respectively and independently, control respective pipes 36, so that cooling water is blown to rolling stock from cooling nozzle of respective pipes 36 just after passing of rolling stock top end part through the zones 34, 35.