| 摘要 |
<p>PURPOSE:To uniformly cool a thick hot-rolled steel plate and to improve flatness of the thick steel plate after cooling by beforehand detecting roughness of the rolling roll surface and controlling cooling water quantity to the width direction of the hot rolled steel plate by this result at the time of water-cooling after hot-rolling the thick steel plate. CONSTITUTION:During carrying the hot-rolled thick steel plate H with table rollers 6, the cooling water is sprayed from plural nozzles 3 arranged to the width direction of the steel plate H, to cool the steel plate H by the water. In this case, as oxide scale on the surface of the steel plate H is thick and has much adherence at the center part and is thin and easily detached at both end parts, cooling becomes unequal by the water cooling and the flatness of the steel plate H is deteriorated. The scale on the surface of the rolled steel plate is greatly influenced by the roughness of the surface of the rolling roll 5, and the rolled part at the center part of the roll having much roughness A develops the scale having thick and much adherence and has water- cooling effect less than it at both end parts. Therefore, the surface roughness to axial direction of the rolling roll 5 is measured, and based on this, by making much quantity of the cooling water from nozzle 3 for water cooling at center part having much roughness, the steel plate H is uniformly cooled and the steel plate having good flatness is obtd.</p> |
