| 摘要 |
<p>PURPOSE:To shorten the time of dehydrogenation treatment for a steel sheet just finished a hot rolling pass, and to attain a superior dehydrogenation effect, by slowly cooling the said steel sheet in a cooling bed covered with a heat insulating cover. CONSTITUTION:A hot slab after removing its surface flaws, is heated by a heating furnace and is hot rolled by a rolling mill into a steel sheet 7 which is then successively conveyed by a roller table 8 into the feed-in side of a dehydrogenation-purpose cooling bed 9 provided with a heat insulating cover; plural steel sheets 7 in a piled- up style are passed in the cooling bed 9 and are slowly cooled for the purpose of dehydrogenation treatment. Hereupon, the time of slow cooling for the purpose of dehydrogenation of the steel sheet 7, and the number of steel sheets 7 in one pile, are determined correspondingly to the hydrogen content of the molten steel and the thickness of the steel sheet 7. The dehydrogenation-purpose cooling bed 9 is covered with a bellows type heat insulating cover 10 internally lined with a heat insulating cloth 11 and freely stretchable in the direction of longitude of the cooling bed 9; hereby, the cooling bed 9 is isolated from the external air and is kept at temperature effective for carrying out a dehydrogenation treatment for the steel sheets 7 by slow cooling them for many hours, so that a superior dehydrogenation effect is attained.</p> |
