| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a coiling temp. control method of a hot-rolled steel sheet, with which the coiling temp. is controlled so as to match to a target temp. at high accuracy, even in the case the coiling temp. is in the low temp. range, such as 400-500 deg.C, or even in the case a scale thickness on the steel sheet is thick or the steel sheet has the large ratio of heavy component, such as Si, Ni, related to the scale thickness. SOLUTION: The temp. TMHF of min. heat flux point changed from a film boiling state to a transition boiling state, and the temp. TCHF of critical heat flux point changed from the transition boiling state to a nuclear boiling state on the water-cooling surface of the hot-rolled steel sheet with respect to a prescribed sampling point, are estimated, respectively. Further, the boiling state of the water-cooling surface is estimated from the relation of respective temperatures TMHF and TCHF of the min. heat flux point and the critical heat flux point, and the temperature of water-cooling surface of the hot-rolled steel sheet, and the heat transfer coefficient of the water-cooling is calculated from a model formula of the heat transfer coefficient of the water-cooling according to the estimated boiling state. Then this heat transfer coefficient of the water-cooling surface to the prescribed sampling point is calculated by using this heat transfer coefficient of the water-cooling.</p> |
