| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent generation of heat scratch without obstructing the productivity by detecting the sheet temperature, the sheet thickness, the sheet speed on a stand outlet side and the temperature and flow rate of cooling water, and estimating the sheet temperature at the roll bite outlet to control the draft. SOLUTION: Temperature detectors 24 are provided on the inlet and outlet sides of a rolling mill of a fourth stand 4 to detect the temperature of a sheet S under rolling at a specified period. Thickness measuring devices 17 are provided on the outlet and inlet sides of the fourth stand 4, and sheet speed meters are provided on the outlet sides of the fourth stand 4 and a third stand 3 to detect the thickness and the sheet speed on the inlet and outlet sides of the fourth stand 4. The sheet temperature at the roll bite outlet in the rolled condition is estimated from these detected values, the temperature of cooling water for the sheet, and the supply amount of cooling water. The sheet temperature rise Tm' is obtained when the sheet temperature rise TE' in the roll bite and the draft are changed, and the draft to satisfy the inequality of TL-Tf>= Tm'-TE' is obtained, where TL is the heat scratch control target temperature, and Tf is the heat scratch outlet estimated sheet temperature.</p> |
