METHOD FOR CONTROLLING SHEET CROWN IN HOT ROLLING LINE

PURPOSE:To improve the shape quality of a rolled stock by comparatively calculating set rolling conditions with an actual operating conditions and a surface temp. distribution of the stock and performing temp. control to a form an optimum temp. distribution on a succeeding stock. CONSTITUTION:A multistage finishing mill 1a...1n and a sheet thickness control unit 3, and a host computer 11 are installed. A thickness gage 6, a thermometer 7, and a temp. controller 8 are installed in the inlet side 5 of the mill; a 2nd thickness gage 13 and a 3rd thermometer 14 are installed in the outlet side 12 of the mill. The host computer 11 compares previously set rolling conditions with actual operating conditions such as a drafting force, position of an intermediate roll 4, and a sheet thickness distribution and forms an optimum temp. distribution by controlling surface temps. of a succeeding rolled stock. Then, the sheet thickness control unit 3 controls a drafting force and a position of the roll 4. The shape quality is improved because crown control is performed in an optimum temp. distribution.