To properly correct zero point error without changing the control contents in plate width control and while making its constitution simple.
The method of controlling the plate width of a rolled material includes: a plate width measuring process (step S1) where the forward rolling of the rolled material, by which the rolled material is rolled from the upstream side to the downstream side, is performed with a reversing rolling mill and the plate width of the rolled material is measured with a plate width meter provided on the downstream side of the reversing rolling mill; a vertical roll opening degree-obtaining process (step S2, step S3) where reverse rolling by which the rolled material is rolled from the downstream side to the upstream side with the reversing rolling mill, is performed and, by bringing vertical rolls into contact with the rolled material at that time, the opening degree of the vertical rolls when the vertical rolls are brought into contact with the rolled material is obtained; and a correcting process (step S4, step S5) where rolling control of the plate width now and after is corrected on the basis of the opening degree of the vertical rolls which is obtained in the vertical roll opening degree obtaining process.
UCHOMAE HIROSHI
NITTA KAZUHIRO
Yoshiaki Naito
Cui Shu Tetsu
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