PURPOSE: To efficiently execute the changeover of an operation mode without bringing about the degradation of a metallic strip with a series of rolling devices which are arranged following continuous annealing and descaling devices.
CONSTITUTION: In a 1st operation mode, the rolling mill 21 of a 1st stand is used and the metallic strip is coiled with a 1st coiler 24. At the time of changing over from the mode to a 2nd operation mode, the tip of the metallic strip from the last coil of a 1st group of coils is passed through by opening the rolling mills 22, 23 of 2nd and 3rd stands, led to a 2nd coiler 25 while threading and coiled. A metallic strip of the first coil of the following 2nd group of coils is rolled with satisfactory thickness accuracy by securing front tension. At the time of changing over from the 2nd operation mode to the 1st operation mode, rough rolling is executed using the rolling mill 21 of the 1st stand while passing the metallic strip following the last metallic strip in the 1st operation mode through all stands and the mode is changed over to the 1st operation mode after securing sufficient back tension.
KANEYASU SHINTARO
UMEO MITSUYUKI