Cold-rolling mill, tandem rolling system, reversing rolling system, modification method of rolling system, and operating method of cold-rolling mill

摘要

By reducing the work roll in diameter, rolling of a harder steel strip than ever and rolling of a steel strip of the same hardness as before at a higher reduction ratio can be performed, while preventing decrease in productivity due to use of such a small-diameter work roll mill as in the cluster type rolling mill. A cold-rolling mill 51 for rolling a metal strip 1 of minimum width not less than 600 mm and maximum width not less than 1,500 mm but not greater than 1,900 mm comprises a pair of upper and lower work rolls 2 for rolling the steel strip 1 to be rolled; a pair of upper and lower intermediate rolls 3 supporting the work rolls 2, respectively; a pair of upper and lower buck-up rolls 4 supporting the intermediate rolls 3, respectively; an axial direction roll shifting device 23 for each of the intermediate rolls 3; and bending devices 10, 11 for each of the work rolls 2 and the intermediate rolls 3. The work rolls 2 each have a diameter not less than 300 mm but not greater than 400 mm, and the intermediate roll 3 each have a diameter not less than 560 mm but not greater than 690 mm.