High productivity and gauge accuracy are required of a tandem cold rolling mill that produces ultra-thin gauge strip, such as a tin mill black plate. Until now, the authors have improved lubrication for cold rolling by developing a new direct rolling oil and a Ti-enhanced work roll having high wear resistance for No. 2 TCM of Chiba Works. As a result, it has been made possible to conduct rolling at an ultra-high speed, that is 2800 m/min, and productivity has been remarkably improved. Furthermore, in order to achieve a major increase in gauge accuracy at high rolling speed cold tandem mill the authors applied a roller bearing to back up roll for high speed rotation and replaced mill motors with high response AC motors. As a result, the gauge accuracy during rolling has been improved to ± 1.0% at a steady rolling speed and ± 1.5% in acceleration and deceleration.
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