This report described the results of our two years' joint research between Nippon Kokan Kabushiki Kaisha and The Japan Steel Works, Ltd. On the plate finisher mill backup roll at N. K. K. Keihin Plant. The problems examined here were the fatigue layer of backup roll bycyclic loading, suitable dressing programme and the wear patterns and surface temperature of work rolls.
The main results obtained were as follows:
(1) The wear patterns of top backup roll were concave and those of bottom backup roll were almost flat. The affected layer of top rolls extended within 1.0 mm depth from the surface, while that of bottom rolls somewhat deeper than 1.0mm. Hardness measurement of the roll surface is considered to be one of the suitable means to ascertain the degree of fatigue.
(4) The suitable dressing programme of this plate mill backup roll is 2.0 mm in dia. Everytime for top rolls and 2.Omm in dia. at initial 3 times and 8.0mm in dia. at the 4th time for bottom roll.
