Hot rolling thick plate on a reversing mill - producing tapered longitudinal sections during intermediate passes

摘要

Thick plate is hot rolled on a reversing mill with the roll gap continuously increased during the passage of the plate through the mill. A prescribed speed is used for both the rolls and the gap-adjustment, so there is a uniform and progressive increase in thickness from the front end of the plate to the back end after each pass, forming a "reverse thickness counter cone" for balancing the roll pressure while still obtaining the required redn. in thickness. The process is pref. carried out on a reversing mill fitted with pressure devices on the back-up rolls, i.e. for obtaining a uniform thickness right across the plate and a computer is pref. used to obtain "cones" or tapered sections in both the longitudinal and transverse directions. Flat plate with close dimensional tolerance across its entire width is obtd. with compensation for the difference in plate temp. between the front and back ends.