METHOD FOR COLD ROLLING OF STRIP IN MILL WITH FOUR-HIGH STANDS DRIVEN THROUGH ROLLING ROLLS Russian patent published in 2003 - IPC

FIELD: metallurgical industry branch, namely cold rolling of strip in wide-strip cold rolling mills having four-high stands with main drive through rolling rolls. SUBSTANCE: method for cold rolling of strip in mill with four-high stands driven through rolling rolls at lubricating rolls during rolling process comprises steps of regulating in separate stands of mill such parameters of rolling as reduction and(or) tension values while taking into account known beforehand parameters: diameters Dr of rolling rolls and diameters Db of backup rolls; length Lb of barrel of backup rolls; length of slopes of barrels of backup rolls; diameters d_b.r, d_b.b of trunnions of bearing units of rolling rolls and backup rolls; horisontal shift of axis of rolling rolls relative to axis of backup rolls in rolling direction Xr; friction coefficients f_r, f_b in bearing units of rolling and backup rolls; also taking into account parameters measured directly at rolling process: power Ndr consumed by electric motors for rotating driven rolls; angular velocity ω_p of rolling rolls; rolling effort P; thickness h₁ of rolled piece; thickness h₀ of initial billet; rear tension To of strip; front tension T1 of strip; at rolling strip measuring in addition: concentration C of emulsol in used emulsion; angular acceleration ε of idle backup rolls at speeding up in each stand; calculating at using above mentioned parameters tgβ being tg of inclination angle of interroll effort relative to axial plane of rolls; f₀ - rest friction coefficient at roll contact according to empiric dependence; then testing for each stand of mill if condition tgβ<0,9f₀ is satisfied; when such condition is not satisfied even in one stand, increasing reduction value in that stand. EFFECT: prevention of increased wear of rolls caused by mutual slipping between rolling and backup rolls at rolling process.