Study and application of the slab camber control model in rough rolling

Abstract

Aimed at the frequently occurred problem of slab camber in rough rolling of hot strip mills, the main factors causing slab camber, including the difference in longitudinal stiffness of the mill on both sides, incoming wedge and running deviation of rolled pieces, were analyzed by combining with the spring equations and analytical method in this paper, and the corresponding adjustment values were respectively calculated. Based on rolling force difference on both sides, the tilting control model of slab camber was established. This model could reflect the quantitative relationship between the main factors and camber, such as the difference in longitudinal stiffness of the mill on both sides, incoming wedge and running deviation of rolled pieces, etc., and then the tilting values of roll gap for controlling camber were calculated in each pass of the rough rolling mill. Comparing with the real values by off-line verification, the averaged ratio of measured and calculated values is 0.977. The results show that the tilting values of roll gap can be estimated by the tilting control model of slab camber in each pass. Since putting the model into a 2250 mm hot strip mill, the camber values not complying with tolerance declined from 24.88% to 6.62%. By improving the control effect of camber, the slab camber problem has been greatly eased.

Keywords

• rough rolling
• slabs
• camber
• deviation
• wedge