Screwdown load deviation model of 5 m heavy plate mill based on influence of back-up roll axial force

Abstract

Screwdown load deviation threatens rolling mill safety and product quality. The contact between a 5 m rolling mill screwdown device and the back-up roll (BUR) bearing chock was simplified to a fixed hinge constraint, and the constraint of the keeper plates on the BUR bearing chock was simplified to a sliding hinge constraint. According to the BUR space force and moment equilibrium, a screwdown load deviation model affected by the BUR axial force was used to simulate the effect of the roll crossing degree on the screwdown load deviation. Screwdown load deviations were calculated for three rolling passes. The results are more consistent with the data than outputs calculated by a model that neglects axial force. Assumptions about the relationship between the load deviation and the work roll axial forces agree with the data. The results show that the BUR axial force causes a dynamic deviation of the screwdown load.

Mechanism generating deviations in the rolling load and strip camber on the plate rolling mill

“…For reasons and control measures of the camber, a lot of theoretical analysis and experiment have been carried out. Based on the spatial force and moment equilibrium of the backup roll (BR), a screw-down load deviation model was established by Ma et al 1 and it was used to simulate the effect of roll cross degree on the screw-down load deviation. To reduce strip camber, a new algorithm based on an estimated entry-side wedge of the bar during rough rolling process was proposed by Kang et al 2 For the 3500-mm medium plate rolling mill in Handan Iron & Steel Corporation (China), a phenomenon studied by Chen and Zhang 3 showed that a strip camber always appeared during the rolling process with a plate thickness of 16 mm, which had become a bottleneck of quality improvement and cost reduction.…”