Improving Thin Strip Profile Using Work Roll Cross and Work Roll Shifting Methods in Cold Strip Rolling

The optimization of rolling parameters in order to achieve better strip shape and to reduce rolling force is a challenge in rolling practice. In this paper, thin strip asymmetrical rolling of aluminum at various speed ratios under lubricated condition has been investigated at various combinations of work rolls cross (WRC) angles and work rolls shifting (WRS) values. The effects of strip width, reduction, and rolling speed on strip shape taking WRC and WRS into consideration are discussed. Results show that strip profile improves significantly when the WRC angle is increased from 0° to 1°, with an associated reduction in rolling force. Increasing WRS value from 0 to 8 mm improves the strip profile as well but not as significantly as when WRC angle is increased. No significant improvement was found in strip shape when the strip width was increased. At higher reduction, the strip shape was improved; a decrease in the rolling force was also observed. A higher speed ratio was found to be effective only at a higher WRC angle. The effect of lubrication on the strip profile was significant. Results indicate that an optimum combination of WRC, WRS, reduction, width, and speed ratio under lubricated conditions can ensure an improved exit strip profile, reduce rolling force, and obtain a better quality strip.

Analysis of Thin Strip Shape and Profile in Cold Rolling: A Way to Improve Strip Profile and Mechanical Properties

Optimisation of the physical and mechanical properties of cold rolled thin strips is achieved by controlling the rolling parameters. In this paper, the factors affecting the low carbon steel thin strip profile of asymmetrical cold rolling have been studied at a speed ratio of 1.3 without lubricant applied. The effect of rolling parameters on the resulting microstructure was also investigated. It was found that under dry condition, work roll shifting and work roll cross angle can improve the strip profile, and the improvement is more significant with an increase of work roll cross angle rather than that of work roll shifting. A slight change in microstructure was evident with increasing work roll shifting values. In addition, effects of rolling parameters on the strip profile and microstructure have also been discussed.

Study on Flatness Control Strategy of a Single-Stand Reversing Cold Rolling Mill

In this paper, an integrated rolls system deformation calculation model is established based on the influence function method combining with pass schedule calculation, rolls wear and roll thermal deformation calculation, and the corresponding calculation procedure has been developed. Then the influence of work roll bending, work roll shifting and intermediate roll bending on transverse distribution of strip thickness, strip crown, quadratic flatness, and quartic flatness are analyzed with the procedure. According to the analysis result, flatness control strategy of the single-stand reversing cold rolling mill is determined. The flatness control strategy will provide the basis for flatness control presetting of the mill. The practical application shows that the flatness control strategy is suitable for flatness control of the single-stand reversing cold rolling mill.

Research on Broken Edge Wave Control Strategy Caused by Edge Drop Control in UCMW Cold Tandem Rolling

Taking MH UCMW cold tandem mill as research object, broken edge wave generating mechanism and characteristics were analyzed which caused by edge drop control. Based on original control strategy, an automatic edge wave control model was developed, and edge drop control strategy was optimized. Effect of taper work roll shifting and taper shape on broken edge wave were analyzed by actual rolling data. Results show that broken edge wave decreases with effective contact depth increasing of taper work roller and strip. Optimized control system application eliminate broken edge wave, and improve automatic shape control accuracy.