The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling for...The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitehcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole de- formation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thick- ness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental re- sults prove the correctness of the improved formula given.展开更多
Feedback control is one of the most important ways to improve coiling temperature control precision during laminar cooling process.Laminar cooling equipments of a hot strip mill and structure of the control system wer...Feedback control is one of the most important ways to improve coiling temperature control precision during laminar cooling process.Laminar cooling equipments of a hot strip mill and structure of the control system were introduced.Feedback control algorithm based on PI controller and that based on Smith predictor were designed and tested in a hot strip mill respectively.Practical application shows that the feedback control system based on PI controller plays a limited role in improving coiling temperature control precision.The feedback control system based on Smith predictor runs stable and reliable.When the measured coiling temperature deviates from the target value,it can be adjusted to the required range quickly and steadily by Smith predictor feedback control,which improves the coiling temperature control precision greatly,and qualities of hot rolled strips are improved significantly展开更多
基金Sponsored by National Natural Science Foundation of China(50974039)
文摘The minimum rolling thickness in asymmetrical rolling was analyzed compared with that in symmetrical rolling. The differential equilibrium equations on forces were established to calculate the asymmetrical rolling force equation by slab method. An implicit expression of the minimum rolling thickness was then derived from the rolling force equation and Hitehcock equation. The results show that permissible minimum rolling thickness of asymmetrical rolling only exists within a specific range of cross-shear ratio, which is termed the cross-shear zone proportion of the whole de- formation zone. Numerical computation was carried out to obtain a discrete solution of the minimum rolling thick- ness. Experiments were designed to investigate the influence factors on cross-shear ratio. Finally, experimental re- sults prove the correctness of the improved formula given.
基金Sponsored by National Natural Science Foundation of China(50634030)
文摘Feedback control is one of the most important ways to improve coiling temperature control precision during laminar cooling process.Laminar cooling equipments of a hot strip mill and structure of the control system were introduced.Feedback control algorithm based on PI controller and that based on Smith predictor were designed and tested in a hot strip mill respectively.Practical application shows that the feedback control system based on PI controller plays a limited role in improving coiling temperature control precision.The feedback control system based on Smith predictor runs stable and reliable.When the measured coiling temperature deviates from the target value,it can be adjusted to the required range quickly and steadily by Smith predictor feedback control,which improves the coiling temperature control precision greatly,and qualities of hot rolled strips are improved significantly
