Papers by Keyword: Cold Rolling Mill

Abstract: VTLG is a new type of laser-based strip thickness gauges for cold rolling mills and offersthe solution for strip thickness measurement that the industry has long been searching for:Irrespective of the alloy, contact-free, highly precise and reliable. This article describes thedevelopments which had to be done so that now with the VTLG a solution is possible that has notbeen possible to date.

Abstract: Aiming at a 1220 strip surface, where the Cold Rolling Mill had chatter marks, on which the reasons for the formation was tracked tested for in-depth study. Based on the vibration test, the analysis was given to the dynamic characteristics of the rack ^[1-3]. It was found that had reaction to the mill that caused the forced vibration mill to further accelerate the formation of chatter marks. In the analysis of the mechanism on the chatter marks, the relationship between chatter marks spacing and vibration source was considered in successfully finding out the cause of the 1220 mill chatter marks generated, and then the chatter marks suppression measures were proposed with satisfied effects.

Abstract: The calculated result of the mathematical model based on the conventional transfer function has bigger deviation than the measured. In this paper the mathematical model of the work roll bending is derived. The modeling is different from conventional modeling used many presumptions and linear processing. The modeling calculated accurately the equivalent load spring using the method of influence function. The simulation results agree well with actual data of the bending system.

Abstract: This paper focuses on a new type of 8-roll cold rolling mill with the back-up bearing roll. Compared to the traditional 6-roll cold rolling mill, a thick-walled bearing roll is used to multi-support the intermediate roll. By the rack, the fan-shaped gears, the eccentric core shaft and the servo-cylinder, the work roll can be pushed down by this screw down device on the top of the mill; By contrast with the 4(6)-roll mill, this type of mill has some characteristics, such as: the small size of rolls, lighter weight, the fast response for the screw down. The bearing roll is fixed by the supporting blocks placed on the rolling-mill housing. So this mill has large traverse rigidity, and this is propitious to the flatness control. By different means of strip flatness adjustments, such as the intermediate roll shifting, the roll bending and the bearing roll adjusting, the strip flatness can be well controlled. The oil-gas lubrication is used in the bearings of the bearing rolls, and the changing rolls equipment is designed for this type of mill too. A series of this type of mills (as 450, 800, 1250, 1450 series) have been produced since it was developed in 1997. The mills for 1250 and 1450 series have been applied in five-stand cold rolling mill and single stand reversing mill, a rolling speed of 800m/min has been achieved.

Abstract: The vacuum flat bed filter is important equipment for the cold strip rolling because the surface quality of cold rolled strip is paid more attention by customer. In the paper, the function, mechanical structure and operation modes of the vacuum flat bed filter for cold strip rolling mill are introduced. The control logic of emulsion liquid level in the filter is discussed. The filter fabric running modes are designed. The control system for vacuum filter is developed based on PCS7 software and S7-400 PLC hardware of SIMENS.

Abstract: In this article, the factors which have influence on the work roll thermal deformation in cold strip rolling and the heat transferring mechanism are discussed. It is considered that there are three directions, radial, axis and circumference, for heat transferring for work roll thermal deformation. Therefore, it is a three dimensions unstable system for work roll temperature field of cold strip rolling. The plastic deformation work and friction heat are calculated by the divided element and digital integration method. The simplified calculation model is built for the heat transferring along work roll. There are four zones for work roll heat transferring: roll gap zone, air zone, emulsion zone, rolls contact zone. The heat transferring between the zones is decided by the temperature difference. The inter temperature field and thermal deformation of work roll can be calculated by two-dimension finite difference method. The work roll temperature and thermal crown of actual application cold rolling mill are analyzed by the model. By the comparison between calculated values and measured values, the work roll thermal calculation model can meet the accuracy requirement of on-line control.

Abstract: In the paper, control principle and working characters of T－WRS&C（Taper Work Roll Shifting and Crossing）cold rolling mill are analyzed. The working schedule and control parameters are worked out. The mill working modes are determined according to different working conditions. The taper work roll shifting is used for edge drop control and the work roll crossing is used for thrust force control when work rolls shifting. The actual application verifies that the edge drop and thrust force can be controlled effectively during cold strip rolling.

Abstract: Regarding 1100mm rolling mill hydraulic AGC system as the research object, on the basis of considering the pipeline dynamic characteristics and adopting position-pressure compound control method, the mathematical model of the hydraulic system is established. This paper analyzes the system dynamic characteristics in different conditions and studies the various static and dynamic error compensation methods.