Authors: Chang Gui Xie, Hai Zeng. 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 ...Vibration Types The complex nature of a five stand cold mill prevents the discussion of all steps performed to date to improve performance. We will discuss three basic types we encountered as we began to increase mill speeds: Rumble, Third Octave and Fifth Octave: Rumble Vibration occurring near 100 Hz was encountered during acceleration
The present invention relates to mill vibration control apparatus and to a method of restricting vibration in a mill stand. During cold rolling of metal, a continuous strip of metal is passed through a mill stand so as to reduce the gauge (thickness) of the metal strip.On account of the self-excited vibration in No. 5 stand of 1420 cold rolling mill, the relationship between rolling lubrications and self-excited vibration of rolling mill was theoretically studied. The self-excited vibration in No.5 stand of the mill was restrained by optimizing the lubrication technical parameters, and the critical stabilized rolling speed was increased from650 m/min to ...
Undesirable vibrations that occurred in cold rolling mills, widely known as chatter, are studied in this article by considering the interaction of three types of vibrations, namely, the longitudina...Keywords: rolling mill vibration, coupling dynamic model, AGC, mill modulus control gain. 1. Introduction The mill vibration has become a bottleneck in the thin steel strip manufacturing [1, 2], as the mill vibration can cause unacceptable product quality degradation in the steel strip, and even severely damage the mill equipment [3, 4].
Due to inclusions in the molten steel during steelmaking, or scratches, chisel marks, etc. on the surface of the steel strip during hot rolling, when cold rolling, a spot-like trace is formed on the surface of the steel strip. Rolling in dirt. The defects are blocky, generally white, and easy to concentrate on a certain length of the steel strip.By the dynamic simulation of ADAMS it is proved that the coupling effect quickens losing the stability of vibration system of the rolling mill, and increases the vibration magnitude.Fourthly, the gap between the bearing bracket and the stands causes impact to vibrate, and the dynamic simulation of ADAMS proves that the fluctuation energy of the ...
Cold rolling mills show a complex vibration behavior, consisting of natural vibrations of the plant mechanics as well as excitations from the drive or bearings but also vibrations caused by defects. The aim of the monitoring is to detect vibrations that are caused by external excitation or faults.The vertical vibration often occurs during the rolling production, which has an influence on the accuracy of rolling mill. In order to effectively suppress the vertical vibration of the rolling equipment, the rolling mill model with vibration absorber device was established. Based on the main resonance singularity of the rolling mill system, the best combination of opening parameters was obtained.
Mill vibrations (chatter) especially occurring at high rolling speeds affect product quality of the cold-rolled material and thus lead to yield losses and quality issues. Among other supportive measures active chatter damping has turned out to be an effective approach to counteract these problems by significantly reducing vibration issues of ...Serious vibration occurred on the F5 stand when producing thin strips on a 1550 cold tandem mill. The field test showed that the dominant frequency of the vibration is 144 Hz, which was close to the natural frequency of the F5 stand. Moreover, there were …
Roll chocks in Rolling Mill. Rolling mills for rolling of steel differ in many aspects with each other. The rolling mills are of different sizes and capacities. The mills roll steel materials of different cross-sections, sizes and qualities and in material conditions which are either hot or cold. The mills have different configurations and ...Mill vibration during cold rolling. February 2007. T. Farley; In common with other rotating machines, rolling mills are prone to many different vibrations during rolling and most do not cause a ...
The elastic deformation of rolling mill elements during the rolling process is important. By knowing the displacement of rolls, the optimum gap between the work rolls can be calculated. In present research, a vibration model with two degrees of freedom is proposed for a cold sheet rolling mill and the stiffness parameters of different mill elements are calculated. A numerical simulation and …Cold rolling mills show a complex vibration behavior, consisting of natural vibrations of the plant mechanics as well as excitations from the drive or bearings but also vibrations caused by defects. The aim of the monitoring is to detect vibrations …
Models for the occurrence of the vibrational instability during rolling known as third octave chatter are presented and discussed. An analysis of rolling mill chatter was performed for the purpose of identifying characteristics of the vibrations and to …Polygonal vibration marks and ripples on roll surface during Grinding. ... Polygonal vibration marks and ripples on the surface of the roller are caused by vibration of the grinding wheel relative to the roller during grinding. ... 6 Hi cold rolling mill, cold rolling mill, forged steel rolls, grinding of rolls. Post author Written by Troy Yang ...
and 150Hz, is a self-excited vibration phenomena typically occurring in the rear stands of tandem cold mills. It can produce significant gauge variations and even cause strip breaks. 3rd octave mill chatter is characterized by a quickly diverging vertical vibration of the rolls for specific rolling conditions (material, mill speed, forces,elastoplastic deformation during cold rolling and its surface quality. MODEL DESCRIPTION In order to reveal the mechanism of defects occur-rence on the surface of steel cold rolled strips during work rolls vibration, the finite element method imple-mented in the DEFORM-2D program was used. The 4th stand of the 5-stand mill 1700 of PAO Severstal ...
Vertical Vibration Model for Unsteady Lubrication in Rolls-Strip Interface of Cold Rolling Mills. Liza Horobets. Download with Google Download with Facebook. or. Create a free account to download. Download Full PDF Package. This paper. A short summary of this paper.(Online version in color.) from publication: Effect of Friction on Tandem Cold Rolling Mills Chattering | Chatter phenomenon in the rolling mills is the undesired mechanical vibrations which ...
In common with other rotating machines rolling mills are prone to many different vibrations during rolling and most do not cause a problem However there are several types of rolling mill vibration that can have a significant impact on the quality and/or productivity of the cold rolling process. Get PriceIn common with other rotating machines, rolling mills are prone to many different vibrations during rolling and most do not cause a problem. However, there are several types of rolling mill vibration that can have a significant impact on the quality and/or productivity of the cold rolling process.