Influence of the speed of stretching the rolled strip on the occurrence of self-oscillations of the tension station of the cold rolling mill 2000

The self-oscillations of the roller of the tension station of the loop accumulator of the cold rolling mill lead to the appearance of cracks on the outer surfaces of the roller during operation. In order to determine the causes of self-oscillations of the crack, we conducted a screening industrial experiment to assess the influence of technological and diagnostic parameters on the state of the tension station of the etching unit of mill 2000. The database of technological and vibration parameters of the mill and the roller of the tension station is a single hybrid database combined with a graphical shell. An industrial experiment is, as a rule, a passive experiment. It is an experiment in which the experimenter does not have the opportunity to interfere in the process of conducting the experiment. But in the case of a cold rolling mill, one single independent experiment requires only 5-6 minutes. Each roll is of different thickness, width, different chemical composition and, accordingly, with different mechanical properties. In addition, the rolling speed, strip tension, strip compression, different friction forces at the tension station are different. Each roll is an independent experiment. If information about technological and diagnostic parameters is stored for a long time, for example, a year or two, this information is enough to work with it as with a laboratory experiment. With a time lag, but with enough information to plan the experiment. It is only necessary to select information from the data array that corresponds to the experiment plan. Using a database a Digital Twin, we carried out an industrial experiment to determine the conditions for the occurrence of self-oscillations of the roller of the tension station and the rolled strip. The results obtained revealed a clear dependence of the occurrence of HC8 self-oscillations on the speed of stretching the strip at the time of cutting out a non-metallic inclusion (Class 3). The stretching speed should be in the range from 0.5 to 1.0 m/s. At stretching speeds in the range from 2.0 to 2.5 m/s, self-oscillations do not occur. There are no conditions for the occurrence of cracks on the end surfaces of the roller.