Lipetsk State Technical University (Lipetsk, Russia):

S. M. Belskiy, Dr. Eng., Prof, e-mail: Belsky-55@yandex.ru
A. O. Stoyakin, Post-graduate student

When rolling strips in the rough group of a hot rolling mill, a defect in shape, which is known as camber, often occurs. Causes of camber-shaped hot-rolled strips are: 1) uneven reduction along the width of the strip in horizontal rolls; 2) rolling of a strip with a defect of the cross-sectional profi le "wedge-shaped": when a strip having a wedgeshaped cross-section enters the rolls, the middle of the rolls does not coincide with the center of the strip, it begins to deviate from the rolling axis. Thus, the strip exiting the rolls is shifted from the center of the roller table, striking the guide rulers and the fence of the roller table, and when the value of the camber is critical, emergencies occur associated with the release of the strip from the roller table. Camber of hot-rolled strips leads to emergency situations, which result is not only in the dead time of the rolling mill and production losses, but also in the risk of injury to mechanical equipment, as well as the health and life risks of maintenance personnel. In the first stands of the rough group of the hot rolling mill, due to the uneven heating of the slab, there is always a unevenness in the mechanical properties of the metal along the width, for example, the yield point: where the temperature of the metal is greater, the yield point is smaller and vice versa. Thus, when rolling a strip, having a higher temperature on one of the edges, in an equidistant gap, the reduction from the side of the heated edge will always be larger. Various methods are used to control the wedge shape of the cross-+ection profi le of the hot-rolled strips. For example, the wedge shape of the profi le of the crosssection of the hot-rolled strip is controlled by the X-ray profi lers behind the last stand of the fi nishing group. Sometimes an X-ray thickness gauge is installed behind the last stand of the roughing group. Such a thickness gauge measures the thickness of the strip at three points: in the middle and in the edge zones, on the drive side and on the service side. In any case, the correction of the gap of the fi rst stands occurs with transport delay. In the present article, the method for correcting the skewness of the roll gap by the results of measuring the temperature of the edge sections of the strip before the stand of the roughing group of the hot rolling mill is considered.
The study was done within the State assignment of the RF Ministry of Education and Science (project № 11.1446.2017/4.6).

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