Synchronization of the roughing group stands at the 1700 rolling mill at PJSC «ILYICH IRON AND STEEL WORKS OF MARIUPOL»

Abstract

The constant increase in consumers’ requirements as well as continuous upgrading made by the leading manufacturers of steel products form the target proper quality of steel products. At present the requirements on the steel products have already exceeded the standards requirements. So, the increased requirements on the hot-rolled coils may include the limitation on the minimal weight. For example, some manufactures utilize coils weighing from 18 t to 30 t. Limitation on telescoping, for example, must not exceed 20 mm or 10 mm; limitation on width tolerance must not exceed ½-¼ of standard requirements; the requirements on mechanical properties are increased as well. Within the current operating conditions of the1700 mill the short distance between the roughing group stands is the significant technical limitation in coils weight increase. Thus, the weight of coils can be increased after synchronization of speed parameters of the roughing group stands. In this paper, the technology of synchronization of the roughing group stands at the1700 rolling mill has been designed due to the roughing schedule distribution. The developed technology makes it possible to increase the weight of coils from 9 tons to 15,83 tons for the intermediate stage of the1700 mill reconstruction. The calculation of the maximum length for 150 mm thickness slab has been performed and it makes 9320 mm. This length can be used for the implementation of the synchronization technology at the1700 mill. Further increase in slab length will result in the necessity of additional operation synchronization of stands №№ 2-3-4. The required motors output calculation of the synchronized stands has been performed taking into account the load while the slab is within the two stands simultaneously. The required motor output has not exceeded the designed limit in 8000 kW