In the context of the master's thesis, various types of rolls for hot rolling of steel are described, including their microstructures, mechanical properties, as well as their position and role in the continuous milling lines. The main technological phases of their manufacturing are shown and explained, and the statistical data of electricity, natural gas and other materials consumption by individual technological phases and types of rolls are given. Within the framework of the experimental work, measurements of the electricity consumption and productivity of induction melting furnaces were performed depending on the induction furnaces operating regimes and the size of the feedstock. The consumption of natural gas in individual technological phases was measured, as well as technological parameters, temperatures and flue gas emissions of the three heat treatment furnaces. The material balance for the production of individual types of rolls is outlined, which also includes the consumption of all alloying additions for the prescribed chemical composition and the preparation of melt. All measurements were carried out in the company Valji d.o.o.
The results show the consumption of the electric energy of the induction furnaces in relation to the type of the feedstock (small size and large solid pieces) and the melting regime (cold starts, charging in liquid heel or hot furnace), the causes for energy losses and the proposed measures for improving the energy efficiency of induction melting. The results of measurements of the technological parameters of the furnaces for heat treatment and the findings regarding their operation, as well as the proposed measures for the more economical implementation of heat treatment, are presented. The energy and mass balance of the production of rolls for hot rolling of steel and the estimated savings in case of implementation of the proposed measures are calculated.
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