In the master thesis, the influence of steel melt flow modifiers in the tundish on the content of non-metallic inclusions in the continuous casting slab was investigated.
In the theoretical consideration, the process of continuous steel casting was described in detail, in particular the importance of tundish design, defects in the semi-finished product and the formation of non-metallic inclusions.
The first step of the experimental work was the numerical modeling of the steel melt flow in the tundish. We simulated the flow of the melt in two tundishes, with the pouring box inserted and with the pouring box and weir inserted. We cast three batches with the first tundish type and three batches with the second tundish type on the continuous steel caster under the same conditions as in the modeling.
The results of the numerical simulations were presented with pictures showing the flow of the melt with different colored velocity zones and with flow lines. For the selected cross sections in transverse and longitudinal directions, we drew plots of the vertical component of the velocity by height and length of the tundish We took samples of end plates from all six casting batches and analyzed the content of nonmetallic inclusions according to the standard DIN 50 602.
Both the results of the numerical simulations and the analysis of non-metallic inclusions show that the use of a weir in the tundish is useful, as it reduces the number of sulfide bands in the steel by almost half.
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