|TKADLEČKOVÁ Markéta||VŠB - Technická univerzita|
|Spoluautoři MACHOVČÁK Pavel, KOVÁČ Marek, GRYC Karel, MICHALEK Karel, SMETANA Bedřich, SOCHA Ladislav|
The paper builds on the previous work of authors devoted a verification of casting technology of 90-ton heavy steel ingot using numerical modelling and operational experiment. Numerical modelling was done in ProCAST software. In the first stage of an extensive modelling research, the conditions of heat transfer used in the setting of calculation of casting and solidification were modified based on experimental thermovision measurement. There were also verified the thermodynamic properties of steel. The results of numerical modelling of macrosegregation in ingot under standard conditions of casting were continuously compared with the results obtained from the analysis of experimentally-cast ingot. Once the agreement has been reached between the numerical and experimental results of the research, the attention was given to verify the effect of boundary conditions of casting on size of macrosegregation in heavy steel ingots. In the case of casting of steel ingots, among the most important and most easily influenced technological boundary conditions include the casting temperature and the velocity of the casting. In contrast, the material of the mould or the grade of cast steel cannot be arbitrarily changed. For this reason, the attention was focused on the verification of the extent of ingot volume defects depending on the casting temperature of steel and casting velocity. Like the best appeared to be the variant, in which it was considered with a decreasing of casting temperature during filling of the mould and simultaneously with longer casting time up by 15 minutes.