|MACHOVČÁK Pavel||VÍTKOVICE HEAVY MACHINERY a.s.|
|Spoluautoři OPLER Aleš, CARBOL Zdeněk, TREFIL Antonín, TKADLEČKOVÁ Markéta, MICHALEK Karel|
A production of heavy forging ingots is usually accompanied by a segregation of elements in the structure of steel. The segregation of the elements causes anisotropy of mechanical properties. But these mechanical parts must meet the strictest criteria, and therefore must be practically free of defects. In order to achieve the best possible quality of heavy forging ingots, the project focused on improving the useful properties of special machine parts was solved. The experimental forging ingot weighing 90 tons was cast due the performance a detailed analysis of the current state of casting and solidification. The ingot was cut and macrostructure and chemical heterogeneity of the ingot was evaluated in detail. Microcleanliness evaluation was also carried out on the samples from this ingot. To assess the composition of oxide non-metallic inclusions ternary diagrams were used. The gained knowledge was also used to specification of the setting of boundary conditions of the numerical simulations, which should help to optimize the production technology of casting heavy forging ingots and minimize the range of porosity and segregation in ingots. The new type of 90 tons ingot was also designed and analyzed. In particular, the extent of porosity and macrosegregation were evaluated. This article describes performance of the experimental ingots casting, the way of cutting, the methodology of chemical analysis and the results of that investigation. The results obtained in the analysis of two different types of 90 tons ingots are here compared.