A vertical cut at the mid-depth of the 15-ton forging steel ingot has been performed by curtesy of the CELSA – Huta Ostrowiec plant.

Some metallographic studies were able to reveal not only the chilled undersized grains under the ingot surface but columnar grains and

large equiaxed grains as well. Additionally, the structural zone within which the competition between columnar and equiaxed structure

formation was confirmed by metallography study, was also revealed. Therefore, it seemed justified to reproduce some of the observed

structural zones by means of numerical calculation of the temperature field. The formation of the chilled grains zone is the result of

unconstrained rapid solidification and was not subject of simulation. Contrary to the equiaxed structure formation, the columnar structure

or columnar branched structure formation occurs under steep thermal gradient. Thus, the performed simulation is able to separate both

discussed structural zones and indicate their localization along the ingot radius as well as their appearance in term of solidification time.

Some metallographic studies performed on the basis of the massive forging steel static ingot, on its cross-section, allowed to reveal the

following morphological zones: a/ columnar grains (treated as the austenite single crystals), b/ columnar into equiaxed grains

transformation, c/ equiaxed grains at the ingot axis. These zones are reproduced theoretically by the numerical simulation. The simulation

was based on the calculation of both temperature field in the solidifying large steel ingot and thermal gradient field obtained for the same

boundary conditions. The detailed analysis of the velocity of the liquidus isotherm movement shows that the zone of columnar grains

begins to disappear at the first point of inflection and the equiaxed grains are formed exclusively at the second point of inflection of the

analyzed curve. In the case of the continuously cast brass ingots three different morphologies are revealed: a/ columnar structure, b/

columnar and equiaxed structure with the CET, and c/ columnar structure with the single crystal formation at the ingot axis. Some

forecasts of the temperature field are proposed for these three revealed morphologies. An analysis / forecast of the behavior of the

operating point in the mold is delivered for the continuously cast ingot. A characteristic delay between some points of breakage of the

temperature profile recorded at the operating point and analogous phenomena in the solidifying alloy is postulated.

The paper presents the effect of tin on the crystallization process, microstructure and hardness of cast iron with compacted (vermicular) graphite. The compacted graphite was obtained with the use of magnesium treatment process (Inmold technology). The lack of significant effect of tin on the temperature of the eutectic transformation has been demonstrated. On the other hand, a significant decrease in the eutectoid transformation temperature with increasing tin concentration has been shown. It was demonstrated that tin narrows the temperature range of the austenite transformation. The effect of tin on the microstructure of cast iron with compacted graphite considering casting wall thickness has been investigated and described. The carbide-forming effect of tin in thin-walled (3 mm) castings has been demonstrated. The nomograms describing the microstructure of compacted graphite iron versus tin concentration have been developed. The effect of tin on the hardness of cast iron was given.

The paper presents an analysis of a selected grade of high silicon cast iron intended for work in corrosive and abrasive conditions. The text describes its microstructure taking into account the process of crystallization, TDA analysis, EDS, XRD and the chemical composition analysis. In order to determine the phase composition, X-ray diffraction tests were carried out. The tests were executed on a Panalytical X'Pert PRO X-ray diffractometer with filtration of radiation from a lamp with copper anode and PIXcel 3D detector on the deflected beam axis. Completed tests allowed to describe the microstructure with detailed consideration of intermetallic phases present in the alloy. Results of the analysis of the examined alloy clearly show that we deal with intermetallic phases of Fe3Si, Fe5Si3 types, as well as silicon ferrite and crystals of silicon. In the examined alloy, we observed the phenomenon of segregation of carbon, which, as a result of this process, enriches the surface of silicon crystals, not creating a compound with it. Moreover, the paper demonstrates capability for crystallization of spheroidal graphite in the examined alloy despite lack of elements that contribute to balling in the charge materials.