The article presents crystallization process of silicon molybdenum ductile cast iron (SiMo). The alloy with 5% silicon content and with

variable amounts of Mo in a range of 0-1% was chosen for the research. The carbon content in the analysed alloys did not exceed 3,1%.

The studies of crystallization process were based on thermal – derivative analysis (TDA). Chemical composition of all examined samples

was analysed with the use of LECO spectrometer. Additionally, the carbon and the sulphur content was determined basing on carbon and

sulphur LECO analyser. For metallographic examination, the scanning electron microscopy (SEM) with EDS analyser was used. Disclosed

phases have been also tested with the use of X-ray diffraction. The results allowed the description of crystallization processes of silicon

molybdenum ductile cast iron using thermal – derivative analysis (TDA). Conducted studies did not allow for the clear identification of all

complex phases containing molybdenum, occurring at the grain boundaries. Therefore, the further stages of the research could include the

use of a transmission electron microscope to specify the description of complex compounds present in the alloy.

The article presents results of pitting corrosion studies of selected silicon cast irons. The range of studies included low, medium and high

silicon cast iron. The amount of alloying addition (Si) in examined cast irons was between 5 to 25 %. Experimental melts of silicon cast

irons [1-3] were conducted in Department of Foundry of Silesian University of Technology in Gliwice and pitting corrosion resistance

tests were performed in Faculty of Biomedical Engineering in Department of Biomaterials and Medical Devices Engineering of Silesian

University of Technology in Zabrze. In tests of corrosion resistance the potentiostat VoltaLab PGP201 was used. Results obtained in those

research complement the knowledge about the corrosion resistance of iron alloys with carbon containing Si alloying addition above 17 %

[4-6]. Obtained results were supplemented with metallographic examinations using scanning electron microscopy. The analysis of

chemical composition for cast irons using Leco spectrometer was done and the content of alloying element (silicon) was also determined

using the gravimetric method in the laboratory of the Institute of Welding in Gliwice. The compounds of microstructure were identify by

X-ray diffraction.

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.