The modification is a widespread method of improving the strength properties of cast iron. The impact in terms of increasing amounts of eutectic grains has been thoroughly studied while the issue of the impact on the mechanical properties of primary austenite grains has not been studied in depth yet. The paper presents the study of both aspects. The methodology was to conduct the melting cast iron with flake graphite, then modifying the alloy by two sets of modifiers: the commercial modifier, and a mixture of iron powder with a commercial inoculant. The DAAS test was carried out to identify the primary austenite grains. The degree of supercooling was determined and the UTS test was performed as well. Additionally carried out the metallographic specimen allowing for counting grains. It can be concluded that the introduction of the iron powder significantly improved the number of austenite primary grains which resulted in an increase in tensile strength UTS.
 Guzik, E. & Porębski, M. (2002). A new complex inoculant for high quality cast iron. Acta Metallurgica Slovaca. 2, 10-15.
 Guzik, E. (2001). Processes of cast iron improvement. Archives of Foundry. Katowice PAN. Monograph 1M.
 Burbelko, A.A., Gurgul, D., Królikowski, M. & Wróbel, M. (2013). Cellular automaton modeling of ductile iron density changes at the solidification time. Archives of Foundry Engineering. 13(4), 9-14.
 Lux, B.(1968). Nucleation and graphite in Fe - C - Si alloys. Recent Research on Cast Iron. Gordon A. Breach. New York-London-Paris.
 Riviera, R., Diószegi, A. & Elmquist, L. (2011). Solidification study of gray cast iron in a resistance furnace. Key Engineering Materials. 457, 108-113.
 Rivera, G.L., Boeri, R.E. & Sikora, J.A. (2004). Solidification of grey cast iron. Scripta Materialia. 50, 331-335.
 Rivera, G.L., Calvillo, P.R., Boeri, R.E., Houbaert Y. & Sikora, J.A. (2008). Examination of the solidification macrostructure of spheroidal and flake graphite cast irons using DAAS and ESBD. Materials Characterization. 59, 1342-1348.
 Kopyciński, D., Guzik, E. & Dorula, J. (2011). Forming of primary austenite in low-sulphur cast iron. Archives of Foundry Engineering. 11, 57-60.