Аннотации:
© 2020. All Rights Reserved. High-silicon cast iron has excellent corrosion resistance in some specific medium. But the effects of pH value, chloride concentration and soil moisture content on corrosion behavior are still unknown. Cast iron is a unique material with a wide variety of microstructures that create many combinations of properties. The chemical composition and microstructure of materials are considered one of the most important factors affecting their properties. This article is devoted to the study of environmental effect on the mechanical properties (hardness) of cast iron and the morphology of graphite. To determine these parameters, three types of cast iron castings were prepared with different silicon contents in the range of 2.29-4.27% and magnesium in the range of 0.012-0.052%. The samples were subjected to hardness tests and microstructural analysis. Analysis of literary sources has shown that magnesium is traditionally used in cast irons as a spheroidizer. As the part of practical work, this statement is confirmed and clearly presented in the graphs. When more than 0.03% of Mg is added to the cast iron, there is a sharp decrease in vermicular graphite (VG) content due to nodular graphite (NG) content increase. Based on the experimental data obtained, it is difficult to assess the effect of silicon on the VG fraction. However, the microstructural analysis of the samples showed that silicon has a significant effect on the metal base of the alloy, which, in turn, correlates well with the results of mechanical hardness tests by the Brinell method.
