Investigation of the effect of carbon equality on microstructure and mechanical properties with thermal analysis methods in lamel graphite cast iron

Keywords: Carbon equivalent, thermal analysis method, gray cast irons In this study; The role and importance of carbon equivalent in cast iron by thermal analysis method and its effect on microstructure and mechanical properties were investigated. In this study, 3 different types of vaccines were used in 5 different ratios, carbon equivalent was determined by ATAS thermal analysis device and pull bars were extracted by pulling pull rods and tensile test was investigated. Gray cast irons are cast iron in the determination of carbon equivalent, where the sum of one third of carbon and silicon is 4,3. Since the silica coming from the vaccine has a significant effect on the carbon equivalent, it has an important role since it affects the solidification process of the alloy. Therefore, the type, amount and content of the vaccine will be reflected in the mechanical properties of the material. We know that the carbon equivalent of the material changes and the ferrite-forming effect in the microstructure. In this study, the effects of this effect were investigated. Atas brand thermal analyzer is used for this purpose. In accordance with the device, 400 grams capacity, 0.8 module cups are used. The carbon equivalent was determined by adding 0.12%, 0.15%, 0.20%, 0.25% and finally 0.30% of the inoculant, which was melted in the induction furnaces and was set as GG 25. During this study, the draw rods were poured for each trial. A total of 16 data were obtained to compare the same study with the unvaccinated. According to the findings of the study; with the carbon equivalent of the material shifting to the left, the formation of ferritic structure and the decrease in its mechanical properties (low hardness, low strength, and low rupture) were observed. However, with the carbon equivalent of the material shifting to the right, the formation of perlitic structure and consequently increase in its mechanical properties (high hardness, high strength and high breakage) were observed. According to vaccine types; mechanical properties have improved with Ba-based SB5 vaccine due to the high perlite structure compared to the others.