Investigation of the Pearlite of Ductile Iron

In this work, it is pretended to investigate an influence of various technological features and the thickness of castings on the pearlite content and its structure. The 5 pieces used had form of various diameters rods made of ductile cast iron in order to achieve various cooling rates. None heat treatment was used to obtain different pearlite contents in the microstructures. The specimens were polished and swabbed with nital to analyze the microstructure. Pearlite content increased with decreasing diameter of bars. The fast cooling rate increased the pearlite content and also affected the lamellar spacing of the pearlite structure, which affects the hardness of the pearlite phase of the ductile iron. This work and the results obtained as consequences of the analysis carried out are novel, although applied methods are well known. This study is directed to researchers of metallurgy departments and engineers of foundries.