Study of the effect of solidification on graphite flakes microstructure and mechanical properties of an ASTM A-48 gray cast iron using steel molds

Abstract

The analysis of heat conduction is a widely used technique for control of metallurgical process and solidified eutectic alloy investigation. The objectives of this research are studies about the effect of solidification on graphite flakes microstructure and mechanical properties of an ASTM A-48 gray cast iron using SKD 11 tool steel, S45C medium carbon steel and SS400 hot-rolled steel molds. These three steel molds are important for heat conduction and different from other works. This analysis involving thermocouples immersed in the molten cast alloy is convenient to quickly obtain solidified ingot data on the behavior of solidification processing. This research intends to describe the thermal analysis using thermocouples, shape of thermal field and the experimental boundary conditions. The Newtonian thermal analysis and the Fourier thermal analysis differ because of the number of used thermocouples. Mechanical properties of structural ASTM A-48 gray cast iron materials strongly depend on their microstructure. Metallographic sections are observed to quantitatively measure the relevant microstructural parameters, as graphite lamellas morphology, eutectic cell size and inclusions content. Results are correlated to the measured mechanical properties: reduced graphite content increases the tensile strength.