Abstract
Flake graphite cast iron containing aluminum is known as a heat-resistant material. Heat-resistant material normally undergoes various temperature changes during service. It is known that flake graphite cast iron containing more than 6mass% of aluminum shows excellent heat-resistant property. In this research, the surface and microstructure of flake graphite cast iron containing 6mass% aluminum oxidized at elevated temperature were investigated.
Flake graphite cast iron containing 6mass% aluminum was heat-treated in air at the temperature combination of 1073K and 1273K. The surface conditions and microstructures were examined by optical microscope, SEM and EPMA. Alumina precipitated at the positions where graphite existed during heat treatment. Internal oxidation advanced inward more rapidly at 1073K than at 1273K. Once, this cast iron was heat-treated at 1273K in air, internal oxidation did not easily advance inward by the next heat treatment, indicating that the heat-resistant property of this cast iron can be improved by simple heat treatment.
