抄録
Graphite steel has spheroidal or globular form of graphite in steel. The spheroidal graphite cast steel is rich in castability and high damping capacity compared with carbon steel. The effect of mechanical properties and heat-treatment of Fe-1.3%C-1.8%Si-0∿6%Ni investigated. Tensile strength of air-cooled specimen with the Ni free specimen was 870MPa. In the air-cooled, tensile strength decreased with increased in the Ni. In the furnace-cooled, tensile strength increased with increased in the Ni. Microstructure of air cooled specimen to 2%Ni was a pearlite and ferrite around the graphite. The matrix becomes the martensite at 4%Ni.