Effect of Sb–Ba–Ce–Si–Fe Post Inoculants on Microstructural and Mechanical Properties of As‐Cast Pearlitic Ductile Iron

Abstract

The effect of the post inoculation by using the newly developed Sb–Ba–Ce–Si–Fe inoculant on the microstructural and mechanical properties of the as‐cast pearlitic ductile iron is investigated. The chemical composition of the post inoculant is 56.1% of Si, 1.4% of Ca, 3.5% of Ba, 4.9% of Ce, 10.3% of Sb and Fe. The post inoculation is simultaneously carried out with the nodularizing treatment of graphite in a ladle. The reasonable additive amount of the Sb–Ba–Ce–Si–Fe inoculant is 0.2%. When the Sb–Ba–Ce–Si–Fe inoculant is added by 0.2%, the pearlite content is 90%, and there are 270 spheroidal graphite nodules per 1 mm2. In addition, the size of graphite nodules is 30–40 μm, and the layer thickness of pearlites is about 125 nm. In this case, the mechanical properties of the as‐cast pearlitic ductile iron are as follows; the tensile strength is 750 MPa, the elongation is 4%, the hardness is HB 270.