Long life inoculant for molten cast iron - contains ferrosilicon, calcium-aluminium silicate(s), silicon carbide, calcium carbide, and prevents formation of white cast iron

摘要

The inoculant contains Fe-Si alloys (I) in which are embedded cpds. (II) of refractory calcium-alumina silicates of compsn. CaO, Al2O3, 2SiO2 + 3Al2O3, 2SiO2, and dicalcium-aluminium silicates (III), plus is not 20% SiC and is not 10% CaC2. The ratio I + II:III is ca. 1:0.05-0.2; and alloys (I) contain 5-30%, pref. 8-15% of cpds. (II). Pref. 0.05-1%, esp. 0.1-0.5% inoculant is used in the molten iron, and is added to the melting furnace, before or in the holding furnace, or in the breast pan of a cupola. From 0.05-4% of the inoculant may also be included in the charge prior to melting. This inoculant prevents the formation of white iron in the castings even when the molten iron is held for long periods prior to casting.