Slow fade inoculant for molten cast iron - comprising iron silicon alloy, high melting calcium aluminium silicate and a di:calcium aluminium silicate contg. carbide(s) of silicon an

摘要

An inoculant for molten cast iron comprises (a) a crystalline, Si.-contg. matrix of iron silicon alloys, (b) high melting point calcium aluminium silicate cpds. in the matrix crystal structure, and (c) a dicalcium aluminium silicate material with up to 20 wt.% SiC and 10 wt.% Ca-C2. The amt. of (b) in (a) is 5-30 wt.%, esp. 8-15 wt.%, and the ratio of (a) + (b) : (c) is 1:0.05-0.2. The inoculant is added to molten cast iron in an amt. of 0.05-1 wt.%, pref 0.1-0.5 wt.%, or is added to the burden before melting in an amt. 0.05-4 wt.%. The inoculant has low-fade properties and is esp. useful for cast iron in a melting furnace or in an appts. for keeping it hot. Because it retains its properties, the amt. of further inoculant required immediately before teeming is reduced and the cast prod. consequently has improved properties such as hardness and reduced porosity. The inoculant can be used in the prodn. of vermicular, flake or nodular graphite cast iron.