Compacted Graphite Cast Irons - Characteristics of Pig and Cast Iron Castings Inoculated by Calcium Containing Alloys

In the present work the possibility to obtain large size castings of compacted graphite cast iron by inoculating ipereutectic pig iron melts with Fe-Si-Ca-Mg-Ti alloys with different calcium contents was first studied. Two alloys have been used: the first contained 4 divided by 5, 5 wt % Ca and the second less than 1 wt % of the element. The amount of inoculant alloy to be added to the melts was calculated so that the content of Mg in the casting agreed with the Sofroni equation. Casting temperatures were in the 1350-1400 degree C range. Samples for different tests were machined from cores obtained from the middle portion of ingot molds made with the compacted graphite pig iron. The use of an inoculant alloy containing 4-5, 5 wt % calcium has been verified feasible for molds of middle size.