A process for producing castings of nodular cast iron.

摘要

The method of producing a nodular cast iron casting comprising the melting of a cast iron bath of low sulphur content and near eutectic composition with a chill value of no more than eight thirty-seconds inch as measured by a standard wedge test. The bath is preconditioned by adding a rare earth and an alkaline earth containing alloy in an amount sufficient to increase the chill value from 50 to 150 percent and then pouring the bath into a mold having at least one reservoir and a dam skimmer gate with the reservoir containing from one-fourth to 1 1/4 percent by weight of a magnesium alloy. The last mentioned alloy is sufficient in amount to retain at least 0.01 percent magnesium in the metal from the bath which passes through the alloy so as to produce a casting containing nodular graphite.