Production of ferritic as-cast structures in sheroidal - graphite iron

摘要

The method comprises (a) providing the mould with a refractory coating between .01 and .06 inch thick; (b) applying a coating of powdered inoculating material over the refractory coating; (c) treating the metal with inoculating material as it is being poured from the mould. The composition of the metal in the resulting pipe comprises 3.0-3.6% carbon, 2.30-3.75% silicon and 0.02-0.07% magnesium. Particularly useful in the manufacture of ductile iron pipe, this method provides for magnesium-treated cast iron to be cast in cylindral centrifugal moulds with a refractory coating, the metal being treated with an inoculating material to promote the formation of graphite.