17 - Sulfur in Molding Sand Effect on Flake Graphite at the Cast Surface of Ductile Iron Castings

Abstract:

This project investigated the role of sulfur in molding sand on the formation of a layer of flake graphite just below the surface of ductile iron castings. Information was compiled by questionnaire from 28 member foundries on the prevalence of this condition and procedures used to control sulfur in system molding sands. Six volunteers participated in round robin testing to determine reproducibility of sulfur analyses methods. Eleven foundries then provided statistical data on system sand sulfur analyses from their own facilities using recommended practices identified in this study. A literature survey identified information on effects of sulfur and threshold levels.