The Suitability of Indian Pig Iron for the production of Nodular Cast Irons

Abstract

The sources and compositions of pig irons available in India are described. The two elements in India n pig iron likely to interface with the successful production of nodular cast iron are phosphorous and titanium. Phosphorous above a certain percentages adversely affects the mechanical properties through its does not hinder the formation of graphitic nodules. Titanium, however interfaces with the formation itself. The harmful effects of titanium can be overcome by the addition of cerium along with the magnesium alloy. The harmful effects of phosphorous cannot be eliminated unless its content is reduced. A series of experiments were carried out to determine the maximum percentage of phosphorous permissible without determination in the mechanical properties o the nodular iron. In this investigation a number of melts were made with varying contents of phosphorous (from 0.02 to %).These were treated with a nickel –magnesium alloy and poured a keel block mould. Tests were carried out on the above heats in the as case and a healed condition. The relation between the various mechanical properties such as tensile strength ductility etc., and the microstructure is discussed in detail. The importance of the proper control of composition is brought out. The maximum permissible required and also on the proportion of the other elements like siliceous, manganese, nickel etc. The various compositions (upto phosphorous contents of about 0.35%) that can confirm to A.S.T.M. Specifications are given. Having determined the maximum phosphorous content the various methods of reducing the phosphorous content in cast iron is discussed, in the light of latest trends in foundry practice.