The effects of Si and C, the main constituents of the alloy in question, on the mechanical properties, corrosion resistance, and shrinkage of acid-resistant high-silicon irons have already been reported by the authors. Successively, in the present investigation, the effects of various alloying elements, i.e., P, S, V, Ti, Al, As, Sn, Mn, Ni, Cr, Mo, Co, Cu and W on these properties have been studied.
The results are summarized as follows:
(1) The elements that had favourable effects on the transverse strength of high-silicon iron were as follows: Ni (0.7%), Co (0.3%), Cr (0.6%), Mo (3%), W (0.8%), V (0.09-0.5%) Ti (0.3%), Al (0.06%), and Cu (0.3-3%). The percentage in parenthesis indicated the optimum content.
(2) The elements that promoted a growth of graphite, such as Cu and Al, decreased the Rockwell hardness, while the elements, the so-called carbide stabilizers, that diminished the size of graphite and gave favour to form hard carbide-phases, such as Mn, P, Cr and Mo increase the Rockwell hardness.
(3) The corrosion resistance to sulphuric acid was improved by additions of Mn, P, Ni, Co, Cr, V, Cu, and As. Among these elements, Cu was most effective. It was adversely affected by Sn and S. For hydrochloric acid Mo and Ni had good effects while Sn and P had deleterious effects.
(4) The shrinkage of high-silicon irons decreased by additions of all alloying elements in the present tests except As.