Spheroidal graphite aluminium cast iron - with high aluminium content for good heat and corrosion resistance

摘要

A spheroidal graphite Al cast iron is prepd. by first preparing a cast iron contg. 2-4% C and then incorporating 9-27% Al, 0.6-2% Si and 0.8-1.4% Mg (w.r.t. the wt. of the cast iron). The cast iron can be prepd. by heating to 1400-1450 (pref. 1430-1450) degrees C and poured onto an Al alloy contg. Si and Mg heated to 600-700 (pref. 630-650) degrees C The cast iron does not require further heat treatment. The iron is cold workable within certain limits and can be machined with tools for conventional Al cast iron. The tensile strength may be =50 kg/mm2 and the elongation Similar or equal to 3%. The cast iron has good heat and corrosion resistance, the latter is much greater than that of lamellar cast irons, even those contg. Al.