Patent ID: 7846381
Filing Date: 2010-12-07
Classification: B22D,C22C

Abstract:
1. A cast iron alloy having: a toughness of at least 6 ft. lb Charpy V at −20° F. and a toughness of at least 10 ft. lb Charpy V at +72° F.; a tensile strength of at least 60,000 psi; a yield strength of at least 40,000 psi; and an elongation of at least 18%; the alloy comprising: (a) 3.30-3.85% Carbon by mass; (b) 2.35-2.90% Silicon by mass; (c) 0.020-0.060% nodularizing agent by mass; (d) 0-0.40% Manganese by mass; (e) 0-0.15% Copper by mass; (f) 0-0.10% Chromium by mass; (g) 0-0.050% Phosphorus by mass; (h) 0-0.030% Sulfur by mass; (i) 0-0.25% Nickel by mass; (j) 0-0.10% any other incidental non-ferrous impurities by mass; and (k) balance up to 100% of Iron; wherein the cast iron alloy is prepared by a process comprising the steps of casting the iron alloy in a mold and cooling the cast iron alloy in the mold at a rate of no more than about 600° F./h, wherein the process does not include annealing.