Patent ID: 6427759
Filing Date: 2002-08-06
Classification: B22C,C22C

Abstract:
A method of casting a marine propeller, comprising the steps of producing a wax pattern substantially identical in configuration to a marine propeller to be cast, coating the wax pattern with a layer of ceramic material to produce a ceramic shell, removing the wax pattern from the interior of the shell, feeding a molten stainless steel consisting essentially of in weight percent:Chromium14.15% to 15.2%â€‚Nickel5.35% to 6.05%Silicon1.0% to 1.5%Copper2.8% to 3.5%Niobium0.15% to 0.45%Tantalum0.15% to 0.45%Carbon0.05% maxManganese0.45% maxSulfurâ€‚0.025% maxIronBalanceinto the interior of the shell, and solidifying the molten stainless steel to produce a cast propeller substantially identical in configuration to said wax pattern, said silicon acting to decrease reaction between the ceramic material of the shell and the molten stainless steel to thereby minimize porosity defects in the cast propeller.