METHOD FOR PRODUCTION OF HEAT-RESISTANT CAST NICKEL ALLOYS AND CASTINGS WITH DIRECTIONAL AND MONOCRYSTALLINE STRUCTURE Russian patent published in 1995 - IPC

FIELD: production of cast heat-resistant alloys. SUBSTANCE: method involves melting an alloy and introducing rare-earth metals into the melt before pouring, producing a charge blank, melting said blank and pouring the alloy into a casting mold followed by directional crystallization. According to the invention, the alloy is deoxidized before introduction of rare-earth metals. The amount of introduced rear-earth metals is found from the equation where P - amount of introduced rare-earth metal; τ - holding time after introduction of rare-earth metals to the beginning of pouring, min.; V_кр - speed of directional crystallization of casting, mm/min; K = 0.03-0.04 - empirical cofficient of proportionality. Rare earth metals are cesium, lanthanum, yttrium, scandium. Preliminary deoxidation of melt is achieved by the use of calcium, introduced in the amount of 0.001-0.015% of the charge weight. EFFECT: higher heat resistance of castings achieved by specifying the amount and method of introduction of rare metals into the metal. 3 cl, 2 tbl