| 摘要 |
A method is provided for producing by centrifugal casting an alloy tubular article of manufacture in the form of a composite tubular product comprised of an outer alloy layer (first alloy) and at least one inner alloy layer (second alloy) while substantially inhibiting the formation of a metallurgical bond between layers in the final casting. The product is produced using a rotatable centrifugal casting mold having a cylindrical inner surface adapted to receive a molten metal alloy. A first layer of an alloy is poured into the rotatable mold, the alloy having a melting point of at least about 1300 DEG C. and generally at least about 1400 DEG C. Centrifugally casting said alloy as an outer layer during rotation of said mold. The outer layer is solidified and cooled to a temperature not exceeding about 92% of its absolute melting point in degrees Kelvin. At least one inner layer is poured into the outer layer, the alloy of the inner having a melting point of at least about 1300 DEG C. and generally at least about 1400 DEG C. The centrifugally cast composite tubular metal product is cooled to ambient temperature to provide a composite tubular product in the as-cast condition characterized by an interface between the layers in which the formation of a metallurgical bond across the interface has been substantially inhibited. The composite casting may then by mechanically hot worked, such as by hot extrusion, to produce a composite tube in which the layers are metallurgically bonded to each other. |
