GB924754A - Process and product of metallurgically joining zirconium to ferrous metal - Google Patents

Abstract

924,754. Extruding. UNITED STATES ATOMIC ENERGY COMMISSION. May 5, 1961 [May 25, 1960; July 28, 1960], No. 16485/61. Class 83 (4). A method of metallurgically joining a mass 13 of predominantly ferrous metal to a mass 14 constituted predominantly of zirconium, comprises arranging the masses in line with the zirconium mass following the ferrous mass in a substantially vacuum-tight malleable ferrous metal can 15 and hot-extruding the can and the masses, while maintaining the vacuum, such operations being preceded by degassing the can and ferrous metal mass by protracted heating without melting while maintaining a substantial vacuum thereon 80 as to remove nitrogen from the ferrous metals. The heating of the ferrous metal mass 13, which may be mild or carbon steel or ferritic, austanitic or martensitic stainless steel, and the can, which may be mild steel, is effected at about 1700‹ F. for 3 to 4 hours at a high vacuum, the mass then being allowed to cool and the vacuum broken by a gas such as a helium or air. The ferrous metal mass 13 is aligned with the mass 14 containing predominantly zirconium, e.g. raw zirconium or an alloy of zirconium and aluminium, chromium, copper, hafnium, iron, manganese, molybdenum, nickel, niobium, tin, titanium, tungsten or vanadium. The abutting surfaces of the masses may be flat, conical or concentrically ridged, one complementary to the other, and a thin layer of niobium or titanium may be placed between the surfaces before they are enclosed in the can 15 which has a tube 16 by which it can be evacuated of gas. The assembly is heated to about 1600‹ F. and placed in an extrusion press consisting of a liner 1 within a container 4, a die 5 and bolster 6 in a holder 7, a die head 8 and a ram 11. When extruded, the masses have a conical interface 23 at which they are metallurgically bonded together and a sheath of mild steel which is then removed. The masses may be extruded into the shape of rectangular-sectioned conduit, I-beams, or tubes having straight or spiral internal and/or external ribs, or a number of alternately-arranged discs of the metals may be extruded to form a rod of alternate pieces of the metals, the rod then being cut to produce a series of nipples for use in joining rods of predominantly ferrous metal to rods containing predominantly zirconium.