Articles, such as tubing, which have excellent corrosion resistance to steam at elevated temperatures and to hydriding, are produced from zirconium alloys containing 0.5 to 2.0 percent niobium, up to 1.5 percent tin, and up to 0.25 percent of a third alloying element such as iron, chromium, molybdenum, vanadium, copper, nickel and tungsten. The articles are formed by beta-treating the alloy, initially deforming the same at a temperature below 650° C. and further deforming the same through cold working stages also below 650° C., annealing the material between the cold working stages at a temperature between 500°-650° C., and final annealing the same at a temperature below 650° C. to provide articles having a microstructure of fine precipitates of less than about 800 Å, homogeneously dispersed throughout the zirconium.

Process for fabricating a zirconium-niobium alloy and articles resulting therefrom

Seamless tubing is formed from welded precursors of zirconium or titanium material by heating successive axial segments of welded tubing completely through the wall of the tubing to convert the material to the beta phase and then rapidly quenching the segments, with the heating and quenching effected so as to prevent the growth of beta grains within the material.

Process for forming seamless tubing of zirconium or titanium alloys from welded precursors

It has been found that modifying standard Zircaloy alloy processing techniques by limiting the working and annealing temperatures utilized after conventional beta treatment results in Zircaloy alloy product having superior high temperature steam corrosion resistance.

Zirconium alloy products and fabrication processes

This is an alloy comprising, by weight percent, 0.5-2.0 niobium, 0.7-1.5 tin, 0.07-0.14 iron, and 0.03-0.14 of at least one of nickel and chromium, and at least 0.12 total of iron, nickel and chromium, and up to 220 ppm C, and the balance essentially zirconium. Preferably, the alloy contains 0.03-0.08 chromium, and 0.03-0.08 nickel. The alloy is also preferably subjected intermediate recrystallization anneals at a temperature of about 1200°-1300° F., and to a beta quench two steps prior to final size.

Zirlo material for light water reactor applications

A fuel assembly for a nuclear reactor compris­ing a fuel cladding tube (11) of three-layer structure having an outer surface (16) in contact with reactor water of the nuclear reactor, an inner surface layer (14) in contact with the nuclear fuel, and an intermediate layer (15) interposed between the outer surface layer and the inner surface layer. the outer surface layer (16) is made of a Zr-based alloy containing Nb, Sn and Mo. The inner surface layer(14) is made of pure zirconium. The intermediate layer is made of a high ductility alloy which is higher in ductility than the outer surface layer (16) and is higher in strength than the inner surface layer(14).

Fuel assembly for nuclear reactor, method for producing the same and structural members for the same

Zirconium-base alloy channels and fuel cladding tubes having unique resistance to accelerated pustular corrosion in the boiling water reactor environment are produced by a heat treatment causing segregation of intermetallic particulate precipitate phase in two dimensional arrays preferably located along grain boundaries and subgrain boundaries throughout the alloy body.

Timothy James Black

Papers

Zirconium alloy heat treatment process and product