Abstract: The present invention relates to a method for making flat, thin elements which consist of: producing a zirconium alloy blank also containing, besides the inevitable impurities, 0.8 to 1.3% of niobium, 1100 to 1800 ppm of oxygen, and 10 to 35 ppm of sulfur; carrying out a &bgr; hardening and hot rolling to obtain a blank and performing on it at least three cold rolling passes with intermediate annealing heat treatments. One of the intermediate heat treatments is performed for a duration of at least 5 hours at a temperature less than 560° C. and all the optional treatments subsequent to the long treatment are carried out at a temperature of less than 620° C. for not more than 15 minutes.

Abstract: A method of manufacturing a tube suitable for use as sheath of a nuclear fuel rod zirconium based alloy. The alloy contains 0.18% to 0.25% iron, 0.07% to 0.13% chromium, 0.35% to 1.70% tin, all percentages by weight, 900 ppm to 2300 ppm oxygen, 80 ppm to 200 ppm carbon, and 50 ppm to 120 ppm silicon. A drawn blank is subjected to successive passes of metallurgical treatment and of heat treatment. The Fe/Cr ratio by weight in the alloy lies in the range 1.6 to 3. The heat treatment includes, after at least one rolling pass, a plurality of annealing passes under an inert atmosphere such that the sum .SIGMA.A is greater than 1.5.10.sup.-17, and advantageously in the range 2.10.sup.-17 to 2.10.sup.-16. The first rolling pass is performed on the tube coming from the drawing operation, without an intermediate annealing. .SIGMA.A designates the sum of the products of the times t (in hours) multiplied by the exponential of --Q/RT, where T is the temperature in K.

Abstract: The invention relates to a tube, bar, sheet or strip resistant both to uniform and nodular corrosion, of a zirconium-base alloy of a composition (% by weight) of Fe 0.1 to 0.35, V 0.07 to 0.4, Q 0.05 to 0.3, Sn below 0.25, Nb below 0.25, trace impurities and balance Zr. The invention also relates to a process for producing these products which have a greatly increased service life. It also relates to composite tube having an internal and/or external alloy sheathing.