Abstract: The invention relates to a method of producing a flat zirconium alloy product with a Kearns factor (cross direction) of between 0.3 and 0.7. The inventive method consists in: producing an ingot containing Nb=0.5 to 3.5%, Sn=0 to 1.5%, Fe=0 to 0.5%, Cr+V=0 to 0.3%, S=0 to 100 ppm, O=0 to 2000 ppm, Si=0 to 150 ppm, the remainder being zirconium and impurities; shaping the aforementioned ingot; performing one or more hot rolling operations in order to obtain a flat product, whereby the last operation is performed at between(810?20×Nb %)° C. and 1100° C. and is not followed by any quenching from phase ?+? or ?; optionally performing an annealing operation at a maximum of 800° C.; and performing one or more cold rolling and annealing operations, said annealing operations being performed at a maximum of 800° C. The invention also relates to the flat zirconium alloy product thus obtained.

Abstract: The method allows ZrF4 to be converted into ZrO2, by carrying out a thermal conversion operation based on solid ZrF4 and water which are heated in a reactor until converted into ZrO2. The initial ratio by weight of ZrF4 to water is in particular between 1/5 and 1/500, and this ratio is maintained substantially for the entire duration of the conversion. The thermal conversion is carried out at a temperature greater than or equal to 300° C. The invention is used in particular for recycling pickling baths for zirconium alloys.

Abstract: A large ingot is produced by casting the zirconium alloy, then the ingot is forged in two stages to obtain the semi-finished product wherein the first stage of forging the ingot is performed at a temperature at which the zirconium alloy is in a state comprising crystalline ? and ? phases.

Abstract: A process for the separation and purification of hafnium and zirconium.

Abstract: A method of fabricating a zirconium alloy flat product, the method being characterized by: preparing or casting a zirconium alloy ingot containing at least 95% by weight of zirconium, and including the usual impurities and alloying elements; shaping said ingot in order to obtain a flat product; subjecting said flat product to a ? quenching operation under conditions that are determined to obtain within the flat product an acicular structure at the end of said ? quenching; subjecting said flat product, after the ? quenching, to a rolling operation performed in a single rolling sequence without intermediate annealing, said rolling being performed at a temperature lying in the range ambient to 200° C., and having a reduction ratio lying in the range 2% to 20%; and subjecting said rolled flat product to an annealing treatment in the a range or in the ?+? range, performed in the temperature range 500° C. to 800° C. for 2 minutes to 10 hours.

Abstract: The alloy contains, by weight, at least 95% zirconium and from 0.01 to 0.1% sulphur and, optionally, at least one element from the group consisting of the elements tin, iron, chromium, hafnium, niobium, nickel, oxygen and vanadium, the balance of the alloy consisting of inevitable impurities. The sulphur is present in the alloy in the dissolved state, thereby improving the creep strength and in the form of uniformly distributed fine precipitates, thereby improving the corrosion and hydriding resistance. The alloy may be heated by a solution annealing treatment in the ? phase followed by a quench or by a soak at a temperature below 950° C. in order to transform it into the ? or ?+? phase.

Abstract: A method for separating a metal (a) from a metal (2), preferably zirconium from hafnium, which consists in dissolving said metals in an aqueous solution wherein said metals are in a state preventing them from passing through a nanofiltration membrane; treating the aqueous medium with a ligand, for example EDTA, which is complexed with metal (1) and/or metal (2), then in passing the resulting treated medium on a filtering membrane allowing through the ligand-metal complexes, but retaining the metals not complexed with the ligand.

Abstract: A method of separating zirconium and hafnium tetrachlorides using a solvent comprising firstly an alkaline metallic solvent comprising a salt made up of an alkali metal chloride and an acidic metal chloride A, for example a chloroaluminate or an alkaline chloroferrate, and secondly an acidic metal or metalloid chloride B of acidity that is less than that of the acidic metal chloride A. The acidic metal or metalloid chloride B may be selected from chlorides of Mg, Zn, and Cu. The method may be a continuous separation method by selective absorption of the tetrachloride vapors by the solvent in the substantially or totally molten state.

Abstract: The invention proposes a zirconium-based alloy also containing, by weight, apart from unavoidable impurities, from 0.02 to 1% of iron having from 0.8% to 2.3% of niobium, less than 2000 ppm of tin, less than 2000 ppm of oxygen, less than 100 ppm of carbon, from 5 to 35 ppm of sulphur and from 0.01% to 0.25% in total of chromium and/or vanadium, the ratio R of the niobium content, less 0.5%, to the iron content, optionally supplemented by the chromium and/or vanadium content.

Abstract: A tubular blank (22) is rolled on a mandrel (14) in a pilgrim rolling mill. In a first rolling stage, a first part of the blank (22) is rolled on a first part (18, 19) of the mandrel (14), with a reduction of the outside diameter of the blank (22) to the outside diameter of the guide tube and a reduction of the wall thickness of the blank (22) to one of a first wall thickness (e1) and a second wall thickness (e2) exceeding the first wall thickness (e1). The mandrel (14) is advanced in the axial direction. A second part of the blank (22) is rolled on a second part (20,21) of the mandrel spaced from the first part in the axial direction with a reduction of the outside diameter of the blank to the outside diameter of the guide tube and a reduction of the wall thickness of the blank (22) to the other of the first wall thickness (e1) and second wall thickness (e2).

Abstract: The invention is a process for inspecting chips and/or fragments of metal or metal alloy to eliminate from them inclusions of a more X-ray absorbent material than the metal or alloy, wherein a field that delimits a portion of these chips and/or fragments is X-rayed. The process produces an X-ray image which is then converted into an electronic image. This image is analyzed in order to detect the inclusion(s) having features. The features include a background correction of the degree of illumination of each pixel in the field in the absence of chips and/or fragments, a field is covered with the portion of chips and/or fragments, and the electronic image is corrected by subtracting the background correction from the degree of illumination of each of its pixels, and the portion of chips and/or fragments is rejected if this corrected image contains at least one relative pixel corresponding to a chosen condition.

Abstract: A product having at least an exterior surface formed by a Zr alloy comprising the following addition elements (% by weight): Sn 0.40 to 1.70, Fe 0.05 to 0.25, Cr 0.03 to 0.16, Ni less than 0.08; the following maximum amounts of impurities (ppm): Al 75, B 0.5, Cd 0.5, C 270, Co 20, Cu 50, Hf 100, H.sub.2 25, Mg 20, Mn 50, Mo 50, N.sub.2 65, Si 120, Ti 50, W 10, U total 3.5; with the balance being O.sub.2 and Zr, wherein the Zr alloy has an Ni content which is greater than 70 ppm and less than 300 ppm.

Abstract: A process for the manufacture of a flat product of zirconium alloy having a width between 50 and 600 mm from a flat cold rolled product. The cold rolled product is heated to the beta range and maintained in the beta range using an infra-red heating device with a wavelength of between 0.8 and 5 microns, the maximum temperature difference over the width of the product being less than 35.degree. C. The product is then rapidly cooled and optionally annealed to obtain a flat product, which can be a strip, sheet or band.

Abstract: A titanium alloy part having a structure comprising ex-beta acicular grains and with equi-axial alpha phases gathered in a plurality of rows at boundaries of the grains. The alloy comprises, by weight, 2 to 5% Mo, 3.5 to 6.5% Al, 1.5 to 2.5% Sn, 1.5 to 4.8% Zr, Fe.ltoreq.1.5%, 4 to 12% Mo+V+Cr, and the balance, titanium and impurities.

Abstract: A method of producing a part having high strength and improved ductility from a titanium alloy having a composition, in percent by weight, or Mo equivalent 5 to 13 and Al equivalent 3 to 8, the balance being titanium and impurities, comprising the steps of hot working an ingot of the alloy including a roughing down under heat and preparation of a blank under heat, preheating to a temperature situated above the real beta transus of the hot worked alloy, and then final working of at least a part of this blank, after which the blank obtained is subjected to a solution heat treatment and then aged. The hot worked blank is cooled from the preheating temperature to a temperature for the beginning of final working which, under the conditions of the cooling of the blank, is at least 50.degree. C. below the real beta tansus and at least 10.degree. C. above the temperature of appearance of the alpha phase, so that the final working is sufficient to end within the alpha nucleation range.

Abstract: Zircaloy 2 or 4 strip is heat treated in the beta range, followed by rapid cooling by passing the strip between a first and second roller pair, each roller pair having two oppositely disposed rollers gripping the strip. Each roller pair is connected to a source of an electric current so as to complete an electric circuit including the source, the roller pairs and the strip, which causes heating of the strip to the beta range. The strip is heated at a rate less than 40.degree. C./sec between 750.degree. and 1000.degree. C., held at 1000.degree.-1100.degree. for less than 2 minutes and cooled at a rate of at least 40.degree. C./sec between 1000.degree. C. and 600.degree. C.

Abstract: The present invention relates to a process for the manufacture of zirconium based tubes formed from layers of varying composition. The process consists in preparing the tubular blank which is intended to form the outer layer of the tube by rolling-soldering a sheet, and then in fitting it onto another tubular blank, or core block, of smaller diameter, which is obtained by piercing a small bar, and which may be coated on the inside with a plating, in soldering the ends of said blanks in order to subject the assembly to a treatment of placing it in solution in a beta phase, followed by soaking it in water and drawing it. The invention is used for the production of Duplex or Triplex type tubes with an improvement in the gross weight of zirconium needed to make 1000 kg of useful metal, with good adherence being obtained between the layers of said tube.

Abstract: The invention relates to a process for the production of a neutron absorbing pellet for use in a nuclear reactor control device, comprising the following stages:a) compactable products are prepared incorporating as % by weight electrolytic crystals or chips of Hf and optionally boron carbide powder with a total weight (HF+B.sub.4 C) of 40 to 100%, the Hf:(Hf+B.sub.4 C) ratio being 0.20 to 1 and optionally other metallic elements melting at above 400.degree. C.;b) these products are mixed and compressed in a mould in one or more filling and compression operations until a pellet is obtained with an apparent density higher than 80% of its average density in the solid state;c) a sintering treatment is optionally carried out on said pellet;d) the pellet is or has been extracted from the mould;e) the pellet is optionally ground.

Abstract: A method of making a strip of ZIRCALOY 2 or 4 is disclosed wherein an ingot is worked, roughly shaped into a billet then quenched from the beta range, hot rolled in alpha range, annealed and cold rolled to 0.3 to 0.9 mm. The O and C, in ppm, are selected to satisfy the formula: O.sub.2 <1200-0.75 x C (R) so that a T texture is obtained systematically for thicknesses of at least 0.8 mm. The disclosure also concerns the strips obtained. The method can be applied to obtaining strips of excellent formability for the production of components for nuclear water reactors.

Abstract: A method of obtaining uranium metal from an oxidized uranium compound, characterized in that the oxidized compound is treated with chlorine and carbon at a first stage, to obtain a chloride which is reduced by electrolysis or metallothermy using a reducing metal at a second stage.