ALLOY AND TUBE FOR NUCLEAR FUEL ASSEMBLY AND METHOD FOR MAKING SAME

摘要

The invention concerns a method for making tubes designed for a nuclear fuel pencil case or guide tube which consists in forming a bar in a zirconium based alloy containing equally 0.3 to 0.25 wt. % of the total iron, of chromium or vanadium, 0.8 to 1.3 wt. % of niobium, less than 2000 ppm of tin, 500 to 2000 ppm of oxygen, less than 100 ppm of carbon, 5 to 30 ppm of sulphur and less than 50 ppm of silicon. The bar is soaked in water after being heated at a temperature between 1000 DEG C and 1200 DEG C. A blank is spun after being heated at a temperature between 600 DEG C and 800 DEG C. The blank is cold-rolled, in at least three of four passes, to obtain a tube with intermediate heat treatments between 560 DEG C and 620 DEG C and s final heat treatment is carried out between 560 DEG C and 620 DEG C in inert atmosphere or under vacuum.