PRODUCTION OF TUBULAR FUEL ELEMENTS, PREFERABLY, OF HEXAGON SHAPE Russian patent published in 2014 - IPC G21C21/10 

FIELD: power engineering.

SUBSTANCE: invention can be used in production of tubular fuel elements of teaching reactors running on fuel of high and low concentration shaped, preferably, to hexahedron. Said prefabricated blank is subjected to hot forming, drawing of formed pipe and quenched. Prior to forming, composite billet is heated in alt bath or resistance kiln to 380-440°C. Round pipe forming is performed with drawing of 7-15, preferably, 8-12. After forming, pipe is produced with wall depth at rear end equal to or higher than finished pipe wall depth by not over 0.10 mm. Drawing is made in tree steps. At first step, drawing with wall thinning is carried out while at second and third steps two-stage forming of round pipe to hexagon. At second pass, preliminary forming is made without thinning and pipe diameter reduction with forming of hexagonal pipe while at third pass final forming is performed. Heat treatment is carried out before first and second drawing passes. Before every heat treatment, pipe is subjected to chemical processing in the solution of nitric acid at 90-100°C.

EFFECT: high-quality diffusion adhesion of shells with core, monocrystalline structure and clean article surface.

8 dwg