Plane strain ductility of Zircaloy-4 tubes as dependent on structure and texture

Zircaloy-4 tubes were cold rolled 50 or 80% to a series of textures normal for regular tube production and finish annealed at 510 and 5750C. Two different types of ring expansion specimens giving local transverse deformation under a plane strain condition were developed. Plane strain tests were performed out-of-reactor at room temperature and 3500C, after which the plane strain ductility was measured as local transverse elongation. Both at room temperature and at 3500C tubes recrystallized at 5750C have higher plane strain ductility than tubes partially recrystallized at 5100C. The plane strain ductility is independent of the texture over the texture range of practical interest for regularly produced Zircaloy tubes. This seems to be a consequence of the fact that the stress ratio sigmasub(theta):sigmasub(2) in plane strain loading varies with the texture in such a way that the degree of texture softening during deformation is the same for all canning tube textures. (Auth.)