The effects of temperature, speed and deformation parameters of plastic processing on the formation of texture and structure in the manufacture of tubes of E125 type zirconium alloy

Pressure tubes in CANDU reactors are fabricated from Zr-2,5 % Nb alloy. One of the most important characteristics of pressure tubes that determine their behavior during operation is the crystallographic texture. The determining role of primary crystallographic orientation is due to the anisotropy of the crystal structure of the main phase of zirconium alloy (α-phase with a hexagonal close packed lattice). When the channel pipes arranged horizontally in CANDU reactor, critical factor is the creep of pipes during operation. Optimal in terms of minimal creep texture characterized by the orientation of the base normal mainly in the tangential direction. This paper describes the effect of heat treatment parameters (strain ingot method, the temperature, the ratio of deformations during liner extrusion QLn), and the effect of the ratio Q by cold working with a given degree of deformation. (authors)