Machining process for zirconium alloy

Abstract

The invention discloses a machining process for a zirconium alloy. The machining processing comprises the following sequential steps of: a hammer cogging working procedure, a beta-phase quenching working procedure, a graded annealing working procedure, an alpha-phase hot rolling working procedure, a middle annealing and cold machining working procedure, and a final finished-product board re-crystallizing and annealing working procedure, wherein the graded annealing working procedure comprises pre-annealing treatment; the re-annealing treatment specifically comprises the following steps of: carrying out the pre-annealing treatment on a water quenched product obtained by the beta-phase quenching working procedure under the environment in a temperature range of 400-700 DEG C for 0.1-3 hours; and carrying out annealing and heat preservation on a product obtained by the pre-annealing treatment under the environment in a temperature range of 500-800 DEG C for 0.5-5 hours. The machining process for the zirconium alloy disclosed by the invention enables second-phase grains in the zirconium alloy to be dispersed and distributed, so as to improve the plastic deformation capability of the zirconium alloy and improve the plastic machining capability of the zirconium alloy; and meanwhile, the machining process for the zirconium alloy further can improve the corrosion resistance of a core structural material prepared by the zirconium alloy in a nuclear reactor.

Description

technical field [0001] The invention relates to the technical field of alloys, in particular to a processing technology for zirconium alloys. Background technique [0002] Zirconium alloy is a non-ferrous alloy composed of zirconium as a matrix and adding other elements. It has good corrosion resistance, moderate mechanical properties and low atomic thermal neutron absorption in high temperature and high pressure water and steam at 300°C-400°C Therefore, zirconium alloys are often used as core structural materials for water-cooled nuclear reactors, such as fuel cladding, pressure tubes, brackets, and tunnel tubes. [0003] The existing zirconium alloy processing technology includes: forging blanking process, β phase quenching process, α phase hot rolling process, intermediate annealing and cold working process, and final recrystallization annealing process of finished plate; among them, the forging blanking process is at 900 In the environment of ℃-1150℃, the as-cast zircon...

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Problems solved by technology

[0004] However, the cooling rate of the core of the large-sized ingot is insufficient after the β-phase quenching process, and precipitates are inevitably generated at the α-phase boundary. The precipitates in the existing zirconium alloy processing technology are distributed in bands, and in the The uneven growth of the α-phase hot rolling process during the heat preservation process leads to the inability to disperse the second phase particles in the zirconium alloy, resulting in poor plastic deformation ability of the zirconium alloy and poor plastic processing ability of the zirconium alloy

[0005] In addition, the precipitated phase is distributed in a band shape and grows unevenly during the heat preservation process of the α-phase hot rolling process, resulting in a larger particle size of the second phase in the zirconium alloy and unable to disperse the distribution, resulting in a core structure made of zirconium alloy. Corrosion resistance of materials decreases in nuclear reactors

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