A Zr-Sn-Nb-Hf alloy bar, composed of the following mass percentage of the composition: Sn 0.8% ~ 1.2%, Nb 0.2% ~ 0.4%, Hf 0.8% ~ 1.6%, allowance for zirconium and inevitable impurities. The invention also provides a method for preparing the alloy rod, which comprises the following steps: 1. Vacuum non-consumable arc smelting to prepare Sn-Nb-Hf intermediate alloy; Two, crushing Sn Nb Hf intermediate alloy, and sponge Zr mixed evenly, pressed into electrode; Three, vacuum consumable arc smelting, get ingot; Four, hot extrusion, semi-finished bar blank; Five, hot extrusion, Zr-Sn-Nb-Hf alloy bar. The Zr-Sn-Nb-Hf alloy bar of the invention has excellent room temperature and high temperature strength and good plasticity, and can be used as the next generation of structural materials under the condition of high fuel consumption.
Zirconium alloys have been widely used in nuclear reactors due to their low neutron absorption cross section, excellent corrosion properties, good machining and mechanical properties. Nuclear fuel element cladding zirconium alloy is one of the key core materials of nuclear power reactor. The advance, safety, reliability and economy of nuclear power are closely related to the performance of the cladding materials used. In the past decades, zirconium alloy cladding of PWR fuel elements has been used satisfactorily in the reactor. However, with the development of nuclear power reactor technology towards increasing fuel consumption and reducing fuel cycle cost, improving reactor thermal efficiency and improving safety and reliability, it is required that the cladding materials withstand higher temperature and radiation metering and maintain high stability. At present, traditional zirconium alloys cannot meet the requirements of advanced nuclear power reactors, so new zirconium alloys must be developed.
Transition metals such as Fe, Cr and Ni were added to these Zr-Sn-Nb alloys, forming Zr2(Fe, Ni)Zintl phase, Zr(Cr, Fe)2Laves phase, and NB-containing (ZrNb)3, Fe(ZrNb)2, FeZr(FeNb)2 and (ZrNb)3Fe phases. The second phase of these intermetallic compounds reduces the plasticity of the material, and the particles of the second phase containing transition metals will dissolve into the matrix after neutron irradiation, thus changing the density and size of the second phase and reducing the corrosion resistance of the alloy. In addition, the impurity elements such as oxygen and carbon introduced in the preparation process of zirconium alloy also adversely affect the properties of the material.
