Preparation method for metallographic sample of zirconium and zirconium alloy microstructures

Abstract

The invention discloses a preparation method for a metallographic sample of zirconium and zirconium alloy microstructures. The method comprises the following steps of pre-cleaning the metallographic sample; successively performing pre-grinding, rough-grinding and fine-grinding on the metallographic sample after the sample surface is cleaned; preparing a solution according to a volume ratio of H2O2 : HF : H2O of 0.8-1.2 : 1 : 2; wiping the sample surface for 30-40 seconds by using the solution; chemical-etching the sample without a scratch on the surface in a solution with the volume ratio of H2O2 : HF : H2O being 0.8-1.2 : 2 : 17 and with the etching time of 40-50 minutes; cleaning the etched sample; draining water; and performing metallographic observation and grain size evaluation. The microstructure diagrams of the zirconium and zirconium alloy have good effect, clear crystal grains, and are helpful for analysis and the grain size evaluation for the zirconium and zirconium alloy microstructures and intermetallic compound forms. The whole operation process is simple and a procedure is relatively short. The corrosivity for H2O2 solution is lower than that of HNO3, so that the method has small harm to health of an operator; equipment investment can be reduced; the quality and speed for sample preparation are increased; and the method is suitable for the analysis and the grain size evaluation for the zirconium and zirconium alloy microstructures.

Description

technical field [0001] The invention relates to a method for preparing a microstructure metallographic sample of zirconium and zirconium alloy, belonging to the field of materials. Background technique [0002] The reserves of zirconium in the earth's crust are about 0.025%-0.028% (mass fraction), which is higher than the reserves of common elements nickel, copper, lead, and zinc. Zirconium alloys have small thermal neutron absorption cross-sections, high thermal conductivity, and good mechanical properties , and has good processing performance and the same as UO 2 Good compatibility, especially for high-temperature water and high-temperature water vapor, it also has good corrosion resistance and sufficient thermal strength, so zirconium alloys are widely used as cladding materials and core structure materials for water-cooled power reactors, and become the preferred choice for nuclear power plants. important structural material. [0003] Zirconium has excellent corrosion ...

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Problems solved by technology

However, this method is complicated in equipment, takes a long time, and the size of the sample is limited

Bai Juli, Xiao Lin, Xue Xiangyi and others used mechanical polishing and chemical polishing to prepare zirconium alloy metallographic samples in the literature "Zirconium, Zirconium and Alloy Metallographic and Scanning Electron Microscopy Analysis Samples". The composition is HF and HNO 3 , this metallographic preparation method has a long process and high requirements for equipment, which is not suitable for microstructure observation and evaluation on the construction site, and HNO 3 It is a strong corrosive solvent, and long-term operation is harmful to the health of operators

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