Nondestructive testing method for metal material fracture toughness

Abstract

The present invention discloses a nondestructive testing method for metal material fracture toughness, and the method mainly includes: performing Charpy impact tests to samples of different damage degrees to obtain the brittle transition temperatures of the samples; performing ultrasonic secondary harmonic measurement to the samples of each type of the damage degrees to obtain the second harmonic ultrasound nonlinearity parameter normalized value of the samples of the type of the damage degree; obtaining the fracture strength factor of the samples of each type of the damage degrees via the fracture toughness tests or by reference of fracture empirical formulas, and making a calibration curve for nondestructive testing fracture toughness; performing ultrasonic secondary harmonic measurement to a metal material under test to obtain the second harmonic ultrasound nonlinearity parameter normalized value of the metal material under test; and obtaining the fracture toughness value of the metal material under test by using the calibration curve. The nondestructive testing method for metal material fracture toughness of the invention is capable of performing testing and evaluation of material fracture toughness of in-service metallic components, and providing a reliable basis for the security service of the metal materials.

Description

technical field [0001] The invention belongs to the technical field of mechanical structure safety assurance and non-destructive evaluation, and in particular relates to a non-destructive detection method for fracture toughness of metal materials. Background technique [0002] Metal materials, such as stainless steel, titanium alloys, nickel-based alloys, etc., are widely used in petrochemical, thermal power, nuclear power, automobile, and aviation industries. Most of the components made of these materials work in harsh environments such as high temperature and high pressure for a long time. They will It is inevitable to suffer from high temperature, creep, and fatigue damage, which will cause material performance degradation, resulting in material failure and safety accidents. Therefore, it is very necessary and necessary to monitor and detect the health of these in-service equipment and components to obtain the remaining strength of the material. Urgent. As a quantitative...

AI Technical Summary

Problems solved by technology

Although the traditional fracture toughness test and small punch test methods can comprehensively reflect the mechanical properties of materials, the shortcomings of these methods are also obvious: 1) The materials for these fracture toughness tests can only be obtained from a local area of ​​the structure, that is, Based on limited statistical data, it cannot reflect the overall mechanical properties of components, and too much sampling will cause the analysis process to be time-consuming and laborious, which is not conducive to rapid detection and analysis

2) The sampling range can generally only be carried out on the surface of the material, which cannot reflect the actual damage state inside the structure

At present, the technologies that can be used for nondestructive testing or evaluation of fracture toughness of metal materials mainly include: electrochemical technology, resistivity measurement, eddy current testing, etc. And the purpose of evaluating the fracture toughness of metal materials, especially the fracture toughness of materials has not been quantitatively detected

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