Large-sized high-temperature blade internal defect three-dimensional nondestructive detection method

Abstract

The invention relates to a large-sized high-temperature blade internal defect three-dimensional nondestructive detection method. The method comprises the steps of carrying out the internal defect detection for a front surface of a gas turbine blade to obtain a two-dimensional grayscale image by utilizing a digital ray device, processing the two-dimensional grayscale image to obtain a two-dimensional size and a two-dimensional position of a defect, carrying out the three-dimensional location for an internal defect of the blade, locating the depth of the defect by utilizing a water dipping ultrasonic method, and judging the existence of the defect by virtue of a defect echo signal; determining a distance from the defect to a detection surface by virtue of the position of the echo signal so as to realize the location of the defect. By integrating the advantages of a digital ray device and a water dipping ultrasonic device, the three-dimensional nondestructive detection of the internal defect can be realized, and the deficiencies that the three-dimensional information cannot be detected by the traditional ray film photographing method and an industrial CT is expensive in price can be overcome.

Description

technical field [0001] The invention belongs to the technical field of gas turbine non-destructive testing, in particular to a three-dimensional non-destructive testing method for internal defects of large high-temperature blades. Background technique [0002] The traditional large-scale high-temperature blades of gas turbines are detected by radiography, which has the advantages of intuition and reliability, and plays an important role in quality control in industrial production. However, this method can only display the two-dimensional information of the defect, and cannot provide the three-dimensional position and volume information of the defect. It can only be estimated by professional and technical personnel based on experience. There are complex detection processes, heavy workload, slow speed, and operating costs. High and susceptible to human subjectivity and other deficiencies. The non-destructive testing methods applied to internal defects of parts mainly include ...

AI Technical Summary

Problems solved by technology

However, low-power CT rays cannot penetrate nickel-based superalloy blades, so they cannot be measured; although high-power CT rays can penetrate, the price is very expensive. A high-power industrial CT equipment costs tens of millions. too expensive for business

Since the high-temperature blades of the gas turbine turbine are made of nickel-based superalloy, the attenuation rate of the radiation is very high, and the thickness that the radiation detection method can penetrate is very limited, and it is impossible to locate the defect in the depth direction; although the ultrasonic detection has a strong penetration ability, it cannot When the probe performs scanning detection, the plane of the probe needs to be parallel to the plane of the object to be measured. Therefore, it is difficult to select a suitable probe for scanning detection of objects with complex and irregular shapes such as high-temperature turbine blades.

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