High-temperature alloy grain size evaluation method based on ultrasonic phase velocity

Abstract

The invention discloses a high-temperature alloy grain size evaluation method based on an ultrasonic phase velocity. The high-temperature alloy grain size evaluation method comprises the four steps of extracting original A wave information of a high-temperature alloy test block, calculating a longitudinal wave sound velocity of the test block, acquiring a phase velocity of the test block and constructing a comprehensive evaluation model. The high-temperature alloy grain size evaluation method has the technical effects that an attenuation coefficient spectrum is obtained through a two-medium multi-element Gaussian sound field model, and then a phase velocity spectrum is calculated according to the attenuation coefficient spectrum based on a K-K relational expression; compared with a phase difference algorithm for calculating the phase velocity, the algorithm disclosed by the invention is higher in stability, and the phase velocity of the curved-surface test block can be possibly extracted; moreover, in a process of using the K-K relational expression, the longitudinal wave sound velocity is used as a reference value, so that the high-temperature alloy grain size evaluation method actually integrates the advantages of a conventional ultrasonic longitudinal wave sound velocity method; meanwhile, the phase velocity and the dispersion degree of the phase velocity are considered, the multi-element sound velocity information is fully used, a comprehensive grain size evaluation model is constructed, and the precision of the sound velocity method for evaluating the grain size of high-temperature alloy is improved.

Description

technical field [0001] The invention relates to a method for measuring the grain size of a high-temperature alloy, in particular to a method for analyzing the phase velocity of an ultrasonic wave in a high-temperature alloy and using the ultrasonic phase velocity to perform non-destructive evaluation on the grain size of a high-temperature alloy. Background technique [0002] High-temperature alloys have outstanding advantages such as no macro-segregation, and are widely used in aerospace, military and other high-end fields, and grain size is an important factor affecting their mechanical properties and service life. [0003] At present, the grain size of superalloys is mainly detected by metallographic analysis. This method has the advantages of intuitive results and high detection accuracy, but the detection efficiency is low. The detection results can only reflect the grain conditions of the observed surface, and the detection accuracy is limited by the detection personnel...

AI Technical Summary

Problems solved by technology

From the actual test situation, if the longitudinal wave sound velocity method is used to evaluate the grain size of superalloys, there is a problem that due to the serious attenuation of sound waves by superalloys, the amplitude of each bottom wave is small, and it is difficult to distinguish the front of the bottom wave from the noise signal. Disadvantages that lead to inaccurate measurement of longitudinal wave sound velocity and ultimately reduce evaluation accuracy

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