Method for calibrating large-angle or small-angle longitudinal wave angle probe for ultrasonic fault detector

Abstract

The invention discloses a method for calibrating a large-angle or small-angle longitudinal wave angle probe for an ultrasonic fault detector, and relates to an instrument calibration method. The method comprises an ultrasonic fault detector, and sequentially comprises the following steps of: preparing a test block used for calibrating the probe and a large-angle or small-angle longitudinal wave angle probe, wherein the test block is a material used by a workpiece during actual fault detection, and drilling two holes with the horizontal heights of h1 and h2 beyond three times of near field of the test block respectively, wherein the h1 is unequal to the h2; moving the probe back and forth on the test block until the two holes display the highest reflection echo on the ultrasonic fault detector respectively, obtaining distances S1 and S2 from the end of transmitting ultrasonic waves in the probe to the two holes respectively, and measuring distances L1 and L2 from the two holes to the front end of the probe; and obtaining a probe inner sound path a, a probe front sound path b and a probe K value according to a mathematical model. The method for calibrating the large-angle or small-angle longitudinal wave angle probe for the ultrasonic fault detector overcomes the defect that proper methods and test blocks for calibrating the K value of the longitudinal wave angle probe, the probe inner sound path a and the probe front sound path b do not exist at present.

Description

technical field [0001] The invention relates to an instrument calibration method, in particular to a calibration method for large-angle and small-angle longitudinal wave oblique probes used in ultrasonic flaw detectors. Background technique [0002] At present, when ultrasonic flaw detectors are used for large-angle and small-angle longitudinal wave flaw detection of workpiece defects, ultrasonic waves are emitted through the probe for workpiece flaw detection, and the detected workpiece defect distance is the sum of the actual distance and the calibration distance. The internal sound path a of the probe traveled inside the probe. In flaw detection work, small-angle longitudinal wave oblique probes are generally used to detect flaws in reworked, newly manufactured bolts (base metals) or shaft workpieces; large-angle longitudinal wave oblique probes are generally used to detect welds of coarse-grained materials such as austenite. Under the existing conditions, the user needs...

AI Technical Summary

Problems solved by technology

Before using this method, customers often do not have a method to calibrate the K value of the longitudinal wave oblique probe, a, b

Moreover, only senior flaw detection personnel are qualified to write the test block production process, while many

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