| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for inspecting a spot welded part, capable of accurately detecting a nugget part of the spot welded part.SOLUTION: The method includes the steps of exciting a synthetic laser ultrasonic wave having a different frequency inside a first metal plate 1 and a second metal plate 2 by irradiating a surface of the first metal plate 1 with transmitted laser; detecting an amplitude and central frequency of a reflected wave of the laser ultrasonic wave; calculating an inclination angle of a rear surface 5 from which the laser ultrasonic wave has been reflected, based on the detected central frequency and first data; and determining whether the reflected wave has permeated the nugget part 11, based on the calculated inclination angle of the rear surface 5, the amplitude of the detected reflected wave, and second data. |
