Method of detecting defaults, in particular internal defaults such as fissures in welded joints.

摘要

1. Method of detecting defaults on both sides of each parent metal/filler metal interface formed by the welding of a first metallic piece (1) on another metallic piece (2), in particular of T-shaped welded joints made of steel with an austenitic structure, comprising the emission of longitudinal ultrasonic waves (40) on the wall or surface of one of the said pieces, towards the interface (4, 6) to be checked, the detection of the echo return and the use of samples comprising discontinuities at predetermined locations for the evaluation of the echoes, characterized in that the echo return is detected substantially at the point of emission (PE) of the longitudinal ultrasonic waves (40), an echo return is compared with a pre-established reference echo with the aid of a standard joint (17, 18, 20) corresponding to the joint to be checked and comprising predetermined standard holes (22, 24, 26, 28, 30) near the said interface and useful for the production of reference echoes different from the echoes produced by the interface and in that the echo return is detected only during the lapse of time determined by the reference echo.