METHOD FOR DETECTING CORROSIVE DAMAGES ON HARD TO REACH SURFACES OF PRODUCTS Russian patent published in 2018 - IPC G01B17/02 

FIELD: defectoscopy.

SUBSTANCE: use to detect corrosion damage on the inner side of the trough-shaped stringers of the center section panels and mid-wing panels of the An-12 aircrafts during their repair at the factory using an ultrasonic thickness gauge UDT-40. Essence of the invention is that the outer surface of the tested parts of the products is cleaned from contamination and a couplant is applied, ultrasonic thickness gauge transducer is mounted on the outer surface of a product, the ultrasonic thickness gauge transducer is moved along a predetermined path, reflection of section profile of the product wall is obtained, simultaneously with obtaining the reflection of section profile of the product, the dimensions of the section are estimated where there is a decrease in readings and the smoothness of the change in the readings of the thickness gauge from the nominal to the minimum value and further increase in the current readings up to the nominal value with the unchanged indicator reading of the minimum value during displacement of the thickness gauge transducer in at least two directions with respect to the location of the defects of continuity and with smooth changes in the readings in an area which area is larger than the area of the converter used, it is concluded that there is corrosion damage, and at abrupt changes in the readings of the thickness gauge on a surface area equal to or smaller than the area of the converter, it is concluded that there are point defects or allowable areal defects.

EFFECT: increase in the accuracy of the classification of defects in the material of products when corrosion damage is detected by providing the ability to classify the types of defects.

1 cl, 3 dwg