METHOD AND DEVICE OF DOUBLE MAGNETIZATION FOR DETECTION AND IDENTIFICATION OF CRACKS IN STEEL PIPELINES Russian patent published in 2025 - IPC G01N27/87 

FIELD: measuring.

SUBSTANCE: invention relates to methods of detecting and identifying cracks in pipelines and can be used to detect and identify cracks in steel sheets or pipes. Essence of the invention consists in the fact that successive magnetization of a portion of the diagnosed object is carried out using a moving magnetic system and measurement of magnetic fields created by defects in the magnetized portion, wherein in moving magnetic system two zones with high and low levels of magnetization are created, but both zones are magnetized in area of technical saturation, in the course of movement, changes in the longitudinal component of the magnetic field in these zones are measured, and then, by comparison, a useful signal is selected, which enables to distinguish signals from cracks from signals from other types of defects.

EFFECT: enabling detection and identification of cracks on the outer side of the pipeline, including stress-corrosion cracks with small opening and depth.

2 cl, 3 dwg