METHOD OF EVALUATING STRESS-STRAIN STATE OF NARROW-PROFILE ARTICLES MADE FROM FERROMAGNETIC STEEL Russian patent published in 2010 - IPC G01N27/72 

FIELD: physics.

SUBSTANCE: essence of the method lies in evaluating stress-strain state of narrow-profile articles made from ferromagnetic steel, which involves generating a magnetising magnetic field in the material of the article and measuring coercive force on the excited section of the article. The monitored section of the article is mechanically loaded, a magnetic field is then generated in its loaded state and the coercive force is measured. The stress-strain state focus of the material is determined by comparing the coercive force values with and without the load. The area of the spot of the magnetising field is stretched along the narrow-profile surface of the article. The longitudinal-stretched magnetic field and the coercive force sensor are scanned along the narrow-profile surface of the article, and the coercive force in both cases is measured in like points of the article.

EFFECT: higher resolving power, accurate detection of the behaviour of the defect and its dimensions due to narrowing of the exciting magnetic field which causes concentration of field lines and using the said field to scan along the narrow-profile surface of the article.

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