ARTICLE QUALITY CONTROL METHOD Russian patent published in 2003 - IPC

FIELD: nondestructive checks. SUBSTANCE: invention relates to methods of checking residual stresses in welded joints and articles made of ferromagnetic and paramagnetic materials subjected to different processes. According to proposed method value of magnetic field strength on surface of article is measured and, basing of obtained result, value of residual stresses acting in direction coinciding with direction of measured magnetic field is determined. Check points are chose on article surface. Magnetic field strength is measured in check points, and values of modulus of difference of magnetic field strength values is check points is found. Mean value of coefficient Kms

characterizing mean level of residual stresses is determined. Minimum coefficient Kmins is found by dividing minimum value of modulus on distance between two check points and maximum coefficient Kmaxs is determined accordingly. Coefficient m = Kmins/Kmaxs or p = Kmaxs/Kmins is found. Coefficient Kms, m or p are compared with corresponding coefficients Km*s, m^* or p^* in similar manner for article in good repair. Article is rejected if obtained results differ from coefficient of article in good repair. EFFECT: improved efficiency of quality control. 8 cl, 6 dwg, 3 ex