NON-DESTRUCTION METHOD OF DETERMINATION OF MECHANICAL STRESS IN SURFACE LAYER OF ITEMS FROM METALS AND ALLOYS Russian patent published in 2008 - IPC G01L1/20 

FIELD: technological processes; measurement.

SUBSTANCE: related to measurement equipment, namely, to non-destruction methods of determination of mechanical stresses in surface layer of items form metals and alloys with different electromagnetic properties. Method is based on phenomenon of skin-effect in conductor. Conducting item is investigated layerwise by means of supply of electromagnetic field of different frequency into it and measurement of item response signal characteristics. Distribution of efficient specific resistance is calculated in the depth of item or increment of efficient specific resistance of item in relation to efficient specific resistance of item made from the same material with known mechanical stresses or in relation to efficient specific resistance of item made from the same material without mechanical stresses. Calibration dependence is removed between efficient specific resistance of item or increment of efficient specific resistance and mechanical stresses of material of investigated item in depths that correspond to preset frequencies. On the basis of removed dependence the distribution of mechanical stresses is obtained in the depth of investigated item.

EFFECT: obtaining the non-destruction method of determination of mechanical stresses in surface layer of metal items.

5 dwg