Том 54, № 9 (2018)

A method is proposed for assessing the quality of nondestructive testing and the technical condition of tanks and vessels used in petrochemical industries, depending on the methods of nondestructive testing employed in technical diagnostics. The probability of revealing a defect was used as a criterion when assessing the quality of technical diagnostics. Estimates are given for the probability of detecting a delamination in the vessel-body wall material of different area using various schemes of applying the basic methods of nondestructive testing. It is shown that the acoustic-emission method makes it possible to significantly increase the probability of detecting a delamination in the equipment wall without increasing the scope of work by virtue of local methods of nondestructive testing. A positive effect is achieved through the use of acoustic-emission testing data (the location maps and hazard levels of acoustic-emission sources) at the stage of planning the procedure of nondestructive testing during technical diagnostics of equipment.

AE control results for cyclic tests of metal samples with a notch are presented. The main stages of the fatigue crack development and standard AE parameters are matched. A criterial plane which allows to separate clusters corresponding to the stages of stable and avalanche-like defect growth has been constructed. It is shown that the boundaries of clusters remain unchanged irrespectively to the differences in the kinetics of damage development.

The effect of plastic deformation on the magnetic parameters of rapid-quenched nanostructured Co₆₆Fe₄Nb_2.5Si_12.5B₁₅ wires was established for the first time, as well as their sensitivity to tensile stresses. Plastic deformation changes magnetic anisotropy induced by the rapid quenching of cobalt-based metal wires, and, as a consequence, determines their magnetic parameters. Remanence is a characteristic that is most sensitive to plastic deformation. A conclusion is drawn that plastic deformation of wires leads to an increase in magnetostriction constant.

Comparative analysis is provided for various definitions of the concept of effective atomic number as applied to the material of a multicomponent object. Definitions in which radiation is and is not taken into account explicitly have been considered. Results of calculating the effective atomic numbers of various substances are presented on the basis of the definitions considered. New formal definitions are proposed for this concept when X-raying a multicomponent object with polychromatic radiation.