ASSESSMENT OF MATERIAL DAMAGE BY MEASURINGS OF ELECTROMAGNETIC PARAMETERS OF THE SURFACE AREA
Background Industrial equipment operated at the enterprises of oil and gas processing have a wide variety of types, styles and design features. To ensure the reliability of assessing its technical condition and forecasting safe life, it is necessary to continuously improve and develop new methods and means of control. The results of studying metal failure, obtained in the second half of the XX century, evidences that the surface layer of material has a number of features that may also be used to obtain information about the state of the object. Aims and Objectives To analyze theoretical and experimental data on failure of metals and the characteristics of the surface layer; to determine physical parameter that allows to assess the thickness of the surface layer and to measure its properties; to verify by experiments the results of theoretical analysis. Results The literature review shows that a thin surface layer of about 100 µ plays a special role in forming the properties of the material. It is sensitive to distortion of the material and performs the function of a protective barrier. Its existence is confirmed by experimental studies of the dependence of the surface energy on the level of cumulative damage, and the protective mechanism is used to improve the performance properties of the material by modifying the surface layers. The analysis of physical characteristics used to assess damage of the material, showed that the surface layer could be detected and studied by measuring electromagnetic characteristics. To check the assumption of electromagnetic parameter sensitivity to the surface «barrier» layer, an experiment was conducted to measure the response of the electrical signal of thin plates. The obtained result confirms that in the metal there is a special surface zone, with a thickness of 75-100 µ and detectable by measurement of electromagnetic parameters. The analysis of physical characteristics used to assess damage of the material, showed that the surface layer could be detected and studied by measuring electromagnetic characteristics. To check the assumption of electromagnetic parameter sensitivity to the surface «barrier» layer, an experiment was conducted to measure the response of the electrical signal of thin plates. The obtained result confirms that in the metal there is a special surface zone, with a thickness of 75-100 µ and detectable by measurement of electromagnetic parameters.