Electromagnetic and magnetic methods of non-destructive testing for control of damage accumulation in structural steels and alloys (review)

Control of the stress-strain state, compressive and tension stresses, accumulated fatigue damage is one of the goals of non-destructive testing. We consider data of current research in the field of eddy current and electromagnetic methods of non-destructive testing aimed at solving the problem of monitoring the accumulated damage in structural steels and alloys. Developments for practical implementation of the coercive force method, the eddy current structurescopy of non-magnetic materials, the method of higher harmonics and remanence-based control, the method of magnetic noise (Barkhausen noise) are considered. The physical foundations of non-destructive testing methods are considered along with their brief comparative analysis. Examples of non-destructive testing of critical units, such as operating oil and gas pipelines, aircraft parts, bearing parts, pressure vessels, crane parts, etc. are given. The possibility of using the eddy current method for control of the austenitic phase of cold rolled austenitic steels (AISI 304, AISI 321, AISI 316) is analyzed. The examples of static and fatigue tests of the samples of various steels and alloys are given: St3, St20, St45, D16T, AMg6, AMg6N, 12Kh18N9T, 08Kh18N9, 40Kh, R91. Metrology issues and the impact of interfering parameters affecting the measurement error are considered. The equipment used for a number of methods is discussed. Conclusions regarding the limits of applicability and limitations of the considered methods are drawn. The review provides links to both the fundamental works in the field of electromagnetic structurescopy and to modern research in this area which is important for the practical implementation of the devices based on electromagnetic and magnetic methods of non-destructive testing.