Abstract: Eddy current non-destructive examination and evaluation of physical properties of a component, such as a generator retaining ring, after experiencing potentially degrading thermal exposure during any stage of manufacture, assembly and service use, is performed to determine whether it is acceptable for service use, requires further modification (e.g., additional heat treatment processing) or whether is permanently unsuitable for service. Eddy current test measurements are correlated with component temperature exposure (e.g., absolute temperature and/or cumulative time-temperature heat absorption) and cumulative alteration of the component physical properties, such as, among others, material yield strength (YS), toughness, and tensile ductility. Using the eddy current test measurements and reference data correlating electrical conductivity with ring material thermal exposure, the component's physical properties are evaluated to determine its serviceability.

Abstract: Eddy current non-destructive examination and evaluation of physical properties of a component, such as a generator retaining ring, after experiencing potentially degrading thermal exposure during any stage of manufacture, assembly and service use, is performed to determine whether it is acceptable for service use, requires further modification (e.g., additional heat treatment processing) or whether is permanently unsuitable for service. Eddy current test measurements are correlated with component temperature exposure (e.g., absolute temperature and/or cumulative time-temperature heat absorption) and cumulative alteration of the component physical properties, such as, among others, material yield strength (YS), toughness, and tensile ductility. Using the eddy current test measurements and reference data correlating electrical conductivity with ring material thermal exposure, the component's physical properties are evaluated to determine its serviceability.