Aerospace gerontology: Retained austenite as an aging mechanism in duplex bearings

Due to economic constraints on new product development in many industries, increasing importance is being placed on safely extending the service lives of existing components and systems, often beyond their original design liv es. Such extended service, however, can lead to the emergence of unanticipa ted aging problems. This paper highlights three approaches for equipment ge rontology that can help identify such aging problems in an orderly way. The first, a spares-based approach, involves an expert review of all component s, comparison of inventory size with use rate, and identification of parts of highest concern for further inquiry. The second, a performance-based app roach, establishes an evaluative effort that examines field data and specia l engineering tests to identify performance shifts that give early indicati on of impending end-of-life. The third, an analytical approach, is a concep tual ideal for aging management in which future equipment reliability is pr edicted based on design, materials and use environment. The implementation of an analysis approach for the aging management of a particular strategic guidance system component is described in the form of a detailed case study ; specifically, the potential role of retained austenite as an aging mechan ism in an accelerometer duplex bearing.