Non-destructive, Contactless and Real-Time Capable Determination of the ?’-Martensite Content in Modified Subsurfaces of AISI 304

Abstract Cryogenic turning can be used to produce deformation-induced martensite in metastable austenitic steels. Martensite exhibits a higher hardness than austenite and increases the wear resistance of workpiece. In order reliably induce desired content subsurface zone during process, non-destructive, contactless real-time testing method is necessary. Eddy current an electromagnetic that non-contact capable. Furthermore, eddy has been integrated into production processes many times. detect transformation paramagnetic ferromagnetic ??-martensite based on change magnetic electrical properties. Thus, newly formed characterized manufacturing process monitored. The objective this study was understand correlation signals with AISI 304 quantify amount formed. measurements were performed within machining center. Several methods for reference measurement are known literature. However, depending used, large discrepancies may occur between determined contents. Therefore, different analytical determine total subsurface. Metallographic sections, etching, Mössbauer spectroscopy, X-ray diffraction two employed. Based subsurface, control achieved future.