Moessbauer measurements of microstructural change in aged duplex stainless steel
- Mitsubishi Heavy Industries, Ltd., Hyogo (Japan)
- Osaka Univ. (Japan)
A duplex stainless steel (ASME SA351 CF8M) has usually been manufactured by a continuous casting technique. It consists of a paramagnetic austenite phase and a ferromagnetic ferrite phase. It has been known that the ferrite phase decomposition occurs in this steel after aging between 300 and 450 C. As a result of phase decomposition, a Fe-rich phase and a Cr-rich phase are produced in the ferrite phase. It is difficult to detect the phase decomposition even by not only optical microscopy but also transmission electron microscopy, since the decomposed structure is very fine. However, Moessbauer measurements that can detect the magnetic hyperfine field of magnetic substance may detect the microstructural change. An averaged magnetic hyperfine field increases in the ferrite phase, due to the production of the Fe-rich phase which has high magnetic hyperfine field. Therefore, the authors investigated the phase decomposition of the duplex stainless steel caused by aging, utilization Moessbauer spectroscopy which has capability of detecting this structural change in the atomic level quantitatively. The authors also investigated the potential of backscattering Moessbauer method for NDE technique.
- OSTI ID:
- 86152
- Report Number(s):
- CONF-9505104--; ISBN 0-87170-548-6
- Country of Publication:
- United States
- Language:
- English
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