1993 Volume 57 Issue 2 Pages 141-146
The effect of Ni on the internal magnetic field and the isomer shift of 57Fe in Fe-Cr alloys containing 3 to 14 at%Cr and 70 to 90 at%Cr were examined at room temperature by Mössbauer spectroscopy. A model Fe-28%Cr-5%Ni alloy was aged up to 5000 h at 723 K to investigate the phase decomposition of ferrite in a commercial duplex stainless steel. The alloy finally decomposed into a Cr-rich phase (α′) and an Fe-rich phase (α) after aging. A paramagnetic absorption peak due to the α′ phase has an isomer shift of −0.110 mm/s at room temperature. The value corresponds to a Cr content of 85(±1)at%Cr. The composition of the α phase was estimated to be 11(±1)at%Cr from the average internal magnetic field and the internal field distribution curve. The result of α phase was consistent with a result obtained by atom probe microanalysis. The latter underestimated the Cr content of the α′ phase in comparison with the Mössbauer effect.
