Time-of-flight Neutron Transmission Imaging of Martensite Transformation in Bent Plates of a Fe-25Ni-0.4C Alloy

The influences of bending deformation and subsequent subzero treatment on the martensite transformation behaviors in a metastable austenitic alloy Fe−25 wt.% Ni−0.4 wt.% C were investigated by the time-of-flight (TOF) neutron Bragg-edge transmission (BET) imaging method. Two-dimensional (2D) maps of martensite phase volume fractions and texture variations due to residual stress and lowering the temperature of the bent samples before and after subzero treatment were obtained by Bragg-edge spectral analysis. The obtained phase volume fractions were quantitatively compared with those determined by neutron diffraction.