Stress and temperature, rather than hydrogen, govern stacking fault evolution during tensile deformation in Fe-24Cr-19Ni steel

Ito, Tatsuya   ; Ogawa, Yuhei*; Gong, W.   ; Kawasaki, Takuro   ; Shibata, Akinobu*; Harjo, S.   

The effect of solute hydrogen on stacking fault evolution in austenitic steels remains debated. In this study, the changes in stacking fault probability in the 111//loading direction grains family () of hydrogen-charged and non-charged Fe-24Cr-19Ni austenitic steels were evaluated using neutron diffraction during tensile deformation at 223 and 177 K. When values were plotted against macroscopic strain, hydrogen apparently enhanced stacking fault evolution. However, when identical data were translated into the form of versus stress, the superficial hydrogen-effect on notably disappeared. Rather, deformation temperature played more predominant role - lower temperature led to higher regardless of hydrogen-charging, reflecting the reduction of stacking fault energy with decreasing temperature. These findings demonstrate that hydrogen has a minor effect on stacking fault evolution compared with temperature and applied stress.