J. Phys. IV France 112 (2003) 407
DOI: 10.1051/jp4:2003912

Crystal structure and lattice dynamics of hydrogen-loaded austenitic steel

S.A. Danilkin¹, M. Hölzel², H. Fuess², H. Wipf², T.J. Udovic³, J.J. Rush³, V.E. Antonov⁴ and V.G. Gavriljuk<sup>5

1</sup>  Hahn-Meitner-Institut, Glienicker Str. 100, 14109 Berlin, Germany
²  Technische Universität Darmstadt, 64287 Darmstadt, Germany
³  NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-8562, U.S.A.
⁴  Institute of Solid State Physics, 142432 Chernogolovka, Russia
⁵  Institute for Metal Physics, 252142 Kiev, Ukraine

Abstract
We investigated the crystal structure and hydrogen vibrations in a hydrogen-loaded AISI 310 type austenitic steel (Fe-25Cr-20Ni) by neutron diffraction and inelastic neutron scattering. The samples with hydrogen content ofH/Me = 0.43 and 0.92 were prepared in a hydrogen gas atmosphere at pressures up to 7.0 GPa. This doping procedure yields a more homogeneous hydrogen distribution within the sample than cathodic charging and allows clarifying the role of the concentration gradients and stresses on the phase transformation. Only fcc phase with increased lattice parameter was observed in both samples, however frequency spectra show a modification of the broad peak into two components at higher H content.

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