On internal friction mechanisms in hydrogen charged stable austenitic stainless steel

Abstract

The internal friction method is used to obtain data on hydrogen diffusion parameters and hydrogen interactions with other solutes as well as crystal lattice defects in a hydrogenated austenitic stainless steel. Such information is important, for example, for development of hydrogen embrittlement mechanisms of the metallic materials. The application of the internal friction data needs, however, adequate understanding on the nonelastic mechanical response mechanisms in the hydrogenated austenitic steels. In spite of the numerous studies, the nature of the internal friction peaks in hydrogen charged steels is still a controversial issue. Furthermore, the high-fugacity electrolytic hydrogen charging commonly used in the internal friction experiments results in a marked concentration gradients of hydrogen, formation of hydride-like phases and damage of the crystal lattice in the surface layers of material. The hydrogenated surface layers may contribute to the internal friction which is also discussed in a number of papers and needs further investigation. The subject of the present study is the mechanistic analysis of the internal friction spectra observed at low temperatures in an electrolytically charged stable austenitic stainless steel.