Effect of hydrogen on atomic bonds in austenitic stainless steel

• Published in: Scripta materialia Vol. 44; no. 12; pp. 2765 - 2773
• Main Authors: SHIVANYUK, V. N, SHANINA, B. D, TARASENKO, A. V, GAVRILJUK, V. G, FOCT, J
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Science 08-06-2001
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Metals. Metallurgy; Mossbauer effect; other γ-ray spectroscopy; Mössbauer effect; other γ-ray spectroscopy; Physics; Austenitic stainless steel; Moessbauer effect; Impurity effect; Hydrogen; ESR; Austenite; Steels; Experimental study
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/S1359-6462(01)00971-X

Hydrogen-caused decohesion was one of the first mechanisms proposed for the explanation of hydrogen-induced embrittlement in metals and alloys. It is often referred to though was never really proven. Interstitially dissolved in the crystal lattice, hydrogen is assumed to assist the creation and opening of cracks due to decreasing atomic bonds. Evidence for the hydrogen-caused decohesion can be sought in the effect of hydrogen on the elastic constants, atomic force constants derived from phonon spectra, measurements of the surface energy etc. In the bcc metals of the V group in the periodic table hydrogen is known to increase the phonon frequencies corresponding to the atomic force constants. This effect is in particular remarkable as it occurs in spite of the large increase in the volume when hydrogen is dissolved in the bcc lattice. A somewhat different situation is observed in the fcc metals where hydrogen decreases the elastic constants, which is attributed to the volume increase. The present article aims to contribute to this topic through the study of the effect of hydrogen on Debye temperature and on the concentration of free electrons in austenitic stainless steels.