Hydrogen embrittlement of Nb. I. Macroscopic behavior at low temperatures

Journal Article · Tue Feb 01 04:00:00 EST 1977 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(77)90116-X· OSTI ID:7218848

Gahr, S; Grossbeck, M L; Birnbaum, H K

The effect of hydrogen on the ductility of niobium was studied in the temperature range 77--300 K. Tension testing and detailed fractographic studies were used to establish the roles of hydrogen concentration, temperature, yield stress and strain rate in the fracture process. It was shown that two ductility minima can be observed in the temperature range examined and that these are related to the precipitation of hydrides during the deformation process. The fracture mode is cleavage in the temperature range of both ductility minima. The solid solution of H in Nb was shown to be a highly ductile alloy; the ductility being terminated by the formation of a stress induced hydride which exhibits cleavage. A mechanism based on the formation of stress induced hydrides was proposed to account for the embrittlement of Nb--H alloys. This mechanism can account for the observed phenomena and should be generally applicable to systems which form stable hydrides or in which hydrides can be stabilized by an applied stress. A qualitative discussion of stress effects on the equilibrium between solid solution and the hydride is given and is related to the observed fracture phenomena.

• Research Organization: Univ. of Illinois, Urbana
• OSTI ID: 7218848
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 25:2; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360105* -- Metals & Alloys-- Corrosion & Erosion
CHEMICAL REACTIONS
DISPERSIONS
DUCTILITY
ELEMENTS
FRACTURE PROPERTIES
HYDRIDATION
MECHANICAL PROPERTIES
METALS
MIXTURES
NIOBIUM
REFRACTORY METALS
SOLID SOLUTIONS
SOLUTIONS
TENSILE PROPERTIES
TRANSITION ELEMENTS