Hydrogen-related phase transformations in austenitic stainless steels |
| |
Authors: | N Narita C J Altstetter H K Birnbaum |
| |
Affiliation: | (1) Department of Metallurgy and Mining Engineering, University of Illinois at Urbana-Champaign, 61801 Urbana, IL |
| |
Abstract: | The effect of hydrogen and stress (strain) on the stability of the austenite phase in stainless steels was investigated. Hydrogen
was introduced by severe cathodic charging and by elevated temperature equilibration with high pressure H2 gas. Using X-ray diffraction and magnetic techniques, the behavior of two “stable” type AISI310 steels and an “unstable”
type AISI304 steel was studied during charging and during the outgassing period following charging. Transformation from the
fcc γ phase to an expanded fcc phase, γ*, and to the hcp ε phase occurred during cathodic charging. Reversion of the γ* and
e phases to the original γ structure and formation of the bcc α structure were examined, and the kinetics of these processes
was studied. The γ* phase was shown to be ferromagnetic with a subambient Curie temperature. The γ⇆ε phase transition was
studied after hydrogen charging in high pressure gas, as was the formation of a during outgassing. These results are interpreted
as effects of hydrogen and stress (strain) on the stability of the various phases. A proposed psuedo-binary phase diagram
for the metal-hydrogen system was proposed to account for the formation of the γ* phase. The relation of these phase changes
to hydrogen embrittlement and stress corrosion cracking of stainless steel is discussed. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|