Stacking fault energy decrease in austenitic stainless steels induced by hydrogen pairs formation
- C.A.C.-CNEA, San Martin (Argentina). Dept. de Materiales
- Faculty de Ingenieria, Uba (Argentina). Dept. de Ingenieria Mecanica y Naval
The decrease of the Stacking Fault Energy (SFE), induced by hydrogen in austenitic stainless steels, was always invoked to explain the formation of {epsilon}-martensite at room temperature during cathodic charging of hydrogen. Pontini and Hermida measured by XRD a reduction of 37 pct of the SPE of an AISI 304 steel at room temperature, in the presence of only 274 ppm of hydrogen. However, the nature of this phenomenon is still unknown. Recently, Obiol et a., using the Atoms Superposition and Electron Delocalization-Molecular Obital (ASED-MO) method, calculated the binding energy for H-H pair formation in the faulted zone of an FCC iron matrix. It was shown that, the H-H pair formation is more likely to occur along directions connecting octahedral interstices of the HCP stacking sequence and that are normal to the {l_brace}111{r_brace} planes. The binding energy found was {minus}5.75 eV, being this value significantly larger than the corresponding one for vacuum: {minus}4.75 eV. In this work, an explanation of the SFE decrease is developed on the basis of this previous result.
- OSTI ID:
- 665221
- Journal Information:
- Scripta Materialia, Vol. 39, Issue 8; Other Information: PBD: 15 Sep 1998
- Country of Publication:
- United States
- Language:
- English
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