Resumen

NASCIMENTO, Fabiana Cristina et al. Structural modification induced by cathodic hydrogenation on plasma nitrided austenitic steel welds. Rem: Rev. Esc. Minas [online]. 2010, vol.63, n.1, pp. 129-135. ISSN 0370-4467.  http://dx.doi.org/10.1590/S0370-44672010000100022.

Structural characterization of weld and outside weld regions of AISI-304 nitrided (20%N + 80%H) and cathodically hydrogenated is presented. Nitriding temperatures were 400, 500 e 550°C. The weld and outside weld regions were compared by XRD, optical microscopy and SEM. The phases γ-austenite, α'-martensite, ε-martensita and α-ferrite and the nitrides: CrN, γ'-Fe₄N e e-Fe_2+xN were identified. Microstructures of both regions and the thermal active zone were similar. For 400°C the stoichiometry of the formed phases was different from that formed at 500°C and 550°C. Hydrogen effects were more intense for 550°C, due to chipping occurrence.

Palabras llave : Nitriding; hydrogenation; austenitic steel; weld; Rietveld.