INFLUENCE OF THE HYDROGEN IN THE FRACTURE TOUGHNESS IN THE STEEL AISI 8630M

Fabrício José Nóbrega Cavalcante¹; José Golçalves de Almeida¹; Saulo Moretti Araújo Duarte¹; Esdras Carvalho da Costa¹; Ronelles de Santana Silva¹; Severino Jackson Guedes de Lima¹; José Hilton Ferreira da Silva¹

¹ UFPB

doi:10.20906/CPS/COB-2015-0161

Resumo

The growth in the use of structural steel has been studied by researchers and companies in underwater applications with the use of materials increasingly resistant to this type of environment. Of this materials, we can highlight the steel AISI 8630M, considered a low-alloy steel. In applications in aggressive environment, makes use of cathodic protection systems for the structures, which promotes the release of hydrogen ions and favors the appearance of unexpected fractures of these materials. In the proposed study, the influence of hydrogen on the fracture toughness was evaluated through the CTOD parameter, in application of the steel 8630M. The results indicated that the presence of hydrogen in the material decreased the fracture toughness of about 25% compared with the material without hydrogen. The fractográficas analysis showed that, despite the influence of hydrogen in steel 8630M, the micromechanics of the fractures were presented, in general, ductile, however, some areas of brittle fracture were observed, showing the drop in material toughness.

Palavras-chave: steel 8630M; Hydrogen; CTOD