ARAÚJO, B. A.; http://lattes.cnpq.br/0265579541739809; ARAÚJO, Bruno Allison.
Abstract:
The present work aims to study the hydrogen embrittlement process in steels
API 5L X60 and API 5L X80. From electrochemical hydrogen permeation
experiments were determined the following parameters - diffusivity, solubility
and permeability in these steels. The studies were performed utilizing two types
of embrittlement hydrogen conditions: environmental and internal hydrogen.
The uniaxial tension mechanical behavior of steel type API 5L X60 and API 5L
X80, with and without hydrogen, were studied. For the study of environmental
hydrogen embrittlement, the steel API 5L X60 had a softening observed by the
decrease in yield strength and increase its deformation. The API 5L X80 steel
was more susceptible to the phenomenon due the deformation decrease of
hydrogenated samples. For the study of internal hydrogen embrittlement, in
both steels the change in deformation was significant and can be attributed to
changes in hydrogen traps due to the hydrogenation process used, the
chemical composition and microstructure. It can be concluded, as reported in
the literature, that reversibly trapped hydrogen is more damaging than that
which is held irreversibly. The fracture surface morphology of samples tested in
tensile tests presented with characteristic ductile by coalescence of microvoids
(dimples). It was observed that the distribution of dimples per unit area was
higher in API 5L X60 steel samples hydrogenated.
