Abstract

REQUIZ, Roberto; ROJAS, Miguel Ángel  and  ROSALES, Adalberto. Daño por hidrógeno en aceros galvanizados. Rev. LatinAm. Metal. Mater. [online]. 2008, vol.28, n.1, pp.51-59. ISSN 0255-6952.

The hydrogen damage susceptibility in hot dip galvanized and zinc electrodeposited on steel in an acid environment considering the surface roughness effect, microstructure and coating thickness is presented. In spite of their different morphologies and coating corrosion, these materials make the hydrogen diffusion more difficult due to their barrier effect. The hydrogen diffusion coefficients have values between 10^-10 and 10^-12 cm²/s. The gradual increase of permeation current density without reaching a maximum as well as the smaller damage on hot dip galvanized substrate surface suggests that this coating could be more protective against hydrogen permeation due to its thickness and the presence of intermetallics compounds. Hydrogen ingress to steel could be delayed by different reticular parameters associated to those intermetallics. On the other hand, the electrodeposited barrier has a less protective effect perhaps be due to some defects in the coating. There were not differences between the coatings surface roughness parameters

Keywords : Galvanized steel; Time lag; Barrier effect; Intermetallics; Hydrogen damage.