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Study of electrochemical hydrogen permeation in iron

Fallahmohammadi, E ; Sharif University of Technology

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  1. Type of Document: Article
  2. Abstract:
  3. Hydrogen diffusion experiments in A106GR B carbon steel pipeline were performed electrochemically at 25°C in NACE,B, solution in various amount of sulfide ion concentration for a thin sample. In this case the effect of concentration of sulfide ion evaluated by study the electrochemical behavior of sample by the galvanostatic way. Generally, sulfur components were found to increase the hydrogen permeation rate. Presence of sulfide layer helped to absorption of hydrogen reduction and exacerbates the amount of hydrogen absorption in steel. this phenomena can be noted that as regard to analysis of corrosion products which formed in the surface sample, the high amount of FeS, The sulfide ion are believed to poison the steel surface which increases the chemical potential of adsorbed hydrogen on the surface. also hydrogen permeation test with the Devanathan and Stachurski, ASTM G148, permeation cell was prepared to evaluate the hydrogen diffusivity and permeation current behavior of steel pipe sample. The hydrogen diffusivity and subsurface concentration (Capp) were evaluated by fitting a series expansion of the diffusion equation to the permeation data. The hydrogen diffusivity in the steel was found to be approximately 9*10-7Cm2/s.The influence of the passive layer on the hydrogen permeation and its influence on the influence evaluation of diffusion and trapping characteristics were discussed
  4. Keywords:
  5. Electrochemical hydrogen permeation ; Hydrogen concentration ; Hydrogen diffusivity ; Pipeline
  6. Source: Journal of Corrosion Science and Engineering ; Volume 14 , February , 2011 , 263–267 ; 14668858 (ISSN)