Metals (Dec 2020)

Effect of Film-Forming Amines on the Acidic Stress-Corrosion Cracking Resistance of Steam Turbine Steel

  • Tim De Seranno,
  • Ellen Lambrechts,
  • Evelyn De Meyer,
  • Wolfgang Hater,
  • Nathalie De Geyter,
  • Arne R. D. Verliefde,
  • Tom Depover,
  • Kim Verbeken

DOI
https://doi.org/10.3390/met10121628
Journal volume & issue
Vol. 10, no. 12
p. 1628

Abstract

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This work evaluates the effect of film-forming amines (FFA) on the acidic stress-corrosion cracking (SCC) resistance of NiCrMoV turbine steel. Contact angle measurements show an increased hydrophobicity of the surface when coating the steel with oleyl propylene diamine (OLDA). According to potentiodynamic measurements and post-mortem scanning electron microscopy (SEM) analysis, anodic dissolution and hydrogen embrittlement still occur when the steel is FFA coated. In situ constant extension rate testing (CERT) in acidic aqueous environment at elevated temperature of FFA-coated steel shows a ductility gain compared to non-coated steel, explained by a decrease in both corrosion rate and hydrogen uptake.

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