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Wednesday, March 19, 2008 - 4:25 PM
Convention Center, Second Level, 220 (Ernest N. Morial Convention Center)
The Effect of Selected Inhibitors on Hydrogen Production, Absorption and Environmental Embrittlement of an Ultra High Strength Steel
Modern ultra high strength steels (UHSS) are engineered to achieve high strength and fracture toughness. Severe degradation in toughness by hydrogen environment embrittlement (HEE) limits the use of low alloy UHSS in marine environments. HEE susceptibility is strongly potential dependant. The research seeks to extend the potential regions of high toughness, and low stable crack growth rate (da/dtII), of an UHSS using inhibitors. Inhibition of the hydrogen evolution reaction kinetics was investigated. The inhibitors’ effect on lowering hydrogen absorption was also determined. Planar samples were charged under conditions representative of crack tips. Absorbed hydrogen was determined as a function of overpotential using the barnacle electrode method and thermal desorption spectroscopy. Studies were then extended to rescaled crevices modeling occluded sites of smaller dimensions to examine the inhibitors’ role under crack tip conditions. Finally, fatigue pre-cracked specimens were utilized in fracture experiments to verify inhibition at various applied potentials. Experimentally determined threshold stress intensity (KTH) and da/dtII were compared against predicted values from models governed by crack tip diffusible hydrogen concentration. The use of inhibitors simulates the performance of smart coatings designed to release ions blocking hydrogen uptake at crack tips, reducing hydrogen production, or altering crack tip electrochemistry and chemistry.
See more of Research in Progress - Coatings and Inhibitors
See more of Research in Progress
See more of The CORROSION 2008 Conference and Expo (March 16-20, 2008)
See more of Research in Progress
See more of The CORROSION 2008 Conference and Expo (March 16-20, 2008)