Prediction of Hydrogen Entry and Permeation in Metals and Alloys
Abstract
This report summarizes results of the past year on our continuing in- situ experiments directed to the problem of hydrogen entry and degradation of materials both for planar surfaces and for the more complicated recessed surface. For the planar surface the hydrogen permeation and scanning tunneling microscopy (STM) techniques are being used, and for the recessed surface the study uses a combined microscopy/electrochemical probe technique and a crevice geometry. Further modeling of the hydrogen permeation technique has led to an experimental procedure that yields two previously unattainable rate constants that are important for controlling hydrogen absorption into a material from an aqueous environment, the hydrogen absorption (entry) and desorption (exiting) constants. STM has been further developed for in-situ study of hydrogen bonding at the atomic scale by successfully imaging hydrogen adsorption on the model Si(100)2X1 surface from a low pressure hydrogen gas phase. For the recessed surface hydrogen entry from an aqueous solution occurs for a much wider range of conditions than previous believed. Chloride ion and acidification indirectly promote hydrogen ion reduction and entry on the recessed surface through their direct effect on promoting the IR-induced mechanism of crevicing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA245286
Entities
People
- Howard W. Pickering
Organizations
- Pennsylvania State University