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Ion and laser microprobes applied to the measurement of corrosion produced hydrogen on a microscopic scale.Use of an ion microprobe and a laser microprobe to measure concentrations of corrosion-produced hydrogen on a microscopic scale. Hydrogen concentrations of several thousand ppm were measured by both analytical techniques below corroded and fracture surfaces of hot salt stress corroded titanium alloy specimens. This extremely high concentration compares with only about 100 ppm hydrogen determined by standard vacuum fusion chemical analyses of bulk samples. Both the ion and laser microprobes were used to measure hydrogen concentration profiles in stepped intervals to substantial depths below the original corroded and fracture surfaces. For the ion microprobe, the area of local analysis was 22 microns in diameter and for the laser microprobe, the area of local analysis was about 300 microns in diameter. The segregation of hydrogen below fracture surfaces supports a previously proposed theory that corrosion-produced hydrogen is responsible for hot salt stress corrosion embrittlement and cracking of titanium alloys. These advanced analytical techniques suggest great potential for many areas of stress corrosion and hydrogen embrittlement research, quality control, and field inspection of corrosion problems. For example, it appears possible that a contour map of hydrogen distribution at notch roots and crack tips could be quantitatively determined. Such information would be useful in substantiating current theories of stress corrosion and hydrogen embrittlement.
Document ID
19720039811
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Gray, H. R.
(NASA Lewis Research Center Cleveland, Ohio, United States)
Date Acquired
August 6, 2013
Publication Date
February 1, 1972
Publication Information
Publication: Corrosion
Volume: 28
Subject Category
Chemistry
Accession Number
72A23477
Distribution Limits
Public
Copyright
Other

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