| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 178693 | Electrochemistry Communications | 2016 | 5 Pages |
•SKP combined with CH,diff calibration is a novel method for spatial H determination.•SKP can map CH,diff with local spatial resolution in samples containing pits.•Local spatial H measurement concept is expandable to a broad range of materials.•Local technique is suitable for development for application to sub-μm length scale.•SKP H detection method applied with front side detection not permeation mode.
The diffusible hydrogen concentration (CH,diff) was mapped spatially, proximate to acidic corrosion pits formed in MgCl2 droplets, on an ultra-high strength stainless steel using a Scanning Kelvin Probe (SKP). A secondary hardened martensitic stainless steel (Fe–11Ni–12Cr–1Mo–0.005C–0.02Mn wt%) was evaluated. Predetermined, uniform CH,diff levels quantified by electrochemical extraction after homogeneous cathodic charging, were calibrated versus the SKP potential at 57% RH (0.16 kPa H2O, 20.26 kPa O2, 79.03 kPa N2, and 0.55 kPa residual gas species) [1]. Calibration enabled estimation of CH,diff near pitted surfaces. Cross-sections of corrosion damage sites after pitting were also examined to determine the distribution of the CH,diff perpendicular to the exposure surface.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide
