Abstract
With the rapid rise of hydrogen-based technologies toward sustainable energy
solutions, understanding and mitigating hydrogen embrittlement (HE) has become
increasingly critical. HE threatens the structural integrity and performance of steels in
demanding industrial applications. Addressing this issue requires advanced methods
to map and understand hydrogen interactions within materials. To tackle this
challenge, we employ Scanning Kelvin Probe (SKP) and Scanning Kelvin Probe Force
Microscopy (SKPFM) for a comprehensive study of hydrogen–material interactions in
three key industrial alloys: super duplex stainless steel (SDSS), X65 pipeline steel, and
high-strength bainitic steel. Our main goals include (i) advancing hydrogen distribution
detection by refining standardized sample preparation and calibration, (ii) comparing a
range of hydrogen charging protocols, including a custom in-situ charging setup, and
(iii) enabling more precise correlation of potential shifts with hydrogen uptake by
bridging macro- and micro-scale hydrogen distribution mapping through accurate
interpretation of SKPFM data and its integration with SKP measurements. Additionally,
Electron Backscatter Diffraction (EBSD) was utilized to characterize the grain structure
and microstructural features, providing critical insights into how hydrogen interacts with
different phases and grain boundaries. Results show that the magnitude of changes in
contact potential difference (CPD) varies across these alloys, indicating both shared
and distinct responses to hydrogen. This study demonstrates that combining SKP and
SKPFM for cross-validation significantly enhances confidence in result interpretation
and broadens insight into hydrogen accumulation in complex industrial alloys,
contributing to hydrogen detection reliability.