Overview

• Oxford, Brookhaven, Argonne and UCL researchers report the findings in Advanced Materials after imaging a single ~700 nm stainless-steel grain for 12 hours at the Advanced Photon Source using Bragg Coherent Diffraction Imaging.
• Hydrogen exposure made dislocations unexpectedly mobile, with defects moving and reshaping even without additional external stress.
• The team directly observed out-of-plane dislocation climb at room temperature, revealing atomic rearrangements not typically accessible under such conditions.
• Hydrogen accumulation reduced the surrounding strain fields of dislocations, delivering the first direct 3D measurement of the theorized hydrogen elastic shielding effect.
• Researchers say the results will inform multiscale simulation frameworks and alloy design, and they are planning follow-up experiments on other defect types to support safer hydrogen technologies.