Design of a non-destructive test for validating models of hydrogen migration

High-strength steels, despite their excellent mechanical properties in normal conditions, can be susceptible to hydrogen embrittlement. Due the service loads or residual stresses, migrates within component and accumulates regions where highest tensile hydrostatic stress occurs. As a consequence, brittle failure occur even if initial mean concentration is lower than critical value. The availability of models predicting diffusion crucial task for design. Several diffusive have been presented literature some general-purpose finite element codes already implemented them. However, validation those still an open issue due difficulty performing accurate local measurements concentration. This study deals with design test potentially able validate migration models. In test, four-point bending configuration applied properly shaped hourglass specimen, previously charged hydrogen, extracted from thin high-strength steel sheets. specimen geometry loading were designed obtain central region which strain field uniform plane exhibits quasi-uniform gradient thickness direction. it expected large enough Hydrogen migrate only direction during typical duration test. evaluated by measuring flux leaving surface solid-state sensor.