In ferritic steels, especially those of higher tensile strength, Hydrogen-Induced Stress Corrosion Cracking (HISCC) can lead to sudden component failure and is thus a safety risk. The interaction of the steel with the diffusing hydrogen leads to changes in the material's properties that can be detected with micromagnetic testing methods. The experiments and measurements described where carried out on tube specimens with martensitic microstructure (steel grade X 20 Cr 13) in order to generally evaluate the potential of micromagnetic testing methods for the early recognition of HISCC.