Influence of gaseous hydrogen on the tensile properties of Fe–36Ni INVAR alloy

No loss in tensile ductility was found for Invar 36 alloy tested in a gaseous hydrogen atmosphere (1 MPa, −50 °C). Fractography revealed no indication of hydrogen assisted damage. Deformation mechanisms of Invar 36 are published in the open literature. Comparing the tensile test results as well as the deformation mechanisms with those of other iron based stable austenitic alloys indicate that the inherent deformation mechanism of Invar 36 comprising of a high portion of dislocation cross slip is an important reason for the negligible loss in tensile ductility under the presence of hydrogen.