Hydrogen embrittlement in locking washer

Several of the hardened and electrolytically galvanized components failed during installation. SEM reveals the brittle intergranular fracture typical of hydrogen embrittlement, mixed with ductile dimple fracture, with occasional gaping grain boundaries and crow feet. From the hardness of 550 HV0.5, a tensile strength of approx. 1800 MPa can be estimated. With such a high strength, even very small hydrogen contents are critical.