Hydrogen embrittlement is one of the Hydrogen damage types that may cause mechanical damage to a
metal. There are indications that a large fraction of all the environmentally activated cracking of ferritic
and martensitic iron-base alloys, even the titanium-base alloys is due in some way to the interaction of
the advancing crack with hydrogen. Due to contact with hydrogen gas, a few ppm of absorbed hydrogen
can cause cracking to the metal.
As an example, the suggestions for the prevention /repair of a crack to a Regen #2 Preheater are
described in the paper.
Key words: Hydrogen embrittlement, ferritic, diluted Sulfur, Methane formation, grain boundaries, Hydrogen
diffusion, electrochemical galvanic reactions, enamel lining