Hydrogen Damage is mechanical damage of a metal caused by the presence of interaction with hydrogen. there are two types of factors. high-temperature moist atmospheres and corrosion processes. sulfides function by decreasing the rate at which hydrogen combines to form molecules. this leads to greater concentrations of hydrogen atoms of the metal surface.

Type of hydrogen damage

Decarburization - It is often produced by moist hydrogen at high temperatures, and it lowers the tensile strength of steel.


Hydrogen attack 


Hydrogen Blistering - The interior surface is in contact with the electrolyte and the exterior is exposed to the atmosphere. Hydrogen evolution occurs on the inner surface as a result of corrosion reaction. some of the hydrogen atoms diffuse into the metal rather than combining into molecules. Hydrogen molecules are formed on the exterior surface. if there is a void, hydrogen atoms are combined in the void to form molecules, which can not diffuse. The concentration and pressure of hydrogen gas increases, which causes damage to the metal.

Hydrogen embrittlement - The same initial cause penetration of hydrogen atoms into the metal structure.



  • Alloys are most susceptible to cracking in their highest strength level. 
  • The tendency for embrittlement is increased with increasing hydrogen concentration in the metal. 
  • Other terms are used to describe hydrogen embrittlement
Hydrogen stress cracking: if the absorption is due to contact with hydrogen gas. 
SCC: if the absorption is due to the corrosion reaction.
Sulfide stress cracking: if corrosion is due to the presence of hydrogen sulfide.