Hydrogen embrittlement in different materials: A review

Hydrogen embrittlement (HE) is a widely known phenomenon in high strength materials. HE is responsible for subcritical crack growth in material, fracture initiation and catastrophic failure with subsequent loss in mechanical properties such as ductility, toughness and strength. This hydrogen is induced in the material during electrochemical reaction and high-pressure gaseous hydrogen environment. LIST, SSRT and TDS techniques are performed to know the effect in mechanical properties and amount of hydrogen available in the material. For microstructure examination SEM, FESEM and TEM are performed to know the effect of hydrogen in the internal crystal structure. Also, various mechanisms which are responsible for crack growth and final fracture are discussed. This paper deals with HE definition, mechanisms which causes HE, subcritical crack growth, the concentration of hydrogen measurement and prevention activities are discussed which act as a barrier for hydrogen diffusion.