Mechanism of Development of Damage of Low-Strength Pipe Steel Due to Hydrogenation Under Operation

Resistance of pipe steels to hydrogen embrittlement is an important indicator of their serviceability. Pipes are manufactured from steels of a wide strength range. With the strength increase, a susceptibility to hydrogen embrittlement in general increases. This regularity is usually true for steels in the as-received state; however, the long-term operation can increase hydrogen susceptibility even of low- strength steels. This is caused by the development of damage dissipated in the metal bulk with the formation of voids due to deformation caused by high-pressure recombined hydrogen in them. Implementation of the hydrogen-induced damage mechanism, associated with the formation of deformation voids, extends the strength range of pipe steels, which become prone to operational hydrogen embrittlement.