Susceptibility of a Welded Joint of 17G1s Steel in a Gas Main to Hydrogen Embrittlement

We study the susceptibility of a welded joint of 17G1S steel to hydrogen embrittlement depending on the sequence of application of hydrogenation and loading. The highly plastic welded joint is susceptible to hydrogen embrittlement under rapid active loading performed after preliminary electrolytic hydrogenation (PEH) in acid solutions only in the presence of stimulants and high current densities. The highest susceptibility to hydrogen embrittlement is exhibited by the base metal and the zone of thermal influence. The PEH of loaded specimens increases the susceptibility of the welded joint to hydrogen embrittlement. Moreover, the higher the stress, the more pronounced the indicated effect. The procedure of plastic prestraining of the welded joint increases its susceptibility to hydrogen embrittlement after PEH. The effect of hydrogen embrittlement after PEH is more pronounced for more intense plastic prestraining but weaker than in the case of hydrogenation in the process of active loading, i.e., under the combined action of stresses and strains.