Measurement Method of Sensitivity for Hydrogen Embrittlement of High Strength Bolts

Mechanical degradation of API X65 pipeline steel by exposure to hydrogen gas

“…Long-term interaction of hydrogen gas and the tested material resulted in 5.4 % and 3.4 % reductions in the ultimate tensile strength of the hydrogen-charged specimens tested at 0.05 mm/min and 0.01 mm/min compared to the ultimate tensile strength of 853 MPa measured in nitrogen gas. These results are consistent with those in previous reports [4][5][6][7] of hydrogen embrittlement, although the degree of hydrogen susceptibility depends also on the chemical composition and the microstructures of the steels.…”

“…Steels exposed to H 2 S or H 2 gas show brittle behavior due to the interactions between active hydrogen and metal surfaces [4][5][6][7]. This hydrogen-induced damage can be attributed to the fast diffusion of hydrogen atoms into the crystalline lattice and their strong interactions with metal atoms.…”

Hydrogen Embrittlement and Diffusion in High Strength Low Alloyed Steels with Different Microstructures

“…In the field, the observation of HE is mainly associated with the presence of hard spots [22] . The critical role of the hard spots can be ascribed to the presence of martensite which is the most susceptible microstructure to HE [11,[23][24][25] . Furthermore, Razzini et al -by visualizing the hydrogen distribution in an artificial hard spot on API 5L X60 steel with the use of a photoelectrochemical technique -demonstrated that the solubility of hydrogen in the heat affected zones of hard spots is higher than in the base material [26] .…”