Hydrogen embrittlement in nickel-based superalloysWednesday (26.09.2018) 15:30 - 15:45 S1/01 - A03 Part of:
Nickel-based superalloys have excellent properties under mechanical and corrosive exposure. Due to this profile they are often used in harsh environments, which are present in oil and gas industry and chemical applications for example. In these surroundings the presence of hydrogen is a well-known problem. Since there is a serious sensitivity to hydrogen embrittlement (HE) of precipitation hardened nickel-base alloys, especially the investigation of the mechanical properties of the interfaces under hydrogen influence is a promising field of research. One suitable method for characterizing local mechanical properties under hydrogen influence is in-situ electrochemical micromechanical testing. Therefore, nanoindentation was used to study the nanomechanical characteristics of a nickel-based superalloy in ex-situ and in-situ hydrogen charged conditions. For the ex-situ charging the nanoindentation measurements were performed, right after charging, 12 and 24 hours, respectively. This procedure shows the influence of the diffusible amount of hydrogen in the charged samples. The results show that the exposure to hydrogen leads to a reduction of the pop-in load. These outcome is related to the minimization of energy needed for dislocation nucleation and the reduction of dislocation mobility.