Evaluation of hydrogen effect on the fatigue crack growth behavior of medium-Mn steels via in-situ hydrogen plasma charging in an environmental scanning electron microscope

Hydrogen Embrittlement as a Conspicuous Material Challenge─Comprehensive Review and Future Directions

“…Also, the produced plastic deformation seemed to be weaker when the crack grew under H atmosphere compared with that under vacuum, as shown from the less pronounced topographical change close to the cracking stage under H. It has to be noted that such crack observation was conducted after H-plasma was switched off and the chamber was pumped to high vacuum again. According to Wan et al, ,, in situ SEM imaging under H-plasma environment in their setup was not possible due to technical limitations of the SEM detector and safety concerns. This means that the SEM probing can only be conducted in situ in position but not in situ in environment.…”

“…(b) The behavior of FCG of an austenite-ferrite two-phase steel subjected to alternative environment of high vacuum and H-plasma. Reprinted with permission from ref . Copyright 2021 Elsevier under [CC BY 4.0 DEED] [].…”

“…The partial pressure of the plasma phase in this setup can reach up to a few tens of Pa, which is much lower in comparison to electrochemical cathodic charging (can reach tens of MPa of H fugacity). Nevertheless, such low-pressure H plasma was shown to be sufficient to cause certain degradation of macroscopic mechanical properties (e.g., tensile ductility and FCG resistance) in certain ferritic and austenite-ferrite two-phase steels. ,, One example is shown in Figure b, which demonstrated the FCG behavior of an austenite-ferrite medium Mn steel loaded under alternative vacuum and H-plasma condition. The growth of the fatigue crack was obviously faster under H atmosphere.…”

Influence of hot-dip galvanization on the fatigue performance of high-strength bolted connections

“…A working distance of ≈30 mm was adopted in order to get secondary electron images from the fracture surface. A peculiar attention was paid to detecting possible traces of hydrogen embrittlement (HE), which has been deemed to play a role in fracture of galvanized details by several researchers [57][58][59][60][61][62][63][64][65]. Figure 8 shows the crack initiation sites as derived from the fractographic investigations of specimens.…”

How much hydrogen is in green steel?

“…However, hydrogen uptake in green steel can also occur in certain downstream processing and/or application environments, much like for any steel produced via the conventional BF-BOF route. This can happen for instance during pickling and galvanizing 42 , storage and transport, when steel products are exposed to hydrogen-rich corrosive environments [42][43][44][45] . Yet, such downstream hydrogen uptake, which may in certain cases lead to hydrogen embrittlement in high-strength steels, is independent of the origin of the production of the raw material (conventional fossil fuel or green hydrogen as reductants).…”