The Potential of the Internal Friction Technique to Evaluate the Role of Vacancies and Dislocations in the Hydrogen Embrittlement of Steels

Abstract

Hydrogen embrittlement of steels is known to have considerable impact in many engineering sectors. To be able to mitigate the hydrogen embrittlement problem, a profound comprehension of the interaction of hydrogen with the steel microstructure is required. Especially the interaction of hydrogen with dislocations and vacancies is very relevant as these defects are known to play an important role in hydrogen embrittlement. At present, thermal desorption spectroscopy is mostly used to study hydrogen–defect interactions. However, information obtained solely by this technique is insufficient to obtain a full understanding of the interaction of hydrogen with these defects in the steel microstructure. Herein, the use of internal friction, as a complementary technique to thermal desorption spectroscopy, to reveal the interaction of hydrogen with dislocations and vacancies, is reviewed based on the present understanding in the literature. Furthermore, the opportunities to use internal friction to characterize the interaction between hydrogen and these defects and to give more insight into the hydrogen embrittlement mechanism are discussed. It is demonstrated that internal friction has not yet been used to its full potential for this purpose, although it entails the opportunity to develop fundamental insights into the hydrogen embrittlement phenomenon.

Phase Transition and Point Defects in the Ferroelectric Molecular Perovskite (MDABCO)(NH4)I3

“…In halide perovskites heated close to the decomposition temperature, it is unlikely that only anion vacancies are formed, since the organic cation is volatile and the prevalent mechanism of decomposition is expected to be the formation of Schottky defects, namely neutral pairs or complexes of cation and anion vacancies. In (TMCM)MnCl 3 , it was assumed that an equal concentration of TMCM + and Cl − was formed [31] for two reasons: (i) A = TMCM is organic and more volatile than inorganic B = Mn; (ii) vacancies on the B-site of perovskites are rare, though they may be created under particular circumstances [40][41][42]. A reason for the tendency to lose A rather than B ions is that the BX 6 octahedra are clearly the stable backbone of the lattice, because the B-X bonds are shorter than the A-X ones and are therefore stronger, especially when they involve a greater charge (B 4+ and A 2+ or B 2+ and A + ).…”

Microstructure Characteristics and Corrosion Behavior of Low‐Alloy High‐Strength Steel used for Armor Layer under Exposure to H2S‐Saturated Solution

“…[7,8] Hydrogen recombination on the steel surface occurs because of the poisoning effect of H 2 S on hydrogen, which results in sulfide stress corrosion cracking (SSCC) and hydrogen embrittlement (HE). [9][10][11] The traditional material used in the exploitation of oil and natural gas resources in the sea is pipeline steel of large thickness and diameter. Traditional pipeline steel is typically used on land or in shallow seas.…”