Multi-scale and spatially resolved hydrogen mapping in a Ni–Nb model alloy reveals the role of the δ phase in hydrogen embrittlement of alloy 718

Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) imaging of deuterium assisted cracking in a 2205 duplex stainless steel micro-structure

“…In addition to a literature survey on SIMS experiments related to hydrogen effects given elsewhere by the authors [12], highly resolved imaging examples are shown by Tarzimoghadam et al [13] who utilized SIMS for the investigations of hydrogen assisted degradation in a Ni based superalloy. Awane [16] studied hydrogen diffusion profiles in an austenitic stainless steel at room temperature by SIMS sputter depth profiling.…”

“…It has to be emphasized, however, that deuterium behaves similarly to hydrogen in metallic microstructures [13,20,21]. With respect to hydrogen embrittlement (HE), deuterium is commonly used as a tracer of hydrogen in analyses of metals by methods such as ToF-SIMS [13,[22][23][24]. The approximate diffusion coefficients for hydrogen in the duplex microstructure are D δ E1.5 X 10 À 11 m 2 /s for ferrite and D γ E 1.4 X 10 À 16 m 2 /s for austenite [25].…”

“…Nishimoto et al [17] detected hydrogen in the ferritic grains by SIMS using a cryogenic sample holder. State-of-the-art ToF-SIMS instruments may provide precise element and phase mappings with a lateral resolution below 100 nm [18], enabling imaging of the microstructure and analysis of its phase dependent chemical composition [13,14,19]. Recently, ToF-SIMS image analysis has substantially been improved by multivariate analysis (MVA) of image data and by data fusion of the chemical and topographic information [14].…”

“…Since the hydrogen distribution in the respective microstructure can usually not be differentiated from hydrogen adsorbed from the rest gas in the analysis chamber of the ToF-SIMS instrument and thus, to avoid confusions about the origin of the measured hydrogen, the specimens investigated in this study have been electrochemically charged with deuterium. It has to be emphasized, however, that deuterium behaves similarly to hydrogen in metallic microstructures [13,20,21]. With respect to hydrogen embrittlement (HE), deuterium is commonly used as a tracer of hydrogen in analyses of metals by methods such as ToF-SIMS [13,[22][23][24].…”

“…In the past few years, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) has been shown to be a powerful tool to precisely map the distribution of hydrogen, along with other elements, in steel microstructures [8,[12][13][14], delivering data from the very surface (with a surface sensitivity below 1 nm) [15]. In addition to a literature survey on SIMS experiments related to hydrogen effects given elsewhere by the authors [12], highly resolved imaging examples are shown by Tarzimoghadam et al [13] who utilized SIMS for the investigations of hydrogen assisted degradation in a Ni based superalloy.…”