The effect of hydrogen on vacancy generation in iron by plastic deformation

Sakaki, Kouji; Kawase, Takeshi; Hirato, Masafumi; Mizuno, Masataka; Araki, Hideki; Shirai, Yoshihito; Nagumo, Michihiko

doi:10.1016/j.scriptamat.2006.08.030

Cited by 139 publications

(49 citation statements)

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“…27) It is known both experimentally and theoretically that hydrogen stabilizes vacancies. 6,28,29) Consequently, hydrogen increases the density of vacancy-type lattice defects along the grain boundary, which causes plastic instability and fractures. It is noted that, in the HESIV mechanism, the fracture surface apparently exhibits intergranular fracture, but fracture mode is inherently ductile transgranular fracture localized near the grain boundary.…”

Section: Hydrogen Embrittlement Mechanism Of Ni-crmentioning

confidence: 99%

<i>In-situ</i> Microbending Tests of Ni–Cr Alloy during Cathodic Hydrogen Charging by Electrochemical Nanoindentation

et al. 2017

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To investigate hydrogen embrittlement susceptibility of an individual grain boundary, microcantilevers were fabricated on Ni-Cr bialloy surfaces by focused ion beam, and microbending tests were conducted during hydrogen charging by electrochemical nanoindentation. For microcantilevers fabricated across a twin boundary and inside a grain, no crack was formed by the bending both in air and during hydrogen charging. On the other hand, for microcantilevers fabricated across a random grain boundary, a crack was formed by the bending during hydrogen charging, whereas no crack was formed in air. Thus, it was identified that, for Ni-Cr bialloy, random grain boundaries are more susceptible to hydrogen than twin boundaries and crystalline planes. To validate these experimental results, slow strain-rate tensile tests were also performed, and subcracks of the fractured specimens were analyzed by electron beam back-scattering diffraction. In accordance with the microbending test results, subcracks were predominantly formed along random grain boundaries, but never along twin boundaries and inside grains. Higher hydrogen susceptibility of the random grain boundaries with lower cohesive energy (i.e., work for separation), smooth fracture surfaces without dimples or tear ridges, and no correlation between strain accumulation and subcrack formation indicate that hydrogen embrittlement of Ni-Cr bialloy is caused by decohesion mechanism, where hydrogen atoms lower cohesive energy at grain boundaries.

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Section: Hydrogen Embrittlement Mechanism Of Ni-crmentioning

confidence: 99%

<i>In-situ</i> Microbending Tests of Ni–Cr Alloy during Cathodic Hydrogen Charging by Electrochemical Nanoindentation

et al. 2017

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“…On the other hand, positron annihilation studies of cathodically charged (i.e. saturated under high hydrogen fugacity and at low temperature) iron [26], stainless steels [27] and nickel [28], have given evidence that hydrogen contributes to the formation of vacancy clusters and increases the recovery temperature. These results are more suitable for the interpretation of IF spectra as the dissociation of 'hydrogen atoms-vacancy clusters' complexes is expected at higher temperatures than the dissociations of 'single vacancy-hydrogen atom (atoms)' complexes.…”

Section: Hydrogen-induced Effects In 316l-type Stainless Steelmentioning

confidence: 99%

Hydrogen-Induced Effects in Annealed and Prestrained 316L-Type Stainless Steel Studied by Mechanical Spectroscopy

Shyvaniuk¹

2016

Metallofiz. Noveishie Tekhnol.

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Annealed and tensile prestrained 316L-type stainless steel is studied by internal friction (IF) method. Low-frequency forced-vibration measurements of IF are carried out in the temperature range of 130-500 K before and after gaseous-hydrogen charging at 543 K and under three different pressures: 0.5, 10, and 100 MPa. Two complex multicomponent IF peaks at about 250 and 365 K are detected after preliminary tensile deformation in hydrogenfree material. As revealed, the low-temperature peak is of relaxation type, and the high-temperature one is a resonant peak. The effect of hydrogen content and hydrogen distribution on IF peaks' features, e.g., background, amplitude and thermal stability, is examined. An increase in stability of vacancies caused by hydrogen is suggested that follows from IF measurements after ageing at 473 K. As experimentally shown, the temperature drop of hydrogenation to 358 K leads to a marked shift of the high-temperature peak toward higher temperatures. A hypothesis about the cause underlying this phenomenon is proposed.За допомогою механічної спектроскопії, а саме, міряння внутрішнього тертя, досліджено неіржавійну сталь типу 316L у відпаленому та дефор-мованому розтягом станах. Низькочастотні міряння внутрішнього тертя на вимушених коливаннях проводилися в температурному діапазоні від 130 до 500 К перед і після газового наводнювання при 543 К та трьох зна-ченнях тиску водню: 0,5, 10 та 100 МПа. Після деформації розтягом у ви-хідному матеріалі виявлено два мультикомпонентних піки при темпера-турах біля 250 та 365 К. Показано, що низькотемпературний пік має ре-лаксаційну природу, в той час як високотемпературний пік відноситься до резонансних. Також було перевірено вплив вмісту водню та його розпо-ділу на властивості піків внутрішнього тертя, а саме, на їх фон, амплітуду та термічну стабільність. Сформульовано припущення про те, що водень сприяє стабілізації вакансій, що випливає із експериментальних дослі-джень наводненої та зістареної при 473 К сталі. Експериментально пока-зано, що зниження температури наводнювання до 358 К призводить до С помощью механической спектроскопии, а именно, измерения внутрен-него трения, исследована нержавеющая сталь типа 316L в отожжённом и деформированном растяжением состояниях. Низкочастотные измерения внутреннего трения на вынужденных колебаниях проведены в темпера-турном диапазоне от 130 до 500 К до и после газового наводороживания при 543 К и трёх значениях давления водорода: 0,5, 10 и 100 МПа. После деформации растяжением в исходном состоянии обнаружены два муль-тикомпонентных пика при температурах около 250 и 365 К. Показано, что низкотемпературный пик имеет релаксационную природу, в то время как высокотемпературный пик относится к резонансным. Также прове-рено влияние содержания водорода и его распределения на свойства пи-ков внутреннего трения, а именно, на их фон, амплитуду и термическую стабильность. Сформулировано предположение о том, что водород способ-ствует стабилизации вакансий, что следует из экспериментальных иссле-дований наводороженной и сос...

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“…The other is that the lower crosshead speed enhances the formation of lattice defects such as mono vacancies or vacancy clusters. [11,[24][25][26] Vacancies that form during plastic deformation without the presence of hydrogen result from dislocation dynamics, such as the interaction and cutting of screw dislocations or combinations of edge dislocations with opposite characteristics located on slip planes an atomic plane distance apart, and are normally so unstable as to disappear immediately at room temperature. [27] In contrast, vacancies that form during plastic deformation in the presence of hydrogen are stabilized immediately by hydrogen since moving dislocations maintain a hydrogen atmosphere under lower strain rates.…”

mentioning

confidence: 99%

“…[27] In contrast, vacancies that form during plastic deformation in the presence of hydrogen are stabilized immediately by hydrogen since moving dislocations maintain a hydrogen atmosphere under lower strain rates. In fact, it has been shown that the formation of lattice defects by plastic deformation is enhanced by the presence of hydrogen, using lifetime measurement of positron annihilation [25,26,28,29] and analysis of hydrogen as a tracer. [24,28] In order to validate the possibility of factors (C), (D), and (E), i.e., to omit the effect of factor (B), smooth bar specimens without any stress concentration were prepared.…”

mentioning

confidence: 99%

Method of Evaluating Delayed Fracture Susceptibility of Tempered Martensitic Steel Showing Quasi-Cleavage Fracture

Matsumoto

Takai

2016

Metall Mater Trans A

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The difference in the hydrogen charging methods, immersion in a NH 4 SCN aqueous solution, and cathodic electrolysis in a NaOH aqueous solution, did not affect the hydrogen state present in the steel, but it did affect the surface state of the specimens through corrosion, causing fracture strength to fluctuate in tensile testes. As for stress application method, the fracture strength at lower crosshead speeds in tensile tests was consistent with that found for hydrogen precharging prior to stress application in CLTs as long as hydrogen charging was conducted by cathodic electrolysis. However, the fracture strength obtained with concurrent hydrogen charging without precharging prior to stress application in CLTs was higher than that with hydrogen precharging prior to stress application in CLTs regardless of the same hydrogen content. In other words, delayed fracture susceptibility was affected by the order of hydrogen charging and stress application for quasi-cleavage fracture associated with local plastic deformation, i.e., dislocation motion. Therefore, by taking into account the cathodic electrolysis in the NaOH solution, the low crosshead speed and the order of hydrogen charging and stress application, the fracture strength in CLTs, and tensile tests coincided with respect to quasi-cleavage fracture even though the stress application methods were different.

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The effect of hydrogen on vacancy generation in iron by plastic deformation

Cited by 139 publications

References 13 publications

<i>In-situ</i> Microbending Tests of Ni–Cr Alloy during Cathodic Hydrogen Charging by Electrochemical Nanoindentation

<i>In-situ</i> Microbending Tests of Ni–Cr Alloy during Cathodic Hydrogen Charging by Electrochemical Nanoindentation

Hydrogen-Induced Effects in Annealed and Prestrained 316L-Type Stainless Steel Studied by Mechanical Spectroscopy

Method of Evaluating Delayed Fracture Susceptibility of Tempered Martensitic Steel Showing Quasi-Cleavage Fracture

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