Mechanism of hydrogen embrittlement

Karpenko, G. V.; Litvin, A. K.; Tkachev, V. I.; Soshko, A. I.

doi:10.1007/bf00715624

Cited by 9 publications

(4 citation statements)

References 11 publications

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“…It is well known that hydrogen reduction of bulk iron oxides produces normally a compact iron layer [25], but if excess hydrogen is present at high temperatures once metallic iron is produced, it will diffuse within and solubilize in the material and stress corrosion cracking and hydrogen embrittlement will occur [28]. Despite extensive study, the mechanism(s) of hydrogen embrittlement and fracture formation is remained unclear [29]. Among the many suggestions, four mechanisms appear to be viable: (i) precipitation of gaseous hydrogen, (ii) formation of hydrides, (iii) deformation localization, and (iv) reduction of cohesion across the grain boundary [30].…”

Section: Evolution Of the Catalyst During The Heating And Reductive S...mentioning

confidence: 99%

An original growth mode of MWCNTs on alumina supported iron catalysts

Philippe

Caussat

Falqui

et al. 2009

Journal of Catalysis

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Section: Evolution Of the Catalyst During The Heating And Reductive S...mentioning

confidence: 99%

An original growth mode of MWCNTs on alumina supported iron catalysts

Philippe

Caussat

Falqui

et al. 2009

Journal of Catalysis

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“…One hundred years later, in 1973, G.V. Karpenko, based on the existing theoretical and experimental data, proposed that the phenomenon of hydrogen embrittlement was regarded as a mechanical-chemical effects of metal selective microplasticizing caused by the chemisorption process of hydrogen activated by stresses [23]. However, until now, there has not been a unified mechanism that can explain the hydrogen embrittlement phenomenon.…”

Section: Mechanism Of Hydrogen Embrittlementmentioning

confidence: 99%

A review on hazards and risks to pipeline operation under transporting hydrogen energy and hydrogen-mixed natural gas

Li,

Song,

Zhang

2024

Sci. Tech. Energ. Transition

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As an efficient and clean fuel, hydrogen energy plays an important role in relieving the energy crisis and achieving the ori-entation of zero carbon emissions. Transportation is the key link in the construction of hydrogen energy infrastructure. For large-scale and long-distance transportation of hydrogen, pipeline transportation has the advantages of high efficiency and cost saving. While using the existing natural gas pipeline to transport hydrogen, it would economize the economic cost, time cost and labor cost. However, the transportation of hydrogen may bring more hazards and risks. Based on the investigation of a large number of literatures, the research advance in hydrogen embrittlement, leakage, combustion and explosion risk of hydrogen and hydrogen-mixed natural gas pipelines was reviewed. The mechanism, research means and evaluation meth-ods of hydrogen embrittlement, as well as the experimental and numerical simulation research results of leakage, combus-tion and explosion were discussed in detail. The definite and important conclusions include: (1) For buried hydrogen-mixed natural gas transportation pipeline, the leakage rate of hydrogen and methane is the same, the formation of the leakage crater is foreign to the nature of leakage gas. (2) When adding less than 25 volume percentage of hydrogen into the natural gas pipelines, the explosion risk would not be increased. Future research should focus on the risk prediction, quantitative risk assessment, intelligent monitoring, and explosion-suppression technical measures of hydrogen and hydrogen-mixed natural gas transportation pipelines, so as to establish comprehensive and multi-level pipeline safety protection barriers.

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“…On the basis of the thermodynamic analysis of a two-phase (metalmicrovoid) system containing hydrogen and Me3C, Me7C 3 , and Me~3C6-type carbides as thermodynamic components, we suggest a new scheme for the evaluation of the partial pressure of methane in the microvoids of the metal. It accelerates self-diffusion in the material [9], intensifies the ability of dislocations to move [ 10,11], and induces high internal pressures inside microvoids [12][13][14][15][16]. Unlike the previous computational schemes, in the proposed scheme, pressure depends on the radius of the microvoid.…”

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confidence: 99%

“…It accelerates self-diffusion in the material [9], intensifies the ability of dislocations to move [ 10,11], and induces high internal pressures inside microvoids [12][13][14][15][16]. It accelerates self-diffusion in the material [9], intensifies the ability of dislocations to move [ 10,11], and induces high internal pressures inside microvoids [12][13][14][15][16].…”

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confidence: 99%

Analytic evaluation of the pressure of methane in microvoids of 2.25Cr-1Mo steel subjected to hydrogen attack

Nykyforchyn¹,

Skrypnyk²,

Didukh³

1998

Mater Sci

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We present an estimate of the partial pressure of methane in microvoids under the conditions of hydrogen corrosion in 2.25Cr-1Mo steel. On the basis of the thermodynamic analysis of a two-phase (metalmicrovoid) system containing hydrogen and Me3C, Me7C 3 , and Me~3C6-type carbides as thermodynamic components, we suggest a new scheme for the evaluation of the partial pressure of methane in the microvoids of the metal. We give an example of the evaluation of the pressure of methane in internal cavities in steel at a temperature of 500"C for a simplified case where the formation of methane is controlled by the amount of carbon formed as a result of the decomposition of carbides. Unlike the previous computational schemes, in the proposed scheme, pressure depends on the radius of the microvoid. In the general case, this approach also takes into account the distance between the analyzed layer and the metal surface, the width of the decarbonized zone, the rates of carbon and hydrogen diffusion in the metal, and many other parameters.High-temperature degradation of heat-resistant and moderately alloyed steels used in chemical, oil-refining, and power-plant industry is caused by the nucleation and growth of microvoids along grain boundaries. As a result of merging, microvoids form intergranular cracks, which lead to failures. Intergranular degradation does not cause any visible unrecoverable deformation in the material because only a small part of the material near grain boundaries undergoes changes. Therefore, it is hardly possible to evaluate the level of degradation of the material by analyzing the deformation of creep acquired by the material. In this case, one must give attention to metallographic analysis and analytic methods for modeling and failure prediction.The localization of high-temperature degradation processes is explained by the action of the mechanisms of deformation and damage (i.e., micromechanisms of grain-boundary diffusion [ 1, 2]) predominant in the temperature and stress ranges typical of the actual operating conditions, i.e., for ~ = 10-102 MPa and T = 400-600~ These parameters are too low to induce creep in the bulk of the material but they are sufficiently high to induce the nucleation of vacancies on the grain boundaries as a result of slip of the boundary dislocations [3,4]. Since, under these conditions, vacancy diffusion along grain boundaries is more intense than diffusion in the bulk of the material [2], the newly formed vacancies diffuse to microvoids, which grow due to the accumulation of vacancies. The inadequacy of the power-creep mechanism under these conditions means that viscous flows are absent in the material. This enables us to reduce the problem of simulation of the growth of grain-boundary voids to the solution of a onedimensional boundary-value diffusion problem. The importance of this problem inspired the appearance of numerous works in this direction [5][6][7][8].The phenomenon of high-temperature degradation becomes even more complicated if hydrogen is present in the materi...

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Mechanism of hydrogen embrittlement

Cited by 9 publications

References 11 publications

An original growth mode of MWCNTs on alumina supported iron catalysts

An original growth mode of MWCNTs on alumina supported iron catalysts

A review on hazards and risks to pipeline operation under transporting hydrogen energy and hydrogen-mixed natural gas

Analytic evaluation of the pressure of methane in microvoids of 2.25Cr-1Mo steel subjected to hydrogen attack

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