scholarly journals Effect of Specimen Geometry on the Thermal Desorption Spectroscopy Evaluated by Two-Dimensional Diffusion-Trapping Coupled Model

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1374
Author(s):  
Yafei Wang ◽  
Songyan Hu ◽  
Guangxu Cheng
Keyword(s):  
Thermal Desorption ◽  
Hydrogen Diffusion ◽  
Coupled Model ◽  
Thermal Desorption Spectroscopy ◽  
Mass Conservation ◽  
Specimen Geometry ◽  
Specimen Preparation ◽  
Two Dimensional ◽  
Dimensional Diffusion ◽  
Transfer Procedures

The hydrogen diffusion process in ferritic steel during thermal desorption tests was simulated using the finite element method based on the two-dimensional diffusion-trapping coupled model. This model was first verified by experimental data to obtain a physically meaningful combination of trap/lattice parameters. Then, the effect of specimen geometry was studied by varying the height of cylindrical specimens with other parameters fixed at constant values. Simulation of desorption spectra with different specimen geometries indicates that the measurement of hydrogen concentration is not affected by the change in specimen geometry due to the mass conservation law, for original thermal desorption spectra (TDS), which are, however, unlikely to be detected in traditional experiments due to the necessity of specimen transfer procedures. Considering the hydrogen escape during rest time (specimen preparation/transfer/evacuation), the measured TDS curves are expected to be strongly dependent on the specimen geometry. The effect of specimen geometry on desorption spectra is more pronounced for smaller specimens, resulting in the dramatic decrease in peak flux and the increased error of Kissinger method in the determination of trap deactivation energy. The present study may contribute to better understanding and more reliable interpretation of the TDS curves by considering the size effect.

scholarly journals Investigation of the Pressure Dependent Hydrogen Solubility in a Martensitic Stainless Steel Using a Thermal Agile Tubular Autoclave and Thermal Desorption Spectroscopy

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 231
Author(s):  
Patrick Fayek ◽  
Sebastian Esser ◽  
Vanessa Quiroz ◽  
Chong Dae Kim
Keyword(s):  
Stainless Steel ◽  
Thermal Desorption ◽  
Hydrogen Diffusion ◽  
Martensitic Stainless Steel ◽  
Thermal Desorption Spectroscopy ◽  
Hydrogen Uptake ◽  
Hydrogen Solubility ◽  
Automotive Components ◽  
Set Up ◽  
Service Application

Hydrogen is nowadays in focus as an energy carrier that is locally emission free. Especially in combination with fuel-cells, hydrogen offers the possibility of a CO2 neutral mobility, provided that the hydrogen is produced with renewable energy. Structural parts of automotive components are often made of steel, but unfortunately they may show degradation of the mechanical properties when in contact with hydrogen. Under certain service conditions, hydrogen uptake into the applied material can occur. To ensure a safe operation of automotive components, it is therefore necessary to investigate the time, temperature and pressure dependent hydrogen uptake of certain steels, e.g., to deduct suitable testing concepts that also consider a long term service application. To investigate the material dependent hydrogen uptake, a tubular autoclave was set-up. The underlying paper describes the set-up of this autoclave that can be pressurised up to 20 MPa at room temperature and can be heated up to a temperature of 250 °C, due to an externally applied heating sleeve. The second focus of the paper is the investigation of the pressure dependent hydrogen solubility of the martensitic stainless steel 1.4418. The autoclave offers a very fast insertion and exertion of samples and therefore has significant advantages compared to commonly larger autoclaves. Results of hydrogen charging experiments are presented, that were conducted on the Nickel-martensitic stainless steel 1.4418. Cylindrical samples 3 mm in diameter and 10 mm in length were hydrogen charged within the autoclave and subsequently measured using thermal desorption spectroscopy (TDS). The results show how hydrogen sorption curves can be effectively collected to investigate its dependence on time, temperature and hydrogen pressure, thus enabling, e.g., the deduction of hydrogen diffusion coefficients and hydrogen pre-charging concepts for material testing.

Thermal Desorption of Hydrogen from AISI 316L Stainless Steel and Pure Nickel

2013 ◽  
Vol 344 ◽  
pp. 71-77 ◽  
Author(s):  
Olga Todoshchenko ◽  
Yuriy Yagodzinskyy ◽  
Hannu Hänninen
Keyword(s):  
Stainless Steel ◽  
Thermal Desorption ◽  
316L Stainless Steel ◽  
Hydrogen Diffusion ◽  
Thermal Desorption Spectroscopy ◽  
Hydrogen Uptake ◽  
Pure Metal ◽  
Pure Nickel ◽  
Aisi 316L ◽  
Aisi 316L Stainless Steel

Hydrogen diffusion and trapping in AISI 316L stainless steel and pure nickel are studied with thermal desorption spectroscopy method. Specific features of hydrogen uptake and desorption for a multi-component alloy in comparison with that for pure metal and the effects of hydrogen concentration profile after electrochemical charging on the hydrogen desorption are discussed. It is shown that hydrogen diffusion and trapping in multi-component alloy are caused by the specific atomic distribution of hydrogen in the crystal lattice of alloy.

scholarly journals Thermal Desorption of Hg Monolayers from Cu(100)

1991 ◽  
Vol 229 ◽  
Author(s):  
Y. J. Kime ◽  
Jiandi Zhang ◽  
P. A. Dowben
Keyword(s):  
Phase Transition ◽  
Thermal Desorption ◽  
Thermal Desorption Spectroscopy ◽  
Two Dimensional ◽  
Inherent Part

AbstractA two dimensional phase transition from one adlayer structure to another is an inherent part of the thermal desorption of one monolayer of Hg on Cu(100). The energetics of this phase transition have been studied using thermal desorption spectroscopy (TDS). The TDS spectra reflect the coexistence of the two structural phases for a range of Hg exposures. The TDS spectra have been analyzed within a Polanyi-Wigner framework modified to account for the phase transition.

scholarly journals A two-dimensional glacier–fjord coupled model applied to estimate submarine melt rates and front position changes of Hansbreen, Svalbard

2018 ◽  
Vol 64 (247) ◽  
pp. 745-758 ◽  
Author(s):  
E. DE ANDRÉS ◽  
J. OTERO ◽  
F. NAVARRO ◽  
A. PROMIŃSKA ◽  
J. LAPAZARAN ◽  
...  
Keyword(s):  
Coupled Model ◽  
Small Scale ◽  
Two Dimensional ◽  
Time Step ◽  
Software Packages ◽  
Front Position ◽  
Circulation Patterns ◽  
Glacier Front ◽  
Order Of Magnitude ◽  
Frontal Ablation

ABSTRACTWe have developed a two-dimensional coupled glacier–fjord model, which runs automatically using Elmer/Ice and MITgcm software packages, to investigate the magnitude of submarine melting along a vertical glacier front and its potential influence on glacier calving and front position changes. We apply this model to simulate the Hansbreen glacier–Hansbukta proglacial–fjord system, Southwestern Svalbard, during the summer of 2010. The limited size of this system allows us to resolve some of the small-scale processes occurring at the ice–ocean interface in the fjord model, using a 0.5 s time step and a 1 m grid resolution near the glacier front. We use a rich set of field data spanning the period April–August 2010 to constrain, calibrate and validate the model. We adjust circulation patterns in the fjord by tuning subglacial discharge inputs that best match observed temperature while maintaining a compromise with observed salinity, suggesting a convectively driven circulation in Hansbukta. The results of our model simulations suggest that both submarine melting and crevasse hydrofracturing exert important controls on seasonal frontal ablation, with submarine melting alone not being sufficient for reproducing the observed patterns of seasonal retreat. Both submarine melt and calving rates accumulated along the entire simulation period are of the same order of magnitude, ~100 m. The model results also indicate that changes in submarine melting lag meltwater production by 4–5 weeks, which suggests that it may take up to a month for meltwater to traverse the englacial and subglacial drainage network.

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