scholarly journals Improved Accuracy of Thermal Desorption Spectroscopy by Specimen Cooling during Measurement of Hydrogen Concentration in a High-Strength Steel

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1252 ◽  
Author(s):  
Eric Fangnon ◽  
Evgenii Malitckii ◽  
Yuriy Yagodzinskyy ◽  
Pedro Vilaça
Keyword(s):  
Thermal Desorption ◽  
Hydrogen Concentration ◽  
High Strength Steel ◽  
Vacuum Chamber ◽  
Thermal Desorption Spectroscopy ◽  
High Strength ◽  
Steel Sample ◽  
Martensitic Steels ◽  
Hydrogen Flux ◽  
Redistribution Of Hydrogen

Thermal desorption spectroscopy (TDS) is a powerful method for the measurement of hydrogen concentration in metallic materials. However, hydrogen loss from metallic samples during the preparation of the measurement poses a challenge to the accuracy of the results, especially in materials with high diffusivity of hydrogen, like ferritic and ferritic-martensitic steels. In the present paper, the effect of specimen cooling during the experimental procedure, as a tentative to reduce the loss of hydrogen during air-lock vacuum pumping for one high-strength steel of 1400 MPa, is evaluated. The results show, at room temperature, the presence of a continuous outward hydrogen flux accompanied with the redistribution of hydrogen within the measured steel during its exposure to the air-lock vacuum chamber under continuous pumping. Cooling of the steel samples to 213 K during pumping in the air-lock vacuum chamber before TDS measurement results in an increase in the measured total hydrogen concentration at about 14%. A significant reduction in hydrogen loss and redistribution within the steel sample improves the accuracy of hydrogen concentration measurement and trapping analysis in ferritic and martensitic steels.

scholarly journals Numerical Analysis of Influence of Hydrogen Charging Method on Thermal Desorption Spectra for Pre-strained High-Strength Steel

2014 ◽  
Vol 54 (1) ◽  
pp. 153-159 ◽  
Author(s):  
Ken-ichi Ebihara ◽  
Takashi Iwamoto ◽  
Yukio Matsubara ◽  
Hiroki Yamada ◽  
Tsukasa Okamura ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Thermal Desorption ◽  
High Strength Steel ◽  
High Strength ◽  
Hydrogen Charging

Prediction on Initiation of Hydrogen-Induced Delayed Cracking in High-Strength Steel Based on Cohesive Zone Modeling

2014 ◽  
Author(s):  
Yanfei Wang ◽  
Jianming Gong ◽  
Luyang Geng ◽  
Yong Jiang
Keyword(s):  
Stress Analysis ◽  
Hydrogen Concentration ◽  
High Strength Steel ◽  
Cohesive Zone ◽  
High Strength ◽  
Cohesive Zone Modeling ◽  
Cohesive Elements ◽  
Cohesive Stress ◽  
Delayed Cracking ◽  
Zone Modeling

This study presents prediction on initiation of hydrogen-induced delayed cracking (HIDC) in hydrogen pre-charged high-strength steel notched bars under a constant load based on hydrogen influenced cohesive zone modeling (CZM). The prediction is implemented by using a three-step sequential coupling finite element procedure including elastic-plastic stress analysis, stress-assisted hydrogen diffusion analysis and cohesive stress analysis with cohesive elements embedded along the potential crack path. Hydrogen influenced linear traction separation law is applied to the cohesive elements. The predicted initiation time of HIDC gives a good agreement with the experimental fracture time reported in a literature. The prediction reproduces the experimental trend that the critical hydrogen concentration for crack initiation is independent of the initial hydrogen concentration, while decreases with increasing load or stress concentration factor of the notch. CZM has a potential to predict HIDC of high-strength steel.

Hydrogen Accumulation in Technically Pure Titanium Alloy at Saturation from Gas Atmosphere

2014 ◽  
Vol 880 ◽  
pp. 68-73 ◽  
Author(s):  
Viktor N. Kudiiarov ◽  
Andrey M. Lider ◽  
Sergey Y. Harchenko
Keyword(s):  
Activation Energy ◽  
Titanium Alloy ◽  
Thermal Desorption ◽  
Hydrogen Concentration ◽  
Pure Titanium ◽  
Thermal Desorption Spectroscopy ◽  
Sorption Process ◽  
Hydrogen Saturation ◽  
Gas Atmosphere ◽  
Hydrogen Accumulation

This paper presents experimental results of study of hydrogen accumulation in technically pure titanium alloy at saturation from gas atmosphere. Automated complex Gas Reaction Controller has been used for hydrogen saturation from gas atmosphere. Temperatures increasing from 350 °C to 500 °C allow increase hydrogen sorption process and as a result significantly increase hydrogen concentration in technically pure titanium alloy. At hydrogen saturation from gas atmosphere at temperature 500 °C increasing of saturation time from 10 minutes to 120 minutes leads to hydrogen concentration increasing from 0.1 wt.% to 1 wt.% and increasing of hydrides volume content throughout the samples. The activation energy for hydrogen evolution has been estimated by thermal desorption spectroscopy method by equal 102 kJ/mol.

Study of the Hydrogen Traps in a High Strength TRIP Steel by Thermal Desorption Spectroscopy

2012 ◽  
Vol 706-709 ◽  
pp. 2253-2258 ◽  
Author(s):  
Diana Pérez Escobar ◽  
Lode Duprez ◽  
Kim Verbeken ◽  
Marc Verhaege
Keyword(s):  
Grain Boundaries ◽  
Thermal Desorption ◽  
Trip Steel ◽  
Cold Deformation ◽  
Thermal Desorption Spectroscopy ◽  
High Strength ◽  
Trip Steels ◽  
Depth Study ◽  
Different Temperatures ◽  
Steel Trip700

Thermal desorption spectroscopy (TDS) is a very important tool in hydrogen related research. It allows to distinguish between the different types of microstructural hydrogen traps based on the analysis of the different temperatures at which hydrogen desorbs from the material during heating. These peak temperatures depend on the metallurgical and microstructural characteristics of the steel under investigation and provide important information on the possible mechanisms for hydrogen embrittlement (HE). In the present work, multiple TDS experiments and an in-depth study of the microstructure were performed on a TRIP steel (TRIP700) that was previously cold deformed in order to make a correlation between the microstructural features of this material, e.g. grain boundaries, dislocations, martensite formation and the peaks that became visible during TDS. The results obtained for the TRIP grade were compared with those obtained for electrolytic pure iron, which only contained a limited amount of possible trap sites such as grain boundaries and an increasing amount of dislocations due to previous application of cold deformation. Significant differences between both materials and a significant impact of the degree of cold deformation for TRIP steels were observed.

scholarly journals Effects of Adding CO2 to Low Level H2S Containing Aqueous Environments on the Corrosion and Hydrogen Penetration Behaviors of High-Strength Steel

2021 ◽  
Vol 59 (8) ◽  
pp. 533-544
Author(s):  
Seung Min Ryu ◽  
Jin-seong Park ◽  
Hye Rin Bang ◽  
Sung Jin Kim
Keyword(s):  
Aqueous Solution ◽  
High Strength Steel ◽  
Hydrogen Permeation ◽  
High Strength ◽  
Steel Sample ◽  
Aqueous Environment ◽  
Hydrogen Atoms ◽  
Low Level ◽  
Low Concentrations ◽  
Hydrogen Penetration

The effects of adding CO2 to low level H2S containing aqueous environment on the corrosion and hydrogen penetration behaviors of high-strength steel were evaluated using a range of experimental and analytical methods. The corrosion rate of the steel sample exposed to a low level of H2S dissolved in an aqueous solution was comparatively higher than the one exposed to a mixture of low concentrations of H2S with CO2 dissolved in the aqueous solution. The higher corrosion resistance of the steel in the mixture of low concentrations of H2S and CO2 was attributed primarily to the three-layer structure of corrosion scale, comprised of an outer Fe-oxide, middle FeS1-X, and inner FeCO3, which formed on the steel sample. In particular, the formation of a thin FeCO3 layer with protective and non-conductive nature may serve as an effective barrier against the penetration of aggressive ionic species in solution, as well as hydrogen atoms formed by cathodic reduction or hydrolysis reactions. Consequently, the hydrogen permeation level, which was measured in a mixture of low-level H2S and CO2, was controlled to a comparatively lower value. Nevertheless, the higher level of hydrogen permeation in a mixture of low levels of H2S and CO2 at the early corrosion stage might increase the potential risk of pre-mature failure by hydrogen-assisted cracking.

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