scholarly journals Hydrogen Concentration Distribution in 2.25Cr-1Mo-0.25V Steel under the Electrochemical Hydrogen Charging and Its Influence on the Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2263 ◽  
Author(s):  
Changdong Yin ◽  
Jianjun Chen ◽  
Dongdong Ye ◽  
Zhou Xu ◽  
Jiahao Ge ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Concentration ◽  
Hydrogen Absorption ◽  
Concentration Distribution ◽  
Hydrogen Permeation ◽  
Diffusible Hydrogen ◽  
Saturation State ◽  
Hydrogen Charging ◽  
Charging Time ◽  
And Diffusion

The deterioration of the mechanical properties of metal induced by hydrogen absorption threatens the safety of the equipment serviced in hydrogen environments. In this study, the hydrogen concentration distribution in 2.25Cr-1Mo-0.25V steel after hydrogen charging was analyzed following the hydrogen permeation and diffusion model. The diffusible hydrogen content in the 1-mm-thick specimen and its influence on the mechanical properties of the material were investigated by glycerol gas collecting test, static hydrogen charging tensile test, scanning electron microscopy (SEM) test, and microhardness test. The results indicate that the content of diffusible hydrogen tends to be the saturation state when the hydrogen charging time reaches 48 h. The simulation results suggest that the hydrogen concentration distribution can be effectively simulated by ABAQUS and the method can be used to analyze the hydrogen concentration in the material with complex structures or containing multiple microstructures. The influence of hydrogen on the mechanical properties is that the elongation of this material is reduced and the diffusible hydrogen will cause a decrease in the fracture toughness of the material, and thus hydrogen embrittlement (HE) will occur. Moreover, the Young’s modulus E and microhardness are increased due to hydrogen absorption, and the variation value is related to the hydrogen concentration introduced into the specimen.

Numerical Investigation on Hydrogen Permeation with Flat Sheet Pd/Ag Membrane for Various Geometries

2016 ◽  
Vol 819 ◽  
pp. 454-458
Author(s):  
Hasan Mohd Faizal ◽  
Takeshi Yokomori ◽  
Toshihisa Ueda
Keyword(s):  
Surface Area ◽  
Hydrogen Concentration ◽  
Concentration Distribution ◽  
Hydrogen Permeation ◽  
Membrane Surface ◽  
Effective Surface ◽  
Membrane Surface Area ◽  
Flat Sheet ◽  
Upstream Pressure ◽  
Analytical Result

The variation in hydrogen concentration distribution on Pd/Ag membrane surface for permeation with H2/N2 mixture was investigated numerically, by varying the diameter of the mixture inlet. A 77wt.%Pd/23wt.%Ag purification membrane with thickness of 25μm and effective surface area of 3.14x10-4m2 was considered. The membrane temperature, total upstream pressure, and inlet H2 mole fraction were set to 623K, 0.25MPa and 0.75, respectively. Meanwhile, the downstream pressure was set at atmospheric. Mean mole flux (feed flow rate/effective membrane surface area) was varied between 0.19-0.95 mol.s-1.m-2. The hydrogen concentration distribution was investigated for various ratios of inlet radius to membrane radius (0.22:1, 0.50:1 and 0.75:1). It is found that hydrogen permeation flux obtained from various hydrogen concentration distributions are almost same, and quantitatively fit with analytical result based on the Sieverts’ equation with the effect of H2 permeation.

Effect of Hydrogen Trapping and Poisons on Diffusion Behavior of Hydrogen in Low Carbon Steel

2018 ◽  
Vol 764 ◽  
pp. 3-10 ◽  
Author(s):  
Lian Cai ◽  
Li Min Zhao
Keyword(s):  
Carbon Steel ◽  
Hydrogen Diffusion ◽  
Hydrogen Permeation ◽  
Diffusion Flux ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Hydrogen Trapping ◽  
Diffusion Behavior ◽  
Hydrogen Charging ◽  
And Diffusion

Effect of hydrogen trapping and poisons on diffusion behavior of hydrogen in commercial cold-rolled low carbon steel was investigated by means of electrochemical hydrogen permeation techniques. The experimental results reveal that diffusion rate and diffusion flux of hydrogen in the materials gradually increase with increasing the number of hydrogen charging and outgassing, and lag time significantly shortens with them, therefore, hydrogen trapping impede diffusion behavior of hydrogen in the materials. Different poisons in the hydrogen charging solution have also resulted in a certain influence on the assessment of hydrogen diffusion behavior.

Effect of the Electro-Chemical Hydrogen Charging Time on Hydrogen Embrittlement of X70 Steel Using for Gas Pipeline

2013 ◽  
Vol 51 (11) ◽  
pp. 813-820
Author(s):  
Chi-Eun Sung ◽  
Hyeon-Jee Jeon ◽  
Jin-Kyung Lee ◽  
In-Soo Son ◽  
Sang-Pill Lee ◽  
...  
Keyword(s):  
Hydrogen Embrittlement ◽  
Gas Pipeline ◽  
Hydrogen Charging ◽  
Charging Time

Control of hydrogen absorption by nickel films obtained upon magnetic spraying of zirconium alloy using the thermoEMF method

2020 ◽  
Vol 86 (8) ◽  
pp. 32-37
Author(s):  
V. V. Larionov ◽  
Xu Shupeng ◽  
V. N. Kudiyarov
Keyword(s):  
Magnetron Sputtering ◽  
Hydrogen Concentration ◽  
Hydrogen Absorption ◽  
Zirconium Alloy ◽  
Hydrogen Adsorption ◽  
Zirconium Alloys ◽  
Nickel Film ◽  
Protective Film ◽  
Nickel Films ◽  
Hydrogen Penetration

Nickel films formed on the surface of zirconium alloys are often used to protect materials against hydrogen penetration. Hydrogen adsorption on nickel is faster since the latter actively interacts with hydrogen, oxidizes and forms a protective film. The goal of the study is to develop a method providing control of hydrogen absorption by nickel films during vacuum-magnetron sputtering and hydrogenation via measuring thermoEMF. Zirconium alloy E110 was saturated from the gas phase with hydrogen at a temperature of 350°C and a pressure of 2 atm. A specialized Rainbow Spectrum unit was used for coating. It is shown that a nickel film present on the surface significantly affects the hydrogen penetration into the alloy. A coating with a thickness of more than 2 μm deposited by magnetron sputtering on the surface of a zirconium alloy with 1% Nb, almost completely protects the alloy against hydrogen penetration. The magnitude of thermoemf depends on the hydrogen concentration in the zirconium alloy and film thickness. An analysis of the hysteresis width of the thermoEMF temperature loop and a method for determining the effective activation energy of the conductivity of a hydrogenated material coated with a nickel film are presented. The results of the study can be used in assessing the hydrogen concentration and, hence, corrosion protection of the material.

Effect of Hydrogen on Mechanical Properties of Pipeline API 5L X70 Steel

2011 ◽  
Vol 146 ◽  
pp. 213-225 ◽  
Author(s):  
T. Bellahcene ◽  
J. Capelle ◽  
Méziane Aberkane ◽  
Z. Azari
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Embrittlement ◽  
Hydrogen Absorption ◽  
Fatigue Tests ◽  
The Finite Element Method ◽  
Effective Distance ◽  
Bending Tests ◽  
Fatigue Initiation ◽  
Api 5L X70 Steel ◽  
Special Soil

The aim of this work is to study the effects of hydrogen absorption on mechanical properties of pipe API 5L X70 steel. This study is conducted in special soil solution NS4 with pH 6.7 It show that the tensile properties like yield stress, ultimate strength and elongation at failure reduced under hydrogen embrittlement. Several fatigue tests (three (03) points bending tests) on roman tile specimens with notch are performed. Fatigue initiation is detected by acoustic emission. A comparison between specimens electrolytically charged with hydrogen and specimens without hydrogen absorption is made and it has been noted that fatigue initiation time is reduced when hydrogen embrittlement occurs. The field of elastoplastic stresses near the notch is computed by the finite-element method with the Abaqus software package. Effective distance and stress are calculated with the volumetric approach and the Notch intensity Factor of the roman tile specimen is determined for each loading value used in our tests.

Hydrogen permeation through a slab sample in the case of high hydrogen concentration

2006 ◽  
Vol 496 (2) ◽  
pp. 735-739 ◽  
Author(s):  
Maurizio Dapor ◽  
Antonio Miotello ◽  
Arturo Sabbioni
Keyword(s):  
Hydrogen Concentration ◽  
Hydrogen Permeation ◽  
High Hydrogen

Inoculation and Fading of Sr-Modified A356.2 Aluminum Alloy in Squeeze Casting

2016 ◽  
Vol 850 ◽  
pp. 671-678
Author(s):  
Jian Wei Niu ◽  
Lie Jun Li ◽  
Hai Jun Liu ◽  
Ji Xiang Gao ◽  
Chuan Dong Ren
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Aluminum Alloy ◽  
Hydrogen Absorption ◽  
Deleterious Effect ◽  
Squeeze Casting ◽  
Eutectic Silicon ◽  
Direct Reading ◽  
Air Bag ◽  
Fading Rate

The inoculation and fading behavior of Sr-modified aluminum alloy A356. 2 were studied for air bag bracket produced by squeeze casting. The effects of Sr, P, B contents and casting temperature on the microstructure and eutectic silicon morphology in different periods of inoculation were investigated by SEM and direct-reading Spectrometer. The influence of inoculation fading rate and addition of Sr on the casting mechanical properties and hydrogen absorption was studied. The experimental results showed that the inoculation process was completed in 1 h, and the eutectic silicon morphology can be maintained in almost subsequent 40 h after the addition of Sr. The fading rate decreased appreciably with the increase of casing temperature, P and B contents. The deleterious effect of the inoculation fading of Sr on the casting mechanical property can be compensated by the squeeze casting.

Stresses in the Surface Layer and Hydrogen Absorption and Diffusion in Cavitation Condition

2014 ◽  
Vol 225 ◽  
pp. 131-138
Author(s):  
Jarosław Chmiel ◽  
Jolanta Baranowska ◽  
Roman Jędrzejewski ◽  
Arkadiusz Rzeczycki
Keyword(s):  
Surface Layer ◽  
Stress State ◽  
Hydrogen Absorption ◽  
Surface Layers ◽  
Fem Modeling ◽  
And Diffusion

Cavitation attack in liquids generated a various states of stresses in surface layers of metals. Differences in stress state effects on hydrogen absorption activated by the cavitation implosion. Results of XRD investigation and FEM modeling shows on inhomogenity of process.

scholarly journals The Effect of Hydrogen-Charging on Mechanical Properties of Austenitic CrNi Steel Fabricated by Wire-Feed Electron Beam Additive Manufacturing

2021 ◽  
Vol 225 ◽  
pp. 01011
Author(s):  
Marina Panchenko ◽  
Eugeny Melnikov ◽  
Valentina Moskvina ◽  
Sergey Astafurov ◽  
Galina Maier ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Hydrogen Embrittlement ◽  
Yield Strength ◽  
Cast Steel ◽  
Solution Treatment ◽  
Fracture Mechanisms ◽  
Hydrogen Charging ◽  
Wire Feed

A comparative study of the mechanical properties, fracture mechanisms and hydrogen embrittlement peculiarities was carried out using the specimens of austenitic CrNi steel produced by two different methods: wire-feed electron beam additive manufacturing and conventional casting followed by solid-solution treatment. Hydrogen-induced reduction of ductility and the increase in the yield strength are observed in steel specimens produced by both methods. Despite hydrogen embrittlement index is comparable in them, the increase in the yield strength after hydrogen-charging is different: 25 MPa for cast steel and 175 MPa for additively manufactured steel. This difference is associated with the peculiarities of phase composition and phase distribution in steels produced by different methods.

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