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Kim Verbeken - One of the best experts on this subject based on the ideXlab platform.
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thermal desorption spectroscopy study of the interaction between Hydrogen and different microstructural constituents in lab cast fe c alloys
Corrosion Science, 2012Co-Authors: Perez D Escobar, L. Duprez, Kim Verbeken, Marc Verhaege, Tom Depover, Elien WallaertAbstract:Abstract Two lab cast steels with variable carbon content were processed to generate different microstructural constituents. The as-quenched martensite microstructure had the highest Hydrogen saturation level while a significant part of this Hydrogen appeared to be diffusible. TDS measurements revealed that the amount of Hydrogen considerably increased with the carbon content and that the activation energies for the active traps in all compounds were similar. Evaluation of the Hydrogen blister formation revealed that the microstructure played a more important role than the amount of carbon on the sensibility of the microstructures to Hydrogen Damage.
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Hydrogen Damage in Multiphase Steels after Electrochemical Charging
2010Co-Authors: D. Pérez Escobar, C. Minambres, L. Duprez, Kim Verbeken, Marc VerhaegeAbstract:INTRODUCTION The harmful consequences of the exposure of steel to a Hydrogen containing environment was first discussed by Johnson [1]. He showed that Hydrogen caused a decrease in ductility leading to Hydrogen embrittlement. High strength steels turn out to be even more sensitive to this phenomenon. Nowadays, the use of high strength steels in Hydrogen rich environments becomes increasingly important in industry. Therefore, before using these steels in this type of environment, a detailed study of their interaction with Hydrogen is a prerequisite to be able to predict the potential Damage, i.e. Hydrogen blisters, Hydrogen embrittlement and Hydrogen induced cracking, which might occur during use. Blisters appear in many materials in the absence of external stress when the Hydrogen concentration is above a certain threshold. The main goal of this work was to study this phenomenon for different types of steels and electrolytes. Most mechanisms trying to explain blister formation suggest that Hydrogen atoms combine into Hydrogen gas molecules at the interfaces such as those between second phase particles and the metal matrix, producing locally high Hydrogen pressure inducing microcracks. The propagation and connection of the microcracks causes formation of the blisters and cracks [2].
A. Alfantazi - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation of the effects of water electrolysis parameters on the amount of Hydrogen Damage in Pb(Zr,Ti)O_3
Journal of Materials Science, 2014Co-Authors: A. Shafiei, A. AlfantaziAbstract:Water electrolysis technique has been used in this work to investigate the interactions between Hydrogen and Pb(Zr,Ti)O_3 (PZT), and the effects of water electrolysis parameters on the amount of Hydrogen Damage have been investigated. Microstructural investigations show that increasing the current density during water electrolysis will increase the amount of Hydrogen Damage, while increasing the voltage during water electrolysis treatment will decrease the amount of Hydrogen Damage. The mechanisms by which changing the current density and voltage affects the amount Hydrogen Damage are tentatively proposed. The changes in the capacitance and dissipation factor of PZT after water electrolysis are investigated, and a simple model has been developed to correlate the electrical properties changes to the thickness of the corroded layer.
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Experimental investigation of the effects of water electrolysis parameters on the amount of Hydrogen Damage in Pb(Zr,Ti)O3
Journal of Materials Science, 2013Co-Authors: A. Shafiei, A. AlfantaziAbstract:Water electrolysis technique has been used in this work to investigate the interactions between Hydrogen and Pb(Zr,Ti)O3 (PZT), and the effects of water electrolysis parameters on the amount of Hydrogen Damage have been investigated. Microstructural investigations show that increasing the current density during water electrolysis will increase the amount of Hydrogen Damage, while increasing the voltage during water electrolysis treatment will decrease the amount of Hydrogen Damage. The mechanisms by which changing the current density and voltage affects the amount Hydrogen Damage are tentatively proposed. The changes in the capacitance and dissipation factor of PZT after water electrolysis are investigated, and a simple model has been developed to correlate the electrical properties changes to the thickness of the corroded layer.
A. Shafiei - One of the best experts on this subject based on the ideXlab platform.
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Experimental investigation of the effects of water electrolysis parameters on the amount of Hydrogen Damage in Pb(Zr,Ti)O_3
Journal of Materials Science, 2014Co-Authors: A. Shafiei, A. AlfantaziAbstract:Water electrolysis technique has been used in this work to investigate the interactions between Hydrogen and Pb(Zr,Ti)O_3 (PZT), and the effects of water electrolysis parameters on the amount of Hydrogen Damage have been investigated. Microstructural investigations show that increasing the current density during water electrolysis will increase the amount of Hydrogen Damage, while increasing the voltage during water electrolysis treatment will decrease the amount of Hydrogen Damage. The mechanisms by which changing the current density and voltage affects the amount Hydrogen Damage are tentatively proposed. The changes in the capacitance and dissipation factor of PZT after water electrolysis are investigated, and a simple model has been developed to correlate the electrical properties changes to the thickness of the corroded layer.
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Experimental investigation of the effects of water electrolysis parameters on the amount of Hydrogen Damage in Pb(Zr,Ti)O3
Journal of Materials Science, 2013Co-Authors: A. Shafiei, A. AlfantaziAbstract:Water electrolysis technique has been used in this work to investigate the interactions between Hydrogen and Pb(Zr,Ti)O3 (PZT), and the effects of water electrolysis parameters on the amount of Hydrogen Damage have been investigated. Microstructural investigations show that increasing the current density during water electrolysis will increase the amount of Hydrogen Damage, while increasing the voltage during water electrolysis treatment will decrease the amount of Hydrogen Damage. The mechanisms by which changing the current density and voltage affects the amount Hydrogen Damage are tentatively proposed. The changes in the capacitance and dissipation factor of PZT after water electrolysis are investigated, and a simple model has been developed to correlate the electrical properties changes to the thickness of the corroded layer.
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Effect of porous alumina coatings on decreasing Hydrogen Damage to Pb(Zr,Ti)O3
Surface & Coatings Technology, 2013Co-Authors: A. Shafiei, Carmen Oprea, Tom TroczynskiAbstract:Abstract Alumina coatings were applied to Pb(Zr,Ti)O 3 plates using the sol–gel technique, to explore the possibilities of decreasing the H 2 Damage to PZT. The coating process development cycle included dip coating in 10 wt.% boehmite sol and firing at 450 °C in air for 5 h. The functionality of the coatings against Hydrogen Damage was evaluated using water electrolysis in 0.1 M NaOH solution, with a constant current density of 100 mA/cm 2 and 7–10 V. Significant reduction of the Hydrogen Damage was observed even though the coatings were highly porous. The mechanism by which the porous alumina coating decreases the Hydrogen Damage is tentatively proposed as prevention of the access of atomic Hydrogen to the surface of PZT. Through this mechanism the porous coatings promote recombination of Hydrogen atoms into Hydrogen molecules on the electrode surface and within the pores of the coating, which prevents the access of the damaging atomic Hydrogen to the surface of PZT.
W. Simka - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen Damage in Superaustenitic 904L Stainless Steels
Journal of Materials Engineering and Performance, 2014Co-Authors: J. Michalska, B. Chmiela, J. Łabanowski, W. SimkaAbstract:In this work, results on the influence of Hydrogen on corrosion resistance and of Hydrogen embrittlement of 904L superaustenitic stainless steel were investigated. The cracking behavior was studied by performing a slow strain rate test in synthetic seawater under varying cathodic polarization conditions. The results showed that the steel’s plasticity varied with the applied cathodic current density. Significant reductions in ductility were found, indicating its susceptibility to Hydrogen-assisted fracture at current density of 20 mA/cm^2. Fractographical examinations showed that an increase in Hydrogenation current density causes a stepwise decrease in ductility on the fracture surface. The effect of Hydrogen on passivity and on pitting corrosion resistance was qualified with the polarization curves registered in synthetic seawater. The conclusion is that Hydrogen may affect the passive film stability and thus may decrease the corrosion resistance of the studied steel. The presence of Hydrogen increases corrosion current density and decreases the potential of the film breakdown. It was also found that the degree of the susceptibility to Hydrogen degradation was dependent on the Hydrogen charging conditions.
Lijie Qiao - One of the best experts on this subject based on the ideXlab platform.
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Role of point defects in Hydrogen Damage at α-Cr2O3/α-Fe2O3 (0001) interface
International Journal of Hydrogen Energy, 2019Co-Authors: Li Chen, Changmin Shi, Hongmei Liu, Dongchao Wang, Lijie QiaoAbstract:Abstract Point defects at the actual α-Cr2O3/α-Fe2O3 (0001) interface control the passive film's protective properties, and their interaction with Hydrogen is a crucial factor, which determines whether possibility of Hydrogen Damage can be reduced or not. We study the role of point defects in Hydrogen Damage at α-Cr2O3/α-Fe2O3 (0001) interface using density functional theory. It is found that Cr vacancy and Fe vacancy at the interface trap H with the lowest binding energy −2.908 eV and −2.798 eV, respectively. The solute atoms such as Zn, Ni and Cu at the interface trap H with negative binding energies, in which the minimum binding energy is −1.603 eV for Cu doped interface with H. Alloying elements Al, Ti, V, Mn, Nb and Mo at the interface lead to positive H binding energies, meaning they could not trap H atom. These results confirm that Cr vacancy, Fe vacancy and alloying elements Ni, Cu, and Zn play significant roles in Hydrogen Damage at the interface of passive films, while alloying elements Mn, Mo, Ti, Nb, Al and V can weaken the possibility of Hydrogen Damage at the interface of passive films. Our findings provide guiding significance of choosing proper alloying elements to obtain Hydrogen Damage-resistant steels in industry.
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Prevent Hydrogen Damage in α-Cr2O3/α-Fe2O3 (0 0 0 1) interface
Applied Surface Science, 2019Co-Authors: Li Chen, Changmin Shi, Hongmei Liu, Dongchao Wang, Lei Gao, Lijie QiaoAbstract:Abstract By means of first-principles calculations based on the density-functional theory, we investigate the vacancy trappings prevent Hydrogen Damage in two dimension α-Cr2O3/α-Fe2O3 (0 0 0 1) interface structure. Our calculations show that H atoms prefer to occupy the unoccupied O atoms octahedral interstitial site (Osite) in the center of the interface structure without vacancy defect, weakening the cleavage strength of Fe and O atoms and decreasing the work function and stability of interface structure. To prevent Hydrogen Damage in this interface structure, we model three Fe, Cr and O vacancy defects in this interface structure, respectively. Fe and Cr vacancy defects with lower H binding energy and higher work function, are better Hydrogen trappings compared to O vacancy. These results confirm the Fe and Cr vacancy defects are effective Hydrogen trappings to prevent Hydrogen Damage for passive film of steel, which has significant practical implications.
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Prevention of Hydrogen Damage Using MoS₂ Coating on Iron Surface.
Nanomaterials, 2019Co-Authors: Li Chen, Changmin Shi, Hongmei Liu, Dongchao Wang, Lijie QiaoAbstract:The prevention of Hydrogen penetration into steels can effectively protect steels from Hydrogen Damage. In this study, we investigated the effect of a monolayer MoS₂ coating on Hydrogen prevention using first-principles calculations. We found that monolayer MoS₂ can effectively inhibit the dissociative adsorption of Hydrogen molecules on an Fe(111) surface by forming a S⁻H bond. MoS₂ coating acts as an energy barrier, interrupting Hydrogen penetration. Furthermore, compared with the H-adsorbed Fe(111) film, the work function of the MoS₂-coated film significantly increases under both equilibrium and strained conditions, indicating that the strained Fe(111) film with the MoS₂ coating also becomes more corrosion resistant. The results reveal that MoS₂ film is an effective coating to prevent Hydrogen Damage in steels.
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Passivation of Hydrogen Damage using graphene coating on α-Fe2O3 films
Carbon, 2018Co-Authors: Li Chen, Changmin Shi, Lijie Qiao, Chuan Jiang, Alex A. VolinskyAbstract:Abstract We report the demonstration of graphene as a passive layer that prevents Hydrogen Damage of steels. The effectiveness of the Hydrogen Damage inhibition is evaluated using graphene on α-Fe2O3 films. It's been observed that the work function increases under both compressive and tensile strains compared with α-Fe2O3 films without graphene coating, which indicates that the graphene coating strained surface layer became more corrosion resistant. The investigation of strain effect on the work function would help fundamentally understand the corrosion behavior. Our findings confirm that the graphene coating is an effective means to inhibit corrosion, even on deformed steels.
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Hydrogen-induced cracking and service safety evaluation for precipitation strengthened austenitic stainless steel as Hydrogen storage tank
International Journal of Hydrogen Energy, 2014Co-Authors: Y. Yan, Lijie QiaoAbstract:Abstract The safety of precipitation strengthened austenitic stainless steels used for Hydrogen storage tanks is of great interest. However, their application may face Hydrogen Damage resulting in Hydrogen-induced delayed failure. Results show that over-loading and Hydrogen-induced failure always occur at the weld part of the alloy. Hydrogen Damage such as microcracks could be observed on the surface of the matrix and the weld during charging even without any applied stress. Hydrogen-induced failure occurred during charging under constant load and the normalized threshold stress decreased exponentially with increasing defined time tc. It is shown that the threshold stress with no Hydrogen-induced failure occurring for expected service life, i.e. forty years, was 713 MPa. Therefore under the service stress, which is less than the threshold stress, 713 MPa, the safety factor of the Hydrogen storage tank for Hydrogen-induced fracture is great enough to indicate the tank to last for the entire designed service time.
