Hydrogen Charging Research Articles

Assessing the effects of loading rate on fracture toughness of AISI 1020 and API 5L X80 steels with hydrogen charging: experimental and numeric simulation study

Assessing the effects of loading rate on fracture toughness of AISI 1020 and API 5L X80 steels with hydrogen charging: experimental and numeric simulation study

Magnetic-stress coupling test of pipeline steel after magnetization saturation with different hydrogen charging times

Magnetic-stress coupling test of pipeline steel after magnetization saturation with different hydrogen charging times

Nano-creep behavior of Ti-based bulk amorphous alloy after electrochemical hydrogen charging

Nano-creep behavior of Ti-based bulk amorphous alloy after electrochemical hydrogen charging

High-Pressure Hydrogen Charge Check-Valve Energy Loss-Based Correlation Analysis Affecting Internal Flow Characterizations

In this study, we analyzed changes in flow characteristics and energy-dissipation characteristics due to changes in hydrogen temperature and inlet/outlet differential pressure in a check valve, which affect the storage safety and reliability of high-pressure hydrogen refueling systems. The effects of flow separation and recirculation flow generation at the back end of the valve were investigated, and the pressure, flow rate, pressure coefficient, and energy dissipation at the core part (where the hydrogen inflow is blocked) and the outlet part (where the hydrogen is discharged) were numerically analyzed. The hydrogen-inlet temperature (Tin) was selected as 233 K, 293 K, and 363 K, and the differential pressure (∆P) was selected in the range of 2 to 10 MPa in 2 MPa steps. To ensure the reliability of the numerical results, mesh dependence was performed, and the effect of the mesh geometry on the results was less than 2%. The numerical simulation results showed that the hydrogen introduced into the core part is discharged into the discharge part, and the pressure decreases by up to 6% and the velocity increases by up to 16% at the 95 mm position of the L-shaped curved tube. In addition, for the hydrogen-inlet temperature of 233 K in the L-shaped curved tube, the flow velocity decreases by up to 60% and the pressure coefficient increases at the 2.3 mm point in the Y-axis direction, indicating that the main flow area is biased towards the bottom of the valve due to the constriction of the veins caused by flow separation. The TDR results showed that the hydrogen discharge to the discharge region increased by 96% at 95 mm compared to 90 mm, and the turbulent kinetic energy of the hydrogen was dissipated, resulting in a temperature increase of up to 4.5 K. The exergy destruction was maximized in the core region where flow separation occurs, indicating that the pressure, velocity, and TDR changes due to flow separation and recombination have a significant impact on the energy loss of the flow in the check valve.

Hydrogen-Induced Degradation of Metallic Materials—A Short Review

Hydrogen is currently used as an energy source, and there are already vehicles (cars and buses) that run on hydrogen in our public spaces. Additionally, in the chemical, petrochemical and nuclear industries, many devices come into contact with hydrogen. This short review covers a broad range of topics related to HE, i.e., the main hydrogen charging methods, aspects related to hydrogen diffusion in metallic materials, and the main models of hydrogen-induced material degradation and their assumptions, and discusses the influence of hydrogen on the properties and degradation of different metallic materials used in the industry based on the latest research results. This review focuses on the four primary groups of materials used in hydrogen devices, i.e., steels, aluminium alloys, nickel alloys and titanium alloys. The basic information on the influence of hydrogen on the structure and properties, mainly elongation, hardness and tensile strength, of these metallic material groups are presented. The influence of the method of hydrogen charging and the time of hydrogen saturation, as well as the effect of structure, on the content of hydrogen in the material, as well as on such material properties as hardness, tensile strength, and fatigue strength, is shown.

Hydrogen-Induced Ductility Loss of GH625 Superalloy Under Thermal Hydrogen Charging

The effect of thermal hydrogen charging on the tensile properties of GH625 superalloy was investigated. The results reveal that hydrogen significantly reduces the ductility of the GH625, leading to a shift from microvoid coalescence (MVC)-induced ductile fracture to intergranular (IG) brittle fracture. Random grain boundaries (GBs) are the primary sites for crack initiation. Hydrogen reduces the critical fracture stress of the δ phase at grain boundaries, causing cracking of the δ phase. Under the influence of hydrogen-enhanced localized plasticity (HELP) and hydrogen-enhanced decohesion (HEDE), the δ/γ interface debonds, forming microcracks that propagate along the fractured δ phase, leading to intergranular cracking. Annealing twin boundaries (TBs) serve as secondary sites for crack initiation. Hydrogen-induced local stress concentration promotes twin boundary sliding and hydrogen segregation reduces twin boundary cohesion strength, which is the primary cause of TB crack formation.

Anisotropy in Hydrogen Embrittlement Resistance of Drawn Pearlitic Steel Wire Evaluated by in-situ Miniature Test and Scanning Electron Microscopy during Plasma Hydrogen Charging

Anisotropy in Hydrogen Embrittlement Resistance of Drawn Pearlitic Steel Wire Evaluated by <i>in-situ</i> Miniature Test and Scanning Electron Microscopy during Plasma Hydrogen Charging

Methodology for Hydrogen-Assisted Fatigue Testing Using In Situ Cathodic Charging.

With hydrogen being a promising candidate for many future and current energy applications, there is a need for material-testing solutions, which can represent hydrogen charging under superimposed mechanical loading. Usage of high purity gaseous hydrogen under high pressure in commercial solutions entails huge costs and also potential safety concerns. Therefore, a setup was developed utilizing a customized electrochemical charging cell built into a dynamic testing system. With this setup, two heat treatment states of AISI 4140 (DIN 1.7225, 42CrMo4) with varying yield and ultimate tensile strength were characterized in constant amplitude tests. S-N (Woehler) curves differ between heat-treated states, and when comparing testing in air with in situ cathodic hydrogen-charged specimens, hydrogen proves to be detrimental to the material properties. For both states considered, the presence of hydrogen leads to a reduction in fatigue life. Fractographic analyses by scanning electron microscopy reveals that for in situ cathodic hydrogen-charged specimens, the crack initiation mechanisms change for the higher strength heat treatment state.

Research on hydrogen-indulced damage detection technology using shear horizontal SH0 mode nonlinear ultrasonic guided waves

ABSTRACT Hydrogen-enriched natural gas pipelines are vulnerable to hydrogen-induced damage, such as cracking, over time, posing safety risks. Regular inspection of high-grade steel pipelines in hydrogen-rich environments is crucial. Ultrasonic testing, known for its sensitivity to early internal defects in plate-like structures, is a promising method for detecting such anomalies. However, its effectiveness in detecting hydrogen-induced damage in pipelines has not been fully validated. This study proposes using Shear Horizontal (SH0) mode nonlinear ultrasonic guided waves for detecting hydrogen-induced damage. X80 steel was selected for the research, with pre-tensile and electrochemical hydrogen charging experiments to prepare the samples. Nonlinear ultrasonic testing with SH0 guided waves was conducted on samples with varying damage levels to observe changes in the ultrasonic nonlinear coefficient during the damage process. A microcrack cluster damage model was developed using MATLAB and COMSOL, combining finite element analysis and 3D X-ray Microscopy (XRM) to explore the relationship between nonlinear ultrasound and hydrogen damage. Results show that as cracks propagate, the nonlinear coefficient first increases and then decreases. Simulations reveal the propagation mechanism of nonlinear ultrasound in hydrogen-induced damage, providing theoretical support for enhanced detection. This approach improves the ability to detect hydrogen-induced damage in pipelines.

Effect of titanium and vanadium nano-carbide size on hydrogen embrittlement of ferritic steels

The effect of TiC and VC nano-precipitate size on the hydrogen embrittlement of ferritic steels was studied in this work. Steels containing two size distributions (10 nm or less and 10 - 100 nm) of TiC and VC carbides are subjected to tensile tests in-situ in an electrochemical hydrogen charging environment. Hydrogen is found to be trapped in interstitial matrix sites on the precipitate/matrix interface with activation energies of 14 - 20 kJ/mol and inside misfit dislocation cores with energies of 27 - 37 kJ/mol. All steels are embrittled by 15 to 20%, except the TiC steel with semi-coherent carbides up to 100 nm, which is embrittled by 37%. This is caused by accelerated intergranular fracture as a result of hydrogen trapped in dislocation pile-ups around grain boundary precipitates. The steel with coherent VC nano-carbides retained the highest strength and ductility during in-situ testing. This is therefore the optimal carbide configuration for use in hydrogen environments.

Structure-Function Analysis of Streptomyces griseolus CYP105A1 in the Metabolism of Nonsteroidal Anti-inflammatory Drugs.

Streptomyces griseolus CYP105A1 exhibits monooxygenase activity to a wide variety of structurally different substrates with regio- and stereospecificity, making its application range broad. Our previous studies have shown that CYP105A1 wild type and its variants metabolize 12 types of nonsteroidal anti-inflammatory drugs (NSAIDs). In particular, the R84A variant exhibited a high activity against many NSAIDs. We successfully crystallized complexes of wild-type CYP105A1 (WT) and the R84A variant with diclofenac (DIF) or flufenamic acid (FLF). In the WT, the carboxyl group of DIF formed a charged hydrogen bond with Arg84. In contrast, in R84A, the carboxyl group formed two bidentate charged hydrogen bonds with Arg73. The C4' atom of the benzene ring of DIF, which undergoes hydroxylation by WT and R84A, was positioned approximately 4 Å from the heme iron. Binding of FLF was nearly the same in both WT and R84A. The carboxyl group of FLF formed charged hydrogen bonds with Arg73. In both WT and R84A, FLF appeared to be fixed by this charged hydrogen bonding with Arg73 during the reaction, and the C4' atom, which undergoes hydroxylation, must face the heme iron. Thus, the dihedral angles of the two N-C bonds connecting the two benzene rings of FLF needed to rotate by 78° and -71°, respectively. The temperature factors of the F-G loop, helix F, and helix G of R84A were remarkably higher than those of WT. This suggests that these regions in R84A are much more flexible compared to those of WT, which may consequently affect substrate binding and product release.

Effects of hydrogen on microstructure evolution and mechanical properties of TB8 titanium alloy.

The influence of varying hydrogen content on the microstructure, mechanical properties, and fracture behavior of the metastable β titanium alloy TB8 after hydrogen charging has been investigated in this study. Several characterization methods, including optical microscopy (OM), x-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), were employed to comprehensively analyze the alloy. The results show that with the addition of hydrogen, hydrogen mainly accumulated at grain boundaries in the form of hydrides. The β phase diffraction peak shifted to a lower angle, which can be attribute to hydrogen-induced lattice distortion. As the hydrogen content increases, γ-TiH hydrides and ε-TiH2 hydrides were observed. Ultimate tensile strength of the alloy firstly increased from 982 MPa to 1636 MPa, and then decreased to 1432 MPa. Uniform elongation decreased from 33% to 19%. Fracture mode transitioned from ductile to brittle with increasing hydrogen. In summary, we hope the outcome of this work could provide important insights toward the hydrogen charging influences the microstructure, mechanical properties, and fracture behavior of the TB8 titanium alloy.

Theoretical study of excited state dynamics of a ratiometric fluorescent probe for detection of SO2 derivatives

Sulfur dioxide (SO2), a toxic air pollutant, can have harmful effects on human health when inhaled or when it forms bisulfite in the body. In the present work, a ratiometric fluorescent probe, 2-(2'-hydroxyphenyl)benzothiazole-3-ethyl-1,1,2-trimethyl-1H-benzo[e]indolium (HBT-EMBI), was selected to study the mechanism of SO2 derivatives detection. This study provides insights into the attributions of ratiometric fluorescence through hydrogen bond dynamics, electronic excitation properties, radiation rates, and excited state intramolecular proton transfer (ESIPT) processes using the density functional theory (DFT) and the time-dependent density functional theory (TDDFT) level. The results confirm that the large Stokes shifts and broad emission spectra of the HBT-EMBI probe are associated with its intramolecular charge transfer (ICT) characteristics and hydrogen bonding-driven ESIPT processes, respectively. After the addition reaction between the probe and HSO3-/SO32-, the conformational populations of HBT-EMBI-HSO3- transfer abnormally from enol configurations to more stable keto configurations, which leads to a distinguished change in the visible color and the ratiometric fluorescence signal, and is not due to the blockage of the ICT process of HBT-EMBI-HSO3-, as previously reported. This work provides a new perspective on the mechanism of detection of SO2 derivatives by ESIPT fluorescent probes.

The impact of encapsulation in cyclodextrin nanocavities on the participation of hydrogen bond assisted intramolecular charge transfer in fluorescence emission

The impact of encapsulation in cyclodextrin nanocavities on the participation of hydrogen bond assisted intramolecular charge transfer in fluorescence emission

Fracture Toughness Assessment of Pipeline Steels Under Hydrogen Exposure for Blended Gas Applications

Hydrogen embrittlement (HE) is a critical concern for pipeline steels, particularly as the energy sector explores the feasibility of blending hydrogen with natural gas to reduce carbon emissions. Various mechanical testing methods assess HE, with fracture toughness testing offering a quantitative measure of defect impacts on structural safety, particularly for cracks arising during manufacturing, fabrication, or in-service conditions. This study focuses on assessing the fracture toughness of two pipeline steels from an existing natural gas network under varying hydrogen concentrations using double cantilever beam (DCB) fracture tests. A vintage API X52 steel with a ferritic–pearlitic microstructure and a modern API X65 steel with polygonal ferrite and elongated pearlite colonies were selected to represent old and new pipeline materials. Electrochemical hydrogen charging was employed to simulate hydrogen exposure, with the charging parameters derived from hydrogen permeation tests. The results highlight the differing impacts of hydrogen on the fracture toughness and crack growth in vintage and modern pipeline steels. These findings are essential for ensuring the safety and integrity of pipelines carrying hydrogen–natural gas blends.

A Review Article on Aquasome

Aquasomes are an innovative class of nanoparticulate carrier systems with significant potential in drug delivery. These three-layered, self-assembled structures consist of a solid-phase nanocrystalline core coated with an oligomeric film, onto which bioactive molecules are adsorbed. The unique water-like properties of aquasomes protect and preserve delicate biological molecules, ensuring conformational integrity and high surface exposure. This characteristic makes them particularly effective in delivering proteins, peptides, genes, and vaccines to specific locations within the body. The core materials, such as calcium phosphate, nanocrystalline carbon ceramics, and tin oxide, support the stability and bioactivity of the loaded drugs. Aquasomes are assembled through non-covalent and ionic bonding, and their structural stability is maintained by interactions among charged groups, hydrogen bonding, and van der Waals forces. These nanoparticles offer a promising delivery solution for drugs facing challenges like chemical instability, low absorption, and significant side effects. Applications of aquasomes in protein and peptide delivery, gene therapy, vaccine delivery, and cancer therapy have demonstrated their versatility and efficiency. Despite their potential, challenges such as controlled drug release and specific targeting need further exploration. Overall, aquasomes represent a fusion of principles from food chemistry, biophysics, and microbiology, offering a robust platform for the targeted and effective delivery of various bioactive molecules.

Effect of Hydrogen on Tensile Properties and Fracture Behavior of Two High-Strength American Petroleum Institute Linepipe Steels

This study explored the influence of hydrogen on the tensile properties and fracture behavior of high-strength API X70 and X80 linepipe steels with bainitic microstructures under varying hydrogen charging conditions. The X70 steel exhibited a ferritic microstructure with some pearlite, while the X80 steel showed a bainitic microstructure and fine pearlite due to the addition of molybdenum. Slow strain rate tests (SSRTs) were conducted using both electrochemical ex situ and in situ hydrogen charging methods subjected to different current densities. The SSRT results showed that in situ hydrogen-charged SSRT, performed at current densities above 1 A/m2, led to more pronounced hydrogen embrittlement compared to ex situ hydrogen-charged SSRT. This occurred because hydrogen was continuously supplied during deformation, exceeding the critical concentration even in the center regions, leading to quasi-cleavage fractures marked by localized cleavage and tearing ridges. Thermal desorption analysis (TDA) confirmed that a greater amount of hydrogen was trapped at dislocations during in situ hydrogen-charged SSRT, intensifying hydrogen embrittlement, even with a shorter hydrogen charging duration. These findings highlight the importance of selecting appropriate hydrogen charging methods and understanding the hydrogen embrittlement behavior of linepipe steels.

Imaging Dihydrogen Bond-Driven Assembly of Borazine on Au(111).

Dihydrogen bonding (DHB) is a peculiar type of attractive interaction occurring between a partially positively charged hydrogen atom and a partially negatively charged hydrogen atom. Borazine represents a prototypical molecule exhibiting dihydrogen bonding in both gas phase, as well as in its crystalline form. For borazine assemblies on solid surfaces, a direct observation and characterization of dihydrogen bonding has remained elusive, possibly due to an intricate interplay of substrate-molecule and intermolecular interactions. Here we present evidence of dihydrogen bonding occurring in borazine assemblies on a Au(111) surface. By means of low-temperature scanning tunneling microscopy, we unveiled distinct configurations, exhibiting single and double dihydrogen bonding. Density functional theory calculations elucidate the interplay between substrate adsorption and intermolecular interactions to stabilize the formation of borazine dimers on Au(111). The dimers constitute the building blocks for the formation of larger assemblies.

Impact of Hydrogen Charging Techniques on Hydrogen Embrittlement Behavior of S960MC AHS Steel

Abstract The study explores the influence of hydrogen embrittlement on advanced high-strength steel S960MC, focusing on the role of different hydrogen charging techniques. Hydrogen embrittlement poses a critical challenge in high-strength steels, compromising their structural integrity and limiting their applications in demanding environments. The findings indicate that S960MC steel demonstrates intrinsic resistance to hydrogen embrittlement when exposed to a hydrogen-supersaturated environment without external factors like electric current or elevated temperature. However, cathodic hydrogen charging significantly enhances hydrogen diffusion into the material, leading up to a 60% decrease in ultimate tensile strength. In contrast, immersion hydrogen charging showed a minimal effect on the mechanical properties. Fractographic analysis showed that cathodic charging led to severe embrittlement, characterized by mixed transcrystalline quasi-cleavage, intercrystalline fractures, and extensive secondary cracking. Conversely, immersion charging resulted in negligible embrittlement, with minimal changes in fracture morphology. These results highlight the critical role of hydrogen charging methods in the embrittlement behavior of S960MC steel, emphasizing the substantial impact of cathodic charging on material degradation.

A three-level model for integration of smart homes, electric vehicle charging stations and hydrogen fuelling stations in reconfigurable microgrids considering vehicle-to-infrastructure (V2I) technology

A three-level model for integration of smart homes, electric vehicle charging stations and hydrogen fuelling stations in reconfigurable microgrids considering vehicle-to-infrastructure (V2I) technology