Article
Materials Science, Multidisciplinary
S. S. Shishvan, G. Csanyi, V. S. Deshpande
Summary: The susceptibility of ferritic steels to hydrogen embrittlement increases with decreasing strain rates. This is explained by the diffusion of hydrogen. However, for pre-charged specimens, lattice diffusion dominates and has no effect at such low strain rates. A model based on the Hydrogen Induced Fast-Fracture (HIFF) mechanism is presented to rationalize the strain rate dependence of hydrogen embrittlement. The dominant kinetics governing the strain rate sensitivity is the hydrogen desorption rates from cavity surfaces.
Article
Chemistry, Physical
Song Huang, Hu Hui
Summary: A practical numerical model with few parameters is proposed in this study for predicting environmental hydrogen embrittlement. The model employs a hydrogen enhanced plasticity-based mechanism in a fracture strain model to describe hydrogen embrittlement. The fracture toughness degradation of three commercial steels in a high pressure hydrogen environment is investigated, and the governing equations for hydrogen distribution and material damage evolution are established. The model parameters are determined based on experimental results, and the predicted fracture toughness reductions are compared with experimental results, showing reasonable accuracy. The proposed method aims to achieve a balance between accurate prediction and practicality for engineering applications, providing a simplified numerical tool for the design and evaluation of hydrogen storage vessels.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Mechanics
A. Zafra, G. Alvarez, J. Belzunce, J. M. Alegre, C. Rodriguez
Summary: The study used laboratory heat treatments to obtain homogeneous coarse-grain tempered bainitic/martensitic microstructures for assessing the fracture behaviour in the presence of internal hydrogen in welds. The results showed that the hydrogen embrittlement experienced by the CGHAZs of both steels was considerably greater than in the base steels.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
A. Zafra, G. Alvarez, J. Belzunce, C. Rodriguez
Summary: This study investigated the suitability of 42CrMo4 steel for high pressure hydrogen gas applications, focusing on the influence of tempering time at 600 degrees C on hydrogen embrittlement sensitivity. Results showed that the fracture toughness of hydrogenated 42CrMo4 steel increased significantly with tempering time, correlated with hydrogen trap density in the steel. The study also identified brittle fracture micromechanisms through SEM analysis and gained insights into hydrogen-steel microstructure interaction using EHP tests.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Chemistry, Physical
Joseph A. Ronevich, Eun Ju Song, Brian P. Somerday, Christopher W. San Marchi
Summary: This study measured the fracture resistance of pipeline welds from different strength grades and welding techniques in air and 21 MPa hydrogen gas. It was found that the fracture resistance of the welds decreased in hydrogen gas with increasing yield strength. Residual stress had a modest influence on fracture resistance, but further studies are needed to better understand its effects.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Materials Science, Multidisciplinary
J. Shang, J. Z. Wang, W. F. Chen, H. T. Wei, J. Y. Zheng, Z. L. Hua, L. Zhang, C. H. Gu
Summary: This study investigates the fracture toughness of X80 and GB20# pipeline steel in hydrogen and actual natural gas/hydrogen mixture, revealing different deteriorating effects on the fracture toughness of the two materials. X80 exhibited the most deterioration in fracture toughness in pure hydrogen gas, while GB20# showed the most serious degradation in the mixture. The fracture surfaces observations indicated different fracture characteristics between X80 and GB20#, with X80 evolving into brittle fracture while GB20# maintaining ductile fracture in lower pressure environments.
Article
Engineering, Mechanical
Joseane M. Giarola, Julian A. Avila, Osvaldo M. Cintho, Haroldo C. Pinto, Marcelo F. de Oliveira, Waldek W. Bose Filho
Summary: Hydrogen embrittlement affects the mechanical properties of steel. This study assessed the influence of hydrogen on the microstructure and fracture toughness of steel welded by friction-stir welding, simulating real-life conditions.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Mechanics
Renata Latypova, Oskari Seppala, Tun Tun Nyo, Timo Kauppi, Saara Mehtonen, Hannu Hanninen, Jukka Ko Komi, Sakari Pallaspuro
Summary: Suppressing hydrogen embrittlement in martensitic steels is a challenge. This study investigates the effects of prior austenite grain (PAG) shape and size on hydrogen embrittlement resistance in 0.25C steel. Anisotropic elongated PAG structure enhances resistance to hydrogen embrittlement, while larger elongated grains are prone to intergranular fracture. Reaustenitised equiaxed PAGs fail with intergranular cracking, accelerating crack propagation rate compared to quasi-cleavage. PAG boundaries mitigate susceptibility to intergranular cracking.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Chemistry, Physical
C. San Marchi, J. A. Ronevich, J. E. C. Sabisch, J. D. Sugar, D. L. Medlin, B. P. Somerday
Summary: Austenitic stainless steels are widely used in harsh environments, including high-pressure gaseous hydrogen service. The tensile ductility of these materials is sensitive to materials and environmental variables, leading to significant ductility loss when exposed to hydrogen. Internal hydrogen influences deformation characteristics, driving local damage accumulation and fracture.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Dannisa R. Chalfoun, Mariano A. Kappes, Pablo Bruzzoni, Mariano Iannuzzi
Summary: Hydrogen permeation experiments were conducted on quenched and tempered low alloy steels with varying Ni contents at different temperatures. The results showed that increasing Ni concentration decreases the permeation coefficient, apparent diffusion coefficient, and hydrogen concentration on the charging surface. Additionally, the study calculated the hydrogen binding energy and trap density, and found that they are not clearly correlated with Ni content.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Kazuki Okuno, Kenichi Takai
Summary: Factors promoting hydrogen-related intergranular fracture in tempered martensitic steel's elastic region were identified through frozen-in hydrogen distribution and tensile tests at -196°C. Results showed hydrogen embrittlement associated with intergranular fracture after precharging with hydrogen, while hydrogen embrittlement was also observed after preloading with elastic stress just before fracture strength at room temperature. The study revealed that reversibly accumulated hydrogen due to stress-induced diffusion onto prior austenite grain boundaries during stress loading at room temperature was responsible for intergranular fracture.
Article
Engineering, Mechanical
Gyo-Geun Youn, Yun-Jae Kim, Jong-Sung Kim, Poh-Sang Lam
Summary: In this paper, a finite element simulation method based on the multi-axial fracture strain model is proposed to predict the effect of hydrogen embrittlement on fracture toughness in 21-6-9 stainless steel. The method is successfully applied to test data and shows close agreement with experimental results.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Materials Science, Multidisciplinary
Ahjeong Lyu, Junghoon Lee, Jae-Hoon Nam, Minjeong Kim, Young-Kook Lee
Summary: In this study, the H absorption and H embrittlement (HE) resistance of medium (3-7 wt%) Mn martensitic steels were investigated. The 7 wt% Mn specimen had the highest diffusible H content due to the highest reversible H trap density when the specimens were electrochemically H-charged. When the diffusible H content was the same, the HE resistance deteriorated due to Mn addition, possibly caused by grain boundary decohesion and H segregation into the grain boundaries. However, this condition was improved by B addition due to enhanced grain boundary cohesion and suppression of H segregation into the grain boundaries.
Article
Materials Science, Multidisciplinary
Tuhin Das, Salim Brahimi, Jun Song, Stephen Yue
Summary: A newly proposed rapid four-point bending fracture test was used to assess the hydrogen embrittlement (HE) susceptibility of two different combinations of quench and tempered steels. The test results revealed significant differences in HE susceptibility among the materials, highlighting the influences of local plasticity and micromechanics on HE. The study also showed that essential fractographic features related to HE failure of martensitic steels remained evident despite fast loading.
Article
Materials Science, Multidisciplinary
O. Zvirko
Summary: The degradation mechanism of pearlitic steels, influenced by operating conditions such as temperature, stress, and hydrogenation, involves a decrease in brittle-fracture resistance, posing a risk to structural integrity. Special attention is given to the development of dissipated damage on the nano- and microscales. The role of hydrogenating media in steel degradation is highlighted.
Article
Mechanics
A. Zafra, G. Alvarez, J. Belzunce, J. M. Alegre, C. Rodriguez
Summary: The study used laboratory heat treatments to obtain homogeneous coarse-grain tempered bainitic/martensitic microstructures for assessing the fracture behaviour in the presence of internal hydrogen in welds. The results showed that the hydrogen embrittlement experienced by the CGHAZs of both steels was considerably greater than in the base steels.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
A. Diaz, I. I. Cuesta, C. Rodriguez, J. M. Alegre
Summary: Hydrogen assisted fracture near welds is the result of a combination of microstructural changes and the accumulation of hydrogen. The simulation results show that there is a higher hydrostatic peak and lattice hydrogen increase for the HAZ-centred crack. A two-type trapping process is also simulated to reproduce the effect of dislocation trapping and micro-structure delayed diffusion.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2021)
Article
Mechanics
G. Alvarez, A. Zafra, F. J. Belzunce, C. Rodriguez
Summary: The influence of hydrogen on the mechanical properties of three structural steels was evaluated using Small Punch Tests. Two pre-charging methods were applied to introduce hydrogen in the samples. The results showed that hydrogen embrittlement grows with the strength of the analysed steel, and embrittlement indexes obtained with Small Punch Tests are lower than those obtained with standard tests.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Mechanical
A. Zafra, G. Alvarez, J. Belzunce, C. Rodriguez
Summary: This study investigated the suitability of 42CrMo4 steel for high pressure hydrogen gas applications, focusing on the influence of tempering time at 600 degrees C on hydrogen embrittlement sensitivity. Results showed that the fracture toughness of hydrogenated 42CrMo4 steel increased significantly with tempering time, correlated with hydrogen trap density in the steel. The study also identified brittle fracture micromechanisms through SEM analysis and gained insights into hydrogen-steel microstructure interaction using EHP tests.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Chemistry, Physical
V. Arniella, A. Zafra, J. Belzunce, C. Rodriguez
Summary: This study focuses on the mechanical behavior of steels in hydrogen-rich environments. Tensile tests were conducted to compare the performance of 42CrMo4 steels under different hydrogen charging conditions, revealing a significant impact on strength and deformation behavior, mainly transitioning from ductile to brittle behavior.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
Guillermo Alvarez, Alfredo Zafra, Francisco Javier Belzunce, Cristina Rodriguez
Summary: This study analyzed the effect of internal hydrogen on the fatigue crack growth rate in the coarse grain region of a welded joint. It was found that internal hydrogen caused embrittlement and increased the fatigue crack growth rate, especially at low frequencies and high load ratios.
Article
Materials Science, Ceramics
Cristina Rodriguez, Covadonga Quintana, Javier Belzunce, Carmen Baudin
Summary: This study analyzes the validity of the standard SPT test for characterizing the strength of advanced ceramics. It establishes a relationship between effective volume and Weibull parameters and proposes an empirical equation for calculating the effective volume of SPT specimens of different thicknesses.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Mechanics
L. B. Peral, A. Diaz, V Arniella, J. Belzunce, J. Alegre, I. I. Cuesta
Summary: The influence of internal hydrogen on the mechanical behavior of 42CrMo4 steel grade was evaluated through internal pressure fracture tests on hydrogen precharged notched cylindrical specimens. The results showed that hydrogen damage increased with testing time, resulting in decreased burst pressure and Notch Mouth Opening Displacement. The susceptibility of hydrogen embrittlement was also discussed.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Mechanics
Luis Borja Peral, Ines Fernandez-Pariente, Chiara Colombo
Summary: This study investigates the decohesion mechanism of CrMo steel in the presence of hydrogen. Experimental tests and numerical simulations are conducted to identify the critical hydrogen concentration that induces crack tip propagation.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Engineering, Mechanical
J. M. Alegre, A. Diaz, R. Garcia, L. B. Peral, I. I. Cuesta
Summary: This paper studies the effect of a non-conventional HIP-cycle on the fatigue behavior of a Ti-6Al-4V alloy manufactured by Selective Laser Melting (SLM). The results show that the present HIP-process allows for good material densification, minimal microstructural coarsening effects, and comparable fatigue properties to the conventional wrought processed material.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Chemistry, Multidisciplinary
I. I. Cuesta, A. Diaz, M. A. Rojo, L. B. Peral, J. Martinez, J. M. Alegre
Summary: Additive manufacturing of metallic materials is widely used in various sectors. In order to ensure reliable performance of parts, it is necessary to study the effect of additive manufacturing on mechanical properties. This paper focuses on the application of Selective Laser Melting technology in the automotive industry and aims to optimize key parameters in the printing process to obtain parts with good resistance.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Analytical
L. B. Peral, P. Ebrahimzadeh, A. Gutierrez, I. Fernandez-Pariente
Summary: The effect of tempering temperature on the corrosion behavior of low carbon steel (F1272) was investigated using electrochemical tests. The results showed that the corrosion resistance of the steel increased with increasing tempering temperature. Additionally, severe shot peening treatment was applied to the sample with the best corrosion behavior, resulting in a decrease in corrosion resistance.
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
(2023)
Article
Engineering, Mechanical
G. Alvarez, V. Arniella, F. J. Belzunce, C. Rodriguez
Summary: The susceptibility to hydrogen embrittlement of quenched and tempered 42CrMo steel was investigated using Small Punch Tests (SPT) with different punch displacement rates. Hydrogen was introduced cathodically using an electrolyte containing 1 M H2SO4 with 0.25 g/l As2O3, and two different cathodic current densities (0.50 and 1.00 mA/ cm2). Various embrittlement indices were used to analyze the results, including energy consumed at maximum load, equivalent biaxial deformation at the failure location, and failed diameter. The results showed that all embrittlement indices increased with decreasing punch displacement rate (resulting in longer hydrogen diffusion time) and increasing cathodic current density (leading to higher hydrogen concentration in the hydrogenated medium). Furthermore, pre-charging the sample before the in-situ hydrogen charged test had no effect on the results, as most hydrogen entered the sample through high plastic deformation induced during the mechanical test.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2023)
Article
Engineering, Manufacturing
G. Alvarez, Z. Harris, K. Wada, C. Rodriguez, E. Martinez-Paneda
Summary: This article evaluates the influence of post-build processing on the hydrogen embrittlement behavior of additively manufactured (AM) 316L stainless steel. The results show that AM 316L exhibits lower ductility at room temperature, but comparable ductility to conventionally manufactured (CM) 316L at -50 degrees C. After hydrogen charging, the ductility of AM 316L is similar to or even better than CM 316L. Feritscope measurements indicate that this improved performance is related to the reduced propensity for AM 316L to form strain-induced martensite.
ADDITIVE MANUFACTURING
(2023)
Meeting Abstract
Surgery
C. Quintana Barcia, C. Rodriguez Gonzalez, C. Betegon Biempica, G. Alvarez Diaz, A. Maestro
BRITISH JOURNAL OF SURGERY
(2021)
