Twin Plates Research Articles

Improvement of Vortex Shedding Control and Drag Reduction on a Square Cylinder using Twin Plates

Improvement of Vortex Shedding Control and Drag Reduction on a Square Cylinder using Twin Plates

Експериментальні дослідження величини прогину пластини для корекції лійкоподібної деформації грудної клітки під впливом згинаючого навантаження

One of the leading methods of reconstruction of the funnel-shaped deformity of the chest is nonresection thoracoplasty, or Nuss surgery. For its implementation, implanted systems consisting of one or two corrective plates are used. The technique is minimally invasive, does not require large incisions and resection of ribs. But there are complications related to the insufficient strength of bone tissue, which according to the literature is defined in a very wide range. Purpose - to determine the dependence of the amount of deflection of single and double plates for the correction of sternum deformity on the amount of bending load; to develop a method of determining the corrective load that the plate exerts on bone structures during correction. Materials and methods. Experimental studies of plates for correction of sternum deformities were performed. We used 6 plates. In the first part of the experiment, each plate was tested separately. In the second part, the plates were connected in pairs, and each pair was tested for bending. In total, 3 pairs of plates were tested. The bending force was gradually increased from 0 N in increments of 50 N. At each step, the deflection of the plate was recorded. Results. The results of experimental studies of single plates showed that the deviation of deflection values did not differ statistically significantly (p>0.05) from the calculated values over the entire range of bending loads. The studies of the twin plates for the correction of sternum deformities also did not reveal statistically significant (p>0.05) differences in the deflection values of the samples obtained in the experiment from the calculated values. The results of the study made it possible to develop a methodology for calculating the force with which the plate acts on the sternum when correcting its deformation. Conclusions. A methodology has been developed for determining the force with which the plate acts on the sternum when correcting a deformation of a certain magnitude. It is confirmed that the calculated data on the deflection of the plate under the influence of bending load and the data obtained in the experiment do not differ statistically significantly. The data obtained can be useful for selecting the size of the corrective plate, the method of its attachment to the ribs, as well as for modeling the options for applying plates to correct various sternum deformities. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the institution mentioned in the paper. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Vortex Control Using Plate Type Floor Splitter in Pump Intake

Pump sump design is very crucial in ensuring a minimum requirement for its operation. Improper pump sump design will influence the development of vortices and swirls that can adversely affect the pump efficiency which subsequently could damage the pump. This can be mitigated by installing an anti-vortex device (AVD) beneath the intake pipe in the pump sump. The AVD works by suppressing the development of vortices and swirls in the flow of water into the intake pipe. ANSI/HI 9.8-2012 standard has outlined various AVD shapes and concepts that can be used. This experimental study was conducted to determine the appropriate parameters and configurations of twin plate floor splitter (TPFS) to suppress the development of vortex in the intake pipe. Geometries and other outlines in experiments were based on the guidelines by ANSI/HI 9.8-2012. The AVD model variations used were models with no floor splitter, single plate floor splitter (SPFS), and TPFS with 25 mm, 45 mm and 65 mm gap variations. The results showed that the distance between the two sides of twin plate affects the number of vortex generation and the swirl angle reduction. The number of vortices increased with the distance between the plates but with lower localized vortex intensity. However, the TPFS models that were used produced a swirl angle of less than 5° with the 25 mm variation producing the lowest swirl angle of 2.41°. The use of TPFS shows significantly improved performance in swirl angle reduction and vortex suppression as compared to no AVD case.

Selection behavior of {10−12} tensile twin variants and its contribution during plastic processing of magnesium alloy

{10−12} tensile twins are successfully prefabricated in the magnesium alloy sheet by bending and straightening. The relationship between twin morphologies and twin variants is established and the effects of the Schmidt factor, geometric compatibility parameter, and local strain field on the twin variant selection are comprehensively explored. The results show that the twin plates in the parallel relationship in the same matrix grains belong to the same variant usually with a high Schmidt factor, while the twin plates that orientate at a certain angle are the parasite variants usually corresponding to low Schmidt factor with respect to the applied stress. Whether the selection behavior of twin variants conforms to Schmidt's law is determined by the local strain field at the position of the twins rather than the matrix grains. The degree of strain compatibility between twins will change the result of the twin variants selection caused by the strain field. Compared to the local strain field, the geometric compatibility parameter between transgranular twins has a greater impact on the choice of twin variants. The twins are preferentially nucleated and have a positive effect on activating the Pyramidal II<a+c> slip of the matrix grains. • A comprehensive analysis of the factors influencing the twin variants selection. • In-grain misorientation quantified local stress field. • Tensile twinning activates the pyramidal II<a+c> slip of the matrix.

Strengthening Contributions of Mechanical Twinning and Dislocations to the Flow Stress of Hadfield High-Manganese Steel: Quantitative Analysis

The flow stress of Hadfield steel is attributed to lattice friction, dynamic strain aging (DSA), mechanical twinning, and forest hardening. However, it has not been clarified yet which mechanism quantitatively contributes most to the work hardening. Here, an austenitic Hadfield steel containing 1.1 wt.% C and 12.5 wt.% Mn was studied, and tensile tests at a strain rate of 1 s−1 were performed to neglect the DSA effect. The lattice friction was estimated by the Hall–Petch relationship. Twin plates characteristics and dislocation densities were estimated quantitatively by TEM and XRD, at 11, 18, 25, 38, and 55% strain levels. A linear approach was utilized to model the flow stress. At 11 and 18% strain, the role of mechanical twinning dominated the work hardening by contributions to the flow stress with 195 and 261.6 MPa higher than the forest hardening contributions which recorded 135.5 and 250.2 MPa, respectively. With the strain level increase, the thicknesses of the twinned plates were increased from 30 to 125 nm at 11 and 55% strain, respectively, resulting in a reduced contribution by the mechanical twinning while a rising effect of dislocations was noticed at large strain levels (38 and 55%) recording contributions of forest hardening to the flow stress with 437.2 and 544 MPa higher than the mechanical twinning contributions which likewise recorded 416.7 and 500.5 MPa, respectively.

Effects of increasing the strain rate on mechanical twinning and dynamic strain aging in Fe-12.5Mn-1.1C and Fe–24Mn-0.45C–2Al austenitic steels

Understanding the relationship between mechanical twinning and dynamic strain aging (DSA) in austenitic steels is necessary for steel development. DSA can be manipulated by changing the strain rate during tension tests, or by alloying austenitic steels with aluminum. In the current study, 12.5%Mn-1.1%C austenitic steel and 24%Mn-0.45%C–2%Al austenitic steel were investigated under different strain rates. Increases in the strain rate resulted in an enhanced resistance of the steels to the plastic deformation only during early stages of strain (at 3% strain) because of mechanical twinning promotion. On one hand, at 25% strain under low strain rate deformation, the Al-alloyed steel showed a tendency to form more twin plates than the Al-free steel as indicated by the transmission electron microscopy. On the other hand, at 25% strain under a high strain rate deformation, the Al-free steel showed an enhanced twin plates propagation due to a stronger self-segregation/depletion of the interstitial atoms (the carbon concentration ranged between 0 and 11 at.%) as revealed by the 3D atom probe tomography. Furthermore, the Al-alloyed steel showed a reduced twin volume fraction with a strain rate increase due to shifting of the stacking fault energy to higher values.

Design of thin micro-architectured panels with extension–bending coupling effects using topology optimization

We design the micro-architecture of thin elastic panels to control their macroscopic behavior, accounting simultaneously for in-plane stiffness, out-of-plane stiffness and the extension–bending coupling effects. Our topology optimization method combines inverse homogenization, the Hadamard shape derivative and a level set method in the diffuse interface context to systematically capture within the unit cell the optimal micro-architecture. The efficiency of the solution method is illustrated through four numerical examples where the designed shape yields an important extension–bending coupling. The deformation responses under tensile loading are assessed numerically both on the complete periodic panel and on its homogenized twin plate. The results demonstrate that the simultaneous control of the in-plane, out-of-plane and their coupled behavior enables to shift a flat panel into a dome or a saddle shaped structure. Moreover, the obtained unit cells are elementary blocks to create directly 3D printable objects with shape-morphing capabilities.

Stresses &amp; Strains in Plate Girder with Different Bracing Systems under Combination of Loadings

Abstract: Lateral buckling is one of the most important factors in the design of steel plate girder. This buckling in the girder can be controlled by many methods. The most popular method is to add the intermediate bracing systems along the length of girder. The unsafely designed intermediate bracing systems can easily lead to serious consequences in the construction stage due to lateral buckling by torsion which happens rapidly and suddenly when the internal force in girder exceeds the ultimate value. Reversely, if the intermediate bracing systems are designed excessively, their specific stiffness will be larger than the required one then it is very costly in both material and installing process In the present study different types of torsional bracing systems are used in twin plate girder of span 8m. As the behavior of plate girders with different type of bracing system changes differently along the length and depth. Changing the layout of bracing systems could also make the design easy and more economical. Keywords: Cross-frame Bracings, Horizontal Bracings, Plate Girder, Finite Element Analysis

Spinodal decomposition and martensitic transformation of the high manganese Mn‒xCu alloys fabricated by additive manufacturing

Mn‒Cu-based shape memory alloys have great potential owing to their excellent shape memory properties, high damping capacity, low production cost, and ease of fabrication. In this study, a selective laser melting (SLM) technique was used to design and manufacture a series of high-manganese Mn‒xCu (x=10–40 wt.%) alloys by blending the elemental powders. Spinodal decomposition and martensitic transformation of the alloys during SLM and heat treatment (HT) processes were investigated and correlated with the tensile, damping, and shape memory properties of the alloys. The results showed that γ‒(Mn, Cu) was the main constituent phase in all of samples subjected to SLM only (hereafter as-SLMed) and the SLMed + HTed Mn‒Cu alloys. The effect of the chemical composition and manufacturing process on the phase structural evolution of the Mn‒Cu alloys were monitored. The spinodal decomposition, martensitic transformation and α-Mn precipitation reactions occurred in the as-SLMed Mn‒xCu samples with x = 15–20 wt.%, x < 30 wt.%, and x < 15 wt.%, respectively. The tensile properties of the as-SLMed Mn‒xCu alloys followed a general downward trend with increasing Mn content, while the corresponding damping capacity and shape memory recovery strain showed the opposite trend. HT can promote spinodal decomposition and martensitic transformation to form an equiaxed γ‒(Mn, Cu) grain, parallel twin plate structure, tweed microstructure, and α-Mn precipitate in the alloys. The SLMed + HTed Mn‒30% Cu alloy displayed a better combination of tensile properties (764, 540 MPa, and 12.5%), damping capacity (tan δ = 0.072 at a strain amplitude of 900 × 10−6), and one-way and two-way (εsme = 1.6% and εtw = 0.7% under the pre-bending strain of 10%) shape memory properties. In addition, the performance of the as-SLMed Mn‒xCu (x = 15–20 wt.%) and SLMed + HTed Mn‒xCu (x = 30 wt.%) alloys is comparable with and even superior to those of multi-component and commercial Mn‒Cu-based alloys, respectively.

Globotriaosylceramide-related biomarkers of fabry disease identified in plasma by high-performance thin-layer chromatography - densitometry- mass spectrometry

Identification of 19 molecular species of globotriaosylceramides (Gb3) in extracts from a Fabry's plasma patient and a healthy control was performed by High-Performance Thin-Layer Chromatography (HPTLC)-densitometry and online coupling to Mass Spectrometry (MS).Separation was carried out on LiChrospher plates using Automated Multiple Development (AMD). Densitometry was performed on twin plates by combining detection in the visible at 550 nm, through previous on-plate orcinol derivatization, and by Ultraviolet 190 nm, using a non-impregnated plate. The latter was directly coupled to an ion-trap mass spectrometer through an automated elution-based interface.Gb3 molecular species, which were identified by HPTLC- Electrospray Mass Spectrometry (+)-MS and confirmed by MS/MS or HPTLC-Atmospheric Pressure Chemical Ionization Mass Spectrometry (+)-MS, are: five isoforms of saturated Gb3; seven isoforms of methylated Gb3; and seven species with two additional double bonds. Twelve of these species were previously reported as biomarkers of Fabry's lysosomal disorder using a Liquid Chromatography-MS-based method, and the other seven are structurally similar, closely related to them.Saturated Gb3 isoforms migrated on LiChrospher plate in one of the separated peaks corresponding to the migration zone of ceramide trihexosides standard. Instead, methylated and unsaturated Gb3 species co-migrated with sphingomyelin species.Ion intensity ESI-MS profiles show that saturated Gb3 species in Fabry's plasma were in higher concentration than in control sample.Before applying the Thin-Layer Chromatography (TLC)-MS interface on HPTLC separated peaks, its positioning precision was first studied using ceramide tri-hexosides as model compound. This provided information on Gb3 peak broadening and splitting during its migration.

Finite strain phase-field microelasticity theory for modeling microstructural evolution

Implementing the phase-field model at finite strains is usually considered unattainable through the spectral method, largely because of the nonlinearity in the transformation-induced microelasticity. Here we present a phase-field microelasticity (PFM) theory at finite strains with a representation in the reference configuration, allowing the spectral method to be readily incorporated. Following the spirit of Khachaturyan’s PFM theory at small strains, the elastic energy is formulated as a functional of microstructure (order parameters) solely, which should automatically satisfy the mechanical equilibrium. Thermodynamic consistency of the current theory under multiplicative decomposition of the total deformation gradient (into elastic and inelastic parts) and in conjunction with hyperelasticity and the time-dependent Ginzburg-Landau equation is shown rigorously. The new theory is first applied to the classical Eshelby’s inclusion problem, where shear-dilation coupling due to geometric nonlinearity is shown and a convergence study between small strain and finite strain theories is also carried out. The effects of geometric nonlinearity on the co-evolution of micromechanics and microstructure is further studied through modeling the growth of {101¯2}〈1¯011〉 deformation twins in magnesium. The simulation results suggest significant differences in terms of the shape of and the stress field around the deformation twin. In particular, the current finite strain PFM theory predicts a deviation of the twin boundary plane from the theoretical K1 plane, which is not captured in the small strain theory nor in the crystallographic theory. A parametric study further reveals that the observed deviation is caused by the tip effect of the finite-sized twin plate when the aspect ratio is relatively small. The symmetry of the stress field distribution around the twin tip is also found to be drastically different between the small strain and finite strain based phase-field modeling. The sharp twin tip observed in experiments is also shown to be likely related to the anisotropy in twin/matrix interface mobility.

Formation mechanism of nanoscale transformation twinning in ultra-low-carbon high-strength pipeline steels

Nanoscale transformation twins (NSTTs) were observed in high-strength pipeline steels of three different grades (X80–X100) having carbon content of 0.038–0.065 wt%. The microstructure and formation of the NSTTs were characterized by field emission transmission electron microscopy. The results showed that the NSTTs were generated in two body-centered cubic microstructures—polygonal ferrite and martensite—in the martensite–austenite (MA) islands. The NSTTs were nucleated at the grain boundaries (GBs) between polygonal ferrite and bainite or triple junctions of MA islands through the emission of Shockley partial dislocation from GBs during the austenite transformation to ferrite and bainite, and extended into the interior of the ferrite grains and MA islands. The NSTTs were typical {112} -type twins. Most NSTTs displayed groups of twins. The thickness of twin plates in the groups of twins was less than 10 nm.

Evolution of Fracture Mode in Nano-twinned Fe-1.1C-12.5Mn Steel

The evolution of fracture mode was investigated in Fe-1.1C-12.5Mn steel with prior introduced nano-twinned structures. The thicknesses of the prior twin plates were manipulated by thermo-mechanical treatments. During the plastic deformation, thin prior twin plates (30–40 nm) were penetrated by dislocations which activated secondary twin systems, and therefore dimple features were promoted in the fractured surfaces due to dislocation accommodation within the nano-twin plates. However, dislocation pile-up on the boundaries of the thick prior twin plates (90 nm) led to trans-granular fracture and formation of cracks. Moreover, prior twin elimination enhanced inter-granular feature appearance in the fractured surfaces because of dislocation accumulation on grain boundaries.

Nucleation of twins and dislocations in V-Ti alloys under various straining conditions

The features of plasticity nucleation in V-4Ti and V-16Ti crystallites under uniaxial tension and bilateral compression are studied. It is shown that the nucleation of plasticity in crystallites is associated with the formation of twins under uniaxial tension. During the development of plasticity, a screw dislocation cell structure is formed between twin plates. The strain and stress at which plasticity nucleates in the material decreases with increasing Ti concentration. It was found that the distribution pattern of Ti atoms in the initial structure has a significant effect on the elastic limit of the simulated crystallites. The plastic deformation of crystallites with 16% Ti under bilateral compression is realized only by the dislocation mechanism. This behavior of the material is due to the low value of the stress at the elastic limit, which is insufficient for the formation of twins.

Structural and Morphological Features of TiNi-Based Powder Manufactured by the Method of Hybrid-Calcium Reduction

An investigation of the structural features and surface morphology of a PV-N55T45 TiNi-based powder manufactured by the method of hybrid-calcium reduction is performed. The TiNi intermetallic compound is found in a two-phase state – B2 and В19′, and the following secondary phases are revealed: Ti2Ni, Ti4Ni2(О, N, С), TiNi3, and Ti3Ni4. It is observed that TiNi-based powder has dual – compact and spongy – morphology. The compact powder particles consist of oval coarse grains of TiNi separated by a massive Ti2Ni interlayer. In the spongy particles, in contrast to the compact ones, the TiNi-phase prevails in the form of a single conglomerate of fine grains measuring 10–20 μm. In the Ni-enriched regions of the TiNi matrix the B19′-martensite is observed in multiple structural-morphological variants. In the compact particles the martensite structure represents orthogonal twin plates having different orientations within one grain. In the spongy particles, there is a different type of the martensite structure with multiple crystals of the B19′-martensite with the pyramidal lath morphology. On the surface of certain particles there is terraced relief formed due to bulk diffusion of atoms, surface diffusion of adatoms, and their interaction with the substrate defects.

Validity and reliability of the WIMU inertial device for the assessment of the vertical jump.

The aim of this study was to test the validity and reliability of the inertial device WIMU (Realtrack Systems SL, Almería, Spain) for the assessment of the vertical jump, counter movement jump (CMJ) and squat jump (SJ). Fifteen soccer players were evaluated in two identical sessions separated by one week. In each session, participants performed three jumps of each type. The flight time was quantified by the inertial device WIMU and by a force platform (Twin Plates; Globus Sport and Health Technologies LLC, Codogné, Italy) at the same time. For the analysis of reliability of the flight time of the CMJ and the SJ, the intraclass correlation coefficient was used. The calculation of the concurrent validity was performed by using the Pearson correlation coefficient (r). This analysis was complemented with the realization of the Bland–Altman plots. For the analysis of reliability, the coefficient of variation and the standard error of the means were calculated. The analysis presented a high validity and reliability of the device. The results show the inertial device WIMU (Realtrack Systems SL, Almería, Spain) as a useful tool for measuring the jump capacity of the athletes, presenting immediate results in real time, on any type of surface and in a simple way since it does not need cables.

Volatiles Mediated Interactions Between Aspergillus oryzae Strains Modulate Morphological Transition and Exometabolomes.

Notwithstanding its mitosporic nature, an improbable morpho-transformation state i. e., sclerotial development (SD), is vaguely known in Aspergillus oryzae. Nevertheless an intriguing phenomenon governing mold's development and stress response, the effects of exogenous factors engendering SD, especially the volatile organic compounds (VOCs) mediated interactions (VMI) pervasive in microbial niches have largely remained unexplored. Herein, we examined the effects of intra-species VMI on SD in A. oryzae RIB 40, followed by comprehensive analyses of associated growth rates, pH alterations, biochemical phenotypes, and exometabolomes. We cultivated A. oryzae RIB 40 (S1VMI: KACC 44967) opposite a non-SD partner strain, A. oryzae (S2: KCCM 60345), conditioning VMI in a specially designed “twin plate assembly.” Notably, SD in S1VMI was delayed relative to its non-conditioned control (S1) cultivated without partner strain (S2) in twin plate. Selectively evaluating A. oryzae RIB 40 (S1VMI vs. S1) for altered phenotypes concomitant to SD, we observed a marked disparity for corresponding growth rates (S1VMI < S1)7days, media pH (S1VMI > S1)7days, and biochemical characteristics viz., protease (S1VMI > S1)7days, amylase (S1VMI > nS1)3–7days, and antioxidants (S1VMI > S1)7days levels. The partial least squares—discriminant analysis (PLS-DA) of gas chromatography—time of flight—mass spectrometry (GC-TOF-MS) datasets for primary metabolites exhibited a clustered pattern (PLS1, 22.04%; PLS2, 11.36%), with 7 days incubated S1VMI extracts showed higher abundance of amino acids, sugars, and sugar alcohols with lower organic acids and fatty acids levels, relative to S1. Intriguingly, the higher amino acid and sugar alcohol levels were positively correlated with antioxidant activity, likely impeding SD in S1VMI. Further, the PLS-DA (PLS1, 18.11%; PLS2, 15.02%) based on liquid chromatography—mass spectrometry (LC-MS) datasets exhibited a notable disparity for post-SD (9–11 days) sample extracts with higher oxylipins and 13-desoxypaxilline levels in S1VMI relative to S1, intertwining Aspergillus morphogenesis and secondary metabolism. The analysis of VOCs for the 7 days incubated samples displayed considerably higher accumulation of C-8 compounds in the headspace of twin-plate experimental sets (S1VMI:S2) compared to those in non-conditioned controls (S1 and S2—without respective partner strains), potentially triggering altered morpho-transformation and concurring biochemical as well as metabolic states in molds.

Microstructural evolution of AZ31 magnesium alloy subjected to sliding friction treatment

Microstructural evolution and grain refinement mechanism in AZ31 magnesium alloy subjected to sliding friction treatment were investigated by means of transmission electron microscopy. The process of grain refinement was found to involve the following stages: (I) coarse grains were divided into fine twin plates through mechanical twinning; then the twin plates were transformed to lamellae with the accumulation of residual dislocations at the twin boundaries; (II) the lamellae were separated into subgrains with increasing grain boundary misorientation and evolution of high angle boundaries into random boundaries by continuous dynamic recrystallisation (cDRX); (III) the formation of nanograins. The mechanisms for the final stage, the formation of nanograins, can be classified into three types: (i) cDRX; (ii) discontinuous dynamic recrystallisation (dDRX); (iii) a combined mechanism of prior shear-band and subsequent dDRX. Stored strain energy plays an important role in determining deformation mechanisms during plastic deformation.

Intraspecies Volatile Interactions Affect Growth Rates and Exometabolomes in Aspergillus oryzae KCCM 60345.

Volatile organic compounds (VOCs) are increasingly been recognized as the chemical mediators of mold interactions, shaping their community dynamics, growth, and metabolism. Herein, we selectively examined the time-correlated (0 D-11 D, where D = incubation days) effects of intraspecies VOC-mediated interactions (VMI) on Aspergillus oryzae KCCM 60345 (S1), following co-cultivation with partner strain A. oryzae KACC 44967 (S2), in a specially designed twin plate assembly. The comparative evaluation of S1VMI (S1 subjected to VMI with S2) and its control (S1Con) showed a notable disparity in their radial growth (S1VMI < S1Con) at 5 D, protease activity (S1VMI > S1Con) at 3-5 D, amylase activity (S1VMI < S1Con) at 3-5 D, and antioxidant levels (S1VMI > S1Con) at 3 D. Furthermore, we observed a distinct clustering pattern for gas chromatography-time of flight-mass spectrometry datasets from 5 D extracts of S1VMI and S1Con in principle component analysis (PC1: 30.85%; PC2: 10.31%) and partial least squares discriminant analysis (PLS-DA) (PLS1: 30.77; PLS2: 10.15%). Overall, 43 significantly discriminant metabolites were determined for engendering the metabolic variance based on the PLS-DA model (VIP > 0.7, p < 0.05). In general, a marked disparity in the relative abundance of amino acids (S1VMI > S1Con) at 5 D, organic acids (S1VMI > S1Con) at 5 D, and kojic acid (S1VMI < S1Con) at 5-7 D were observed. Examining the headspace VOCs shared between S1 and S2 in the twin plate for 5 D incubated samples, we observed the relatively higher abundance of C-8 VOCs (1-octen-3-ol, (5Z)-octa-1,5-dien-3-ol, 3-octanone, 1-octen-3-ol acetate) having known semiochemical functions. The present study potentially illuminates the effects of VMI on commercially important A. oryzae's growth and biochemical phenotypes with subtle details of altered metabolomes.

Improving hydrogen embrittlement resistance of Hadfield steel by thermo-mechanical flash-treatment

Nano-twins microstructures were introduced in a high carbon manganese steel by a novel flash thermo-mechanical treatment in order to achieve high resistance to hydrogen embrittlement. Nano-twinned grains decreased hydrogen diffusivity through the bulk material, although it absorbed more hydrogen than the twins-free specimens. Moreover, it was shown that after electrochemical hydrogen charging, the nano-twins microstructures can reduce dislocations glide during plastic deformation, resulting in forming of fine twin plates.