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Herein, poly(2,3-benzopyrrole)/zinc oxide nanoflower (PBZNF) was synthesized and its optimised amount was blended in the polymeric epoxy resin to get superlative coating for carbon steel displaying ultrahigh hydrophobicity and excellent corrosion retardation. The composite and formulated coatings characterised using relevant structural techniques. EC (epoxy coating), ZNF/EC, and 0.05 g, 0.10 g and 0.15 g PBZNF blended EC for carrying out EIS study where in 0.10PBZNF/EC coating over carbon steel reflected highest hydrophobicity (139.1°) and Rct = 3.01 × 109 Ω cm2 in 3.5% NaCl solution after 42 days with 93.91% found as its protectivity and inducing scratches, EIS of 0.10PBZNF/EC demonstrated 1.17 × 109 Ω cm2 after 48 h. [ABSTRACT FROM AUTHOR]

Equimolar reactions of Zn2+ and Cd2+acetates with the carbothiohydrazide, [2‐HO‐C6H4‐C(H) = N‐N(H)‐C(=S)‐N(C2H4)2O] chelating agent (H2L) have produced the binuclear [M(L)]2 metal chelates. The isolated compounds have been evaluated by elemental analyses, XRD, molar conductivities, 1H and 13C‐NMR, FTIR, FAB‐MS, UV–Vis, and thermal analyses. The crystal structure of the chelating agent has been resolved and indicates the presence of the chelating agent exclusively in its E conformer regarding the C(H) = N bond. Elemental analyses and molar conductance data indicated that the investigated metal chelates are nonelectrolytes and were formed with 2 M:2 L stoichiometry. FT‐IR along 1H‐NMR spectral data gave evidence for a di‐anionic chelating agent that bonded with central metal ions via azomethine N, deprotonated phenolic O, and thiolate S atoms. The anti‐corrosion performance of the chelating agent and its metal chelates have been evaluated for protecting carbon steel (CS) in 15% HCl aqueous solution using electrochemical examination (EIS and PDP), surface examination (SEM and XPS) and theoretical approach (DFT calculations and MC simulation). The results revealed that [Zn(L)]2 complexes remarkably performed with an inhibition efficiency of about 94.7%, which was better than those for [Cd(L)]2 complex (93.0%) and H2L (88.2%), respectively. The EIS results revealed the gradual rise of charge transfer resistance (Rct) with concentration, while the PDP proved the mixed‐type inhibition performance with cathodic advantage consistent with the Langmuir adsorption model. It was verified that the Zn (II) complex could adsorb on the metallic surface, forming a protective layer responsible for mitigating the corrosion reaction and ions diffusion. This study provided novel inhibitors with structures designed and developed for inhibiting the corrosion process with marked performance. The results derived from various methodologies contribute to a substantiated interpretation of the mechanism of inhibition. [ABSTRACT FROM AUTHOR]

The development of an accurate and meticulously designed simulation model for heat distribution during welding has helped maintain the popularity of welding as a reliable approach for attaching components. A simulated heat source involves uneven heating, resulting in uneven deformation and stress. An ANSYS simulation is used to analyze the stress in a welded flat plate. The simulation models are created using SOLIDWORKS software. The model employs the temperature-dependent characteristics of alloy steel to function as a thermal model that evaluates stress and the distribution of heat within the structure. This study offers a comprehensive examination of welded joints through the utilization of THERMO-MECHANICAL Finite Element Analysis (FEA) tools, specifically ANSYS. The study focuses especially on the analysis of single U and unsymmetrical double U welding connections. The study examined the heat distribution, thermal loads, and impacts on fixtures associated with welding, specifically focusing on the design of the welding joint. The results indicate that the heat from welding caused a maximum deformation of 0.55 mm for the single U joint and 0.54 mm for the double U welding joints. Both joint configurations displayed significant thermal stress at a distance of 5 mm from the center of the weld. According to the ANSYS models, the heat-affected zone (HAZ) has a length of 45.4 mm for a single U joint and 53.6 mm for an unsymmetrical double U joint. The second aspect of this investigation involves assessing the comparative durability or thermal strains of various depositions in the previously mentioned joint. Moreover, it is essential to assess the expected heat distortion and stress when examining prospective welding materials for on-site use. This will enhance the implementation of the material. [ABSTRACT FROM AUTHOR]

Nanostructured duplex stainless steel (DSS) was prepared using mechanical alloying (MA) and spark plasma sintering (SPS). The ball milling was performed under nitrogen atmosphere. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to identify the phases and carry out morphological investigations, respectively. XRD spectra revealed that ferrite phase formation dominated during the initial stages and austenite phase emerged after several hours of ball milling. Lattice parameter calculations showed a decrease in lattice parameter up to 5 h and later increased at 10 h of milling. A decrease in crystallite size was observed up to 10 h of milling. SPS was performed in vacuum at an optimized temp. of 1000 °C for a fixed holding time of 10 min, heating rate of 100 °C/min, cooling rate of 200 °C/min and under an applied pressure of 50 MPa. The electrochemical performance of DSS alloys was examined using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results showed that alloy Fe-18Cr-3Mn-1Mo-1Si-0, 22N-5Ni (wt.%), has the highest corrosion resistance among the designed alloys. [ABSTRACT FROM AUTHOR]

Additive friction stir deposition (AFSD) is a solid-state metal additive manufacturing technique, which utilizes frictional heating and plastic deformation to create large deposits and parts. Much like its cousin processes, friction stir welding and friction stir processing, AFSD has seen the most compatibility and use with lower-temperature metals, such as aluminum; however, there is growing interest in higher-temperature materials, such as titanium and steel alloys. In this work, we explore the deposition of an ultrahigh-temperature refractory material, specifically, a tantalum–tungsten (TaW) alloy. The solid-state nature of AFSD means refractory process temperatures are significantly lower than those for melt-based additive manufacturing techniques; however, they still pose difficult challenges, especially in regards to AFSD tooling. In this study, we perform initial deposition trials of TaW using twin-rod-style AFSD with a high-temperature tungsten–rhenium-based tool. Many challenges arise because of the high temperatures of the process and high mechanical demand on AFSD machine hardware to process the strong refractory alloy. Despite these challenges, successful deposits of the material were produced and characterized. Mechanical testing of the deposited material shows improved yield strength over that of the annealed reference material, and this strengthening is mostly attributed to the refined recrystallized microstructure typical of AFSD. These findings highlight the opportunities and challenges associated with ultrahigh-temperature AFSD, as well as provide some of the first published insights into twin-rod-style AFSD process behaviors. [ABSTRACT FROM AUTHOR]

The materials used in concentrating solar power (CSP) systems are becoming of interest because of the high energy efficiency of energy storage. Molten salts can be used as both heat-storage media and heat-transfer fluid in a CSP system. In molten salts, steel alloys used in vessels and pipelines are highly vulnerable to hot corrosion. To protect steel alloys, applying a coating is an excellent strategy to extend the life of the alloy. NiCrAl coatings are well-suited for high-temperature environments. The purpose of this study was to investigate the corrosion behavior of NiCrAl with Si addition coatings on AISI304 in molten salt. NiCrAl coatings with and without Si addition were deposited using the high-velocity oxygen fuel (HVOF) technique. The corrosion test was performed using an immersion test in modified solar salt with 0.5% NaCl at 400–600 °C. Gravimetric methods evaluate the weight change for immersion tests. At 400 °C, an increased amount of weight gain due to the oxidation reaction and molten salt infiltration was observed. At 600 °C, the corrosion reaction was more dominant, and apparent oxidation was decreased; however, oxidation products NiO and sodium aluminum silicate were detected. Si addition supports the formation of the protective oxide sodium aluminum silicate, which inhibits molten salt oxidation reaction and molten salt infiltration. [ABSTRACT FROM AUTHOR]

High manganese steel (HMS), widely utilized in railway transportation, often encounters the compounded challenge of high stress impact and corrosion, ultimately leading to environmentally assisted cracking. To comprehend this phenomenon, we delved into the stress corrosion cracking (SCC) behavior and mechanism of HMS in a SO2-polluted marine environment, employing both slow strain rate test (SSRT) and constant load U-bend test (CLUT). By comparing the SCC behavior in three distinct test solutions: 0.01 M NaHSO3, 0.01 M NaHSO3 with 1 wt% NaCl, and 0.01 M NaHSO3 with 3.5 wt% NaCl, we discerned the varied influence of Cl− and SO2 on SCC. Analyzing the stress–strain curves from SSRT and the cross-sectional crack morphologies from CLUT provided insights into the SCC susceptibility of HMS in these solutions. Notably, the SCC susceptibility in 0.01 M NaHSO3 exceeded 40%, while in the solution containing 3.5 wt% NaCl, it significantly surpassed 65%. Further examination, including an analysis of the rust layer's elemental distribution and phase composition, electrochemical testing of the rust layer, and an assessment of corrosion morphologies on the base metal, revealed the relative contributions of various corrosive media to SCC. This comprehensive study not only sheds light on potential SCC mechanisms but also offers valuable insights for evaluating the service life of HMS and identifying areas for performance optimization of this critical high manganese steel alloy. [ABSTRACT FROM AUTHOR]

This paper is aimed to study the corrosion resistance of Cr10Mo1 alloy corrosion-resistant steel (CR) in the seawater–sea sand concrete pore solution (SWSSCPS), compared with low-carbon steel (LC) and stainless steel (SS). X-ray photoelectron spectroscopy (XPS), SEM, atomic force microscope, and Mott–Schottky curve tests are applied to obtain information on the composition, structure, and morphology of the corrosion-resistant (CR) passive film. Finally, the difference between CR passive film and the other two kinds of steels under chloride attack is investigated, and the apparent morphology, microstructure, and chemical composition of the CR passive film during the attack are analyzed. With the exposure time increased, the passive film and interfacial integrity of CR are approximately equivalent to that of SS in terms of phase angle in the midband and low-frequency band modulus, indicating the anticorrosion performance of CR has a much better effect than that of LC and close to that of SS. The results reveal that the FeO in the passive film outer layer and a high amount of Cr2O3/Cr(OH)3 in the inner layer prevent CR from further corrosion by chloride ions. [ABSTRACT FROM AUTHOR]

AISI 5140 steel is an alloy frequently used in the manufacturing and automotive industries. This steel alloy is shaped using different manufacturing methods and cooling is required during this process. This research study included the milling of AISI 5140 steel utilizing various cutting settings and cooling/lubrication procedures. For this purpose, two cutting speeds (75–100 m/min), two feed rates (0.075–0.100 mm/rev), and four cooling media (dry, MQL, flood, nanofluid) were used. Then, 5% Mo nanoparticles were added to the nanofluid cutting fluid. Machinability and power consumption analyses were carried out using the input parameters selected in light of the manufacturer's recommendations and studies in the literature. The effects of sustainable cutting fluids and their parameters on machinability and power consumption were investigated through experiments. This study concluded that the use of nanofluid led to improvements in surface roughness, flank wear, and power consumption characteristics. It was determined that the flood environment is the most effective in reducing the cutting temperature. As a result, it is predicted that nanofluid cutting fluids can be used during machining. [ABSTRACT FROM AUTHOR]

This article aims to investigate aging temperature effects on the wear and corrosion characteristics of stainless steel alloy Custom 450. Electrochemical measurements were performed in 1 M H2SO4 solution. Pin-on-disk tests and microstructural evaluations were also done. The results displayed that the steel hardness increased when the aging temperature was raised to 500 °C. However, higher temperatures resulted in a hardness reduction of about 11% compared with annealed specimens. Such observation was due to the increase in the reversed austenite content by up to 10.7%. The aged specimen's wear rate was reduced by about 85% when the aging temperature was 500 °C, based on the high hardness. The suggested wear mechanism changed from abrasive and cutting wear mode to the adhesive wear mechanism when the aging temperature increased. Tafel polarization tests showed that corrosion rates of specimens decreased by about 99% when the aging temperature increased to 600 °C. This was attributed to increasing the amount of the reversed austenite phase, and Ni-rich precipitates in the aged martensite matrix. [ABSTRACT FROM AUTHOR]

The machining of austenitic stainless steel alloys is usually characterized by high levels of adhesion and built-up edge; therefore, improving tribological conditions is fundamental to obtaining higher tool life and better surface finish. In this work, three different Al0.6Ti0.4N coatings are compared, two deposited by Cathodic Arc Evaporation (CAE) and one with High-Power Impulse Magnetron Sputtering (HiPIMS). The effects of the micromechanical properties and the microstructure of the coatings were then studied and related to the machining performance. Both arc-deposited coatings (CAE 1 and 2) exhibited similar average tool life, 127 min and 128 min, respectively. Whereas the HiPIMS lasted for only 21.2 min, the HiPIMS-coated tool had a much shorter tool life (more than six times lower than both CAE coatings) due to the intense adhesion that occurred in the early stages of the tool life. This higher adhesion ultimately caused built-up edge and chipping of the tool. This was confirmed by the cutting forces and more deformation on the shear band and undersurface of the chips, which are related to higher levels of friction. The higher adhesion could be attributed to the columnar structure of the HiPIMS and the (111) main texture, which presents a higher surface energy when compared to the dominant (200) from both arc depositions. Studies focused on tribology are necessary to further understand this relationship. In terms of micromechanical properties, tools with the highest plasticity index performed better (CAE 2 = 0.544, CAE 1 = 0.532, and HiPIMS = 0.459). For interrupted cutting machining where adhesion is the main wear mechanism, a reserve of plasticity is beneficial to dissipate the energy generated during friction, even if this was related to lower hardness levels (CAE 2 = 26.6 GPa, CAE 1 = 29.9 GPa, and HiPIMS = 33.6 GPa), as the main wear mechanism was adhesive and not abrasive. [ABSTRACT FROM AUTHOR]

The goal of this research is to fabricate a novel type of highly active porous electrode material, based on stainless steel and dedicated to water electrolyzers. The main novelty of the presented work is the innovative application of the molten salts treatment, which allows the design of a highly developed porous structure, which characterizes significantly higher catalytic activity than untreated steel substrates. The equimolar mixture of NaCl and KCl with 3.5 mol% AlF3 was used as the molten salt. The surface modification procedure includes the deposition of an Al layer with application at the potential of −1.8 V and following dissolution at −0.9 V, to create a porous alloy surface. The cathodic polarization measurements of the prepared porous stainless steel electrodes were measured in a 10 mass% KOH solution. Moreover, the amount of hydrogen generated during constant voltage electrolysis with a hydrogen sensor in situ was also measured. The porous stainless steel alloy showed higher current density at lower potentials in the cathodic polarization compared to untreated stainless steel. The cathodic polarization measurements in alkaline solution showed that the porous 304 stainless steel alloy is an excellent cathode material. [ABSTRACT FROM AUTHOR]

A Monte Carlo simulation method capable of replicating the kinetics of M23C6 precipitation in 347H stainless steels was developed for the purpose of producing synthetic microstructures that approximate its microstructural evolution under aging periods of up to 10,000 hours at temperatures between 600 °C and 750 °C. To accomplish this, experimental data from the literature was used to parameterize simulations and replicate the nucleation and growth kinetics of M23C6 particles within 347H and similar austenitic stainless steel alloys. These simulations were found to have considerable fidelity to previous efforts to study the precipitation of M23C6 in other 300 series stainless steel alloys. Synthetic 347H microstructures were then generated that accounted the effects of aging temperature, duration, dislocation density, and the presence of boron within the microstructure. These simulations predict several key trends, those being that (1) the size of M23C6 precipitates decreased with aging temperature and (2) the growth rate of M23C6 particles decreased with aging temperature. Further, while (3) the addition of dislocation density due to creep conditions resulted in increasing intragranular nucleation of M23C6 precipitates with increasing dislocation density and (4) B additions within the microstructure led to modest increases in precipitate size above 700 °C, which indicates that more complex physics are necessary to account for the presence of B. [ABSTRACT FROM AUTHOR]

The effect of Nb alloying on the suppression of austenite grain coarsening behavior during pseudo–carburizing is investigated in high–temperature–carburized SAE4320 bearing steel. To explore the role of the Nb element in the pseudo–carburizing process, the morphology, composition, size, and distribution of NbC precipitates were analyzed. The results show that the fine austenite grain observed in Nb micro–alloyed steel is caused by the pinning effect of NbC precipitates, which hinders the coarsening of austenite grains and changes the growth dynamics of austenite grains. After the SAE4320 carburized bearing steel with the addition of 0.45 wt.% Nb element is kept at 1150 °C for 4 h, the PAG size is still below 20 μm, which indicates the Nb element has obvious advantages in limiting PAG growth at high temperatures and shows great potential for the development of high–temperature carburized bearing steel. [ABSTRACT FROM AUTHOR]

In this work, an AISI 4340 high-strength steel alloy was surface machined to have four different grades of roughness (Ra). The impact of changing Ra on the corrosion of the steel alloy in 3.5% NaCl solutions after 40 min and 24 h was performed using various electrochemical techniques. The cyclic polarization experiments showed that an increase in Ra increases the steel corrosion via enhancing the corrosion current of the alloy. The electrochemical impedance plots also indicated that an increase in Ra reduces the corrosion resistance of the alloy by decreasing the diameter of the semicircle obtained by the Nyquist spectra. The change in potentiostatic current vs time measurements, which were obtained at −350 mV (Ag/AgCl), confirmed that pitting attack occurs and its intensity further increases with increasing Ra for all steel samples. An increase in immersion time also reduces the resistance to corrosion due to the iron dissolution from the surface of the steel alloy. After corrosion, the surface was analyzed using a scanning electron microscope and energy dispersive spectroscopy investigations. [ABSTRACT FROM AUTHOR]

In situ X-ray diffraction (XRD) was used to compare nitrogen low-energy ion implantation (LEII) into austenitic stainless steel 316Ti and super austenitic stainless steel 904L. While the diffusion and layer growth were very similar, as derived from the decreasing intensity of the substrate reflection, strong variations in the observed lattice expansion—as a function of orientation, the steel alloy, and nitriding temperature—were observed. Nevertheless, a similar resulting nitrogen content was measured using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Furthermore, for some conditions, the formation of a double layer with two distinct lattice expansions was observed, especially for steel 904L. Regarding the stability of expanded austenite, 316Ti had already decayed in CrN during nitriding at 500 °C, while no such effect was observed for 904L. Thus, the alloy composition has a strong influence only on the lattice expansion and the stability of expanded austenite—but not the diffusion and nitrogen content. [ABSTRACT FROM AUTHOR]

The present study evaluates the ratcheting response of notched cylindrical samples made of 1045 steel alloy subjected to asymmetric loading cycles using the kinematic hardening framework, coupled with Neuber's rule. Test samples with V-shaped and semi-circular edge notches were first heat-treated under different conditions, resulting in various material hardness values at the notch root region. Local ratcheting at the notch root of samples was found to be highly dependent on the notch shape and the heat treatment conditions. HT1 samples with a lower hardness of 12 RC at the notch region possessed higher values of ratcheting, while ratcheting at the notched region for HT2 samples with 40 RC dropped to half of that in HT1 samples. The higher hardness of 50 RC at the notch edge of HT3 samples promoted the initial yield strength and the yield surface through the kinematic hardening rule with a larger translation into the deviatoric stress space as compared with samples HT1 and HT2 with 12 and 40 RC, respectively. The local ratcheting strain in sample HT1, with semi-circular notches ( K t = 1 .65) at a stress ratio ( S m a x / S u l t ) of 0.965, remained below 1.80% during the first hundred loading cycles. The local ratcheting decreased to 1.2% for sample HT2 and further dropped to 0.9% for sample HT3. The yield surfaces were translated consistent with the magnitude and direction of the backstress increments, as the applied loading excursion exceeded the elastic limit. Through the use of the Ahmadzadeh–Varvani (A–V) hardening rule, the predicted ratcheting values at notch roots were found to be larger in magnitudes as compared with those of experimental data, while the predicted local ratcheting through the Chaboche (CH) hardening rule fell below the experimental data. Results consistently showed that as sample hardness increased, the local ratcheting at notch roots decreased. [ABSTRACT FROM AUTHOR]

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In order to meet the demand for rapid repair of roll surface, laser cladding technology was used to clad the self‑designed and prepared high vanadium semi high speed steel alloy powder on the surface of roll alloy steel. Considering the difference between the structures of forged steel roll and laser cladding layer, in order to stabilize the structure, the cladding layer was tempered with 500 ℃ and 2 h. The results show that the phase composition of the cladding layer is mainly martensite. The surface of the cladding layer is mainly fine equiaxed crystal, and the intragranular martensite is distributed in parallel in needle shape, which is decomposed into ferrite and carbide after tempering. The average hardness of the cross‑section of the cladding layer is 663. 4 HV, 1. 8 times that of the substrate. The average friction coefficient of the cladding layer is 0. 708, the wear rate is 6. 142×10-6 mm3 ·N-1 ·m-1, the wear performance is 25 times higher than that of the substrate, and the wear morphology is good, in accordance with the wear amount results. [ABSTRACT FROM AUTHOR]

Purpose: After cemented total hip arthroplasty, the risk of periprosthetic fracture (PPF) of taper-slip stems is higher than that of composite-beam stems. We aimed to assess the conditions resulting in PPFs of taper-slip stems using a falling weight. Methods: Taper-slip stems were fixed to five types of simulated bone models using bone cement, and the fractures were evaluated by dropping stainless-steel weights from a predetermined height onto the heads. The periprosthetic fracture height in 50% of the bone models (PPFH50) was calculated using the staircase method. Results: For the fixation with 0° of flexion, the values for PPFH50 were 61 ± 11, 60 ± 13, above 110, 108 ± 49, and 78 ± 12 cm for the cobalt–chromium–molybdenum alloy, stainless steel alloy (SUS), titanium alloy (Ti), smooth surface, and thick cement mantle models, respectively; for the fixation with 10° of flexion (considering flexure), the PPFH50 values were 77 ± 5, 85 ± 9, 90 ± 2, 89 ± 5, and 81 ± 11 cm, respectively. The fracture rates of the polished-surface stems were 78.6 and 35.7% at the proximal and distal sites, respectively (p < 0.05); the fracture rates of the smooth-surface stems were 14.2 and 100%, respectively (p < 0.05). Conclusion: The impact tests demonstrated that the conditions that were less likely to cause PPFs were use of Ti, a smooth surface, a thick cement mantle, and probably, use of SUS. [ABSTRACT FROM AUTHOR]

This study evaluated the gamma and neutron-shielding parameters, electron and charge particles' interaction properties of three different stainless steel-based alloys (2507SS, 304SS and AISI1018) with densities of 7.82, 7.81 and 7.82, respectively for deployment in nuclear reactor construction. Gamma shielding parameters were evaluated with Phy-X/PSD, Py-MLBUF and GRASP computer programs within the energy range of 0.2 MeV to 15 MeV. The relative deviations (RD %) between two of these computational platforms were calculated. Fast Neutrons Effective Removal Cross-Sections (FNRCS) and Macroscopic Removal cross-section (MRCS) values for fast neutrons were calculated with Phy-X/PSD and MRCS software, while thermal/fast neutron attenuation factors were calculated with NGCals software. The continuous-slowing-down approximation (CSDA) range and total stopping power (TSP) values of H+ and He++ ions were estimated with SRIM Monte Carlo code in a wide energy range of 1–20 MeV. The projectile range of electrons was computed with ESTAR NIST software within the kinetic energy of 0.01–1000 MeV. Gamma-ray, thermal neutron and fast neutron transmission factors (TFs) values were calculated for all samples for a range of well-known energies. From the obtained results, all evaluated parameters were dependent on the composition of shielding materials, the type of radiation and the photon energy of the radiation. The maximum MAC values obtained from the three alloy samples are 0.1505 cm2/g for 2507SS, 0.1453 cm2/g for 304SS and 0.1459 cm2/g for AISI1018 at 0.02 MeV. These results projected 2507SS as a better shielding alloy when compared with other investigated alloy samples. Considering the closeness of densities of investigated alloy samples the shielding and interaction properties of all alloy samples gave excellent and similar results implying that all investigated alloys will effectively serve as a radiation-shielding material in a nuclear reactor. [ABSTRACT FROM AUTHOR]

Low‐carbon martensitic steel is the key material of automobile lightweight. Unfortunately, the strategies for increasing the material strength, such as processing to create line defects (dislocations), tend to decrease the ductility. Herein, a strategy to circumvent this problem in an inexpensive, microalloy low‐carbon (0.32%) martensitic steel by regulating the accelerated cooling stop temperature after hot rolling is developed. Steel with fine austenite grains embedded in a highly dislocated martensite matrix is developed by cold rolling followed by saltwater quenching and low‐temperature tempering. This deformed process produces dislocation hardening, but retains high ductility both through the glide of intensive mobile dislocations. The proposed strategy provides a pathway for the development of high‐strength, high‐ductility materials. [ABSTRACT FROM AUTHOR]

The document is a contents list for the Journal of Analytical Atomic Spectrometry. It includes the ISSN, cover image, and inside cover image for the current issue. The contents list also provides information on various articles and papers featured in the journal, covering topics such as atomic spectrometry updates, in situ online detection of atmospheric particulate matter, high-sensitivity analysis of trace elements in water, and other related subjects. The journal aims to connect the world with the chemical sciences and is published by The Royal Society of Chemistry. [Extracted from the article]

Femtosecond laser-ablation spark-induced breakdown spectroscopy (fs-LA-SIBS) and out-of-bag random forest regression (OOB-RFR) were developed for accurate quantitative analysis of the elements manganese (Mn), chromium (Cr), and nickel (Ni) in steel alloys. A femtosecond laser operating at 1 kHZ was used as the laser ablation source and a spark discharge unit was utilized to enhance the peak intensity of atomic emission. The characteristic lines of Mn, Cr, and Ni elements in steel alloys were determined using the NIST database. The two hyperparameters ntree and mtry of RFR were optimized through OOB error, and the OOB-RFR model was obtained. In the experiment, the predictive performance of OOB-RFR, support vector machine (SVM) regression, and partial least squares regression (PLS) on steel alloy spectral data was compared and analyzed. The results indicate that the OOB-RFR model exhibits lower computational iterations and higher performance than other models in regression prediction of Mn, Cr, and Ni elements. In the OOB-RFR model, the root mean square error (RMSE), the average relative error (MRE) and the coefficient of determination (R2) of Mn, Cr, and Ni elements in the training samples were 0.0051, 0.0018 and 0.9976, respectively, and the RMSE, MRE and R2 of the three elements in testing samples were 0.0018, 0.0009 and 0.9369, respectively. Therefore, the combination of the fs-LA-SIBS technique and OOB-RFR has great potential in the rapid determination of elements in steel and even in the metallurgical field. [ABSTRACT FROM AUTHOR]

In order to promote the understanding of bainitic transformation in nitrogen alloyed steels, the microstructure, transformation kinetics, and diffusion/precipitation characteristics of an isothermally heat-treated carbon-free system Fe–5Cr–N were investigated. Quenching dilatometry was used to perform heat treatments at temperatures between 400 °C and 500 °C and simultaneously receive information about the transformation kinetics. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) investigations indicate a plate- to lenticular-like, fully ferritic microstructure with nanometer scale CrN. In order to analyze the diffusion and precipitation behavior of nitrogen, atom probe tomography measurements were performed. On the one hand, nitrogen segregation was found, and on the other hand, the presence of CrN precipitates and preliminary stages of CrN nitrides were validated. [ABSTRACT FROM AUTHOR]

Hydrogen embrittlement (HE) continues to be a limiting factor in implementing high strength steel alloys in applications such as fasteners. In this work, 9260 bar steel was heat treated to produce quench and tempered (Q&T) martensite and quench and partitioned (Q&P) microstructures at hardness levels between 52 and 54 HRC. The Q&P microstructures consisted of lath martensite, retained austenite, martensite-austenite (M/A) constituents, and intercritical ferrite in some conditions. The Q&P process promoted higher strength and uniform elongation than the Q&T martensite, though also exhibited a relatively low degree of post-uniform elongation except in the lowest quench temperature condition. Slow strain rate tensile and circular notch tensile tests were performed on all conditions after electrochemical hydrogen charging at hydrogen levels of 1–1.5 ppm. The Q&T condition exhibited a better slow strain rate performance and notch tensile strength after hydrogen pre-charging than the Q&P conditions. In the Q&P conditions subjected to slow strain rate tensile tests, a higher HE susceptibility is correlated with higher quench temperatures, which had lower austenite stability and more fresh, non-tempered martensite in the initial microstructure. However, the HE susceptibility was comparable for all of the Q&P conditions in the notch tensile tests. [ABSTRACT FROM AUTHOR]

Variations in the microstructure and the dominant fretting wear mechanisms of carbon steel alloy in oscillatory sliding contact against stainless steel in a dry atmosphere were evaluated by various mechanical testing and microanalytical methods. These included scanning electron microscopy and energy dispersive spectrometry with corresponding elemental maps of the wear tracks, in conjunction with cross-sectional transmission electron microscopy of samples prepared by focused ion beam machining to assess subsurface and through-thickness changes in microstructure, all as a function of applied load and sliding time. Heavily dislocated layered microstructures were observed below the wear tracks to vary with both the load and sliding time. During the accumulation of fretting cycles, the subsurface microstructure evolved into stable dislocation cells with cell walls aligned parallel to the surface and the sliding direction. The thickness of the damaged subsurface region increased with the load, consistent with the depth distribution of the maximum shear stress. The primary surface oxide evolved as Fe2O3 and Fe3O4 with increasing sliding time, leading to the formation of a uniform oxide scale at the sliding surface. It is possible that the development of the dislocation cell structure in the subsurface also enhanced oxidation by pipe diffusion along dislocation cores. The results of this study reveal complex phase changes affecting the wear resistance of steels undergoing fretting wear, which involve a synergy between oxidative wear, crack initiation, and crack growth along dislocation cell walls due to the high strains accumulating under high loads and/or prolonged surface sliding. [ABSTRACT FROM AUTHOR]

Periodic truss-based lattice materials, a particular subset of cellular solids that generally have superior specific properties as compared to monolithic materials, offer regularity and predictability that irregular foams do not. Significant advancements in alternative technologies—such as additive manufacturing—have allowed for the fabrication of these uniquely complex materials, thus boosting their research and development within industries and scientific communities. However, there have been limitations in the comparison of results for these materials between different studies reported in the literature due to differences in analysis approaches, parent materials, and boundary and initial conditions considered. Further hindering the comparison ability was that the literature generally only focused on one or a select few topologies. With a particular focus on the crashworthiness of lattice topologies, this paper presents a comprehensive study of the impact performance of 24 topologies under dynamic impact loading. Using steel alloy parent material (manufactured using Selective Laser Melting), a numerical study of the impact performance was conducted with 16 different impact energy–speed pairs. It was possible to observe the overarching trends in crashworthiness parameters, including plateau stress, densification strain, impact efficiency, and absorbed energy for a wide range of 3D lattice topologies at three relative densities. While there was no observed distinct division between the results of bending and stretching topologies, the presence of struts aligned in the impact direction did have a significant effect on the energy absorption efficiency of the lattice; topologies with struts aligned in that direction had lower efficiencies as compared to topologies without. [ABSTRACT FROM AUTHOR]

Changing the metallic card clothing on a carding machine is costly when the spinning mills want to card different fibers from cotton to terylene or vice versa. This article proposes a newly developed cylinder card clothing compatible with cotton and terylene fibers by Nb alloying of AISI 1090 steel so that the spinning mills can change the type of fiber without changing the card clothing. Based on an idea developed from classical carding balance theory to study the adaptability of the cylinder card clothing for cotton and terylene fibers, the wall shear stress was used as the basis for compatibility analysis of carding behavior and bearing capacity with cotton and terylene fibers and as the focus of this study. Nb alloying of AISI 1090 steel showed good wear resistance in carding areas after heat treatment with high hardness above 840 Hv0.2 and extremely fine grain grade of 13.5 class, which increased about 25% compared to conventional 80 WV. The testing results in the spinning mills, including one cotton and two terylene fibers, showed good performance with this newly developed card clothing. In conclusion, the card clothing made of Nb alloying of AISI 1090 steel can handle different fibers with acceptable carding performance. [ABSTRACT FROM AUTHOR]

One of the strict standards for alloys used in the aerospace and power plant industries is not to use remelted alloys. The appearance of undesirable particles and inclusions in the melt during recasting process generally affects the alloy's mechanical and physical properties. In this study, the heat-resistant stainless steel alloy 1.4930 (GX 14CrCoMo 1310) was melted three times by investment casting method, and at each stage of melting and casting, the samples were put through mechanical properties tests and microscopic examinations. The obtained results demonstrated that the quantity of formed inclusions significantly decreases the formability (about 50% in amount of elongation) while improving the mechanical properties (YS about 12% and UTS about 2%). The particles themselves also change and transform during each stage of melting, casting and solidification. [ABSTRACT FROM AUTHOR]

The macrostructure, microstructure and alloying element microsegregation of electroslag remelted (ESR) 7Cr13 steel with different nitrogen contents (0.043, 0.084, 0.164 pct) were studied. The maximum solubility of nitrogen in7Cr13 steel was calculated to be 0.161pct. The peritectic reaction does notoccur once the N content of the steeexceeds 0.121 pct, which leads to the coarsening of the grains of the remelted ingot. The width of the mushy zone decreases but the depth of the metal bath increases with the increase of N content from 0.043 to 0.164 pct. The reduction in the width of the mushy zone is beneficial to the reduction of the local solidification time and the refinement of the secondary dendrites. The microstructure of the ingot is composed of austenite, martensite and eutectic carbides, and irrespective of the N content of as-cast ingot. Nitrogen increases the equilibrium distribution coefficient of N, C and V elements, which is beneficial to the suppression of microsegregation of these elements during liquid steel solidification. The refinement of secondary dendrites makes the distribution of Cr element more uniform although the addition of nitrogen reduces the equilibrium distribution coefficient of Cr. [ABSTRACT FROM AUTHOR]

The influence mechanism of shielding gas composition (SG1 with 50 vol pct N2 + 50 vol pct Ar, SG2 with 70 vol pct N2 + 30 vol pct Ar, and SG3 with 90 vol pct N2 + 10 vol pct Ar, the corresponding samples were named as sample SG1, sample SG2, and sample SG3, respectively) on phase transformation and mechanical properties of high nitrogen steel (HNS) repaired by underwater laser direct metal deposition (UDMD) at an ambient pressure of 0.3 MPa was systematically elaborated. Results showed that the elevated nitrogen content in shielding gas increased the nitrogen partial pressure above the molten pool, thereby enhancing the nitrogen solubility inside the molten pool. This led to a reduction in porosity defects from sample SG1 to sample SG2 and their virtual absence in sample SG3. Meanwhile, the elevated nitrogen partial pressure facilitated nitrogen absorption process from heat source space, thereby raising the austenite transition starting temperature and increasing austenite fraction from sample SG1 to sample SG3. Some of the absorbed nitrogen atoms dissolved into the matrix, providing extra solid solution strengthening, while the remaining ones reacted with Cr to form Cr2N. Furthermore, the elevated nitrogen content in shielding gas would compromise the protective effect on the molten pool by enlarging the compressed air (drainage gas) backflow area, thereby introducing more oxygen into the molten pool, and resulting in more oxide formation. Additionally, with the increase of nitrogen with higher thermal conductivity in shielding gas, the molten pool cooling rate would be accelerated. Consequently, the refined grain and denser dislocation network were expected. Approximately, 70 vol pct of nitrogen content in shielding gas was recommended, as it effectively inhibited porosity defects and regulated the formation of intermetallic compounds (oxides and Cr2N), leading to superior mechanical properties (sample SG2). [ABSTRACT FROM AUTHOR]

This paper presents a method to predict the double-pass flow stress behavior of hot-rolled niobium (Nb) micro-alloyed steel by combining the constitutive model and back-propagation neural network (BPNN) model (the machine learning (ML) model). The constitutive model is used to predict the first-pass flow stress behavior, and the BPNN model is used to predict the second-pass flow stress behavior. The results show that the ML model can accurately predict the double-pass flow stress behavior at different temperatures and holding time. The second-pass flow stress predicted by the BPNN model is compared with those predicted by the mathematical model in the previous literature. The results show that the BPNN model can more accurately predict the second-pass flow stress than the mathematical model in the previous literature. In addition, the static softening fraction during the interval time is calculated by using the predicted double-pass flow stress curve in this paper. The results show that the precision of the static softening fraction calculated in this paper is not only higher than that of the traditional Avrami kinetic model but also higher than that of the traditional model which couples recovery, precipitation and recrystallization. Therefore, the ML model for predicting the double-pass flow stress behavior has high accuracy and provides a theoretical basis for predicting the double-pass flow stress behavior of other alloys. [ABSTRACT FROM AUTHOR]

Watchmaking manufacturers obtain their bracelet links from machining drawn metal profiles. But, today, there is another process that represents an alternative to manufacture them: metal injection molding using metal powders (MIM technology). This process is less expensive than the machining of drawn metal profiles. The aim of this study was to evaluate the corrosion behavior and the nickel cation release of two stainless steel alloys: 316L MIM and 904L MIM. The general corrosion behavior was evaluated by the rotating electrode technique; the galvanic corrosion measurements were conducted with a 316L AISI bulk coupling partner. The pitting corrosion behavior was evaluated in FeCl3 0.5 M media (according to ASTM G48-11). For comparison, a complementary study was conducted on 316L and 904L bulk alloys. The Ni cation release tests were conducted on 316L and 904L MIM and bulk samples according to EN 1811. Different electrochemical parameters were measured and calculated (open circuit potential, polarization resistance, corrosion current and Tafel slopes, coulometric analysis). Generally, if MIM steels are compared with conventional steels, their corrosion resistance behavior is inferior. In the couplings studied, the galvanic currents generated are very important. The shape of the curves also reveals the presence of localized corrosion phenomena. According to tests in ferric chloride, MIM steels were noted to have inferior behavior compared to conventional steels. MIM type 904L steels are comparable in behavior to conventional type 316L steels. The quantities of nickel released according to EN 1811 were very significant (2 mg cm−2 week−1 up to 24 mg cm−2 week−1) and did not meet the requirements of the European directive (0.5 µg cm−2 week−1). In conclusion, conventional steels studied under the same experimental conditions revealed a better behavior compared to MIM steels independently of the phenomenological parameters chosen. [ABSTRACT FROM AUTHOR]

Irradiation creep is known to be an important process for structural materials in nuclear environments, potentially leading to creep failure at temperatures where thermal creep is generally negligible. While there is a great deal of data for irradiation creep in steels and zirconium alloys in light water reactor conditions, much less is known for first wall materials under fusion energy conditions. Lacking suitable fusion neutron sources for detailed experimentation, modeling, and simulation can help bridge the dose-rate and spectral-effects gap and produce quantifiable expectations for creep deformation of first wall materials under standard fusion conditions. In this paper, we develop a comprehensive model for irradiation creep created from merging a crystal plasticity representation of the dislocation microstructure and a defect evolution simulator that accounts for the entire cluster dimensionality space. Both approaches are linked by way of a climb velocity that captures dislocation-biased defect absorption and a dislocation strengthening term that reflects the accumulation of defect clusters in the system. We carry out our study in Fe under first wall fusion reactor conditions, characterized by a fusion neutron spectrum with average recoil energies of 20 keV and a damage dose rate of ≈ 3 × 10 − 7 dpa/s at temperatures between 300 and 800 K. [ABSTRACT FROM AUTHOR]

Introduction: Among alloys of medium-carbon and high-strength steel, EN 24 steel is characterised by its nickel-chromium-molybdenum composition. EN 24 steel is highly suitable for application in heavy-duty projects due to its notable resilience to damage, especially when exposed to low temperatures. With the objective of minimising surface irregularities, this research endeavours to enhance the milling process of EN 24 steel by employing coated tungsten carbide (WC) tool inserts. Methods: Feed rate, cutting speed, depth of cut, and cutting fluid are all crucial process factors in the experimental investigation. Four distinct levels are applied to each factor. The research utilises the Design of Experiments (DOE)-based Central Composite Design of Response Surface Methodology. To predict output parameters, mathematical models are developed utilising analysis of variance (ANOVA) for optimisation purposes. Results and discussions: Through the utilisation of multi-objective optimisation, the optimal combination for tungsten carbide inserts was determined, which provided surface irregularities of 0.301 µm. Cutting speed (CS) of 149.507 m/min, feed rate (FR) of 340.27 mm/min, depth of cut (DOC) of 0.599 mm, and cutting fluid (CF) of 12.50 L/min are the optimal parameters.The surface morphologies of the machined workpiece at particular parameter values can be discerned through scanning electron microscope (SEM) analysis, yielding significant insights. The optimal parameters that have been identified provide practical recommendations for improving the milling method of EN 24 steel when tungsten carbide inserts are utilised. Understanding the milling process in its entirety is facilitated by SEM analysis of surface morphologies and microstructures under particular cutting conditions. The morphology and surface irregularities of the machined workpiece are evaluated using profilometry, which provides additional insight into surface integrity. The discourse investigates the potential applications and implications of the results, as well as suggests directions for further study concerning the enhancement of milling processes for similar steel alloys. [ABSTRACT FROM AUTHOR]

Palladium films hold signicance due to their remarkable affinity for hydrogen diffusion, rendering them valauble for the seperation and purification of hydrogen in membrane reactors. However, palladium is expensive, and its films can become brittle after only a few cycles of hydrogen separation. Alloying with silver has been shown to overcome the problem of palladium embrittlement. Palladium‐silver films have been produced via several methods but all have drawbacks, such as difficulties controlling the alloy composition. This study explores two promising jet printing methods: Inkjet and Aerosoljet. Both methods offer potential advantages such as direct patterning, which reduces waste, enables thin film production, and allows for the control of alloy composition. For the first time, palladium‐silver alloys have been produced via inkjet printing using a palladium‐silver metal organic decomposition (MOD) ink, which alloys at a temperature of 300 °C with nitrogen. Similarly, this study also demonstrates a pioneering approach for Aerosol Jet printing, showing the potential of a novel room‐temperature method, for the deposition of palladium‐silver MOD inks. This low temperature approach is considered an important development as palladium‐silver MOD inks are originally designed for deposition on heated substrates. [ABSTRACT FROM AUTHOR]