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EU's Carbon Border Adjustment Mechanism (CBAM) has been promulgated. The steel industry is included in CBAM, which will undoubtedly affect the export trade of China's steel manufacturers to the EU. It is necessary to analyse the impact of CBAM on China's steel industry quantitatively. By establishing a system dynamics model that can simulate the operation mechanism of the steel supply chain in China, we have clarified the impacts of CBAM on the China's steel export and carbon reduction. Moreover, we have reasonably set up scenarios that represent the possible decarbonisation paths of China's steel industry and evaluated the implementation effect of each policy in these scenarios. The analysis shows that CBAM will lead to a decrease of 32% in export volume and a loss of 58% in export profits for China's steel exporters. The environmental benefits of CBAM are limited. Due to the low trade exposure, CBAM is unable to promote a large-scale carbon reduction in the China's steel industry. Although CBAM will bring great pressure to steel exporters, a comprehensive policy of adopting more emission reduction measures can greatly improve the carbon reduction efficiency, effectively reduce the negative impact of CBAM, and maintain the stability of steel exports. [ABSTRACT FROM AUTHOR]

AbstractThe objective of this research work was to assess Teucrium luteum subsp. flavovirens essential oil (EOTL), for the first time, as novel and eco-friendly corrosion inhibitor for carbon steel (CS) in 1.0 M HCl medium. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and surface analysis were employed to assess the effectiveness of the EOTL. The findings indicate that the EOTL reduces the corrosion of CS in hydrochloric acid and offered an inhibition efficiency (IE) of 91% at a dosage of 2.00 g/L at 298 K. The PDP data showed that EOTL behaved as a mixed-type corrosion inhibitor. The effect of immersion time and temperature on the corrosion inhibition performance of EOTL was also studied. It was found that the IE increased only up to 24 h and decreased with prolonged immersion time. In addition, the IE diminished with increasing temperature. The EOTL molecules adsorbed on the CS surface following Langmuir adsorption isotherm, with an adsorption energy ranging from −16 to −27 kJ/mol, an indication of physico-chemical adsorption mechanisms. The SEM/EDX results provide evidence of the presence of a protective film of the inhibitor on the surface of the CS. Theoretical studies using DFT, Monte Carlo simulations, molecular dynamics simulations and mean square displacement were conducted to given insight into the contributions of the four main components of EOTL. This work not only introduces a sustainable alternative to conventional corrosion inhibitors but also provides a robust understanding of the underlying mechanisms, hence contributing to advancement in corrosion science. [ABSTRACT FROM AUTHOR]

The effect of temperature on the corrosion resistance performance of the passivation film (PF) formed at 20 °C to 60 °C was investigated systematically in Cl− ion or/and SO42− ion solution. It is found that the temperature accelerates the growth rate of PF and increases the thickness of PF. In addition, the critical chloride ion concentration of PF at 20 °C to 40 °C, and that of PF at 50 °C and 60 °C, which is increased by 15.8%. In the single SO42−, all the PF were not depassivated with the increased concentration of SO42−. However, at the presence of Cl−, the PF were depassivated once the concentration of SO42− reaches 0.18 mol/L. These results show that in a single ion environment, the corrosion resistance of PF increased with the passivation temperature, while the impact of temperature on the corrosion resistance of PF is negligible in the combine solution of 3.5 wt% Cl− and SO42− ions. [ABSTRACT FROM AUTHOR]

A biocompatible Zr54Al17Co29 bulk metallic glass (BMG) becomes a potential candidate for medical device materials due to its excellent properties; however, the effort to investigate the material performance in medical devices has never been attempted. Surgical blades were developed from Zr54Al17Co29 BMG composition using different sizes of plates to address the microstructural variation. Their cutting abilities were investigated using a designed indentation-cutting rig for sharpness tests and compared to commercial carbon steel (CS) blades. While the fully amorphous structure was confirmed in a 2 mm BMG, the presence of nanocrystal phases was implied in the 3 mm BMG. The BMG blades showed extremely higher cutting-edge quality compared to the commercial ones. In addition, the sharpness improvement was shown in 2- and 3-mm BMG blades with the blade sharpness index (BSI) of 0.29 and 0.34 compared to commercial blade BSI of 0.37. The BMG blades also showed good durability indicated by the higher edge resistance from deformation. These phenomena were determined by the absence of grain boundary and dislocation of BMG thus performing a higher elastic strain than the crystalline material to avoid plastic deformation on the extremely small cross-sectional area of the cutting edge during substrate incision. [ABSTRACT FROM AUTHOR]

Erosion corrosion is a common problem that affects boiler tubes, particularly those in power plants and industrial settings where hard water and abrasive particles are present in the flow. These particles can cause physical erosion to the surface of the tubes, which can then lead to further corrosion. This type of corrosion is often accelerated by the high temperatures and pressures present in a boiler system, as well as the presence of oxygen. The combination of physical erosion and chemical corrosion attack can cause significant damage to the tubes, reducing their ability to efficiently transfer heat and potentially leading to system failure. Therefore, it is important to predict rates of erosion to prevent costly and potentially dangerous failures. The focus of this paper is an investigation into the effects of erosion caused by hard water particles on a carbon steel boiler tube elbow (ANSI 16.9). A semi-empirical procedure, which considers properties of the material and flow parameters, is developed for predicting erosion rates. The study revealed that the primary erosion damage occurred on the extrados of the bend. The findings indicated that particles within the flow began to separate from the front wall surface, resulting in significant erosion along the lateral sides. The disappearance of erosion from the front surface of the bend was also consistent with the erosion patterns observed on the eroded pipe sample, which was extracted from the line. Moreover, it was demonstrated the presence of two different erosion patterns in the separation region, which matched qualitatively the erosion pattern observed on the sample wall. [ABSTRACT FROM AUTHOR]

The study introduces an enhanced concentric spiral-coil EMAT to tackle low signal-to-noise ratio (SNR) in high-temperature carbon steel forging defect detection. With a non-overlapping concentric coil design, simulations and experiments were conducted, utilizing a finite element model with circuit-field coupling to optimize parameters. Results show the improved EMAT enhances SNR by up to 20.96 dB compared to traditional designs. High-temperature tests demonstrate its capability to detect Ф5 mm holes at 650℃, with SNR increasing by 11.24 dB as temperature rises from 100℃ to 500℃, validating the optimization method’s effectiveness. [ABSTRACT FROM AUTHOR]

Current global 3D metal printing research is focused on powder bed fusion and direct energy deposition. Several materials are presently under research to assess their post-additive manufacturing properties, and to process them in industries using advanced manufacturing techniques. This study investigates the electrochemical, mechanical, and metallurgical properties of wire arc additively manufactured (WAAM) ER70S-6 alloy walls on AISI S235 plates, emphasizing ship component fabrication. The corrosion resistance of both materials is assessed through Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization testing in a 3.5% NaCl solution. Surface and cross-sectional morphologies are analyzed using optical microscopy and scanning electron microscopy, while energy dispersive spectroscopy is employed to study the chemical composition of the corrosion products. Moreover, the hardness of the WAAM-deposited ER70S6 wall is found to be highest in the uppermost layers of deposition due to the presence of acicular ferrite and ferritic-bainite microstructure. Tensile and Charpy impact strength for AISI S235 and WAAM-deposited ER70S-6 exhibit similar performance at room and low temperatures. Interestingly, the WAAM sample demonstrates a 60% higher elongation than the AISI S235 sample. Hence, the findings from this experimental work suggest that WAAM-deposited carbon steel exhibits favourable corrosion resistance and comparable mechanical properties to AISI S235. Consequently, WAAM is emerging as a promising alternative to conventional manufacturing techniques for fabricating ship components, repairing and modifying hull structures, manufacturing nozzles, propeller blades, fin-like structures, structural components, and more. [ABSTRACT FROM AUTHOR]

The main objective of the Steam Cracker is to produce monomers prone to polymerization. The drawback is that polymerization can occur in the Steam Cracker itself. The main monomers fouling precursor is Butadiene. All along the separation process, Butadiene concentration and process temperature change. This implies step changes in polymer structure and fouling level. Several techniques are used to control this fouling, including oxygen ingress control, the use of additives such as antioxidants and free radical scavengers. By a catalytic effect, the metal surfaces can also be a polymerization initiator. The objective of passivation is to modify the Carbon Steel surface into stable magnetite and maghemite. Using electrochemistry to characterize different Carbon Steel samples, we were able to improve our passivation procedure. And when applying metal passivation, we were able to increase run length of Depropanizer reboilers limiting the fouling rate and its impact on operation. [ABSTRACT FROM AUTHOR]

To reduce the carbon emissions for society's sustainable development and satisfy customers' personalized delivery service, this paper addresses the cap-and-trade policy and multiple service levels into a p-hub median problem. In the hub network designing, single-assignment patterns between hubs and demand nodes, the choice of transportation mode for each O-D pair and the uncertainties of carbon emission and price are taken into account. Based on a fuzzy chance-constrained programming approach, a fuzzy mathematical model under an expected cost-minimization context with some fuzzy constraints is first presented. Then a two-phase approach is proposed to solve the proposed model. Finally, in view of the comparative analysis with small- and large-scale Turkish instances, serval managerial insights are finally obtained for government and logistics companies in the reduction of carbon emission and the hub network's total designing cost for the sustainable development. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive characterization of the microstructure evolution and distribution of interfacial bonding properties in the original rolled plates and a welded AISI 304/Q235B clad plates. The findings reveal that an uneven diffusion layer, rich in chromium (Cr) and nickel alloy elements, is formed at the interface of the heat-affected zone during the welding process. The thickness of the diffusion layer reaches 10 μm in the overheated region. This nonuniformity results from the dilution of alloying elements from stainless steel into carbon steel. The presence of the diffusion layer contributes to the highest microhardness value at the weld metal interface. Tensile-shear experiments indicate a 22% increase in the tensile-shear strength of the overheated zone interface compared to the base metal interface, accompanied by a 30% decrease in elongation. While the diffusion layer enhances the interface shear strength, it reduces the interface plasticity, thereby increasing the risk of fracture. Fracture analysis of the overheated zone interface reveals brittle fracture characteristics, with a small amount of Cr present. In contrast, the interface of original rolled plates displays characteristics of ductile fracture, which emphasizes the intricate interaction between brittle and ductile fracture behaviors at the interface. These observations stem from the nonuniform diffusion layer, distinct microstructure distribution, and varying rates of crack propagation. [ABSTRACT FROM AUTHOR]

The laser welding between high strength steel and carbon fiber reinforced polymer (CFRP) was explored in order to improve the mechanical properties and capacity to reflect physical relationships. The influence of process parameters on the mechanical properties of the joint was analyzed by RSM based on the experimental results. A residual regression method was proposed, using the residual block as the core structure and combined it with the fundamental concept and structure of the residual network. The residual regression model with two-layer residual block structure was compared with the RSM model at the same time, and the feasibility of this method was validated by experiments. The results show that the mechanical properties of the hybrid joint increase with the increase of the input laser energy per unit time. The proposed residual regression model can directly characterize the relationship between process parameters, intermediate physical quantities, and shear force and has better prediction accuracy and more physical relationships than RSM. The optimized parameters are laser power 1100 W, welding speed 9 mm/s and defocus distance 15 mm. [ABSTRACT FROM AUTHOR]

A study of the effect of height correction of the engagement of helical gears on contact pressures, tooth wear and durability using the author's method of calculating metal-polymer gears was conducted. Carbon steel 0.45%C was chosen for the pinion, and polyamides PA6 or PA6 + 30% CF were chosen for the gear. At different helix angles and shift coefficients the estimation of maximum contact pressures in engagement is carried out. Quantitative and qualitative regularities of influence of both factors on contact pressures considering conditions of teeth engagement are established. The teeth linear wear is differentiated during the engagement cycle depending on parameters of correction and helix angle. Its values have been established at the characteristic engagement points: at the entrance; at the entrance to the central phase and at the exit from it; at the exit from the engagement. The durability is significantly affected by both the correction of engagement and the helix angle. Quantitative and qualitative regularities of this influence are established. The presence of the optimum shift coefficients at which the gears durability will be the highest has been established. MP gears with a gear made of PA6 + 30CF will have significantly higher durability than PA6. [ABSTRACT FROM AUTHOR]

The objective of this study is to extract amino acids from fish processing discards for the preparation of highly effective and degradable corrosion inhibitors. The composition of fish processing discards extract (FPDE) was characterized by HPLC and FTIR. The results showed that the main components of FPDE are amino acids and contain a large number of unsaturated functional groups. Electrochemical techniques (electrochemical impedance spectroscopy (EIS) and Tafel), surface analysis (XPS and AFM), and molecular dynamics simulations (MDS) were conducted to investigate the corrosion inhibition mechanism of FPDE for carbon steel in 1 mol/L HCl. As shown by electrochemical tests, FPDE exhibits mixed-type corrosion inhibition with a maximum inhibition efficiency of 93.3%. FPDE exhibits excellent corrosion inhibition properties on carbon steel surfaces by forming a high coverage film through chemisorption and physisorption. Indeed, the advantages of remarkable inhibition efficiency and facile extraction methods allow FPDE to become a promising corrosion inhibitor for practical applications. [ABSTRACT FROM AUTHOR]

Earthquake-resistant steel building structures adopt steels of various strengths as structural members. As strength levels increase, their uniform elongations decrease, which affects their deformation capacities under cyclic loading. This study conducted 63 cyclic loading tests in small (± 2%) and large (± 12%) strain regions on different structural steels for earthquake-resistant steel buildings. The result reveals, irrespective of the different strength levels, the cyclic deformation capacity up to fracture and ultimate point can be evaluated in a unified manner extended to ± 10% and ± 12%, respectively. The findings can provide insights for determining the suitability of a steel for application in seismic buildings. [ABSTRACT FROM AUTHOR]

A novel POEGMA-b-(PMEEU-co-PMAA) (poly(oligo(ethylene glycol) methacrylate)-b-poly((methacrylamidoethyl) ethylene urea)-co-poly(methacrylic acid) block copolymer has been synthesized by RAFT polymerization as a corrosion inhibitor. Structural characterization of the block copolymer was done by FTIR, 13C NMR and 1H NMR spectroscopic techniques. The carboxylic acid and cyclic urea units on the block copolymer exert a synergistic effect on corrosion inhibition through chelating of the metal ions or adsorption to the metal surface. Corrosion inhibition of SAE 1012 carbon steel in a 1 M HCl medium has been investigated in the presence of 5 mM polymer using both experimental (electrochemical impedance spectroscopy, Tafel polarization (TP), weight loss) and theoretical approaches. Also, SAE 1012 carbon steel surface morphology changes were followed by energy dispersive X-ray spectroscopy and scanning electron microscopy. Electrochemical techniques indicated that the presence of PMEEU-co-PMAA segments of the polymer in the acid solution inhibits corrosion of SAE 1012 carbon steel. The inhibition efficiency of the polymer was found to be about 85%. According to TP studies, PMEEU-co-PMAA segment acts as a mixed type corrosion inhibitor. The adsorption of PMEEU-co-PMAA molecules onto the metal surface follows Langmuir adsorption isotherm. The Kads value calculated from the equilibrium constant of the adsorption process reflects a strong interaction. SEM and EDAX studies provide evidence of PMEEU-co-PMAA adsorption on the metal surface. [ABSTRACT FROM AUTHOR]

Various techniques, such as electrochemical impedance spectroscopy, potentiodynamic polarization, linear polarization resistance, and scanning electron microscopy, were used to investigate the inhibitory effect of pomegranate peel extract (PGPE) on the corrosion of carbon steel in a simulated concrete pore solution containing 0.5 M NaCl and in mortar exposed to chlorides. The results obtained revealed that the corrosion resistance of steel, in the presence of the PGPE, was greater than that of the inhibitor-free system, validating the ability of the pomegranate peel extract to produce a protective layer on the steel surface.The optimal concentration of pomegranate peel extract found is around 500 mg/L, with an inhibition efficiency estimated at 97.39%. It is worth indicating that the adsorption of PGPE was found to follow the Langmuir isotherm model. Furthermore, using the principles of quantum chemistry, the adsorption of PGPE constituents on the surface of carbon steel was shown to occur via donor-acceptor interactions. A plant extract-based inhibitor was developed to prevent steel corrosion in alkaline media. The pomegranate peel extract shows a high inhibition efficiency of about 97.39%. Passive films on the surface of carbon steel with/without pomegranate peel extract were analyzed by SEM. DFT analysis was used to simulate the adsorption processes of the main constituents of pomegranate peel extract. Two possible adsorption mechanisms for pomegranate peel extract were proposed. [ABSTRACT FROM AUTHOR]

To organize the safe handling of activated material, knowing the residual dose rates is crucial. In this work, we present the pre-experiment activation analysis for an experiment in which tungsten blocks are irradiated by 800-MeV protons. In this analysis, we use the Monte Carlo N-Particle (MCNP) code for radiation transport, Attila4MC for unstructured mesh generation, and Activation in Accelerator Radiation Environments (AARE), including CINDER2008, for activation analysis. If the tungsten blocks must be removed within a day after the experiment, then exposure to personnel entering the room must be reduced. One exposure-reduction strategy is to add carbon steel shielding around the tungsten blocks, efficiently reducing the dose from the activated tungsten. However, the shielding becomes activated itself during irradiation: 56Mn is the dominant contributor for short decay times. The actual schedule at the time of the experiment allowed sufficient cool-off time for the tungsten in the room so that additional shielding was not necessary. A less rigorous comparison of the calculated values with the post-experiment measurements showed reasonable agreement. [ABSTRACT FROM AUTHOR]

Clean-integrity processing of nuclear-grade AISI 316L austenitic stainless steel components finished by the wire brush and sequent flap discs is performed for high-performance manufacturing of the nuclear power plant equipment. Two steel wire brushes of AISI 304 austenitic stainless steel and 65Mn carbon spring steel are used for the grinding under a spindle speed of 550–2000 rpm. Sequent polishing is carried out by the flap discs using silicon carbide cloth under 2000 rpm. An equivalent pitting corrosion resistance to that of the original stainless steel in 3.5% NaCl solution is obtained for finished samples by the combined processes. The contaminants composition of ground stainless steel samples is determined by the redness degree of chromaticity inspection. The contaminants microstructure and finishing-induced microstructure are dependent on the impedance phase angle change in eddy current impedance diagrams. The surface clean-integrity of nuclear-grade stainless steel is characterized by the series of nondestructive evaluation methods. [ABSTRACT FROM AUTHOR]

Shielded metal arc welding (SMAW) is one of the most important processes of joining two metals or materials because of its high efficiency and low time requirement. This work studied the tensile strength of SMAW dissimilar mild steel (MS) and medium carbon steel (CS) with various process variables such as Welding Current (WC), Electrode Angle (EA), and Root Face (RF). The chosen variable ranges are WC of 140,180 and 200Amp, EA of 30,45 and 60 degrees and RF of 1,2 and 3 mm respectively to identify the important variables on Tensile strength (TS). Design of experiments (DOE) is executed as per Taguchi L9 OA for recognizing the optimal level of variables to accomplish maximum tensile strength. The experimental result is witnessed that the highest TS (201.38 MPa) is attained at sample-8 when WC −140 Amp, EA-45 degree and RF-1mm are maintained whereas the lowest TS (41.61 MPa) is obtained at sample-9 due to increment of the electrode angle (60 degree) and root face (2 mm), Analysis of variance result is revealed that Electrode Angle is the most important variable (73.97%) which improves TS of the SMAW joints, followed by Root face (6.24%) and Welding current (5.12%). [ABSTRACT FROM AUTHOR]

The anti-corrosive effect of the extract in ethanol of Justicia brandegeeana (Acanthaceae) against carbon steel AISI 1020 in sulfuric acid medium 1 mol L-1 was investigated. In addition to the effect of seasonality, several techniques were used to investigate the anti-corrosive activity, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), linear polarization resistance (LPR), and weight loss. The chelating effect was analyzed by UV-Vis spectrophotometry and the surface was analyzed by scanning electron microscopy (SEM). The results showed that the inhibition efficiency is dependent on the concentration of the extract, reaching its maximum at 1500 ppm and despite having good thermal stability (82.41% inhibition at 70°C), it decreases with increasing temperature, indicating a physisorption behavior. The extract obeyed the Langmuir isotherm and the Tafel curves characterized it as a mixed inhibitor, with a tendency to cathodic region. It also presented a 52% chelating effect against Fe+2 ions, and the SEM analysis indicated a protection with the presence of plant extract, thus minimizing surface roughness. These results indicated the J. brangeeana ethanol extract as a green anti-corrosive agent. [ABSTRACT FROM AUTHOR]

The use of steel fibres in reinforcing concrete has proven to enhance certain mechanical and durability properties of concrete; however, as a material that presents enhanced properties, its environmental performance should also be analysed. This study aims to quantify the carbon emissions of steel fibre-reinforced concrete beams using a functional unit that considers the mechanical and durability performance of concrete through a whole life cycle assessment methodology that includes the benefits/load after the end-of-life. A cradle-to-grave approach, which considers the end-of-life stage and the benefits/loads beyond the system boundary, was performed to compare the embodied carbon of conventionally reinforced concrete and steel fibre-reinforced concrete beams. The results show that the addition of steel fibres as reinforcing material to concrete can reduce the area of steel required in the tension zone of a conventionally reinforced concrete beam and the embodied carbon of concrete by an average of 33% and 37%, respectively. [ABSTRACT FROM AUTHOR]

The study investigated the corrosion-inhibitory properties of three synthetic triazole Mannich bases on C1018 carbon steel using various electrochemical techniques. The inhibitors, namely 4-amino-2-[(4-methylpiperazin-1-yl)methyl]-5-(pyridin-4-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (4MPT), 4-amino-2-[(piperidin-1-yl)methyl]-5-(pyridin-4-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (PPT) and 4-amino-2-[(morpholin-4-yl)methyl]-5-(pyridin-4-yl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (MPT), demonstrated the high inhibition efficiencies of 92.8%, 93.3% and 92.6%, respectively, and adhered to the Langmuir adsorption isotherm. The inhibitors also functioned as mixed-type inhibitors and improved the protective layer on the metal surface. The study also utilized scanning electron microscopy - energy dispersive x-ray (SEM-EDX) analysis to examine the surface morphology of the uninhibited and inhibited carbon steel specimens. Furthermore, density functional theory (DFT) was utilized for theoretical calculations, which corroborated with experimental measurements. [ABSTRACT FROM AUTHOR]

This study conducted a basic investigation to improve the solidification cracking susceptibility of carbon steel. BTR is one of the susceptibilities to solidification cracking, and it is said that solidification cracking susceptibility is reduced when BTR is smaller. BTR of three commercial filler metals was evaluated by using Trans-Varestraint test. EPMA and EDS analysis of the weld metal microstructure revealed two compounds. The white structure was composed of silicon, manganese, and sulphur, and the black structure was Ti-based compound. Theoretical analysis of BTR was conducted by applying a two-phase peritectic solidification model in FA mode and considering MnS crystallization during solidification segregation. The analysis results indicated that BTR of carbon steel is attributed to the difference in solidification completion temperatures, and carbon is the most deleterious element. Also, MX compound (Ti, C, N) crystallized in addition to MnS at the end of solidification. Theoretical analysis was conducted for Ti virtual addition materials because MX compound (Ti, C, N) crystallization by Ti addition may lead to BTR reduction by trapping C in the liquid phase. The results showed that Ti addition reduced BTR. The amount of C in the residual liquid phase was reduced by an increase in MX compound (Ti, C, N) crystallization due to Ti addition. Based on theoretical considerations, it can be concluded that Ti addition to carbon steel is effective in reducing BTR. [ABSTRACT FROM AUTHOR]

Structural cables are used to design critical bridge structures. These are not typically redundant; a loss or compromise of a few cables can lead to the progressive collapse. Previous experimental research has shown that the degradation of material properties and thermal expansion of structural cables is more onerous than the standard carbon prestressing steel. Despite its importance for design no well-validated methodology exists to aid in the thermal performance of structural cables in the event of a fire, particularly for spiral and locked-coil cables which inherently are complex due to their cross-sectional geometry. A state-of-the-art methodology for modelling structural cables' thermal response is presented. The methodology will enable the development of an understanding of the temperature distribution and thermal deformation in a cable cross-section and allow estimation of post-fire resilience. Validation is performed against experiments of locked-coil and spiral cables, subjected to realistic pool fires. The cables range from 22 to 100 mm in diameter and are constructed of galvanized or stainless steel. The cables are modelled undergoing non-linear thermal analysis in LS-DYNA. 2D models are found to provide conservative estimates for critical values such as peak temperature with 90% accuracy, while 3D models provide slightly more conservative estimates. [ABSTRACT FROM AUTHOR]

Aluminized carbon steel C45 samples of 0.44 wt.% carbon content were immersed half in a molten salt mixture (NaCl + Na2SO4 with a ratio of 1:3) at a temperature of around 973 K over three different exposure periods: 8, 24, and 72 h. It was observed that a new intermetallic layer (emergent layer) formed at the interface between the steel substrate and the pre-formed intermetallic layers as a result of further outward and inward diffusion of Al, Fe, and C, as indicated by a metallographic study involving SEM combined with EDS spot analysis and elemental analysis. It was also observed that flake-like new phases precipitated in both halves, largely composed of Fe–Al–C–O elementary components, where presumably, the steel C45's high carbon content and the prolonged exposure to high temperatures contributed to further chemical reactions between the elements of HDA specimens and the molten salts' aggressive Cl and S elements. Moreover, they accelerated the rate of oxidation/corrosion of the hot-dip aluminized C45 steel specimens at high temperatures. Gibbs free energies calculations of some of the corrosion products confirmed the composition of the oxide scale detected experimentally. [ABSTRACT FROM AUTHOR]

This study provides two case studies involving carbon steel and 3%-Cr steel exposed to a CO2–H2S environment with a moderate scaling index. The carbon steel tubing show shows pitting and severe corrosion, whereas the 3% chromium steel tubes are undamaged. XRD results showed that the chromium-rich layer did not alter scaling on both tubes. Investigations using SEM and EDS reveal the formation of a dense and compact layer in the 3%-Cr steel, which serves to resist corrosion. In contrast, carbon steel has a porous structure and is easily detachable due to wall shear stress caused by slug movement. In 3%-Cr steel, the EDS analysis reveals a compact layer with a significant number of chromium, which is an indication of a Cr-rich iron oxide layer. Potentiodynamic polarization shows that the anodic curve is shifting, which means that the rate of corrosion is slowing down. This study shows that 3% Cr steel is a good choice for a mixed CO2–H2S environment with a high total dissolved solid (TDS). [ABSTRACT FROM AUTHOR]

The crimping and aggregation of graphene in the matrix often affect the properties of the composites. Herein, we successfully constructed the fluorinated graphene oxide (FGO) with interlayer support structure to improve the properties of epoxy composites. We employed diamine as a spacer and investigated the effects of three diamines with different structures on the modification of FGO in detail. FGO modified by p-phenylenediamine (PPD-FGO) had maximum interlayer spacing, presenting good stability and antiaggregation properties. Moreover, the addition of PPD-FGO makes epoxy resin composite transform from brittle material to ductile material, and the impact strength was significantly improved at both room temperature and 77 K. Meanwhile, the thermal properties were maintained very well, showing a slight increase. In addition, PPD-FGO/epoxy composite coating displayed good anti-corrosion performance for carbon steel. This work not only provides a new method to improve the properties of epoxy resin but also gives a new direction for the application of FGO. [ABSTRACT FROM AUTHOR]

This paper presents effect of flaw orientation on magnetic flux leakage (MFL) and remote field eddy current (RFEC) inspection of small diameter (19.05-mm outer diameter, OD and 2.77-mm wall thickness, WT) seamless low carbon steel tubes. Artificial electro-discharge machined (EDM) notches in three carbon steel Tubes A (orientations from 0° to 90° in steps of 10° and 50% WT depth), B (70° orientation and depths from 10% WT to 100% WT in steps of 10% WT) and C (50° orientation and depths from 10% WT to 60% WT in steps of 10% WT) were used to investigate the detectability of notches with different orientations and depths. Studies on different notch orientations reveal that RFEC technique detected all the notches with good signal-to-noise ratio (SNR), while MFL technique detected the notches with orientations from 40° to 90°. The effect of notch orientation is observed more in MFL technique as compared to RFEC technique. Further, the effects of scanning speed and notch depth for the detection of oriented notches were studied. Studies reveal that the effect of scanning speed is also more (40 times) dominant in MFL technique as compared to RFEC technique. Studies also reveal that the scanning effect is again dependent upon the notch depth. For 70° oriented notches, MFL technique is found to be more sensitive to notch depth as compared to RFEC technique. For 50° oriented notches, RFEC technique is found to be more sensitive to notch depth as compared to MFL technique. [ABSTRACT FROM AUTHOR]

The rapidly expanding built environment in the northern Gulf of Mexico includes thousands of human built structures (e.g. platforms, shipwrecks) on the seabed. Primary-colonizing microbial biofilms transform structures into artificial reefs capable of supporting biodiversity, yet little is known about formation and recruitment of biofilms. Short-term seafloor experiments containing steel surfaces were placed near six structures, including historic shipwrecks and modern decommissioned energy platforms. Biofilms were analyzed for changes in phylogenetic composition, richness, and diversity relative to proximity to the structures. The biofilm core microbiome was primarily composed of iron-oxidizing Mariprofundus, sulfur-oxidizing Sulfurimonas, and biofilm-forming Rhodobacteraceae. Alpha diversity and richness significantly declined as a function of distance from structures. This study explores how built structures influence marine biofilms and contributes knowledge on how anthropogenic activity impacts microbiomes on the seabed. [ABSTRACT FROM AUTHOR]

The advantageous physical and chemical properties of carbon-fiber-reinforced polyetheretherketone (CFRPEEK) make it a suitable friction pair for water hydraulic components. To explore the selection of friction pair materials, this paper investigated the tribological properties of CFRPEEK, stainless and carbon steel in water and high water-based fluids, and evaluated them using reciprocating friction and wear tester. After the test, the wear surface morphology of the contact surface was observed under an electron microscope. The results show that the degree of friction between specimens is dependent on the load and frequency. Meanwhile, both 316L and CFRPEEK have good tribological properties in both mediums. Microscope observation analysis showed that CFRPEEK surfaces easily absorb water to create a water film, thus improving its performance and reducing wear. Additionally, the friction between stainless and carbon steel in high water-base fluid will generate a lubricating film, the surface of which shows excellent tribological properties. The final conclusion was that the choice of material for plunger pair material depends on the medium, with 304-316L being more suitable for high water-based fluids, while CFRPEEK-316L is more suitable for water. [ABSTRACT FROM AUTHOR]

The effect of quench–polish–quench (QPQ) nitriding temperature and rare earth yttrium (Y) content on the microstructure and properties of Q235 steel was investigated. The nitriding layer is divided into an oxide layer (Li2Fe3O4 and Fe3O4), a compound layer (Fe3N), a diffusion layer, the addition of Y effectively increased the steel performance after nitriding, but too much rare earth yttrium will inhibit the nitriding effect. The thickness of nitriding layer of Q235 carbon steel increased and then decreased with the increasing of rare earth Y content, and the thickest nitride layer was obtained using 2%Y at 580°C. The best hardness and corrosion resistance was obtained using 2% Y at 565°C. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) are spherical zero-dimensional carbon nanomaterials, generally below 10 nm in size, which have received increasing attention in the field of corrosion because of various advantages such as good water solubility, abundant raw materials, and environmental protection. In this work, water-soluble carbon dots (CDs) with particle sizes of 5–10 nm are obtained by electrochemical oxidation with anhydrous ethanol. FTIR, Raman, UV–Vis, XPS, and TEM are used to characterize the obtained CDs, and electrochemical tests are used to investigate the anti-corrosion performance of the CDs. The results reveal that the corrosion inhibition performance increased with the addition of CDs, and the highest corrosion inhibition efficiency reaches 98% when the addition amount is 200 mg/L. Moreover, the inhibition mechanism for CDs needs to be further investigated, and the stable adsorption of CDs on carbon steel to form adsorption film may be the key factor for its good corrosion inhibition performance. [ABSTRACT FROM AUTHOR]

Direct-fired supercritical CO2 (sCO2) power cycles are being commercialised to revolutionise fossil energy as a low-emission power source. To lower the cost of this technology, less expensive steels are needed in the lower temperature segments of the cycle. However, there are concerns about internal carburisation of steels in sCO2.1 A consistent observation is that thin, Cr-rich oxides appear to reduce C ingress compared to thick Fe-rich oxides formed on 9–12% Cr ferritic-martensitic steels. Advanced austenitic stainless steels (SS) like alloy 709 (20Cr-25Ni) are able to continue to form Cr-rich oxides at 650°C, while a conventional type 316 H SS formed a Fe-rich scale. The C diffusion profiles in SS specimens were quantified at 550°C–650°C using glow discharge optical emission spectroscopy and electron probe microanalysis. Analytical transmission electron microscopy was used to compare the thin protective Cr-rich oxide formed on alloy 709 in sCO2 at 650°C to that formed in ambient air. [ABSTRACT FROM AUTHOR]

Effect of Al or Ti addition on the ferrite formation in ultra-low oxygen (about a few tens ppm) weld metal of low carbon steels were investigated. A bead-on-plate welding experiments were performed with a Tungsten Inert Gas (TIG) welding system. The double nozzle was attached to the welding torch used, Ar was passed along the outer nozzle and He is added along the inner nozzle. Optical micrographs showed that primary ferrite appeared along prior austenite grain boundaries and that as the temperature is decreased ferrite side plates were grew into grain interior. Their formation positions were approached to the welding end as the decreasing Al and increasing Ti content. This change in ferrite formation position attributed on the ferrite formation temperature, which was assumed to increase as the decreasing Al and increasing Ti content. Energy dispersive X-ray spectroscopy analysis of inclusions showed that Al and Ti were mainly associated with 0, it was obvious that the inclusions in the steels were Al- and Ti- oxide inclusions. Al-oxide inclusions were not favourable acicular ferrite nucleation sites and the inclusions contributing to acicular ferrite formation were Ti-oxide ones. The number density of acicular ferrite was small. This indicated that acicular ferrite formation was suppressed because the number density of inclusions was low under the ultra-low oxygen welding condition. [ABSTRACT FROM AUTHOR]

Two novel cationic Gemini surfactants (2CnGeQS, n = 12, 18) was designed and prepared via amidation and quaternization reaction. The molecular structure of the 2CnGeQS was confirmed by FTIR, 1H NMR and elemental analysis. The critical micelle concentration (CMC) of aqueous solutions of these surfactants was determined by surface tension measurements, and the surface activity parameter, such as effectiveness (πCMC), efficiency (pC20), critical micelle concentration (CMC), maximum surface excess (Гmax), minimum surface area (Amin), were obtained. The results showed that 2CnGeQS have a higher surface activity than conventional monomeric surfactant. The CMC decreases with an increment in hydrophobic chain length, however, the surface tension at the cmc (γCMC) shows the opposite trend. The thermodynamic parameters indicate that both micellization and adsorption processes of 2CnGeQS were spontaneous. In addition, the results obtained from weight loss measurements show that 2CnGeQS exhibits a greater protective effect than that of DTAB; inhibition efficiency (ηw%) of 2C12GeQS, 2C18GeQS%, and DTAB is 95.6%, 96.86%, and 52.8% for A3 carbon steel at 1 × 10−3 M. [ABSTRACT FROM AUTHOR]

A microscopic finite element model validated by the quasi-static mechanical test on lithium ion battery cell is presented in this study. The investigated condition involves three-point bending and cell discharge test, which include the mechanical response and thermal response of lithium ion battery cell. The cell is investigated through computational simulation. Results show great correlation between the experiment and finite element simulation. A microscopic model requires a greater effort during simulation. Investigating the fracture on steel casing and cell core is possible by considering the fracture mechanism in steel shell and jelly roll. The classic von-Mises criterion is applied to predict the failure of carbon steel shell, and the maximum von-Mises strain criterion is used to investigate the jelly roll region. On the basis of the verified battery cell model, battery package with microscopic model, including cell core (cathode, anode, and separator) is constructed to analyze the mechanical response of battery pack. The von-Mises criterion is used to predict the fracture point location of the battery pack with various packing modes and packing densities. [ABSTRACT FROM AUTHOR]

Adhesion strength between a substrate and its oxide scale grown on hot-rolled low carbon steel was evaluated by a hybrid numerical-experimental analysis of artificial spallation results. Interfacial fracture of the scale was reproduced by a scratch tester, in which the onset of interfacial fracture was identified by examining the mechanical responses along with microscopic observation. Critical traction at interface was solved quantitatively by numerical inverse analysis with finite element method. Influence of residual stress on adhesion strength was also investigated. Finally, validity of the identified adhesion strength was confirmed by analytical comparison with energy release rate reported in previous research. [ABSTRACT FROM AUTHOR]

Modern advancements and emerging trends in automobile technology have shifted the primary focus of the OEMs to make vehicles lighter, faster, and reliable. Weight has always been a major concern in commercial medium/heavy-duty vehicles. The leaf springs account for 20% of the sprung weight of the vehicle thereby making the suspension system one of the heavy components of an automobile. This paper focuses on analysing the potential of aluminium alloy as a candidate material in leaf spring so as to make the suspension system lighter and more reliable. Aluminium alloy is one of the appropriate materials to proceed with because of its lightweight, strength, and non-significant deformation during load cycles. Three-dimensional CAD model of standard leaf spring was created in DS CATIA V5R19 software and computational analysis were carried out in ANSYS Workbench 18.1 by defining material as plain carbon steel (structural steel) and Aluminium alloy for comparative study. The results of the analysis that the reduction in weight of the leaf spring using aluminium alloy was approximately 64.71% along with a significant reduction in equivalent stress induced at different loading condition with a maximum reduction of 45.30% equivalent stress at the fully loaded dynamic condition. [ABSTRACT FROM AUTHOR]

Pulsed eddy current (PEC) technique has been used to detect corrosion under insulation (CUI) for decades, but whether and how the wire mesh laid in the insulation layer affects the detection remains ambiguous. This paper touches on this issue for the first time. The insulated structure was simplified to a carbon steel plate covered by a cladding with an air gap representing the insulation layer, in which the wire mesh was situated. Finite element simulations were performed on the simplified model and found that the aluminium or stainless steel wire mesh had little effect on eddy currents in the plate, while the mild steel wire mesh could cause a considerable increase in the probe footprint and a significant drop of the eddy current density. For the mild steel wire mesh, the magnetic permeability and wire diameter were the main factors affecting the probe footprint and eddy current density. Afterwards, simulations were conducted to analyse the effect of the mild steel wire mesh on the PEC probe performances for evaluating the CUI depth and found that the mild steel wire mesh led to decreases in both the PEC signal amplitude and decay rate. The simulation results were finally verified by experiments. [ABSTRACT FROM AUTHOR]

An analytical model is conceived to correlate thermal processing parameters, phase transformation parameters, microstructural features and the resultant hardening response of steel. Three equations evolved thereby readily resolve the issues of direct graphical determination of hardenability parameters, variation of unhardened core region with the diameter of steel and quantitative prediction of the microstructure. The model is successfully validated with existing experimental database of hardenability parameters following chemical composition-cum-grain size method as well as in view of own experimentation carried out on available steel. This elucidates a new conduit of understanding thermal processing-based solid state phase transformation in steel. [ABSTRACT FROM AUTHOR]

The present study investigates the influence of heat input on microstructure evolution and mechanical properties of nitronic steel and super duplex stainless steel dissimilar welded joints. For this experimental purpose, carbon steel filler (ER70S–2) was employed using gas tungsten arc welding (GTAW) with two heat input conditions: lower (0.624 kJ/mm) and higher (1.01 kJ/mm). The welded joint was subjected to the microstructure of different zones, including weld metal, base metals, and heat-affected zones/interfaces were accomplished by optical microscopy, scanning electron microscope. Tensile test, Impact test, and Vickers microhardness were conducted to study the mechanical properties. Microstructural evolution in the weld metal and heat-affected zone reported the presence of Type II boundary and macrosegregation. Hardness test investigation reveals that the weld metal's hardness rises compared to the base metals. Moreover, the weldment hardness decreases at higher heat input than lower heat input. The tensile test study reveals that the lower heat input weldment exhibits more elongation and tensile strength than the higher heat input weldment. The Charpy impact tests show that the average toughness value increases with heat input. The results also indicate that the lower and higher heat input specimen exhibited brittle fracture. [ABSTRACT FROM AUTHOR]

Electroless nickel (EN) coatings have attract much attention due to their ability to provide a corrosion-resistant hard surface. However, the technological advancement demands the development of reinforced coatings with improved tribological performances. In this work, electroless nickel/black phosphorus nanosheets (EN-BP) coatings were prepared by an electroless plating method to provide friction-reducing and antiwear properties for a Q235 carbon steel. The influences of the concentration of black phosphorus and testing conditions on the tribological performances of the coatings were investigated. The results showed that the hardness of the EN-BP coating increased by 48.98% with the introduction of 0.01 g/L BP nanosheets in the plating solution, and the coefficient of friction reduced by 44.5% in pH 8 NaHCO3 solution, respectively, compared with those in pure water. The friction reduction and antiwear mechanism was ascribed to the action roles of the interlayer shear of BP nanosheets and protective lubrication films composed of NiO, Ni(OH)2, SiO2, and PxOy generated on the sliding coating surfaces. The excellent tribological properties of the EN-BP coatings show their promising application prospects in marine industry. [ABSTRACT FROM AUTHOR]

As part of ongoing research to validate the efficacy of a potentiodynamic polarization technique of determining the critical chloride threshold (CCRIT) value of steel reinforcing bars exposed to chloride-contaminated concrete, the present work reports CCRIT values of carbon steel exposed to NaCl, CaCl2 and MgCl2. The increasing use of locally available multi-chloride anti-icing agents in Ontario during the winter season, which are brine solution with ~21% chloride as NaCl, CaCl2 and MgCl2, resulted in a need to understand the impact of these salts on the threshold values. The potentiodynamic polarization method allowed the influence of these salts on CCRIT values of carbon steel rebar to be determined in a significantly shorter period than existing standard methods. Cement pastes with varying admixed chloride as NaCl, CaCl2 and MgCl2 were cast with 0.5 w/cm ratio and their pore solution content was expressed after 28 days curing for cation and anion analyses. The resulting pore solution composition revealed increasing Ca, K and Na cations and increasing chloride and sulphate anions when the cement pastes were admixed with chloride as NaCl. However, sulphates decreased in the pore solution when the pastes were prepared with CaCl2 and MgCl2. The consequence of the latter findings was that the threshold values by mass of pore solution of the carbon steel rebar exposed to these chloride compounds were significantly lower than bars exposed to pore solution with NaCl. Nevertheless, the conversion of these values to percentage by mass of cementitious materials gave surprisingly similar values for all three chlorides [ABSTRACT FROM AUTHOR]

A new aromatic Schiff base with azo linkage has been synthesized and characterized by FT-IR, 1H-NMR, and 13C-NMR spectroscopy. The new compound 2-(((5-mercapto-1,3,4-thiadiazol-2-yl)imino)methyl)-4-(p-tolyldiazenyl)phenol (5, denoted as AT) was tested as a carbon steel corrosion inhibitor in 1 M H2SO4. The presence of AT in 0.04 mM concentration at 303 K achieved excellent inhibition efficiency values, 96.6 and 97.4% by potentiodynamic polarization and weight loss measurements, respectively. The adsorption process of AT on carbon steel surface was found to obey Langmuir adsorption isotherm with the highest Kads value 476,190 M−1 at 313 K, and ΔG values −25.53, −26.49, −25.97, and −25.78) kJ mol−1 over the studied range of temperatures 303–333 K, indicating the spontaneous formation of stable protection film through a strong adsorption process. Density function theory (DFT) studies were employed for further investigations about the nature of the interaction between the molecules of AT (both of its tautomers) and metal surface. SEM and AFM analysis were used to confirm the inhibition by comparing the morphology of the corroded surface with the inhibited one. [ABSTRACT FROM AUTHOR]

Two novel Schiff bases derivatives of 1 H–1,2,4-triazole-3-yl)imino (L1 and L2) were synthesized and investigated as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency of L1 and L2 was inspected by gravimetric measurements, electrochemical method, and quantum chemical calculations. L1 and L2 inhibitory efficiency is related to the test's concentration. The created compounds were characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analysis. The corrosion inhibition property of the synthesized Schiff base on carbon steel, the main component of pipelines used in oil and gas fields, in 1 M HCl medium was investigated using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). From the loss-weight data it was found the inhibition rises by the grown inhibitor concentration, which at 1 mM of L1 and L2, receiving a record level in ηw of 92.3% and 93.9%, respectively. The prepared Schiff bases act as good mixed-type corrosion inhibitors, according to potentiodynamic polarization experiments. Both inhibitors' adsorption on CS surfaces followed the Langmuir adsorption isotherm, with both physisorption and chemisorption. The impact of the molecular structure of the synthesized Schiff bases was examined using the density-functional theory (DFT) method and molecular dynamic (MD) simulation. [ABSTRACT FROM AUTHOR]

During machinability, the combination of machining process parameters and the material properties of the component to be machined plays an important role. Material properties depend upon the type of phase form present and the grain size of the formed phases, which in turn depends upon the prior treatment given to alter the initial room temperature types and form. Accordingly, spheroidization treatment was carried out on medium carbon steel (AISI1040) by altering the initial room temperature structure through normalizing and hardening treatment. Machinability experiments were performed on CNC machine by varying machining process constraints. Tool wear and surface roughness of the machined component obtained by turning were analyzed and correlated. Using Minitab and full factorial design, the ANOVA study was carried out. With the help of regression analysis, residual and main effect plots combined optimization (tool wear and surface roughness) was targeted. ANOVA result shows excellent machinability for the asbought-spheroidized condition where feed has a 67% contribution to tool wear (TW) whereas the depth of cut has a 71.91% contribution to surface roughness (SR). Also, the optimized regression values obtained for machining parameters are feed (0.39 mm/rev), depth of cut (0.6 mm), and spindle speed (780 rpm) with composite desirability of 0.8174. TW and SR experimental values for the optimized machining parameters are 0.039 mm and 2.89 µm, respectively, and the difference between the actual and optimized values is less than 5%. [ABSTRACT FROM AUTHOR]

Waste matter is an abundant source of recyclable materials. This study presented the corrosion inhibitor role of unripe banana peel extract (UBPE) for carbon steel in acidic environments: 1.0 M HCl, 0.5 M H2SO4, and 0.5 M HCl/0.25 M H2SO4. The aim was to demonstrate the robustness of the HCl-UBPE-steel system with respect to competing ions in the solution, and as such, generalizing its mechanism. The localized corrosion in HCl, general corrosion in H2SO4, and their theoretical midpoint were, respectively, subjected to 95.91%, 83.33%, 91.50% corrosion inhibition efficiency when UBPE was added at 3000 ppm. A protective film on the steel surface was found as the cause by electrochemical characterizations and its behavior was explained via protonation of corrosion inhibitor and rust formation on steel surface undering varying acid conditions. Therefore, the work suggests UBPE as corrosion inhibitor for steel in strongly acidic conditions containing chloride and sulfate ions. Unripe banana peel – water extract (UBPWE) acts as an eco-friendly effective inhibitor for steel in aggressively acidic environments. Carbon steel exhibits more localized corrosion in HCl solution, but more general corrosion in H2SO4 condition. UBPWE performed 95.91, 83.33, and 91.50% of inhibition efficiency for steel in HCl, H2SO4, and mixed conditions. The effective inhibition performance is assigned to the presence of a protective layer on the steel surface. [ABSTRACT FROM AUTHOR]

High strain hardening rate is usually pursued for high ductility. Here we report that moderate strain hardening rate is desired for producing better ductility and high yield strength, which is demonstrated in a medium carbon TRIP steel. By adjusting the temperature for bainitic transformation, the morphology, carbon content and residue stress of retained austenite were tuned to tailor the TRIP kinetics during tensile tests, which produced moderated but long-lasting strain hardening for high ductility while at the same time resulted in high yield strength. This strategy should work well for most materials, which usually have a limited ultimate strength. A principle is proposed and verified that an optimized moderate strain hardening rate is desired to produce the best mechanical properties for metallic materials. [ABSTRACT FROM AUTHOR]

Ganoderma lucidum, a wood-decaying fungus, has been at the center of pharmaceutical research for its disease curative and preventive abilities due to its abundant antioxidant-rich phytoconstituents. Herein, we have explored its outstanding inhibition properties in the protection of steel from environmental degradation. Its triterpenoid constituents were extracted, characterized by liquid chromatography/multi-stage mass spectrometry, and applied in both experiments (electrochemical, gravimetric, 3 D optical profiling, SEM, and FTIR tests) and computation (quantum chemical calculations and molecular dynamics simulation) to reveal its metallic corrosion suppression efficacy. 36 constituent triterpenoids were effectively characterized from the extract. In comparison with corresponding electrochemical tests conducted with the crude extract of Ganoderma lucidum, an inhibition efficiency of 83.1% at 1.0 g/L was recorded for the triterpenoid extract against 93.9% for 1.0 g/L crude extract, and both extracts displayed mixed-typed corrosion inhibition properties, exhibiting improved performances with increasing concentrations and exposure time while their effects were gradually decreased with temperature increments. The potential presence of the triterpenoids was confirmed on the carbon steel surface by the surface analytical techniques, and the experimental data were in full compliance with the Langmuir adsorption isotherm model. Computational methods estimated the adsorption performances of some selected triterpenoids on Fe (110) surface. An exclusive study of the corrosion inhibition influence of triterpenoids for metal protection in an acid environment is hereby presented for the first time, and the reported results will benefit future explorations of triterpenoids in inhibitors design and synthesis. [ABSTRACT FROM AUTHOR]

The effectiveness of acid solutions as a quenching agent for medium carbon steel and 5083-H22 aluminium alloy was investigated in this work. The samples were quenched in different acidic solutions. Solution A consists of 99% water +1% HCl, solution B consists of 97% water +3% HCl and solution C consists of 95% water +5% HCl. Thermal camera of type FLIR T600 was used to calculate the heat transfer time between the samples and the media. The microstructural characteristics of the quenched specimens were examined with an optical microscope. The mechanical properties such as yield strength, tensile strength, elongation and hardness were obtained by the conventional method. The results reveal that the samples quenched in solutions B and C show a significant increase in terms of strength compared to samples quenched in water. The accelerated cooling in solutions B and C has a double advantage which leads to an increase in the strength of the steel without a great degradation of the deformation properties, and that's what all mechanical engineers aspire. The obtained results on 5083-H22 aluminium alloy confirm the superiority of solutions B and C over water as a quenching agent in terms of strength, hardness and elongation. [ABSTRACT FROM AUTHOR]