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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]

Measurement of coating–substrate interface stiffness can indirectly characterize interface bonding quality. This paper proposes a noval quantitative inversion coating–substrate interface stiffness method based on the multi-resonance frequencies of a constructed ultrasonic echo phase derivative spectrum (UEPDS). The theoretical relationship between UEPDS resonance frequencies and interface stiffness is derived. The detection frequency and high-sensitivity interface stiffness range are optimized based on the sensitivity analyzed. Numerical simulation and experiment are implemented on a 0.48 mm aluminum layer/carbon steel substrate specimen to prove the validity of the proposed ultrasonic method. The simulation results show that the maximal relative error between the inversion and the preset interface stiffnesses is reduced from 23% to 8% compared with the traditional ultrasonic reflection coefficient amplitude spectrum-based (URCAS-based) method. The experiment results indicate that the UEPDS-based inversion interface stiffnesses have the same trend as the nominal contact pressures between the coating–substrate interface. [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 application of superhydrophobic coatings on carbon steel (CS) surface represents an effective strategy for mitigating corrosion in these materials. This study presents the preparation of superhydrophobic Ni/Mn-TiO 2 composite (SNMT) coatings on CS substrates through a facile one-step electrodeposition technique. The formation mechanism of SNMT coatings was meticulously analyzed under varying conditions of nanoparticle types and concentration levels. The inclusion of TiO 2 nanoparticles, with an optimal additive concentration of 1 g, facilitated the formation of numerous low surface energy, cauliflower-like microstructures on CS interface. Surprisingly, the results indicate that SNMT coatings maintained commendable superhydrophobicity even post-exposure to superficial damages such as tape peeling, sandpaper wear, and knife-scratch, as evidenced by a static contact angle (CA) exceeding 158° and a sliding angle (SA) below 2°. Furthermore, the corrosion inhibition efficacy of SNMT coatings was quantitatively assessed via dynamic potential polarization curves in a simulated seawater environment. The results demonstrated that SNMT coatings exhibited excellent corrosion inhibition performance in simulated seawater solution, with a protection efficiency (PE) reaching 96.5 %. In conclusion, superhydrophobic surfaces can effectively inhibit the penetration of corrosive liquids. The durability and robustness of such superhydrophobic surfaces advocate for their potential widespread application in enhancing the longevity and reliability of CS in corrosive environments. [Display omitted] • A SNMT coating was rapidly synthesized by one-step electrodeposition on carbon steel. • This coating revealed superhydrophobic property with CA of 163.5° and SA of 1.8°. • The corresponding corrosion resistant mechanism was revealed. • This coating was highly stable with extraordinary anti-corrosion, abrasion resistance and self-cleaning effect. [ABSTRACT FROM AUTHOR]

The impact of N,1-dibenzyl-5-methyl-1H-pyrazol-3-carboxamide (BPC) on the carbon steel (CS) corrosion in hydrochloric acid (1 M) was studied in this work, considering concentration and temperature effects. Electrochemical investigation indicated that BPC functions as a mixed-type inhibitor. For an optimal BPC concentration of 125 ppm, the inhibition efficiency of 91.55% was obtained at 298 K. According to adsorption isotherm of Langmuir, the BPC adheres to the CS with standard adsorption free energy (ΔG°ads) of − 26.76 kJ mol−1. Furthermore, the calculation of dissolution activation parameters revealed an increase in energy (Ea) from 46.48 to 94.97 kJ mol−1, an elevation in the enthalpy (∆Ha) from 43.89 to 92.37 kJ mol−1, and a rise in the entropy (∆Sa) from − 91.17 to 51.43 J mol−1 K−1 in the presence of 125 ppm of BPC. The experimental results were confirmed by quantum chemistry calculations based on density functional theory (DFT) and molecular simulations using the Monte Carlo method. These theoretical approaches also allowed for a comparison of the inhibitory performances of BPC with its protonated form, BPCH, the latter being found more effective. Moreover, the study of the radial distribution function g(r) predicted that the nature of the bond formed with the steel surface is of a chemical type. [ABSTRACT FROM AUTHOR]

Hydrogen from water splitting is more powerful, clean, and more energy-efficient than fossil fuels. Since the electrode material influences the performance and operating cost of industrial electrolyzers, this work induces technological innovation through Fe x Cu (1−x) alloys with electrocatalytic action toward the hydrogen evolution reaction (HER). The materials were galvanostatically deposited on 1020 carbon steel. It was used electrolytes formulated with deep eutectic solvents (DES) and aqueous solvents (AQS) were used to verify their influence on the coatings' composition, morphology, and electrocatalytic activity. The results proved that even after fixing the operating conditions (electrochemical potential, current density, and deposition time), the alloys produced in DES are richer in Fe (≅ 77-85%, w/w). For comparison, those obtained from AQS have greater proportion of Cu (≅ 65%, w/w). Stoichiometry changes also alter the topography, surface area, and electrocatalytic activity of Fe x Cu (1−x) alloys for hydrogen production. The electrochemical studies carried out also revealed that the association between Fe and Cu as alloying elements has a positive synergistic effect of reducing the HER overpotential by around 125 mV, using 1 mol L−1 KOH at 296 K. Considering stability and resistance to corrosion, Fe x Cu (1−x) alloys produced in DES stood out as the most promising for possible adaptation in electrolyzers developed for large-scale hydrogen production. • Fe content in DES presents more than 75 at%, and in aqueous shows 37 at%. • FeCu_DES shows granular shapes combined with fern-like structures morphology. • The addition of Cu in the electrocatalysts increases the active surface area. • FeCu_DES15 electrocatalyst shows a low overpotential of −235 mV for HER at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Multispecies bacterial attachment to carbon steel surfaces is not fully understood; for example, as to why the attachment of certain bacteria influences corrosion. In this study, finished steel, A 106 GB was exposed to a mixed bacterial culture in a batch reactor system at a constant temperature of 35 °C to evaluate the corrosion rate with and without bacterial influence. Cultures collected from the cooling tower site were exposed to coupons and were grown in a batch reactor. Atomic force microscopy (AFM) was used to obtain roughness parameters. Surface morphology and colonisation patterns were observed by scanning electron microscopy (SEM). 16S rDNA sequencing indicated predominance of Pseudomonas sp. and Clostridium sp. on the rough surfaces. Cell colonisation of surfaces showed no time-related differences, with differences observed on surface roughness parameters. Intergranular and uniform corrosion was observed. The smooth finished steel surface performed best in resisting corrosion. [ABSTRACT FROM AUTHOR]

Today, one of the most visible areas of development in technology and science is building materials technologies. Every day, a new building materials, alternatives and products of different qualities are developed and offered to the construction industry. In applications of architectural structures, in addition to metals containing iron such as steel and its derivatives, which we call ST37, non-ferrous metals such as copper, zinc, titanium and especially aluminum or alloys of these metals are also preferred. In this study, comparative analysis of the preference criteria for using aluminum metal and its alloys and ST37 steel metal, which are among the metal samples mentioned above, as facade materials, were examined. Facades with 1050, 5005 and 5754 quality alloys, which are the most preferred aluminum alloys for facade cladding, were compared with carbon steel facades called ST37. Considering the preference criteria, it has been determined that aluminum and its alloys are generally found to be suitable for their performance in areas where lightness, corrosion resistance and energy efficiency are preferred, while ST37 steel is used in applications where it meets structural durability, high temperature and low-cost expectations due to its content. [ABSTRACT FROM AUTHOR]

The newly designed 8-quinolinol-benzimidazoles, 5-(5-nitrobenzimidazol-2-yl)8-quinolinol (NBLQ) and 5-(5-methylbenzimidazol-2-yl)8-quinolinol (MBLQ), were explored for the protection of carbon steel (C–S) in hydrochloric acid electrolyte (1 M HCl) at 303 K using electrochemical, surface analysis techniques, and computational approaches. The findings exhibited that the examined 8-quinolinols have remarkable inhibiting characteristics, with their inhibition performances reaching a maximum of 96.6% for NBLQ and 93.9% for MBLQ at a concentration of 10−3M, respectively. Polarization study revealed that the 8-quinolinols acts as mixed-type inhibitors. NBLQ and MBLQ preserved the metal from the corrosive electrolyte by getting adsorbed on the C–S surface following the Langmuir isotherm adsorption model. Thermodynamic variables were assessed for activation and adsorption processes. The C–S surface morphology was investigated using scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDS), which confirmed the formation of a protective thin film on the metal surface. The experimental findings are supported by computational correlations (density functional theory (DFT) and molecular dynamics (MD) simulations). Furthermore, the Fukui function and local softness indices were calculated to identify the most likely nucleophilic and electrophilic attack sites. [ABSTRACT FROM AUTHOR]

The evolution of non-metallic inclusions (NMIs) in the industrial production process of 42CrMo4 medium carbon alloy steel was analyzed by 3D-XRM and 2D methods. The results show that, as refining proceeds, the single-existing Al2O3 inclusions are transformed into Al2O3-CaO and CaS (MgO)-Al2O3-CaO. During the steel refining process, slag particles were entrapped into the molten steel and reacted with the relevant elements. As a result, these particles were eventually incorporated into the billet as large-sized inclusions with a composition similar to that of the refining slag. The MnS precipitation behavior of the non-final composition of the molten steel during solidification throughout the refining process was revealed by experiments and theoretical calculations. Meanwhile, MnS is prone to non-homogeneous nucleation and precipitation on the surface of Al2O3 in the late stage of refining, which is crucial for the modification of MnS and Al2O3. Meanwhile, 3D-XRM technology has successfully performed non-destructive characterization of industrial samples to obtain three-dimensional feature information of inclusions in steel. In combination with traditional 2D characterization and destructive 3D characterization, the data information for the NMIs study can be further expanded. [ABSTRACT FROM AUTHOR]

Improving the corrosion resistance of carbon steel is of great importance to realize widely use in various industries. The anti-corrosion coating is a significant protective strategy. Therefore, uniform aluminum coatings (AlOx-CS), electrodepositing in ionic liquid electrolyte at room temperature, was developed to enhance corrosion resistance of carbon steel. The lower part of the electrode has a better distribution uniformity than the upper part of the electrode, and the distribution of a line has the lowest variance. The uniform AlOx-CS coating is the most corrosion resistant due to sealed Al2O3 layers. The corrosion rate of the AlOx-CS coating is 0.4 mm a−1. The self-corrosion current density of AlOx-CS coating is 34.4 μA cm−2, nearly 2 times compared with pristine carbon steel. The impedance value with AlOx-CS coating is increased by nearly 300 times compared with pristine carbon steel. The morphology and composition of aluminum-based reinforced coatings had no significant changes in atmospheric exposure, 3.5 pct NaCl salt spray and 3.5 pct NaCl immersion environments. The aluminum-based reinforced coatings can enhance the lifespan of carbon steel materials, while also reducing economic losses and safety hazards. [ABSTRACT FROM AUTHOR]

The fatigue life and reliability of wrought carbon steel castings produced with an optimized mold design are predicted using a finite element method integrated with reliability calculations. The optimization of the mold is carried out using MAGMASoft mainly based on porosity reduction as a response. After validating the initial mold design with experimental data, a spring flap, a common component of an automotive suspension system is designed and optimized followed by fatigue life prediction based on simulation using Fe-safe. By taking into consideration the variation in both stress and strength, the stress-strength model is used to predict the reliability of the component under fatigue loading. Under typical loading conditions of 70 kN, the analysis showed that 95% of the steel spring flaps achieve infinite life. However, under maximum loading conditions of 90 kN, reliability declined significantly, with only 65% of the spring flaps expected to withstand the stress without failure. The study also identified a safe load-induced stress of 95 MPa on the spring flap. The findings suggest that transitioning from forged to cast spring flaps is a promising option, particularly if further improvements in casting design reduce porosity to negligible levels, potentially achieving 100% reliability under typical loading conditions. This integrated approach of mold optimization coupled with reliability estimation under realistic service loading conditions offers significant potential for the casting industry to produce robust, cost-effective products. [ABSTRACT FROM AUTHOR]

This article has made an approach towards the multipass turning of AISI 4340 alloy steel with minimum quantity of coolant to determine the Optimal Turning Parameters for simultaneous maximisation of material removal rate and minimisation of surface roughness. Nine experimental runs were planned according to Taguchi's Design of Experiments and performed on Computer Numerically Controlled Lathe Machine with high carbon steel as a tool. The mathematical models developed for surface roughness and material removal rate at different levels of speed, DOC & feed rate are considered as objective functions. Less than 5% error was observed when experimental results were compared with Regression and ANN Models for both responses. A multi-objective genetic algorithm and a Grey relational analysis were used to determine the optimal turning parameters and the results were validated experimentally. The MOGA provides the best optimal parameters for the simultaneous achievement of SR minimisation and MRR maximisation. Results reveal that speed and feed rate have a significant effect on responses. The Pareto Front Plots extracted from MOGA provide the minimum Ra value, 2.32 µm and for the same point, maximum MRR is 6894.22 mm3/min. However, the experimental method could not meet this Ra value, but the recorded minimum was 2.67 µm and the MRR was 6544.79 mm3/min. [ABSTRACT FROM AUTHOR]

This study examines a tragic explosion at Linyuan Petrochemical Park in Kaohsiung, Taiwan, resulting in two fatalities, two severe injuries, and significant financial losses. Taiwan's Industrial Development Bureau (IDB) investigation attributed the incident to a ruptured Ethyl Propyl Diene Monomer (EPDM) rubber hose during catalyst changeover, releasing flammable liquids and triggering a violent vapor cloud explosion. Because of lacking process safety information (PSI), the plant manager failed to identify the risk of incompatibility between EPDM rubber and olefin and failed to replace the EPDM hose with a compatible material or select a carbon steel pipe timely. By not carefully considering the impact of facility siting in the process hazard analysis, TASCO also was unaware that the control room was too close to the process area. As a result, the control room was destroyed at the onset of the accident. Inadequate Management of Change (MOC) impeded the hazard identification for the catalyst changeover procedure, thereby failing to identify defects in this operating procedure. Finally, a false level alarm caused the operator to partially close the control valve downstream of the hose, indirectly leading to the pipe rupture, and this highlights a lack of Mechanical Integrity (MI) in this plant. [ABSTRACT FROM AUTHOR]

The present research deals with the production and characterization of geopolymers prepared by mixing metakaolin with sodium silicate, sodium hydroxide solution and different amounts of electric arc furnace dust derived from the production of carbon steel, to be used by the construction industry. Specimens with compositions containing 90, 80, 70, 60 and 50 g of metakaolin and respectively 10, 20, 30, 40 and 50g of electric arc furnace dust powder were prepared. A blank composition containing metakaolin, sodium silicate, sodium hydroxide solution and free from electric arc furnace dust were also prepared for comparison. After production and hardening, all samples were characterized regarding compressive strength and water absorption. Hardened samples with compositions containing 10 and 30g of electric arc furnace dust were then submitted to a release test in order to evaluate the heavy metals elution. It has been observed that the addition of electric arc furnace dust worsens the pastes workability during their production in this way limiting the amount of electric arc furnace dust which may be added to the geopolymeric matrix. However, samples containing 90 g of metakaolin and 10 g of electric arc furnace dust still maintain fair compressive strength (about 27 MPa), low water absorption (about 28 %) and display limited elution of heavy metals. An additional thermal treatment of 1h at 700 °C, performed to induce sintering of the geopolymeric composites and therefore to reduce their porosity, did not lead to materials with improved performances. [ABSTRACT FROM AUTHOR]

Asphalt is widely used as a coating resin due to its excellent adhesion strength and cost-effectiveness; however, its limited corrosion protection necessitates enhancement. In this study, poly(amidoamine) (PAMAM), combined with zinc oxide (ZnO) nanoparticles, was incorporated into the asphalt matrix to improve its anticorrosive properties. Various ratios of PAMAM-ZnO nanocomposite (1, 2, 4, and 6% by weight) were added to the asphalt binder, with the materials characterized using XRD, ¹H-NMR, and SEM techniques. The 2% PAMAM-ZnO/asphalt ratio exhibited the most significant improvement, achieving a corrosion protection efficiency (η%) of 97.93%, as confirmed by Tafel analysis, and a charge transport resistance (RCT) of 75.91 Ω cm² according to electrochemical impedance spectroscopy (EIS) data. A combination of barrier formation and sacrificial protection drives the corrosion inhibition mechanism. The PAMAM-ZnO nanocomposite forms a highly uniform layer on the carbon steel surface, creating an effective physical barrier that prevents the penetration of corrosive agents, thereby minimizing defects like pinholes. This barrier effect is complemented by the sacrificial protection provided by the ZnO nanoparticles, which are more reactive than the underlying steel and preferentially interact with corrosive ions (e.g., chloride ions). This interaction leads to the formation of stable ZnO corrosion products, which enhance the barrier and reduce the likelihood of corrosion on the steel surface. Additionally, PAMAM facilitates the even distribution and strong adhesion of ZnO within the asphalt matrix, ensuring a durable protective layer. The synergic impact between the polymer barrier and sacrificial ZnO protection results in the exceptional corrosion resistance observed in the 2% PAMAM-ZnO/asphalt formulation, offering a promising approach for advanced anticorrosive coatings. [ABSTRACT FROM AUTHOR]

Local Khulays clay was modified to prepare polystyrene clay nanocomposite (PCN) coatings on carbon steel. The PCN coatings were added to microcapsules (MCs) loaded with the corrosion inhibitor PCN(MC). The microcapsules were prepared by the encapsulation of rare-earth metal Ce+3 ions and isobutyl silanol into polystyrene via the double emulsion solvent evaporation (DESE) technique. From characterization techniques, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) with EDX. SEM and FT-IR confirmed the success of the preparation of the PCN(MC). Nanoindentation tests were performed on the thin-film samples. A significant reduction in both the hardness and the reduced modulus was observed for the PCN film compared to the PS film. Electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) all showed an enhanced protection efficiency (%PE) of 3% PCN(MC) over 3% PCN at high temperatures and at different times. The smart coatings were proven by applying the thermal and the mechanical triggers for the 3% PCN(MC) coating. The mechanism of the release of inhibitors was discussed. The self-healing properties of 3% PCN(MC) were evaluated. The enhanced properties of the developed PCN(MC) coatings make them attractive for potential applications in the oil and other industries. [ABSTRACT FROM AUTHOR]

Cold-finished carbon steel bars were bonded by means of the transient liquid phase bonding (TLPB) process using amorphous metallic foils of the eutectic Fe-B composition as filler material. A homogeneous microstructure throughout the joint was obtained. Traces of borides in the middle of the joint were the only distinguishable microconstituent from the base metal due to the TLPB process. The B concentration profile across the joint was measured by neutron radiography and was found to be composed of a central sharp peak with a maximum concentration of 15.9 ppm B superimposed over a broad peak (base width of ≈ 5 mm) with a maximum concentration of 13.3 ppm B. Owing to this low range of B concentrations, boride precipitation was almost suppressed, and only a scarce number of borides were observed at the joint. The resulting boride structure was identified as Fe23B6 by synchrotron microfocused X-ray diffraction, and its stabilization at room temperature is discussed. The bonded samples were subjected to a bend test, with a bending angle of 180°, and no cracks were observed. In tension tests, the bonded samples attained an ultimate tensile strength (UTS) of 434 MPa, an elongation of 32.3% and a reduction area q of 51.2%—78.6%, 165.6% and 75.4%, respectively, of the base metal. The fracture of the bonded samples occurred at the joint. It was determined that the decrease in UTS compared with that of the base metal was due to the recovery, recrystallization and grain growth that occurred during the TLPB thermal cycle. In addition, from fracture surface observation, it was found that the decrease in q in bonded samples was caused by the presence of traces of borides at the joint, which were the result of the liquid phase that solidified during the cooling stage. [ABSTRACT FROM AUTHOR]

Quenching and partitioning (Q&P) heat treatments have recently gained attention as promising methods for the third generation of advanced high‐strength steels, particularly in industrial applications like automotive. This study investigates the microstructural evolution during Q&P in two medium‐carbon high‐silicon and aluminum‐alloyed steels, exploring potential additional phase transformations controlling the final structure. The choice to focus on Si and Al‐ medium‐carbon steel is linked to the lower cost of these elements compared to commonly alloying elements like Ti, Cr, Mo, and V, while still achieving high mechanical properties through Q&P. The Q&P process is analyzed by varying the volume fraction of primary martensite (M1) at 0.25, 0.50, and 0.75, with partitioning temperatures ranging from 350 to 550 °C for 30 min. At 350 °C, a significant volume fraction of stabilized austenite (up to 0.3) is observed. However, concurrent reactions such as nanostructured bainite and martensite formation lead to deviations from the theoretical constrained carbon equilibrium (CCE). At higher temperatures (450–550 °C), tempering reactions, including cementite precipitation and pearlite formation, reduced the austenite final fraction. The study highlights that heat treatment design, particularly partitioning temperature, must be tailored to the specific steel composition due to the varying effects of Si and Al. [ABSTRACT FROM AUTHOR]

ABSTRACT To evaluate the global seawater corrosivity and ensure the service safety of marine equipment, the methods of seawater corrosivity classification, which contained the standard metal corrosion rates method and the environmental factors evaluation method, are proposed and then applied to the seawater corrosivity classification in typical China seas. By comparing the results from both methods, the feasibility of the environmental factors evaluation method based on the grey relational model is verified. Furthermore, with the collection and processing of typical seawater factors data of global ocean, the corrosivity of global seawater is classified into six grades with the corrosion test data of carbon steel as baseline, and its distribution in different months is visualized by means of ArcGIS technology. The results show that the sea areas with high corrosivity are mainly located at equatorial and tropical sea areas, and for carbon steel, seawater temperature was the main influence on seawater corrosivity. [ABSTRACT FROM AUTHOR]

ABSTRACT Dissimilar metal welds are utilized in the energy industry to connect two materials with different material characteristics. In the case of nuclear power plants, the connected materials tend to be low‐alloyed steel and high‐alloyed material. Despite different material and corrosion properties, under the proper environmental conditions, the used construction materials and weld metals are protected either by a passive layer or by a high‐temperature oxide. Although dissimilar metal welds are used in both primary and secondary circuits, the most frequently documented damage is in the secondary circuit, where, in addition to material heterogeneities, local environmental heterogeneities may form. For dissimilar metal welds in WWER nuclear power plants, a water–water energetic reactor, a subtype of pressure water reactor, we note two main types of attack near the dissimilar fusion boundary: on the carbon steel side or on the high‐alloyed weld metal side (X10CrNiMoN16‐25‐6). The possible causes of the latter “atypical” corrosion attack are debated and can be generalized as a consequence of change of the grain boundary condition. [ABSTRACT FROM AUTHOR]

In this paper, the interface structure and carbon diffusion of stainless steel–carbon steel-laminated composites after heating at different temperatures and times are studied. The experimental results show that the interface structure of the stainless steel–carbon steel-laminated composite is composed of a decarburization layer of carbon steel, an intermetallic compound layer and a carburization layer of stainless steel. When the heating temperature is lower than 500 °C, the interface structure basically does not change over heating time. When the heating temperature is between 550 and 850 °C, as the heating time increases, the stainless steel undergoes sensitization, and the carbon diffuses from carbon steel to stainless steel. The diffusion rate is positively related to the susceptibility to the intergranular corrosion of stainless steel, resulting in an increase in the thickness of the decarburization layer of carbon steel, the further carburization of stainless steel and an increase in the degree of sensitization of the stainless steel surface. When the heating temperature is larger than 900 °C, as the heating time increases, carbon steel undergoes austenitization, stainless steel undergoes solid solution strengthening, and carbon diffuses from the stainless steel to the carbon steel, resulting in the disappearance of the decarburization layer of carbon steel and the carburization layer of stainless steel. In this paper, a reference is provided for the heat treatment temperature set and the service temperature upper limit of the stainless steel–carbon steel-laminated composite. [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]

Synthetic textiles such as polyesters are essential for daily life. However, large‐scale production generates large amounts of waste. This study introduces a new approach for valorising polyester textile waste (PTW) by transforming it into a catalyst for biodiesel production via pyrolysis. Specifically, a metal/carbon composite (PTW + steel slag [SS] composite—PSC) with enhanced catalytic properties was prepared by pyrolysing PTW with SS. The alkaline metals in SS facilitate the carbonisation of PTW via decarboxylation, resulting in a PSC rich in carbon, iron, and alkaline compounds. This composite featured mesopores that were larger than the micropores (MPs) typically found in PTW char. The use of porous material (silica) in thermally induced transesterification has been proven to be an efficient method for biodiesel production, achieving a yield of 97.20 wt.% in 1 min (faster than the 93.82 wt.% yields in 60 min observed from conventional alkali‐catalysed transesterification). However, the high reaction temperature (≥ 360°C) poses economic/technical challenges. To overcome this, PSC has been employed as a catalyst in thermally induced transesterification, leveraging its mesoporous structure and high alkaline content, particularly calcium oxide. The PSC achieved a biodiesel yield of 98.10 wt.% at a markedly lower reaction temperature of 120°C within 1 min. This performance was not attainable using silica or PTW char under similar conversion conditions. These findings highlight the potential of PSC produced through the pyrolysis of PTW and SS as effective catalysts for biodiesel production. This process is a promising strategy for converting waste into valuable resources and mitigating the environmental impacts associated with polyester waste. [ABSTRACT FROM AUTHOR]

In this investigation hot rolled steel bars of 1.24 weight % carbon steel are subjected to incomplete austenitization based cyclic quenching treatment. Each cycle consists of inserting the specimen in an electric resistance furnace at a temperature of 894 °C and holding for a short duration (6 minutes), followed by oil quenching to the room temperature. Such a typical thermal cycling results in the evolution of a novel microstructure that comprises of large clusters and blocks of cementite in a matrix of martensite after 3 and 4 cycles. Accordingly, a significantly high hardness (7.13 GPa) is achieved on execution of 3 cycles which envisages a new pathway of incomplete austenitization based cyclic quenching treatment for development of new‐generation plain carbon hypereutectoid tool steel. [ABSTRACT FROM AUTHOR]

Purpose: Machinery operating in a sand-dust environment is more susceptible to sand particles. The purpose of this paper is to investigate the impact of sand particle deposition rate, surface hardness and normal load on the tribological performance. Design/methodology/approach: A predictive model to approximate the number of sand particles within the pin-on-disc contact surface is proposed. The efficacy of the model is validated through experimental method, which replicates a sand environment with two distinct particle deposition rates. Dry sliding friction experiments are also conducted using 45 carbon steel and H90 brass pins against GCr15 bearing steel discs. Findings: When at high particle deposition rate [6.89 × 10–5 g/(s·mm2)], the contact surfaces are separated by particles, resulting in an indirect metal contact. While at low deposition rate [6.08 × 10–8 g/(s·mm2)], there is an alternating occurrence of direct and indirect metal contacts. In sand environment, the specific wear rate of 45 and H90 decreases by 50% and 33%, respectively, compared to non-sand environment when the applied load is 2.45 N. However, it is only 0.18% for 45 but remains significant at 25% for H90 at load of 9.8 N. Originality/value: The predictive model and experimental method used in this paper are helpful for understanding the interaction between particles and sliding surfaces, thereby providing a solid foundation for material selection and load optimization of friction pairs influenced by sand-dust environments. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2024-0155/ [ABSTRACT FROM AUTHOR]

Pipe-type cable systems, including high-pressure fluid-filled (HPFF) and high-pressure gas-filled cables, are widely used for underground high-voltage transmission. These systems consist of insulated conductor cables within steel pipes, filled with pressurized fluids or gases for insulation and cooling. Despite their reliability, faults can occur due to insulation degradation, thermal expansion, and environmental factors. As many circuits exceed their 40-year design life, efficient fault localization becomes crucial. Fault location involves prelocation and pinpointing. Therefore, a novel pinpointing approach for pipe-type cable systems is proposed, utilizing accelerometers mounted on a steel pipe to capture fault-induced acoustic signals and employing the time difference of arrival method to accurately pinpoint the location of the fault. The experimental investigations utilized a scaled-down HPFF pipe-type cable system setup, featuring a carbon steel pipe, high-frequency accelerometers, and both mechanical and capacitive discharge methods for generating acoustic pulses. The tests evaluated the propagation velocity, attenuation, and pinpointing accuracy with the pipe in various embedment conditions. The experimental results demonstrated accurate fault pinpointing in the centimeter range, even when the pipe was fully embedded, with the acoustic pulse velocities aligning closely with the theoretical values. These experimental investigation findings highlight the potential of this novel acoustic pinpointing technique to improve fault localization in underground systems, enhance grid reliability, and reduce outage duration. Further research is recommended to validate this approach in full-scale systems. [ABSTRACT FROM AUTHOR]

In this study, the synthesis of a long-chain aliphatic amino compound and its sour corrosion inhibition properties were reported. Oleylamine was obtained through the reaction of 4-(Aminomethyl) pyridine with 1-chloro-octadecane. The identification and characterization of reaction products were carried out through Fourier transform infrared spectroscopy (FTIR) and gas chromatography/mass spectroscopy (GC-MS). Oleylamine was tested as a sour corrosion inhibitor for steels. Different concentrations of oleylamine (0, 5, 10, 25, and 100 ppm) in a sour saline electrolyte were analyzed. The dynamic anticorrosive behavior of oleylamine on carbon mild steel (AISI 1018) surfaces was evaluated using a laminar flow of 100 rpm and tested with potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) measurements. After electrochemical testing, the surface of the steel specimens that were used was characterized with Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The electrochemical results of the anticorrosive efficiency of oleylamine for steel showed an exponential behavior as a function of inhibitor concentration. At a concentration of 20 ppm of the inhibitor, the anticorrosive efficiency did not show any significant changes. However, at 100 ppm of the inhibitor, an efficiency of over 95% was achieved. After the electrochemical tests, the surface of the steel samples with the inhibitor revealed the formation of an inhibitor layer that prevented the corrosion of the steel. [ABSTRACT FROM AUTHOR]

Geothermal energy generation faces challenges in efficiency, partly due to restrictions on reinjection temperatures caused by scaling issues. Therefore, developing strategies to prevent scaling is critical. This study aims to simulate the scaling tendencies and corrosion effects of geothermal fluids on various construction materials used in scaling reactor/retention tank systems. A range of materials, including carbon steel, austenitic stainless steel, duplex stainless steel, two proprietary two-part epoxy coatings, and thermally sprayed aluminium (TSA), were tested in a simulated geothermal brine. Experiments were conducted in a laboratory vessel designed to replicate the wall shear stress conditions expected in a scaling reactor. The tests revealed varying scaling tendencies among the materials, with minimal corrosion observed. The dominant scale formed was calcium carbonate, consistent with geochemical modelling. The findings suggest that despite the high operating temperatures, the risk of corrosion remains low due to the brine's low chloride content, while the wettability of materials after immersion may serve as a useful indicator for selecting those that promote scaling. [ABSTRACT FROM AUTHOR]

In the construction area, as well as in the restoration of old and historical buildings, different metallic materials are frequently in contact with gypsum plaster. Due to the high porosity of gypsum plaster, and particularly in high relative humidity environments, the risk of corrosion exists. In the present work, carbon, galvanized and stainless steel, as well as copper, were embedded in gypsum plaster (with varying water/gypsum ratios) and exposed to different environmental conditions, and the corrosion rate was assessed by electrochemical techniques. Stainless steel showed very low corrosion rates, carbon and galvanized steel showed considerable corrosion rates, and copper showed moderate corrosion rates. The higher the humidity, the higher the corrosion rate, independently of the water/gypsum ratio. A comparison with results obtained for the same materials embedded in mortar was performed. Except for stainless steel, the corrosion rates obtained in gypsum are higher than those obtained in mortar, being this difference up to two orders of magnitude. The differences in the pH of both matrices explained the lower corrosion rates measured in mortar. [ABSTRACT FROM AUTHOR]

The Cuban coastal line is reported to be one of the most aggressive in the world. Three ways to estimate corrosivity category of the atmosphere were considered. The influence of meteorological parameters on chloride deposition rate (Sd) $({S}_{d})$ in saline solution form was considered as a first way. Corrosion rate (rcorr) $({r}_{\text{corr}})$ calculated by dose response function is considered a second way. It was confirmed that atmospheric corrosion of AISI‐1020 carbon steel is influenced by Sd ${S}_{d}$ and Pd ${P}_{d}$ in salt solution form. A critical Sd ${S}_{d}$ level from which rcorr ${r}_{\text{corr}}$ could increase was estimated. The presence of typical crystalline phases of carbon steel confirmed that formation mechanism led to cracking of the corrosion products layer. It justified the increase of rcorr as a function of time until reaching a very high (C5) corrosivity category as the third assessment way. rcorr ${r}_{\text{corr}}$ was predicted up to 20 years of exposure. A correspondence between the three assessment ways existed. [ABSTRACT FROM AUTHOR]

Industrial boilers operate in extreme environments and are prone to degradation caused by high temperature oxidation, corrosion, and erosion. Protective coatings provide boiler components with protection to prolong their operation lifetime. Thus, a glass-ceramic coating has been developed using a slurry spray technique on carbon steel AS/NZS 3678 substrates. Microstructure, mechanical characteristics, and high temperature performance of the coating were investigated. The coating composed of chemically inert oxide ceramics dispersed in a glassy silicate binder matrix. The adhesion strength of the coating was 10.79 ± 0.86 MPa. Coating mass loss after abrasion test was 0.013 % of the tested specimen. The coating withstood at least 75 air quenched thermal shock cycles from 800 °C to the room temperature without any visible spallation and cracks. The coating mostly remained undamaged after cyclic oxidation at 800 °C for 10 cycles. However, minor iron oxide formation was observed, specifically, in relatively thin sections of the coating. The oxidation resistance of the boiler steel has been improved with the developed coating. The linear oxidation rate constant of the boiler steel has been statistically reduced from 6.90 × 10−4 mg cm−2 s−1 to 1.95 × 10−4 mg cm−2 s−1 for coated steel (p = 0.007). The developed slurry spray glass-ceramic coating is a potential candidate for boiler environments. [ABSTRACT FROM AUTHOR]

High-temperature processes induce creep and corrosion, primarily resulting in failure of thin-walled pressure vessels. Investigating alloy creep behavior in these vessels is crucial due to its often undetected nature, leading to sudden and costly failures, posing irreversible risks to health and the environment. This study investigates the creep behavior of carbon steel A516-Gr70 at different loads at a constant temperature of 600 °C. The specimens were subjected to high-temperature creep tests until failure at the specified temperature and at different loads of 100, 150, and 250 kg. The results indicated a nearly linear correlation between the creep rate in the stable region and the applied load. Additionally, it was observed that utilizing the hardness versus time-to-failure diagram enables the prediction of the remaining creep life of the components. [ABSTRACT FROM AUTHOR]

The high-temperature shaping of steels is accompanied by the formation of surface scales composed of oxide layers. However, the oxidation kinetics and morphology of these scales remain poorly understood. This study analyses the formation of oxide layers on AISI 4140 steel at varying oxidation times (20, 40 and 60 min) at 1000 °C. The analysis revealed the presence of hematite, magnetite, and transformed wustite in the oxide layers, along with clusters of alloying element oxides, predominantly chromium and iron oxide (FeCr2O4). There was a direct correlation between the duration of the oxidation process and the thickness of the scale and the number of defects observed in the material. The coating layer of alloying element oxides demonstrated insufficient adhesion to the steel substrate. Similarly, the oxides of alloying elements within this layer exhibited low cohesion among themselves. The alloying elements are present in all oxide layers, but in greater quantity in the layer in contact with the steel substrate, where a reduction in their concentrations was observed over time. This indicates that the alloying elements tend to disperse as the thickness of the alloying element oxide layer increases over time. [ABSTRACT FROM AUTHOR]

Currently, the demand for heat production by geothermal energy is increasingly strong amid the controversy surrounding non-renewable forms of energy. In France, the Dogger aquifer in the Paris Basin (DAPB) produces saline geothermal waters (GWs) that are hot (70–85 °C), anaerobic, and slightly acidic (pH 6.1–6.4), and are characterized mainly by the presence of Cl−, SO42−, CO2/HCO3−, and H2S/HS. These GWs are corrosive, while the well casings used are carbon steel. GWs have been continuously treated since the 1990s by corrosion inhibitors at the bottom of production wells to reduce water–steel interactions and scaling issues. Electrochemical experiments to optimize inhibitors were carried out on site, protected from the ambient atmosphere, with actual geothermal water, using water tapping at the wellhead. Currently, carbon steel corrosion/scaling, corrosion inhibition phenomenology, and kinetics evaluation remain important challenges. These issues are, of course, linked to the durability of installations. The novelty of our work consists of our validation of a modus operandi that properly reproduces, at the laboratory scale, operating conditions similar to those encountered on the types of geothermal installations. Particular attention was paid to characterizing waters and gases from 13 production wellheads that were modelled with PhreeqC® Version 3 hydrogeochemical software and the Thermoddem thermodynamic database for implementing standardized reconstituted geothermal water (SRGW), a well-balanced water representative of the major elements and dissolved gases of actual DAPB geothermal waters. The developed electrochemical setup enabled us to analyze corrosion mechanisms such as those observed on site and to investigate corrosion inhibition using petrosourced and biosourced inhibitors. The modus operandi constitutes a reference for further investigations, at the laboratory scale, of corrosion inhibition. These investigations may include screening and optimizing the formulas of petrosourced and biosourced inhibitors for use in DAPB waters. [ABSTRACT FROM AUTHOR]

Recently, due to special regulations concerning environmental issues, the traditional inhibitors were replaced by green-/natural-based environmentally friendly inhibitors including plant extracts. The present work was investigated to evaluate the apple pomace extract as a potent renewable chemical for inhibiting the metal corrosion progress in a 1 M HCl aquatic solution. After the addition of 1000 ppm apple pomace extract, the electrochemical impedance spectroscopy (EIS) and polarization approaches showed that the steel inhibition index was raised to 90% by controlling the metal dissolution and H-evolution mechanisms. The weight loss study results proved 89% corrosion inhibition efficiency by introducing 1000 ppm apple pomace extract into HCl-containing media. The atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM) surface studies reflected high smooth steel substance availability after inhibition, and contact angle outcomes displayed the semi-hydrophobic nature of the inhibited surfaces. The thermodynamic and adsorption isotherm mechanism evaluation results displayed that the protection occurred via monolayer inhibitor film construction by endothermic adsorption interactions. The entropy values fluctuated between − 75.82 and 0.65 kJ.mol−1 which are responsible for the physical/chemical adsorption types. [ABSTRACT FROM AUTHOR]

This review summarizes the use of film-forming amines (FFAs) for corrosion protection in water/steam industrial circuits, focusing on carbon steel. It discusses industrial feedback on FFAs' benefits and challenges, alongside experimental methods for studying their inhibition and structural properties. Key research areas include FFAs' corrosion inhibition mechanisms, adsorption kinetics, and layer structures. The review also identifies knowledge gaps and suggests future research directions to deepen the understanding of FFAs. [ABSTRACT FROM AUTHOR]

In this paper, an attempt was made to determine the load-bearing capacity of a bonded joint of galvanized steel elements with carbon fiber reinforced polymer (CFRP) fabric. This issue is extremely relevant to the use of bonded carbon fiber fabric as a mean of reinforcing hot-dip galvanized steel structures. This technique is used in engineering practice for both hot-rolled and cold-formed steel elements. In order to obtain the necessary parameters for modelling bonded joints of galvanised steel thin-walled elements, laboratory tests were carried out. In the first stage, four specimens made of 50 mm diameter steel cylinders bonded to 16 mm thick hot-dip galvanised steel sheet of S350 GD were subjected to the pull-off test. In this connection the SikaWrap 230C composite fabric embedded in SikaDur 330 adhesive layer was investigated. In the second stage, the axial tensile test of the bonded butt joint using the same materials was performed. In this stage, 10 hot-dip galvanised steel sheet samples of S350 GD and 16 mm thickness were tested. The discussion on the failure mechanism in the context of the bonding capacity of the composite joint was carried out. Moreover the advanced numerical model using the commercial FE program ABAQUS/Standard and the coupled Cohesive Zone Model was developed. The significant influence of the preparation method of steel element surface and the thickness of the adhesive layer on the failure mechanism of the joint and the value of the maximum failure force was shown. [ABSTRACT FROM AUTHOR]

Because conventional inhibitors are nonbiodegradable and harmful, the development of ecofriendly corrosion inhibitors is gaining popularity. The anti-corrosive efficacy of 2-(2-Methyl-5-nitro-1H-imidazol-1-yl) ethanol on carbon steel in an chloride solution was evaluated in this study using a variety of approaches such as electrochemical measurements and computational studies. The results showed that increasing the concentration of 2-(2-Methyl-5-nitro-1H-imidazol-1-yl) ethanol from 0.1 to 3.0 g/L enhanced the inhibition efficiency (IE%) to 90.18-91.71 %. The high ΔE(eV) value of 0.239 and the interaction and binding energies of - 995.45 and 995.45 for 2-(2-Methyl-5-nitro-1H-imidazol-1-yl) ethanol molecules onto Fe (110) substrate were further supported by quantum chemical analytics, which also supported the empirical results. The results show that 2-(2-Methyl-5-nitro-1H-imidazol-1-yl) ethanol has a bright future as an effective and environmentally safe inhibitor for preventing carbon steel from corroding in corrosive media. [ABSTRACT FROM AUTHOR]

Aluminum-modified plasma nitriding was developed in this research by the addition of a few FeAl particles around samples of 42CrMo middle carbon alloy steel during plasma nitriding. The goal of this study was to enhance nitriding efficiency and the combined performance of the steel. The research results show that nitriding efficiency was greatly enhanced, by about 6 times, with the effective hardening layer rising from 224 μm to 1246 μm compared with traditional plasma nitriding at 520 °C/4 h. More importantly, the compound layer increased just a little bit, from 11.64 μm to 14.32 μm, which remarkably reduced the ratio of the compound layer's thickness to the effective hardening layer's thickness, thus being quite beneficial to decreasing the brittleness level, making the brittleness level decrease from Level 4 to Level 1. Also, extremely high surface hardness and excellent wear resistance were obtained by aluminum-modified plasma nitriding due to the formation of hard phases of AlN and FeAl in the nitrided layer, with the surface hardness rising from 755 HV0.025 to 1251 HV0.025 and the wear rate reducing from 8.15 × 10−5 g·N−1·m−1 to 4.07 × 10−5 g·N−1·m−1. In other words, compared with traditional plasma nitriding, wear resistance was enhanced by two times after aluminum-modified plasma nitriding. Therefore, this study can provide comprehensive insights into the surface characteristics and combined performance of aluminum-modified plasma nitriding layers. [ABSTRACT FROM AUTHOR]

The effect on the corrosive behavior of three new-type Si-based weathering steel and the addition of Ni, Mo, and Mn was investigated. Carbon steel was used for comparison. For this purpose, wet/dry cyclic corrosion tests for 6, 15, 30, 45, and 60 cycles, each cycle lasting seven days, were conducted in simulated industrial environments. Mass loss measurements estimated the corrosion rate. The oxide layer was analyzed by electrochemical impedance spectroscopy (EIS), and rust formation was investigated by SEM microscopy. X-ray diffraction (XRD) was used to determine the crystalline structure of corrosion products produced after exposure. The weathering steel with a higher amount of Si and the one with the addition of Ni, Mn, and Mo had the lowest corrosion rates and presented similar corrosion performance after 15 cycles. The rust layer formed in the simulated industrial environment is rich in the α-FeOOH phase, and its amount increases with exposure time. [ABSTRACT FROM AUTHOR]

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This review paper examines the techniques and factors involved in pipe wall processing, with a focus on the essential technologies utilized in this field. The study revealed crucial elements, such as ASTM A350-LF2 Class 1 carbon steel, renowned for its exceptional mechanical qualities and ability to withstand low temperatures. An exhaustive analysis has been conducted on the chemical makeup of this steel to comprehend its capacity to adjust and endure in various operational environments. The study focused on examining several particle separation processes, including as turning, milling, drilling, and grinding, in order to determine the exact equipment and criteria needed for each technique. The cooling and lubricating process received particular emphasis, with thorough investigation of several agents, including CASTROL HYSOL T15, and their impact on surface quality and tool longevity. The utilization of these compounds has been discovered to substantially decrease tool temperature and enhance machining quality. Upon closer examination of the processing techniques specified in section A-A of the tube wall, it was determined that advanced procedures such as floating plug drawing and micro-sized spiral tube hydroforming were discovered. These techniques allow the attainment of superior surface quality and precise dimensions, which are crucial for guaranteeing the structural integrity of the pipe. Cutting tools, processing equipment, and coolants and lubricants are essential components in the manufacturing of pipe walls. Nanoparticulate cooling and lubrication systems, which are advanced technologies, have demonstrated their effectiveness in minimizing friction and heat during machining. As a result, these systems enhance productivity and prolong the lifespan of tools. According to the article, the essential components for attaining high-quality manufacture of pipe walls are cutting tools, processing equipment, and coolants and lubricants. Additional study is advised to enhance processing parameters, create ecofriendly coolants and lubricants, and utilize artificial intelligence for predictive modeling and optimization of processing. This establishes the groundwork for future research and innovation in the pipe wall production business, with the objective of attaining enhanced efficiency and sustainability in production processes. [ABSTRACT FROM AUTHOR]

This study investigates the efficacy of newly synthesized inhibitor with a dual function of corrosion inhibition and biocide for control of microbial influenced corrosion (MIC) in carbon steel API 5LX in the cooling tower water (CTW) environment. Four types of N-substituted tetrabromophthalic inhibitor (N-TBI) were synthesized, and the structural characterization was performed via proton nuclear magnetic resonance spectroscopy, thermogravimetric analysis and high-resolution mass spectrometry. These studies revealed the distinctive optical, thermal, and dielectric properties of the synthesized inhibitors. The corrosion inhibition efficiency has been evaluated by the weight loss (WL) analysis and electrochemical measurements (ECM) and biofilm assay. Biofilm assays and WL showed that inhibitor II exhibited the highest inhibition efficiency 74% and 79% respectively than others. Further ECM showed that the higher charge transfer resistance and the lower corrosion current, suggesting a protective film formed on the metal surface which was due to the adsorption of the N-TBI. Fourier transform infrared spectroscopy confirmed the adsorption of the N-TBI as C–O stretching and C–H bending with the Fe complex. X-ray diffractometer revealed that the presence of inhibitors in the corrosion product (Fe3O4, Fe2O3, FeH2O2, FeS) were highly reduced than the control system. Overall, this study highlighted the potential application of N-TBI with dual function of corrosion inhibition and biocide to control the MIC for carbon steel API 5LX used in the CTW environment. [ABSTRACT FROM AUTHOR]

In this research, the microstructure of three melt‐spinning ribbons with a weight‐based composition of Fe–25Cr–5Ni and varying carbon contents (0.02, 0.10, and 0.38 wt%) is evaluated. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are used for microstructural characterization. SEM analyses consist of image acquisition and electron backscatter diffraction. TEM analyses consist of bright‐field image acquisition, selected area electron diffraction, high‐resolution TEM, and local chemical composition measurements by energy‐dispersive X‐ray spectrometry. According to the results, the ribbons show different microstructures resulting from different solidification paths. The ribbon containing 0.02%C presents a predominantly ferritic microstructure, and austenite solid‐state precipitation is not suppressed. It occurs as grain‐boundaries allotriomorphs and secondary Widmanstätten side plates. As a result of carbon additions, the ribbon containing 0.10%C shows a microstructure composed of nearly equal parts ferrite and austenite, along with M23C6 (M = Cr15.6Fe7.4) nanometric carbides. The cube‐on‐cube orientation relationship is found between M23C6 and austenite. Lastly, the ribbon containing 0.38%C exhibits austenitic microstructure with islands of ferrite surrounded by M7C3 (M = Cr4.14Fe2.86) carbides. [ABSTRACT FROM AUTHOR]

The interaction of microalgae on the reinforced concrete with corrosion inhibitor is not well understood. Moreover, the inhibition role of microalgae on corrosion has been reported in recent years. In this study, the corrosion inhibition behavior of Q235 carbon steel (CS) due to the presence of Chlorella sp. and benzotriazole (BTA) in alkaline artificial seawater was investigated by means of weight loss, electrochemical measurements including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization curves, and surface analysis including scanning electron microscopy, energy dispersion spectrometer, and X-ray photoelectron spectroscopy. The results of reduced corrosion rates in the algae-BTA system demonstrated that Chlorella sp. could facilitate the corrosion inhibition efficiency of BTA on the CS specimens. Moreover, polarization measurement showed the algae-BTA system had a mixed-type corrosion inhibition effect. The mechanisms of inhibition were proposed to be the precipitation of iron complexes such as Fe-BTA-EPS and Fe-BTA and iron compounds on the steel surface in the presence of the microalgae and BTA–. This study highlights the application of CS corrosion control by combining biological and chemical approaches that can be used for future research and practice, rather than purely chemical approaches. [ABSTRACT FROM AUTHOR]

In the pickling process and acidizing program for oil wells, the acidic corrosion of metals is a problem that needs to be addressed. Various acid corrosion inhibitors have been studied and used to mitigate the acidic corrosion of carbon steel. In this paper, the corrosion inhibition of 2‐aminobenzothiazole (2 N‐BT), 2‐amino‐4‐hydroxybenzothiazole (2 N4O‐BT), and 2‐amino‐6‐hydroxybenzothiazole (2 N6O‐BT) on carbon steel in 0.5 mol/L HCl was investigated using electrochemical and quantum chemical methods. All three molecules exhibited corrosion inhibition effects. Compared to 2 N‐BT, 2 N4O‐BT and 2 N6O‐BT showed less sensitivity to the environmental conditions and the surface state of the metal. Among them, 0.0010 mol/L 2 N6O‐BT demonstrated the highest and most persistent corrosion inhibition, exhibiting a mixed inhibition mechanism with cathodic inhibition dominance. The adsorption of 2 N6O‐BT on the carbon steel surface was found to be non‐uniform, preferentially adsorbing at certain active sites on the surface, following Freundlich‐Langmuir thermodynamic characteristics. It showed initial strongly adsorbed points and weakly adsorbed regions. With continued adsorption of 2 N6O‐BT, the differences between strongly adsorbed points and weakly adsorbed regions decreased. The introduction of hydroxyl groups, especially in 2 N6O‐BT, extended the negative potential region and enhanced the coordination activity of the molecule, generating the orbital distribution that was advantageous to flat adsorption and the formation of feedback bonds. This provided a molecular structural basis for the excellent corrosion inhibition properties of 2 N6O‐BT. [ABSTRACT FROM AUTHOR]