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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]

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]

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 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]

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 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]

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]

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]

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]

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]

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 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]

The oxygen evolution reaction (OER) presents a major challenge for water splitting due to its slow kinetics. In this study, Co-Fe-Gr nanocomposite coatings were developed on carbon steel via electrodeposition using graphene (Gr) at concentrations of 0.02, 0.04, and 0.06 g/L to enhance OER performance. The sample with 0.02 g/L Gr exhibited a unique cauliflower-like morphology with aligned cobalt, as revealed by FE-SEM, leading to an increased electrochemical surface area. This optimal nanocomposite (Co-Fe-Gr (0.02 g/L)) demonstrated a low overpotential of 88 mV at 10 mA cm2, high stability (4.2 mF cm⁻2), and low resistance (R = 7.5 Ω cm⁻2). Additionally, it showed a small Tafel slope of 6.6 mV/dec and maintained stability after 12 h. A turnover frequency (TOF) of 73.6 s⁻1 indicated that graphene doping significantly reduced the adsorption energy of intermediates, greatly enhancing OER activity for efficient water splitting applications. [Display omitted] • Co-Fe-Gr nano-composite electrocatalysts were fabricated using an electrodeposition process. • Increasing the Gr content increased the Gr sheets and reduced the number of active sites. • The Co-Fe-Gr (0.02 g/L) with cauliflower-like morphology had an electrochemically active surface. • The Co-Fe-Gr (0.02 g/L) nano-composite showed the highest electrocatalytic activity. [ABSTRACT FROM AUTHOR]

The focus of this research is to examine the feasibility of using laser texturing as a method for surface preparation prior to thermal spraying. The experimental part includes the thermal spraying of a Stellite 6 coating by High Velocity Oxygen Fuel (HVOF) technology on laser-textured substrates. The thermal spraying of this coating was deposited both on conventional substrate material (low carbon steel) and on substrates that had been previously heat treated (nitrided steel). The properties of the coatings were analysed using scanning electron microscopy (SEM), optical microscopy (OM) and Raman spectroscopy. Adhesion was assessed through a tensile adhesion test. The results showed the usability of laser texturing in the case of carbon steel, which was comparable or even better than traditional grit blasting. For nitrided steel, the problem remains with the hardness and brittleness of the nitrided layer, which allows for the propagation of brittle cracks near the interface and thus reduces the adhesion strength. [ABSTRACT FROM AUTHOR]

In this investigation, the efficacy of PCA-GLU, a polymer obtained by copolymerizing citric acid and glutamic acid, as a corrosion inhibitor for carbon steel was investigated in a 3.5wt% NaCl solution. Electrochemical impedance spectroscopy (EIS) techniques and potentiodynamic polarization (PDP) measurements were used to evaluate the corrosion inhibition. The findings demonstrate that PCA-GLU has a 96.73% corrosion inhibition efficiency. Additionally, when the inhibitor concentration rises, the corrosion inhibition efficiency rises as well, reaching an ideal concentration of 400 mg/L. Furthermore, PCA-GLU can create an adsorption layer on the surface of Q235. This paper verifies the adsorption mechanism of PCA-GLU through molecular dynamics simulations of the system and quantum chemical calculations of corrosion inhibitors in solution. Ultimately, our research findings validate that PCA-GLU is an efficient corrosion inhibitor in safeguarding carbon steel against corrosion in marine environments. [ABSTRACT FROM AUTHOR]

In this present work, a damage-coupled cyclic plasticity model has been developed for more accurate ratcheting–fatigue life estimation under strain and stress controlled ratcheting. Ratcheting–fatigue damage behavior under uniaxial multistep strain-controlled ratcheting shows that the incremental mean ratcheting strain deteriorates the elastic slopes cycle by cycle, by means of ratcheting damage. Severe ratcheting strain accumulation rate has been observed in tertiary region under uniaxial stress controlled ratcheting. The proposed damage-coupled model has been constructed which incorporates both fatigue damage and damaging effect of the accumulated mean plastic strain. The proposed model incorporates a critical fatigue damage parameter which can predict effects of early fatigue crack nucleation due to combined ratcheting and fatigue damages. The performance of the proposed damage-coupled model has been investigated in the present study based on the critical fatigue damage parameter. The proposed model is calibrated on experimental data of SA333 Gr. 6 carbon steel and SA508 Gr. 3 steel. The proposed formulations have been applied in user material subroutine UMAT of finite element software, ABAQUS. The proposed model has been validated by comparing predicted ratcheting behavior with experiments for the two different steels. All the predicted number of cycles to failure are located within 0.5 times error band. The proposed damage-coupled model has demonstrated excellent capabilities of predicting ratcheting–fatigue life under cyclic loading with ratcheting damage. [ABSTRACT FROM AUTHOR]

The carbon steel pipe line of the dehydrogenation tail gas system in a certain styrene unit has a thinning rate of 55.51% and a corrosion rate of up to 5.29 mm/a after one year of use, which restricts the long-term stable operation of the plant. The corrosion of the dehydrogenation tail gas carbon steel pipeline was inspected through electromagnetic eddy current scanning, ultrasonic thickness measurement, and macroscopic inspection. The impact of corrosive medium, process operating parameters, on-site pipeline location and material on pipeline thinning in the dehydrogenation tail gas system was analyzed. The results indicate that the localized corrosion and thinning of the dehydrogenation tail gas carbon steel pipeline are caused by a combination of carbon dioxide corrosion and erosion corrosion under certain temperature and pressure. To alleviate corrosion issues, it is recommended to re-evaluate the process operating conditions of the dehydrogenation tail gas system, add cooling equipment before the dehydrogenation tail gas compressor, or upgrade the pipeline material to 304 austenitic stainless steel. Or consider adding corrosion inhibitors to the dehydrogenation exhaust system. At the same time, regular electromagnetic eddy current scanning or ultrasonic thickness measurement should be carried out to monitor the relevant pipelines and prevent leaks in a timely manner. [ABSTRACT FROM AUTHOR]

Within the scoop of environmental sustainability, the elaboration of efficient inhibitors using biomaterials was investigated. Beginning with careful extraction of lignin from raw Alfa fibers. Following this, the study examined the synthesis and characterization of a new generation of corrosion inhibitors based on clays and lignin biopolymer. A comprehensive characterization of powder samples sepiolite-lignin (SP-L) and bentonite-lignin (BN-L) was executed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR) analysis and scanning electron microscopy (SEM) images. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were conducted on carbon steel immersed in 3%NaCl solution containing SP-L and BN-L composites, showing an interesting inhibition efficiency of 92.0% and 90.2%, respectively. The surface characterization of carbon steel, subsequent to immersion in 3%NaCl solution without and with SP-L or BN-L was conducted using XRD, FT-IR and SEM coupled with energy-dispersive X-ray spectroscopy analysis. Interestingly, the results of the blank sample revealed a deposition of corrosion products; mainly FeO(OH), Fe3O4 and iron carbonate (FeCO3), while SP-L and BN-L samples revealed an organic layer adsorbed onto the CS surface acting as a protective barrier. [ABSTRACT FROM AUTHOR]

This study investigates the effect of pressure (burn‐off and forging) on the mechanical properties of the joint between a wear‐resistant tool steel and a low‐alloy steel using linear friction welding. The authors have previously demonstrated the feasibility of joining these dissimilar materials, but the impact of pressure on the mechanical properties of the bimaterial joint remains unclear. To address this, weld samples are prepared using different pressures and are characterized through microstructural analysis, microhardness, tensile testing, and fractography. The results show that the strength of the joint between the wear‐resistant tool steel and the low‐alloy carbon steel increases as the pressure increases up to a certain point, after which a decrease is observed. The highest joint strength is achieved at a pressure of 360 MPa. The microhardness profile measurement reveals a distinct transition zone at the interface between the two materials, with varying hardness values. The hardness of the low‐alloy carbon steel increases near the interface, while that of the wear‐resistant tool steel decreases. This transition zone is found to be narrower at higher pressures. Microstructural characterization shows that the grain structure near the interface differs from that of the starting base materials. [ABSTRACT FROM AUTHOR]

The curcumin‐malic acid‐aspartic acid polymer (PCMA) as a new water treatment agent was prepared by solid phase synthesis of curcumin, malic acid and aspartic acid. The static scale inhibition experiments showed that PCMA can inhibit CaCO3 and CaSO4 scale formation by 100.0 % and had excellent scale inhibition effect under various experimental conditions. The mechanism of action of PCMA was obtained by X‐ray diffraction, scanning electron microscope and molecular dynamics simulation. Electrochemical test showed that PCMA is an anodic corrosion inhibitor that achieves 93.1 % corrosion inhibition by forming a protective film on the surface of Q235 carbon steel. Besides, fluorescence spectra proved that PCMA has stable fluorescence intensity. [ABSTRACT FROM AUTHOR]

Microbially influenced corrosion represents a critical challenge to the integrity and durability of carbon steel infrastructure, particularly in environments conducive to biofilm formation by nitrate-reducing bacteria (NRB). This study investigated the impact of NRB biofilms on biocorrosion processes within oil/water recovery operations in Algerian pipelines. A comprehensive suite of experimental and analytical techniques, including microbial analysis, gravimetric methods, and surface characterization, were employed to elucidate the mechanisms of microbially influenced corrosion (MIC). Weight loss measurements revealed that carbon steel samples exposed to injection water exhibited a corrosion rate of 0.0125 mm/year, significantly higher than the 0.0042 mm/year observed in crude oil environments. The microbial analysis demonstrated that injection water harbored an average of (4.4 ± 0.56) × 106 cells/cm2 for sessile cells and (3.1 ± 0.25) × 105 CFU/mL for planktonic cells, in stark contrast to crude oil, which contained only (2.4 ± 0.34) × 103 cells/cm2 for sessile cells and (4.5 ± 0.12) × 102 CFU/mL for planktonic cells, thereby highlighting the predominant role of injection water in facilitating biofilm formation. Contact angle measurements of injection water on carbon showed 45° ± 2°, compared to 85° ± 4° for crude oil, suggesting an increased hydrophilicity associated with enhanced biofilm adhesion. Scanning electron microscopy further confirmed the presence of thick biofilm clusters and corrosion pits on carbon steel exposed to injection water, while minimal biofilm and corrosion were observed in the crude oil samples. [ABSTRACT FROM AUTHOR]

Using the method of gravimetric and electrochemical measurements, the corrosion rate of St3 steel in the water basins of the Takhtakerpi and Shemkirchay hydroelectric power stations has been determined. To establish the expected corrosivity of water, the chemical composition and some physicochemical parameters of the above waters have been determined. As a result of long-term measurements carried out over one year, it has established that steel in the water basins of the Takhtakerpi and Shemkirchay hydroelectric power stations corrodes at a rate of 0.04 g/m² h and (0.07÷0.08) g/m² h, respectively. And in the atmosphere of these hydroelectric power plants, steel corrodes at a low rate, approximately an order of magnitude lower. Analysis of water taken from these hydroelectric power stations showed a very low content of corrosive ions, the concentration of which, especially in the Shemkirchay reservoir, corresponds to spring water. By taking polarization curves it has been established that the rate of steel corrosion is controlled by the concentration of dissolved oxygen in water. [ABSTRACT FROM AUTHOR]

This study investigates sweet corrosion mitigation methods focusing on the efficacy of inhibitors. Specifically, it examines the performance of two types of inhibitors: water-soluble and oil-soluble. Utilising a Rotating Cylinder Electrode (RCE) setup, turbulence is induced in saline solutions to assess the impact of inhibitors on the corrosion of carbon steel. Scanning Electron Microscopy (SEM) is employed to analyse corrosion degradation patterns and material damage mechanisms. Given the prevalent use of inhibitor injection in the oil sector, it is crucial to evaluate and compare the effectiveness of various inhibitors to recommend optimal options and further studies. The findings contribute to advancing corrosion mitigation strategies, providing insights into the performance of inhibitors in flow environments and aiding in the development of more effective corrosion control measures for carbon steel structures. The inhibitors under study are sourced from local oil company vendors. With a projected duration of six months and a total budget of KD 9850, this investigation aims to provide valuable insights into corrosion mitigation strategies. [ABSTRACT FROM AUTHOR]

Surface carburized steels are extensively utilized in gears due to their exceptional properties. The quality of the carburized layer is crucial in enhancing the contact fatigue and wear resistance of the components. However, the conventional carburizing method takes a long time and induces a carbon emissions problem. In this study, the 18Cr2Ni4WA steel was double tempered (650 °C/4 h) after carburizing at 930 °C and 950 °C. The microstructural evolution, carbide precipitation, and mechanical properties of different carburized layers were analyzed. The results showed that increasing the carburizing temperature can control the microstructure of the carburized layer while reducing the carburizing time by over 60%. The high carbon content improves the strength of the carburized materials at 950 °C, and the inhibition of dislocation motion and grain boundary by the precipitation of more carbides ensures the stability of grain size, maintaining the strength of the materials. The carburized specimens at 950 °C showed an excellent combination of strength and plasticity in different carburized layers due to the variations in solid solution strengthening, dislocation strengthening, precipitation strengthening, and grain boundary strengthening induced by carbon atoms. This study holds significant reference for the advancement of modern steels carburized at high temperatures in a short time. [ABSTRACT FROM AUTHOR]

In this work, leaves of Silybum marianum (L.) Gaertn were extracted by a one-step extraction method using ethanol as a solvent, and the Silybum marianum (L.) Gaertn extract (SMGE) was firstly employed as a green corrosion inhibitor for carbon steel in 0.5 mol/L H2SO4. The corrosion inhibition performance was studied using weight loss and electrochemical methods, and the anti-corrosion mechanism of SMGE is further analyzed through some surface characterizations and theoretical calculations. The results indicate that SMGE can act as a mixed-type corrosion inhibitor and possess superior corrosion inhibition performance for carbon steel in H2SO4 solution, and the optimum corrosion inhibition efficiency reached 93.06% at 800 ppm SMGE combined with 60 ppm KI. The corrosion inhibition efficiency increased with the rising inhibitor concentration. Surface characterizations illustrated that the inhibitor could physico-chemically adsorb on a metal surface, forming a hydrophobic, protective film. [ABSTRACT FROM AUTHOR]

Carbon steel is the most common steel alloy. Carbon steel may be the best-known industrial material for use in design for its economic value and reliability in performance. It is nonetheless challenging to find the information needed to efficiently design safe and reliable systems that are manufactured from carbon steel. Historically, carbon steels were considered to be the same material with the same properties and design values for all product forms such as forgings, bars, or plates, including castings. Now, designers want to know the properties and performance of steel components, based on the manufacturing process as well as the alloy. While the use of steel mill products allows designers to use standard mill products, based on precalculated load capacity listed in the building construction codes, custom components like castings are more difficult to design. The designer must determine what properties and quality measures to use in the analysis of the component's safety. Often the design is based on the minimum properties required in the specification with no given context for the actual distribution of properties for these type of products. Mechanical property allowances for design, which are statistically supported for steel castings are not available. Steel Founders' Society of America (SFSA) has collected the ordinary testing results for commercial carbon steel heats from a variety of producers, in order to develop an extensive data set of properties. This data set has been analyzed and is compared to steel mill properties, specifications, and allowable design values, which are embedded in the American Institute of Steel Construction-Specification for Structural Steel Buildings (AISC-ASD), and the ASME Boiler and Pressure Vessel Code (ASME BPVC). This analysis demonstrates the capability of carbon steel castings to provide safe and reliable service that is compatible with steel mill products in fabrications or other structures. Statistically supported values for tensile properties for steel castings are reported and compared with other steel products. Significant findings show: (1) Carbon steel castings have properties compatible to other product forms such as forgings and mill products. (2) Carbon steel components meet the design allowables included in the ASME BPVC and AISC-ASD requirements with similar properties to other structural steels. (3) The use of net-effective area and a fraction of the UTS for allowable stress design by AISC is comparable to the challenge of creating thick-section complex-geometric design of steel castings. (4) The proposed limit for design, based on the ratio of yield strength to ultimate tensile strength (YS/UTS) provides a reasonable guide for safe and reliable design for steel castings as well as structural steel shapes. (5) The proposed quality index (QI) for steel casting provides satisfactory guidance for the lower bound of commercial cast alloys at 280 ksi. This is also the common upper level of specification requirements. [ABSTRACT FROM AUTHOR]

The corrosion and material evaluation study in (a) water‐based simulated black liquor and (b) water‐based simulated black liquor at super‐critical conditions was successful. The conclusion from the testing program was that the most resistant alloy for the defined conditions is the chromium‐rich carbon steel candidate P91 (UNS K91560). This is a type of creep strength‐enhanced ferritic alloy, which is steel designed to retain strength at high temperatures. The P91 abbreviation represents the material's chemical composition, that is, 9 wt% chromium (Cr) and 1 wt% molybdenum (Mo). Further work is required to conclude the corrosion resistance for the P91 quality at supercritical conditions in the welded condition and to better understand caustic corrosion mechanisms. [ABSTRACT FROM AUTHOR]

In this work, the influence of part dimensions on the microstructure of low‐alloy steel during its austempering has been studied. 0.41C‐0.24Si‐0.63Mn‐0.93Cr steel of different diameters ranging from 5 to 16 mm has been austempered at 350 °C for 10 min. Despite similar austempering conditions, an increase in the size and fraction of acicular/polygonal ferrite has been noted with an increase in the diameter of the samples. From the experimental observations and analytical calculations based on multi‐dimensional transient heat transfer analysis, the cooling rate during austempering has been observed to increase with a decrease in the sample diameter. Variation in ferrite grain size and fraction is due to different cooling rates encountered by different sized specimens during austempering. Close agreement between the experimental and theoretically estimated ferrite grain size due to variation in cooling rate during austempering has been noted. [ABSTRACT FROM AUTHOR]

The inhomogeneity present in the deformation and microstructure during the open die forging of large size ingot significantly influences the mechanical properties of the final part. This study aims to develop a microstructure-based finite element (FE) model and investigate the influence of deformation path on microstructure evolution during the upsetting process of large size ingot of a high strength steel. The difference in deformation path is achieved by modification in anvil shape such as flat, v shape, convex, and concave die. To achieve this goal, hot compression tests were carried out using the Gleeble 3800 thermomechanical simulator. Utilizing the acquired and corrected flow stress data, a material model and a microstructure model were established, and both formulated models were then integrated into the Forge NxT 3.2 finite element simulation software through the inclusion of a dedicated user subroutine. The predictions from the FE analysis were validated with experimental results on standard size hot compression specimens, which allowed for the accurate prediction of the dynamic recrystallized average grain size at the end of hot deformation. Afterwards, the validated FE model was scaled up to simulate the industrial upsetting process, making it possible to investigate the effect of deformation path on inhomogeneity of strain and microstructure evolution at the end of upsetting process for large sized forged ingots. An evaluative analysis of four die geometries, aimed at identifying the optimal die shape for minimizing inhomogeneity in strain and grain size across a large size forged ingot, was conducted. It was found that the convex die provokes the lowest deformation, while the concave die induces the highest deformation values at the center of the ingot. Utilizing the coefficient of variation as an indicator of heterogeneity, it was determined that the v-die and concave die resulted in a more consistent grain size distribution compared to the flat and convex dies. [ABSTRACT FROM AUTHOR]

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The stirring energy of bottom blowing is one of the most important factors affecting the steel scrap melting in converter. In this paper, a three-dimensional turbulent-multiphase-solidification/melting-solute transport coupling mathematical model is developed to investigate the molten metal flow and scrap melting behaviors in a steelmaking converter under asymmetric bottom blowing conditions. The mathematical model is verified by hot-state experiments. The results show that the dead zone volume fraction and mixing time can be reduced by 3 pct and 30 second by asymmetric bottom blowing, which can provide greater stirring kinetic energy for the molten bath, especially at the bottom of the molten bath, thereby accelerating the melting rate of the steel scrap. In Scheme A1, the time required for the complete melting of the steel scrap is 434 second, which is reduced by 96 second compared with the scheme of symmetrical blowing. Asymmetric bottom blowing can promote the heat exchange between low-temperature molten metal around steel scrap and high-temperature melt in other regions, so that the temperature field around steel scrap is stable at about 1710 K. Meanwhile, it can effectively promote the diffusion of carbon in steel scrap and then promote the rapid melting of scrap. [ABSTRACT FROM AUTHOR]

There is a direct correlation between surface roughness and electrode tool status in the Electrical Discharge Machining (EDM) process. The quality of the machined surface of workpieces is becoming even more critical in recent industries. In general, electrode wear evaluation plays a vital role in the EDM process, affecting the operation cost and the accuracy of the required dimensions and geometric shape. This study presents a new method to evaluate the copper electrode wear during machining AISI 1005 carbon steel in the EDM process using a 3D laser scanner that measures the lost volume of the electrode. The results of the proposed method were compared with those of the conventional method. Laser technology was used to accurately measure the dimensions and surface characteristics of the electrode by scanning the electrode surface and the electrode view topology before and after the machining process. The processed data was saved on a computer connected to the laser scan device, converted to STL files, and sent to a 3D system (Geomagic Control X software). This software utilizes accurate mathematical algorithms to determine the available volumetric differences in the electrode. The experiments used Design-Expert 13 software, selecting three machining parameters: Current (Ip), pulse on time (Ton), and pulse off time (Toff). The results showed that the Tool Wear Rate (TWR) obtained by the two methods showed a mean absolute deviation of 3.6%, with an insignificant error on the effect of the machining parameters on TWR (1.01% for Ip, 1.92% for Ton, and 2.29% for Toff). [ABSTRACT FROM AUTHOR]

This study investigates the effects of initial billet size variations on material flow behavior in hot forging processes, aiming to optimize the forging process using validated predictive models. Material and high-temperature compressive tests inform mathematical models, while simulations are conducted via the finite element method (FEM). Results align with the Zener-Hollomon and Cingara-McQueen approaches. The Arrhenius model predicts AISI 1045 steel flow stress with an R² of 0.968 and an average absolute relative error (AARE) of 7.079%. The Cingara-McQueen equation achieves an R² of 0.997 and an AARE of 2.960%. Reducing billets size from 260 mm to 230 mm decreases the material usage by up to 11.5%, while maintaining workpiece integrity. Experimental and simulated loads exhibit an AARE of about 2.69%, thereby indicating potential cost and efficiency improvements in hot forging processes. [ABSTRACT FROM AUTHOR]

This study focused on optimizing the hot forging process for AISI 1045 medium carbon steel ball joints, which is crucial for enhancing both their mechanical properties and production efficiency. Traditional hot forging processes often face challenges due to variations in flow stress and microstructural outcomes, which can result in a suboptimal product performance. To address these challenges, this research employed the Taguchi method in conjunction with a finite element (FE) simulation to identify the optimal forging parameters. The Arrhenius constitutive model, based on the Zener–Hollomon parameter, was applied to predict the flow stress with a high level of accuracy, achieving a coefficient of determination (R2) of 0.968 and an average absolute relative error (AARE) of 7.079%. An analysis of variance (ANOVA), a statistical innovation that partitions the total variation into components linked to key process factors, was utilized to determine the significance of these parameters. The ANOVA revealed that the billet temperature played a significant role in influencing the preforming force, finishing force, and mean stress, with a maximum impact of 62.30%, 59.50%, and 94.20% on the variation in the response variable, respectively. Additionally, the friction factor significantly affected the preforming and finishing forces, contributing 36.19% and 38.28%. The validation of the model through both simulations and practical experiments is a testament to the reliability of this research, demonstrating the accuracy of the model with minimal discrepancies in the forging forces and exhibiting errors of just 2.88% and 3.40%. Furthermore, microstructure modeling successfully predicted the key outcomes, such as the grain size and pearlite volume fraction, validating the effectiveness of the simulation in forecasting microstructural characteristics. [ABSTRACT FROM AUTHOR]

This paper presents the results of research from the renovation of functional parts of crane wheel surfaces. The aim of the research was to verify the possibilities of changing the chemical composition of the additive materials for submerged arc cladding, in order to increase the resistance of the wheel surfaces to wear. The base material of the crane wheel was heat-treated carbon steel for castings, mat. no. 1.0553. The renovation process was carried out on three equal wheels. Conventionally used additive material, the same one used for the interlayer and two covering layers, was used on one wheel. On two other wheels, newly increased tubular wires with a higher proportion of carbide-forming additives (Cr, Mo) were used for the carbide coating of two covering layers, in addition to their conventional additive material. Low-alloy additive material was applied to the newly elevated wires. The quality of the clads was assessed using non-destructive tests. Subsequently, microstructural analysis was carried out on the test samples taken from the renovated wheels, by means of light microscopy. On the cross cuttings, the course of hardness was evaluated using Vickers analysis. The resistance of functional surfaces to adhesion wear was evaluated based on weight losses measured using the AMSler experimental equipment. The results of the experiments showed an increase in the tribological resistance of the surfaces, specifically by 45% due to the newly developed wire C1 and by 18% due to wire B1, and it is therefore possible to recommend renovation. [ABSTRACT FROM AUTHOR]

The mechanism causing the dramatic intensification of the corrosion deterioration of carbon steel pipes in a crude oil storage facility has been investigated. This study considers a number of factors affecting corrosion in crude oil, such as the water content, the corrosivity of the aqueous phase, the kinetics of water–oil separation, the effect of dissolved oxygen, the effect of the crude oil quality, the degree of stagnancy inside of the pipes, the possible contribution of microbially induced corrosion (MIC) and the presence of deposits. The key root of the corrosion intensification was the separation of the water phase, supported by stagnancy, which eventually led to the formation of stable shallow pits surrounded by cathodic areas. [ABSTRACT FROM AUTHOR]

In the present study, directional and spatial variations in the mechanical properties are calculated in two nuclear-grade materials. In practice, multiple ASTM standard specimens are tested to measure mechanical properties of any material. The variations obtained in the properties during the tests are generally neglected assuming such variations are due to experimental uncertainties. However, such variations may indicate some degree of anisotropy and spatial inhomogeneity in the material due to component fabrication. In the present study, multiple miniaturized tensile specimens are tested. These specimen materials are taken across the thickness and at different geometrical locations in the two manufactured nuclear-grade components. The experimental load versus displacement data of all the specimens are then used to evaluate stress-strain data and cohesive zone parameters. These parameters are determined for each tested specimen separately to gather variations over the geometries of the components. Subsequently, TPB specimens are analyzed employing these parameters to calculate variations in fracture initiation toughness over the geometry. The key findings of the present work include higher strengths in circumferential direction in comparison to the longitudinal direction for SA333 Gr6 steel. A new equation is developed to correlate the material toughness with the fracture toughness with a proportionality constant of 2.7778 for low-alloy carbon steels. The study showed that directional and spatial variations in Jini are less pronounced in 20MnMoNi55 compared to SA333Gr6 materials. This finding is crucial for safety analyses in nuclear components and indicates that this methodology can be applied more widely across different materials. [ABSTRACT FROM AUTHOR]

After a brief review of the history of pearlite structures in carbon steels, particularly on the pearlite formation mechanism, recent experimental investigations on the pearlite substructure are presented to express a distinct point of view. The water‐quenched high‐carbon pearlite substructure is investigated in detail by means of scanning electron microscopy and transmission electron microscopy. In the experimental observation results, it is shown that the cementite layer or ferrite layer in pearlite is composed of fine grains, which cannot be simply explained by traditional nucleation and grain growth mechanisms. However, the fine grain structure can be explained by the martensitic transformation products (twinned martensite with ultrafine grains of α–Fe and twinning boundaries ω–Fe (or ω–Fe3C)) and detwinning process. Upon tempering or detwinning, recrystallization of the ultrafine grains of both crystalline phases occurs to form the initial pearlite structure, while the grain size of both phases is still fine. The twinned martensite can be treated as the precursor of pearlite structure (pearlite nucleation stage), and the detwinning process can be regarded as the growth of the pearlite structure. Thus, the pearlite reaction can be described as follows: austenite → twinned martensite → pearlite. [ABSTRACT FROM AUTHOR]