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Valve metals are metals that can undergo surface modification through micro-arc oxidation (MAO). Iron is not considered a valve metal and cannot undergo MAO. Steel is a widely used alloy due to its excellent properties, including high toughness, good workability, and low cost. However, its weak corrosion and abrasion resistance limit its range of application and service life. Al 2 O 3 ceramic coating is formed on the surface of non-valve metal low carbon steel using MAO technology. The surface morphology and composition of the MAO coatings on non-valve metals are investigated through characterization. Tribological experiments show that the coefficient of friction of the samples obtained from the MAO power supply frequency of 1400 Hz is the smallest. After conducting a corrosion resistance test following MAO treatment, the impedance increased by three orders of magnitude and the corrosion rate decreased by one order of magnitude. The use of MAO treatment can expand the use of steel and shows promise for application to other non-valve metals. [ABSTRACT FROM AUTHOR]

In recent years, numerous innovative approaches have emerged to enhance the corrosion resistance of materials. This study investigates the effect of enhancing mild steel corrosion through the incorporation of unzipped multiwalled carbon nanotube oxides (UMCNO) into epoxy resin. Additionally, the effect of various operating parameters, such as temperature, UMCNO concentration, salt concentration, duration of exposure, and coating thickness, have also been considered in the study. The Box–Behnken method was used for experimental design and correlation of corrosion rate with various operating parameters, followed by analysis of variance of both five‐ and three‐parameter models. Notably, despite variations in temperature and salt concentration, the corrosion rate remained negligible, confirming its suitability in various marine conditions. Furthermore, it was observed that the corrosion rate of mild steel coated with epoxy decreased with the addition of UMCNO. A corrosion rate of 0.182 mpy was observed for epoxy resin incorporated with 0.5 % UMCNO over a 14‐day period, which is lower compared to other conditions. Electrochemical impedance spectroscopy and potentiodynamic polarization analysis showed higher corrosion‐resistant properties in epoxy coating incorporated with UMCNO. In addition, it was evident from the contact angle measurement that the corrosion rate of mild steel was highly dependent on the concentration of UMCNO. [ABSTRACT FROM AUTHOR]

Study of sodium silicate from rice husks as coating material is reported. The extraction was conducted via precipitation method with sodium hydroxide, nitric acid and ethanol at pH 8. The resulting silica was tested as hydrophobic coating by coating it on a glass surface. Based on the value of the contact angle, silica has good hydrophobic properties. The highest hydrophobic properties were obtained from sample, which labeled as Si10A:Si5B with an average contact angle of 105.3 °. Investigation of the potential application of sodium silicate as an inhibitor of corrosion has been conducted by coating it on steel surfaces. The effect of the concentration of sodium silicate was conducted at 0, 10, 20 and 30 ppm and found that the morphology of steel coated with 20 ppm has the lowest corrosion rate with 81 % inhibition efficiency. [ABSTRACT FROM AUTHOR]

Cu-Al-Mn (CAM) shape memory alloys (SMAs) are cost effective, have a high low-cycle fatigue life and superelastic limit, and a wide temperature application range compared with other types of SMAs. These characteristics of CAM SMAs have resulted in increased interest in their use in civil engineering applications, particularly as reinforcement in concrete structures and as dampers in steel structures. However, these applications require machining of the CAM SMA bars for connection with other structural elements. This study presents the methods and results of the first systematic research on the machinability of CAM SMAs. The key machinability characteristics of CAM SMAs: chip formation, cutting temperature, tool wear, workpiece surface roughness, and diameter deviation, were studied and compared with those of conventional NiTi SMAs and commonly used steels: mild steel (MS) and 304 stainless steel (SS). The effects of a wide range of cutting parameters: cutting speed ranging from 15 to 120 m/min , feed rate ranging from 0.1 to 0.2 mm/revolution , and depth of cut ranging from 0.5 to 1.5 mm, were investigated. The results from this study showed that the tool wear from machining CAM SMAs was close to that from machining SS and slightly higher than that from machining MS, but much lower than that from machining NiTi SMAs. In all the cases considered here, the tool wear from machining CAM SMAs was found to be 0.6–1.8 times that from machining SS, 0.8–2.4 times that from machining MS, and 1/7–1/21 that from machining NiTi SMAs. After a continuous machining test with a total cutting length of 4.5 m, the nose wear from machining CAM SMAs was found to be 1.6 times that from machining MS, the average flank wear from machining CAM SMAs was found to be three times that from machining MS, and the diameter deviation (relative diameter difference from that of the first sample) of CAM SMAs was only 10 μm larger than that of MS. [ABSTRACT FROM AUTHOR]

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

An attempt has been made to fabricate electroless duplex (Ni-P-ZnO/Ni-P-SiC) coatings on the mild steel materials. Present investigation focused on ZnO and SiC nanoparticles concentration on the corrosion resistance and microhardness of duplex coating. Coated substrates are characterised by using the X-ray diffraction analyses to know the structure of deposit. Surface morphology and element composition was evaluated by means of scanning electron microscope (SEM) attached with the energy dispersive spectrometer (EDX). Coating was heat treated for 1 hour at 400°C temperature. Microhardness of the coatings was examined by using Vickers microhardness tester. Corrosion parameters of the duplex coating were evaluated by performing the potentiodynamic polarisation studies in 3.5% NaCl solution. Experimental observations confirm that Ni-P-SiC outer layered coating offers maximum microhardness and duplex coating with Ni-P-ZnO as external layer provides maximum corrosion protection. Maximum load bearing ability of SiC nanoparticles offers superior microhardness to the Ni-P-SiC external layer coatings. Higher electrochemical resistive ZnO nanoparticles provide good corrosion protection to the Ni-P-ZnO external layer coatings. Formation of intermetallic compounds after heat treatment process enhances the both the coatings microhardness and resistance to corrosion. [ABSTRACT FROM AUTHOR]

In this study, trimercapto‐S‐triazine trisodium salt (TMT) with threefold rotational symmetry as a corrosion inhibitor was introduced into 2 mol ⋅ L−1 ZnSO4 medium. By electrochemical measurements, the corrosion inhibition efficiency of the zinc electrodes was 92.52 % when the concentration of TMT corrosion inhibitor was 2 mmol ⋅ L−1. Based on the microstructural characterization and theoretical analysis of Zn electrodes, it was confirmed that S and N atoms of TMT corrosion inhibitor serve as alternately zinc‐philic adsorption sites with sixfold rotational symmetry for the formation of intermolecular complexes. Adsorption energies of TMT on Zn surfaces were calculated and indicated that the bonds of Zn−N and Zn−S promoted anchoring adsorption on sixfold symmetric (002) plane of zinc. Meanwhile, TMT corrosion inhibitor can adsorb Zn2+ from the electrolyte and directionally deposit them on the surface of Zn (002), effectively avoiding the occurrence of dendrites. This study changes the common knowledge that organic corrosion inhibitors must form hydrophobic films to have corrosion inhibition performance, and provides a new approach for using small organic molecules with anchoring adsorption as metal corrosion inhibitors. [ABSTRACT FROM AUTHOR]

The aim of this paper was to investigate intumescent coatings based on polyfurfuryl alcohol (PFA) resin as a binder benefiting from high char yield and low smoke emission. To this end, the coatings composition in terms of PFA binder resin, long oil alkyd plasticizing resin, TiO2 pigment, and flame-retardant additives (FR) was changed as input parameters according to a mixture design-of-experiments. The corresponding changes in the backside temperature of mild steel substrate (Tb), residual char expansion ratio, limiting oxygen index, and char residue (wt% @1000 °C) were studied as the response variables describing fire performance characteristics of the coatings. The results showed that the backside temperature of the plate increased and the expansion ratio decreased with increasing in the alkyd resin concentration. Also, the flame-retardant efficiency of coatings strongly depends on the content of FR additives. When the content of PFA and alkyd resin was increased at a high level (35 and 4 wt%, respectively), the Tb of the coated plates reached 415 °C rapidly, due to the cracking of the coating and the lower concentration of FR additives. However, the formula with higher FR content, i.e., 68 wt%, showed the lowest Tb value ca. 128 °C. Flame-retardant characteristics directly depended on the expansion ratio of the coatings and the morphology of the char layer remaining on the substrate after the flame test; therefore, coatings with a higher expansion ratio showed lower backside temperature. The findings were supported by examining of the remaining char morphology after a flame test by optical microscopy and validated by comparing the predicted and actual responses for optimization. The value of absolute relative deviation was obtained in the range of 1.6–7.9, which indicates a good agreement between the proposed and experimental results. [ABSTRACT FROM AUTHOR]

In this study, BF2 complexes of pyridyl‐isoindoline‐1‐ones (BPIO) has been firstly designed and investigated as an excellent corrosion inhibitor for the mild steel in 1 M HCl. The corrosion protection properties of BPIO were studied by using a series of experiments. The results indicated BPIO has excellent inhibition performance, and inhibition efficiency of BPIO reached up to 96.6%. The effects of immersion temperature and time were investigated by weight loss experiments to evaluate the stability of adsorbed BPIO film in protecting steel surface. Based on potentiodynamic polarization studies, BPIO acted as one mixed‐type corrosion inhibitor with predominant anodic effectiveness, and its adsorption on the mild steel follows the Langmuir adsorption isotherm. The values of ΔGads suggested the adsorption of BPIO on the mild steel surface was through a combination of chemisorption and physisorption. The adsorption of BPIO molecules on the steel surface was further identified by the techniques of scanning electron microscopy (SEM) and X‐ray photoelectron spectroscopy (XPS). The quantum chemical calculations based on density functional theory (DFT) and molecular dynamics (MD) simulations were used to optimize the BPIO molecular structure and investigate the inhibitive properties on the theoretical level, which agreed well with the experimental results. Besides, BPIO has been used for the development of water soluble metal antirusting agent. [ABSTRACT FROM AUTHOR]

A series of 4-ferrcenylbutyl carboxylate esters with different alkyl chain length (C2-C4) of carboxylic acids were synthesized using Fe3O4@SiO2@(CH2)3-Im-bisEthylFc[I] nanoparticles as catalyst and have been characterized with FT-IR, 1H NMR, and 13C NMR. Ferrocenyl-based esters were used as corrosion inhibitors of mild steel in the 1M HCl solution as corrosive media. The corrosion inhibition efficiency of the synthesized ferrocenyl-based esters has been assessed by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), atomic force microscopy (AFM), and scanning electron microscopy (SEM). The 4-ferrocenylbutyl propionate showed a more effective corrosion inhibition behavior among the studied esters with 96% efficiency after immersion in the corrosive media for 2 weeks. The corrosion inhibition mechanism is dominated by formation of passive layer of inhibitor on the surface of the mild steel by adsorption. Moreover, the adsorption characteristics of 4-butylferrcenyl carboxylate esters on mild steel were thoroughly explored using density functional theory calculations. It was found that the Fe atoms located around the C impurity in the mild steel are the most efficient and active sites to adsorb 4-butylferrcenyl carboxylate esters. [ABSTRACT FROM AUTHOR]

In this investigation, pulsed current electro-deposition (PCE) was used to prefabricate Ni–Co/SiC + TiN composite coatings (NCSTCCs) on mild steel surfaces. The research focused on the influence of two electrodeposition parameters, pulse frequency (PF) and duty cycle (DC), on NCSTCF features including microscopic surface morphology, crystal orientation, grain size, microhardness, SiC and TiN nanoparticles (NPs), deposition quantity, and corrosion resistance properties. The results indicated that NCSTCCs produced under a 10% DC showed minimal SiC and TiN contents with a percent volume of just 5.6 v/v% and 5.4 v/v% respectively under the fixed condition of 60 Hz PF. However, the three-dimensional surface diagram indicated that the Ni–Co/SiC + TiN composite film deposited at 50% DC and 10 Hz PF displayed the highest SiC and TiN contents (11.6 v/v% and 11.7 v/v%) among all the films. Furthermore, NCSTCCs deposited under 50% DC and 10 Hz PF had peak microhardness at 667.4 kg/mm2, while the composite film achieved a microhardness of 514.1 kg/mm2 when prepared using 10% DC and 60 Hz PF. Moreover, when the DC and PF were at 50% and 10 Hz respectively, the Ni–Co/SiC + TiN composite film presented the maximum charge transfer resistance (4915.7–4927.2 Ω·cm2), indicating an excellent corrosion resistance. [ABSTRACT FROM AUTHOR]

An innovative green organogel was designed to simultaneously tackle inorganic compounds (i.e., iron corrosion) and organic substances (i.e., acrylic coatings) as undesired materials possibly present on the surface of altered indoor metal artworks. Poly-3-hydroxybutyrate (PHB), ethyl lactate (EL), and deferoxamine B (DFO) were employed in the formulation as thickening agent, organic solvent, and complexing agent, respectively, aiming to propose a sustainable and less harmful chemical cleaning method for metal care. The components were selected because they are bio-sourced, renewable, biodegradable, and non- or low-toxic materials. A multi-modal protocol of analysis was carried out to characterise the newly designed PHB-EL-DFO organogel. The cleaning performance of the novel formulation was assessed on mild steel mock-ups presenting both corrosion and organic coating to be removed. The conducted multi-analytical approach verified that the PHB-EL-DFO gel was able to tackle the two undesired materials simultaneously in an adjustable and easy-to-use way thanks to a modular application. [ABSTRACT FROM AUTHOR]

This study subjected nuclear-grade 20# pipeline steel to cyclic freeze–thaw ice plugging tests, simulating the plastic deformation experienced by pipes during ice plug removal procedures. Subsequently, the dislocation morphology and mechanical properties of the specimens post cyclic ice plugging were examined. The cyclic ice plugging process led to an increase in the dislocation density within the specimens. After 20 and 40 cycles of ice plugging, the internal dislocation structures evolved from individual dislocation lines and dislocation tangles to high-density dislocation walls and dislocation cells. These high-density dislocation walls and cells hindered dislocation motion, giving rise to strain hardening phenomena, thereby resulting in increased strength and hardness of the specimens with an increasing number of ice plugging cycles. In addition, a large stress field was generated around the dislocation buildup, which reduced the pipe material's plastic toughness. The findings elucidate the effects of cyclic ice plugging on the microstructure and properties of nuclear-grade 20# pipeline steel, aiming to provide a theoretical basis for the safe and stable application of ice plugging technology in nuclear piping systems. [ABSTRACT FROM AUTHOR]

Additive manufacturing is becoming increasingly widespread and has developed very dynamically in recent years. For the processing of metals, powder or wire is usually used as the feedstock. The energy source used in wire-based processes is usually electric arcs or lasers. In this contribution, a technological approach for additive manufacturing of metal structures by induction melting with pulsed generator power is used. Therefore, the principle of oscillating Lorentz forces is utilized in this approach and analytically investigated with the aid of a FE simulation model. In the experiments, a continuously fed steel wire is inductively melted and deposited dropwise onto a substrate heated to different preheating temperatures without the use of a nozzle or crucible. [ABSTRACT FROM AUTHOR]

In the present work, novel and effective quinoline-based polybenzoxazines coatings were prepared on cotton fabrics and mild steels to improve the hydrophobic properties and corrosion resistance, respectively. For this purpose, four quinoline containing mono-oxazine-based benzoxazines were synthesized using 8-hydroxyquinoline (Q), and various monoamines, such as: butylamine (ba), hexylamine (ha), octylamine (oa) and aniline (a). The molecular structure of the benzoxazine monomers was verified by 1H-NMR and FTIR spectroscopy. The effect of the aliphatic and aromatic functional groups of the benzoxazines on oxazine ring-opening curing was investigated, and the influence of their corresponding materials on thermal and morphological properties was also elucidated. These quinoline-based monomers have been successfully coated onto the surface: i) cotton fabrics to be used as a water – oil separation method; and ii) mild steel as inhibitor of the corrosion. In this sense, cotton fabric coatings exhibited highly hydrophobic properties (contact angle from 124° to 139°), and subsequently the water oil-separation efficiency was measured to the material that presented the highest contact angle (Poly Q-oa), obtaining a 91% separation efficiency. For benzoxazines coatings on mild steel, impedance tests have indicated that these polymers are corrosion inhibitor effectives. Finally, the antibacterial properties of the quinoline based benzoxazines was also analysed, indicating good antibacterial resistance owing to the existence of long alkyl chains in their respective molecular structure. According to the results obtained from numerous analyses, the quinolone-based polybenzoxazines can be considered as successful materials for applications such as corrosion resistance, oil-water separation, marine coating and microelectronics insulation. [ABSTRACT FROM AUTHOR]

Normally, aluminum-based (Al-based) anti-corrosion coatings are prepared by flame spraying and other coating technologies to improve the corrosion resistance of metal materials in the marine environment. However, the prepared coatings are usually found to be poor in quality owing to the shortcomings of traditional thermal spraying technologies, such as flame spraying, including the low jet temperature and low particle in-flight velocity. In this paper, pure Al coatings and Al/SiC composite coatings were prepared on the surface of low-carbon steel by innovatively adopting plasma transferred wire spraying technology and making full use of the technological advantages of plasma spraying. In addition, the experiments have shown that larger SiC particles play a role in shot peening during the spraying process, allowing Al droplets to spread and overlap more fully, effectively improving the density of the coating and reducing defects such as pores and cracks in the coating. However, there is no significant effect on improving the bonding strength of the coating. Therefore, the porosity of pure Al coating and Al/SiC composite coating is 3.9% and 2.5%, respectively; the microhardness is 36 HV0.1 and 102 HV0.1, respectively, increasing by about three times; the bonding strength with the matrix is 39.0 and 36.5 MPa, respectively; the corrosion resistance of Al/SiC composite coating is significantly better than that of pure Al coating, and the wear rate is reduced by 7 times compared to pure Al coating. [ABSTRACT FROM AUTHOR]

This study explores the influence of various parameters on bead profiles within the wire arc additive manufacturing (WAAM) process, specifically focusing on ER70S-6 low-carbon steel to produce thick-walled parts. The critical geometric characteristics under scrutiny are bead width (BW) and bead height (BH), with the primary goal being optimization. The research methodology incorporates the utilization of the Taguchi method, analysis of variance (ANOVA), regression modeling, and grey relational analysis (GRA) to scrutinize and enhance process parameters. The results reveal that a rise in wire feed speed (WFS) from 5 to 8 m/min and voltage (V) from 18 to 24 V leads to a substantial increase in BW, with contributions of 79.90% and 4.77%, respectively, according to ANOVA. Conversely, a rise in traverse speed (TS) from 0.3 to 0.6 m/min results in a reduction in BW by 11.90%, while the impact of gas flow rate (GFR) is relatively minor. Regarding BH, a rise in WFS within the 5–8 m/min range significantly enhances BH, with an ANOVA contribution of 17.78%. In contrast, higher voltage and TS lead to a reduction in BH, with TS exhibiting the dominant influence at 46.08%, followed by voltage at 31.13%, and WFS at 17.78%. The GFR exerts a negligible impact at 0.88%. To address the challenge of multi-objective optimization, GRA is proficiently employed, resulting in recommended process parameters for BW and BH: WFS = 8 m/min, V = 18 V, TS = 0.3 m/min, and GFR = 18 L/min. These results are robustly validated through experimental verification, affirming the accuracy of predictive models. [ABSTRACT FROM AUTHOR]

AISI P20 tool steel is commonly used for engineering of die holders, rails, plastic molds, wear strips, bolsters, shafts, and backers. When normally heated and sub-cooled, it experiences metallurgical modifications. Because the essential aspect of the "wire-electro discharge machine (WEDM)" is product finishing, this research examines the parametric responses when machining parent metal and sub-cooled metal (AISI P20). Thus, it is always necessary to choose a proper parametric arrangement for reaching maximum material removal rate (MRR), cutting speed with minimum surface roughness (SR), and kerf width. The effects of pulse on time, wire speed, discharge current, wire tension, and flushing pressure on individual machining reactions are also discussed in this study. An orthogonal array was created using Taguchi's mixed experimental approach. The measurement alternatives and ranking according to compromise solution (MARCOS) method, the Honey Badger Algorithm, and the Taguchi-MARCOS method are engaged to obtain the important machining constraints and the optimal parametric settings for each response. When compared to the parent material, sub-cooled material has a greater cutting speed, SR, kerf breadth, and MRR. Here, cutting speed, MRR, and fitness were maximized along with minimization of SR and kerf width using the Honey Badger Algorithm as compared to both the MARCOS and Taguchi-MARCOS methods. According to ANOVA, for both parent and sub-cooled material, discharge current was the most significant and influential factor. The sub-cooled material's machined surface contains smaller deposits and more spherical globules than the parent material, which has bigger melted deposits. [ABSTRACT FROM AUTHOR]

Corrosion protection of carbon steel in 1% NaCl salt solution saturated with carbon dioxide was studied by potentiodynamic polarization method in the presence of three newly synthesized dissymmetric cocogem surfactants—N,N′-bis(2-hydroxypropyl) hexamethylenediammonium octanoate stearate (NNBOS), N,N′-bis(2-hydroxypropyl) hexamethylenediammonium octanoate oleate (NNBOO) and N,N′-bis(2-hydroxypropyl) hexamethylenediammonium octanoate linolenate (NNBOL). Experimental results revealed that all three compounds—NNBOS, NNBOO and NNBOL—possess high inhibitor efficiency on the protection of carbon steel in 1% NaCl solution saturated with carbon dioxide. Increase in concentrations of NNBOS, NNBOO and NNBOL inhibitors up to 100 ppm in the medium causes increase in their protective effects up to 99.4%. The study of polarization curves confirmed belonging of all three inhibitors to mixed-type inhibitors. Adsorption of inhibitor on the surface of C1018 carbon mild steel corresponds to negative value of Langmuir isotherm model Δ G ads 0 . Thermodynamic data for adsorption process were calculated and discussed. Effect of molecular structure on the inhibitor protective effectiveness was studied. Experiments revealed that adsorption energy of NNBOL inhibitor at a concentration of 100 ppm is higher than adsorption energy of NNBOS and NNBOO inhibitors. It occurs due to the presence of three unsaturated double bonds in linolenic acid residue in NNBOL compound corresponding to experimentally determine high inhibitor efficiency. [ABSTRACT FROM AUTHOR]

The current work assessed the corrosion inhibitory efficacy of three ligands, namely methyl 2-((2-hydroxynaphthalen-1-yl)diazenyl)benzoate(MDN), 1-((3,4-dimethylphenyl)diazenyl)naphthalen-2-ol (DDN), and 3-((2-hydroxynaphthalen-1-yl)diazenyl)benzonitrile (HDN). Electrochemical and quantum methodologies, along with UV–Vis, SEM, and EDX, were employed. The anticorrosion process was comprehensively investigated. Potentiodynamic polarization validated the mixed type nature of inhibitors by demonstrating a drop in the cathodic hydrogen evolution reaction and the anodic metal dissolution, resulting to a significant decrease in corrosion current densities. Enhanced rates of effectiveness are achieved with higher inhibitor doses. Electrochemical impedance spectroscopy investigations confirmed the formation of a protective layer at the metal/solution interface, demonstrating that charge transfer was the primary cause of mild steel corrosion. The inhibitory potencies of the studied inhibitors at 10−3 M were 94.65, 94.56, and 93.63% for MDN, DDN, and HDN, respectively. The presence of several attributes in the molecular skeleton, such as nitrogen heteroatoms, aromatic rings, and the ester substituent group (CO2CH3), enhanced the availability of non-bonded and π-electrons and created stable covalent bonds by donating electrons to the iron surface. The inhibitory efficiency was better than 89% across all temperature ranges, suggesting the potential benefits of inhibitors at elevated temperatures. Adsorption trials revealed high effectiveness in corrosion control on mild steel, with Langmuir-based physisorption and chemisorption. The impact of electronegative O and N atoms, along with aromatic rings, in forming protective coatings was demonstrated by quantum chemistry computations which linked molecular structure and charge density patterns to the inhibition potency of MDN, DDN, and HDN, highlighting MDN's strong adsorption capacity. [ABSTRACT FROM AUTHOR]

The corrosion inhibition of Thymus leptobotrys Murb essential oil (TLMEO) is evaluated for mild steel (M-S) in 1M HCl solution using electrochemical and surface analysis. Results showed that TLMEO acted as a potential corrosion inhibitor and shows the highest inhibition efficiency of 91.7% at 2g/l concentration. Electrochemical studies suggest that TLMEO acted as a mixed- and interface-type of corrosion inhibitor. The TLMEO inhibits metallic corrosion through an adsorption mechanism that follows Langmuir's adsorption isotherm model. The adsorption mechanism of corrosion inhibition was further supported using SEM–EDX, and surface studies. In addition, the anti-corrosion mechanism of the main TLMEO compounds was studied using computational techniques: Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations. Theoretical results were consistent with the experimental findings that were reported. [ABSTRACT FROM AUTHOR]

In this study, the behavior of soft clay improved with a conductive jute geotextile-encased stone column was investigated, considering the effects of electrokinetic coupling. The study findings suggest that electrokinetic-coupled encased stone columns (e-ESCs) improve the dewatering efficiency, consolidation settlement rate, and shear strength of the soft clay compared to nonelectrokinetic encased columns. After the inclusion of e-ESCs, the time required to remove 50% of the total discharge was decreased by 92% compared to encased stone columns (ESCs). A significant decrease in the volumetric shrinkage and surface cracks was observed for e-ESC-improved soft clay. Further, due to anode corrosion during the process, brass electrodes experienced a 4.25% loss in weight at the end. The consumed power per unit weight of treated soil (Wh/kg) at the end of the test period was 24.03, 19.70, 20.10, and 23.38 Wh/kg for the e-ESC with mild steel, copper, brass, and aluminum anodes, respectively. The findings showed that the choice of anode material affects the characteristics of soft clay, such as undrained shear strength, pore water discharge, flow pattern, and moisture content. Further, a noteworthy modification in the physicochemical properties of clay was observed. [ABSTRACT FROM AUTHOR]

Context: The corrosion of mild steel is a significant issue in various industries, prompting the need for effective corrosion inhibitors. This study focuses on understanding the corrosion inhibition properties of organic compounds derived from isoxazole, namely series Iso(a), Iso(b), Iso(c), Iso(d), Iso(e), Iso(f), Iso(g), and Iso(h), which could have implications for materials science and industrial applications. By investigating the influence of different substitutions on these compounds, valuable insights can be gained into designing better corrosion inhibitors for practical use. Methods: Theoretical studies were conducted using density functional theory (DFT) with the B3LYP functional and the 6-31G (d,p) basis set. These calculations enabled the evaluation of various parameters including frontier orbital energies (EHOMO, ELUMO), energy gap (∆E), electronegativity (χ), absolute hardness (η), softness (σ), fraction of transferred electrons (∆N), as well as local properties such as natural atomic populations and Fukui indices. Additionally, molecular dynamics simulations were performed to study the adsorption behavior of the inhibitors on the surface of Fe (110). The simulations were conducted using Materials Studio version 8.0 software package using COMPASS force field to understand the impact of different functional groups on the inhibitors before and after adsorption on the iron surface. [ABSTRACT FROM AUTHOR]

Achieving repeatability in part production remains a challenge in laser-wire feed directed energy deposition (LW-DED). It is necessary to understand the laser-wire deposition and bead aspect ratio varying the process conditions to achieve repeatability. Laser energy density is one of the key process parameters that affect the dimensions of the deposit. So, this study discusses the fundamentals of depositing the copper-coated ER70S-6 low carbon steel wire. The laser energy density effects on aspect ratio, overall porosity, microstructure, and microhardness are presented. The bead morphology changes with the change in laser energy density. Single track deposited sample results helped in understanding the melt transition for material deposition and dimensional resolution of the deposited track. [ABSTRACT FROM AUTHOR]

Aluminium honeycomb core is a thin-walled cellular structure extensively used in crash resistance applications in automotive industry. To overcome current challenges in adhesive-bonded honeycomb, new fabrication route using micro friction stir lap welding has been proposed. With a specific energy absorption capacity as high as 28.2 kJ/kg in flatwise impact testing, fabricated honeycomb demonstrated its potential for industrial applications. The structure exhibited no weld cracks or cell wall delamination, unlike adhesive-bonded honeycombs. However, in friction stir welding of thin sheets (0.5 mm), achieving an optimized heat input is challenging due to limited scope for variation in process parameter and tool design. Therefore, control of heat outflow by proper selection of backing plate material is the alternative approach for achieving desirable joint performance. Experiments with backing plates having a range of thermal diffusivities demonstrated that joint produced with mild steel backplate exhibited maximum shear-tensile strength. Conversely, joint with aluminium backplate exhibited poor plastic flow of material. Effective sheet thickness and lap width were predominantly affected by heat accumulation in weld, resulting in different failure modes. [ABSTRACT FROM AUTHOR]

Buckling behaviour of axially and circumferentially loaded cylindrical shells made of high‐strength steels In the past, shell structures have largely been made of mild steels or austenitic stainless steels. However, high‐strength duplex stainless steels acc. to DIN EN 10088‐4, ‐5 are increasingly being used, e. g. in biogas fermenters. The use of high‐strength steels and duplex stainless steels not only reduces steel consumption and production costs, but also assembly costs, and thus significantly increases the competitiveness of tanks and silos in steel construction compared to containers made of other construction materials, e. g. concrete. One prerequisite, however, is that the problem of stability failure in the form of shell buckling can be eliminated. The European design standards for shell structures EN 1993‐1‐6, ‐4‐1, ‐4‐2 are developed for mild steels and do not take into account strength verification formats for ring‐stiffened and axially stiffened circular cylindrical shells for high‐strength structural steels and stainless steels with a nonlinear material behaviour below the 0.2 % yield strength. For this reason, within the framework of the IGF research project no. 21719N "Load‐bearing behaviour of meridionally and ring stiffened tanks and silos made of high strength (duplex) steels and low‐temperature steels for pressure vessels", systematic investigations are carried out on (un‐)stiffened circular cylindrical shells at the Institute of Metal and Lightweight Structures at the University of Duisburg‐Essen and the Testing Institute for Steel, Wood and Stone at the Karlsruhe Institute of Technology. The first results of this research project are presented here. [ABSTRACT FROM AUTHOR]

AbstractThe objective of the study is to determine the most effective induction heating parameters for melting pure zinc selectively over the mild steel substrate surface. The numerical simulation on effect of induction heating parameters on the mild steel substrate is studied using COMSOL Multiphysics 5.6 software. The optimised effective parameters are used for the experimental analysis for the validation. Variables such as coil configuration, stand-off distance (SOD), coil current and frequency were systematically changed, and optimal settings were chosen on the basis of time temperature contour curve and the heating rate within the material. Results of the numerical analysis portrayed that a pancake coil geometrical configuration, SOD of 2 mm, coil current of 300 A and alternating frequency of 300 kHz were found as the optimum set of parameters for the effective surface repair. An experimental investigation was carried out by depositing a thin layer of zinc on mild steel substrate using the optimized parameters. The surface integrity of the coated specimen was examined through the high-resolution optical microscopy, X-ray diffraction and electron back scattered diffraction (EBSD) techniques. The hardness property of the coated specimen was examined with a Vickers microhardness tester. The microstructure analysis and hardness measurement showed that consistent coating is achieved without affecting the base metal/substrate properties. The experimental results very much coincide with the numerical simulation. [ABSTRACT FROM AUTHOR]

High-strength steel (HSS) members with welded sections exhibit a notably lower residual compressive stress ratio compared with common mild steel (CMS) members. Despite this difference, current codes often generalize the findings from CMS members to HSS members, and the previous unified residual stress models are generally conservative. This study focuses on the membrane residual stress distribution in Q690 steel welded box sections. By leveraging experimental results, the influence of section sizes and welding parameters on membrane residual stress was delved into. A larger plate size correlates with a decrease in the residual compressive stress across the section, with a more pronounced reduction observed in adjacent plates. Additionally, augmenting the number of welding passes tends to diminish residual stresses across the section. Results showed that membrane residual stress adhered to the section's self-equilibrium, while the self-equilibrium in the plates was not a uniform pattern. A reliable residual stress simulation method for Q690 steel welded box sections was established using a three-dimensional thermal–elastic–plastic finite element model (3DTEFEM) grounded in experimental data. This method served as the cornerstone for parameter analysis in this study and set the stage for subsequent research. As a result, an accurate unified residual stress model for Q690 steel welded box sections was derived. [ABSTRACT FROM AUTHOR]

The change in the corrosion activities of SS304 and the carbon steel A36 were studied during their exposure for 30 days to hybrid pumice-Portland cement extract (CE), to simulate the concrete–pore environment. The ionic composition and the initial pH (12.99) of the CE were influenced by the reduction of Portland cement (PC) content, volcanic pumice oxides and alkaline activators. Because of the air CO 2   dissolution, the pH decreased and maintained a constant value ≈ 9.10 (established dynamic ionic equilibrium). The CE promoted the passivation of both steels and their free corrosion potential (OCP) reached positive values. On the surfaces, Fe and Cr oxides were formed, according to the nature of the steel. Over the time of exposure, the presence of chloride ions in the pumice caused a localized pitting attack, and for carbon steel, this fact may indicate an intermediate risk of corrosion. The chloride effect was retarded by the accumulation of SO 4 2 − ions at the steel surfaces. Based on electrochemical impedance (EIS), the polarization resistance (Rp) and the thickness of the passive layers were calculated. Their values were compared with those previously reported for the steels exposed to CEs of Portland and supersulfated cements, and the hybrid cement was considered as a PC "green" alternative. [ABSTRACT FROM AUTHOR]

The corrosion inhibition performance of the corrosion inhibitors is related to their adsorption behavior on the metals' surface, in general, most of researchers focus on the Langmuir adsorption isotherm to deduce physisorption and chemisorption of corrosion inhibitors, however, which experiences a serious argument in recent years. Furthermore, the famous researchers in corrosion field believe that it is wrong to use the Langmuir adsorption isotherm to determine the adsorption behavior of corrosion inhibitors. Simulation methods such as density functional theory (DFT) and molecular dynamics simulation (MD) are treated as effective tools to deeply insight and gain the adsorption behavior of corrosion inhibitors, which can well illustrate the corrosion inhibition mechanism. The quantum chemical parameters obtained from DFT simulation and adsorption energy calculated from MD simulation could well confirm the physisorption or chemisorption states between the corrosion inhibitor and metal surface. Thus, we systematically review the advantages of DFT and MD simulations in analyzing and probing the corrosion inhibition mechanisms of the corrosion inhibitor. [ABSTRACT FROM AUTHOR]

The pursuit of advanced multifunctional compounds has gained significant momentum in recent scientific endeavours. This study is dedicated to elucidating the synthesis, rigorous characterization, and multifaceted applications—encompassing anti-corrosion, antimicrobial, and antioxidant properties—of Diethyl 4-(5-bromo-1H-indol-3-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate. The 1,4-dihydropyridine derivative was meticulously synthesized through a strategic reaction of ethyl acetoacetate, ammonium acetate, and 5-bromoindole-3-carboxaldehydein the ethanol medium at 60 C. Subsequent spectral validations were conducted using sophisticated techniques, namely FTIR, NMR, and Mass spectrometry, resulting in data that perfectly resonated with the hypothesized chemical structure of the compound. Its anti-corrosive potential was assessed on mild steel subjected to an aggressive acidic environment, employing comprehensive methodologies like gravimetric analysis, Tafel polarization, and EIS. Concurrently, its antimicrobial prowess was ascertained against a spectrum of bacterial and fungal pathogens viz., Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas, Candida albicansandAspergillusniger, leveraging the disc diffusion method and using Gentamicin as a reference standard.The empirical results illustrated a substantial decrement in corrosion rates with ascending concentrations of the organic compound, achieving an apex of anti-corrosive efficacy at 81.89% for a concentration of 2 × 103 M. Furthermore, the compound outperformed Gentamicin in antimicrobial screenings, manifesting superior efficacy against all tested pathogens. The antioxidant potential, quantified using the DPPH free radical scavenging assay against ascorbic acid as a benchmark, was found to have an IC50 value of 113.964 ± 0.076 µg/ml.This comprehensive investigation accentuates the paramount potential of the synthesized dihydropyridine derivative in diverse domains—from industrial applications as a corrosion inhibitor to therapeutic avenues given its pronounced antimicrobial and antioxidant capabilities. The compelling results obtained pave the way for expansive research and development initiatives cantered around this multifaceted compound. [ABSTRACT FROM AUTHOR]

The experimental measurements of ${2D}$ 2 D micro/nanolayered dimples' dimensions (both geometry and pattern) on the published tensile fractographs of a series of austempered high-strength low-carbon bainitic steel are carried out and interpreted with the corresponding initial microstructural features and tensile mechanical responses as a function of austempering temperature. [ABSTRACT FROM AUTHOR]

Nitrogen‐containing corrosion inhibitors have a wide range of promising applications, and current conventional corrosion design and evaluation methods are largely based on empirical speculation and extensive exploratory experiments. Unfortunately, these efforts are often associated with high costs, long lead times, and a lot of "blind work." In this work, we have computationally screened the quantum chemical parameters of five nitrogen‐containing corrosion inhibitor molecules and their corrosion inhibition properties by a molecular simulation method based on density functional theory calculations. The ultimate relationship between the corrosion inhibition efficiency (IE) of an adsorbent and its quantum chemical parameters was analyzed using linear regression by comparing the various quantum mechanical parameters of each inhibitor molecule, as well as the fraction of electrons (ΔN) that are transferred to the metal surface from the chemisorbed inhibitor molecule. Five different nitrogen‐containing corrosion inhibitor molecules were screened based on structural similarity. Meanwhile, their corrosion inhibition performance was evaluated using the most relevant structure–activity equations. The results showed that the synergistic effect between the corrosion inhibition performance and the orbital energies of highest occupied molecular orbital and lowest unoccupied molecular orbital was optimal under the HF/6‐31G(d) method, and the corresponding structure–activity relationship was established. Based on these results, a specific inhibitor molecule was found to have excellent corrosion inhibition performance with a predicted corrosion IE of up to 94.12 %. [ABSTRACT FROM AUTHOR]

Cladding with a stick electrode is one of the oldest arc processes for adding a deposit on a base material. The process is suitable for outdoor working, but the disadvantages are low productivity and large dilution rates. In this work, a simple solution is proposed, which would enable cladding of a larger area with one pass and decrease the dilution rate at the same time—a new type of electrode was developed, exhibiting a rectangular cross-section instead of a round one. Hardfacings, welded with E Fe8 electrodes according to EN 14 700 Standard were welded on mild steel S355 J2 base material with three different coated stick electrodes. The first one was a commercially available, standard, round hardfacing electrode, the second was the same, but with a thinner coating, and the third one was a newly developed rectangular electrode. All three types had equal cross-sections of the metallic core and the same type of coating. Manufacturing of the rectangular electrodes in the laboratory is explained briefly. One- and multi-layer deposits were welded with all three types. Differences were observed in the arc behavior between the round and rectangular electrodes. With the rectangular electrode, the microstructure of the deposit was finer, penetration was shallower, and dilution rates were lower, while the hardness was higher, residual stresses predominantly compressive, and the results of instrumented Charpy impact tests and fracture mechanics tests were better. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of Imidazolium cation-based ionic liquids having different anions were reported in the present article. The physicochemical and spectral analyses were used to characterized these ionic liquids. The theoretical studies using the B3LYP method provide optimized structure, HOMO–LUMO plots, thermodynamic parameters, and quantum descriptors. The anti-corrosive property of Imidazolium cation-based ionic liquids was observed in 0.5 M H2SO4 corrosive medium at 303, 313, 323, and 333 K temperatures by various strategies like gravimetric studies, electrochemical impedance spectroscopy, potentiodynamic polarization studies, and scanning electron microscopy (SEM). The interesting feature of this article is that both ionic liquids follow different adsorption isotherms. IL-1 ionic liquid shows physisorption adsorption behavior, and IL-2 exhibits mixed adsorption (chemisorptions and physiorption). The electrochemical strategies and Egap value obtained from DFT reveal the maximum inhibition efficiency of IL-2 for the corrosion process in an acidic medium on mild steel. Potentiodynamic polarization studies reveal the mixed type behavior for ionic liquid inhibitors. EIS results indicate that the inhibition efficiency improved by enhancing ionic liquids concentration. The protective layer formation or adsorption of ionic liquid on metallic surface was confirmed by SEM. In the present article, the proposed mechanism shows the blockage of anodic and cathodic sites by ionic liquids to inhibit the corrosion process on mild steel in an acidic medium. [ABSTRACT FROM AUTHOR]

The structure and properties of coatings formed on the structural steel surface are studied. The coatings were applied by non-vacuum electron beam surfacing of Cr–Ni–Ti powder mixtures. The high-quality surface layers have been obtained, the corrosion resistance of which corresponds to the properties of the austenitic Ni–Cr stainless steel. For this purpose, the phase composition and elemental distribution of alloying components in the coatings are assessed, the structural features are analyzed, and the physical, mechanical, and adhesion characteristics are determined. It is shown that coatings up to 2400 μm thick, the structure of which is a γ-solid solution of Ni and Fe, are formed on the steel surface. The ultimate strength of the formed material reaches 856 MPa, which is by a factor of 1.3 higher than that of the austenitic Ni–Cr stainless steel 12–Cr18–Ni9–Ti. The adhesive strength of the coatings reaches 560 MPa. The corrosion resistance of layers of different compositions surfaced on low-carbon steel under the influence of a 65% nitric acid is studied. It has been established that the corrosion resistance of surface-alloyed layers in the 65% nitric acid solution exceeds the resistance of the base material by 30–70 times. [ABSTRACT FROM AUTHOR]

In this research, corrosion inhibition of 2-(4-methoxyphenyl)-benzothiazole as a novel inhibitor was considered by electrochemical impedance spectroscopy (EIS). Obtained data from EIS were assessed to model the corrosion inhibition procedure over the equivalent circuit. Experimental design approach in the field of corrosion science was studied in this research. It is an essential step in studying the corrosion of mild steel data of multifaceted chemical systems to control the number of principal factors. The multivariate statistical design of experiments (DOE) method represents a hopeful and efficient optimization technique, which can overwhelm the limits of traditional optimization methods. Achieved optimum values by DOE were 25 °C, 0.001 M and 2 M for temperature, inhibitor and hydrochloric acid concentrations, respectively, which gave 97.8% inhibition efficiency. The inhibitory and adsorption of the inhibitor molecules were investigated by the quantum calculation and molecular dynamics (MD) simulation. The quantum calculations reveal suitable intrinsic molecular parameters of the inhibitor. MD simulations predicted the parallel orientation of the inhibitor on the Fe(110) surface and the proper adsorption energy. [ABSTRACT FROM AUTHOR]

L-Glutathione reduced (GSH) is a small molecule peptide found in large quantities in living organisms, particularly in animal liver cells. Its unique structure gives it great potential to act as an environmentally friendly and efficient corrosion inhibitor. The inhibition properties of GSH for mild steel in simulated concrete pore solutions (SCPS) containing chlorine was investigated by electrochemical tests and SEM-EDS surface analysis. According to the experimental results, GSH mainly blocked the cathodic corrosion reaction and has a corrosion inhibition efficiency of up to 92.3% at room temperature, enhancing the corrosion resistance of mild steel. The isothermal adsorption results indicate that the adsorption behavior of GSH on the surface follows the Langmuir isothermal adsorption model. Both quantum chemical calculations (QC) and molecular dynamics simulations (MD) show that GSH can be effectively adsorbed onto mild steel substrates, thus protecting the surface from erosion. Finally, the results of the above experiments and theoretical calculations are combined to elucidate the inhibitive mechanism: GSH molecules binds to the iron surface via the sulfur, nitrogen and oxygen atoms in the molecule, thus adsorbing to the iron surface in a tiled manner and forming a protective film to prevent the corrosive material from contacting the iron surface. [ABSTRACT FROM AUTHOR]

The use of green-soluble inhibitors in the corrosive medium as alternatives to traditional inhibitors has increased due to the toxicity of the commonly used substances. These novel substances are selected owing to their low cost, ease of application as well as maintenance, and low environmental risk. This work aims to evaluate ethanolic-water extracts from post-harvest soybean (Glycine max) by-products as corrosion inhibitors for mild steel in an aggressive medium of sodium chloride. Soybean extracts were obtained by percolation at a controlled flow rate and temperature. To evaluate the anticorrosive efficiency, polarization curves of AISI 1030 steel were carried out at 1 and 7 days of immersion with different concentrations of the soybean extract. Weight loss measurements were carried out alongside potentiodynamic measurements. The steel samples were analyzed by scanning electron microscopy. The soybean extracts obtained reduced the corrosion rate of the steel, showing an efficiency of 30% at day 1. The inhibition efficiency increased up to 80% after 7 days of incubation with 2000 ppm of the extract. A Langmuir adsorption model was fitted to weight loss measurements. Kads and ΔGads obtained from the model were characteristic of physisorption. The corrosion potential was shifted toward more negative values, classifying the ethanolic-water soybean extract as a cathodic inhibitor. The steel surface for the samples incubated with 2000 ppm of soybean extract was greatly improved showing significantly fewer agglomeration of corrosion products. Soybean leaves are a promising by-product useful to produce ethanolic-water extracts to be used as green corrosion inhibitors. [ABSTRACT FROM AUTHOR]

There is a general inverse relationship between strength and toughness in low‐carbon steels. The transformation‐induced plasticity (TRIP) effect of retained austenite (RA) can help overcome this contradiction by providing strain hardening and transformation toughening during service. In this study, the effect of RA on the microstructure evolution, cryogenic mechanical properties, and fracture behavior of multi‐alloyed Ni‐containing steel is explored. Two well‐established techniques are employed to tailor the RA: quenching–intercritical tempering (QIT) and quenching–lamellarizing–intercritical tempering (QLIT). QLIT steel has a 25.1 vol% RA fraction, which is twice that of QIT steel, and offers exceptional stability at –196 °C. As a result, QLIT steel exhibits superior cryogenic mechanical properties in comparison to QIT steel, including a 6.9% increase in yield strength up to 1228 MPa, a 36.6% increase in elongation up to 33.2%, and a 147.4% increase in impact energy up to 193 J. These improvements are due to the higher fraction of RA transformed into the martensite during tensile deformation, resulting in an enhanced TRIP effect and increased work‐hardening rate. The exceptional stability of the RA also provides more sustainable TRIP toughening during cryogenic impact deformation, which helps to arrest crack propagation. [ABSTRACT FROM AUTHOR]

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

Purpose: The aim of this paper is to solve the toxic and harmful problems caused by traditional volatile corrosion inhibitor (VCI) and to analyze the effect of the layered structure on the enhancement of the volatile corrosion inhibition prevention performance of amino acids. Design/methodology/approach: The carbon dots-montmorillonite (DMT) hybrid material is prepared via hydrothermal process. The effect of the DMT-modified alanine as VCI for mild steel is investigated by volatile inhibition sieve test, volatile corrosion inhibition ability test, electrochemical measurement and surface analysis technology. It demonstrates that the DMT hybrid materials can improve the ability of alanine to protect mild steel against atmospheric corrosion effectively. The presence of carbon dots enlarges the interlamellar spacing of montmorillonite and allows better dispersion of alanine. The DMT-modified alanine has higher volatilization ability and an excellent corrosion inhibition of 85.3% for mild steel. Findings: The DMT hybrid material provides a good template for the distribution of VCI, which can effectively improve the vapor-phase antirust property of VCI. Research limitations/implications: The increased volatilization rate also means increased VCI consumption and higher costs. Practical implications: Provides a new way of thinking to replace the traditional toxic and harmful VCI. Originality/value: For the first time, amino acids are combined with nano laminar structures, which are used to solve the problem of difficult volatilization of amino acids. [ABSTRACT FROM AUTHOR]

The illustrations above demonstrate that as the percentage of niobium increases, the grain size decreases, leading to an increase in the stability of transformation induced plasticity steel. This, in turn, results in improved mechanical strength. The optimal volume fraction of retained austenite for a significant transformation induced plasticity effect to occur is reported to be in the range of 10 vol. %–20 vol. %. The volume fraction of retained austenite directly determines the carbon content and grain size of the retained austenite, its two main stabilization factors. The stability of the retained austenite dictates when the strain‐induced martensite transformation (SIMT) occurs during straining of transformation induced plasticity high strength steel. Unstable retained austenite transforms almost immediately upon deformation, increasing work hardening rate and formability during the stamping process. At the appropriate stability of the retained austenite, the Strain‐Induced Martensite Transformation begins only at strain levels beyond those produced during stamping and forming, and the retained austenite is still present in the final part; it can transform into martensite in the event of a crash, providing greater crash energy absorption. The tensile strength level of micro‐alloyed transformation induced plasticity steels may exceed 1 GPa. Grain refinement mechanism is considered as the most applied mechanism used in increasing of steel strength without deterioration of ductility and toughness. Recently, it was proposed that the grain refinement could act positively on promoting the transformation induced plasticity effect of advanced high strength steel through improving the stability of retained austenite. In this research, quenching and partitioning heat treatment technique was applied to four grades of low carbon steel with different percentage of niobium. Then, the effect of niobium on grain refinement has been detected by microstructure observations. Mechanical properties and strain hardening properties of investigated steel have been determined. In addition, by using x‐ray diffraction, as well as a new electric resistance‐based sensor, it was possible to characterize the stability of the retained austenite through the plastic deformation of steel. Grain refinement by using of niobium has a great impact on promoting the stability of retained austenite against the plastic stress at the plastic deformation zone. [ABSTRACT FROM AUTHOR]