Sulfate-reducing bacteria (SRB) are a major contributor to microbiologically influenced corrosion (MIC) of high-strength steels exposed to marine and oil–gas environments, yet the role of antimony (Sb) microalloying in SRB-MIC has not been systematically investigated. The effect of Sb addition on SRB-MIC of 690 MPa-grade high-strength steel was investigated during 7-day exposure to Desulfovibrio vulgaris (D. vulgaris) in anaerobic ATCC 1249 medium at 37 °C. Multiscale characterization integrating SRB activity, electrochemical testing, surface analysis, phase-equilibrium calculations, and thermodynamic analysis was used to correlate matrix microstructure, biofilm evolution, SRB-MIC products, and interfacial electrochemistry. Although increasing Sb progressively mitigated SRB activity, SRB-MIC resistance exhibited a non-monotonic dependence on Sb content. Moderate Sb addition (0.05wt.%) improved microstructural homogeneity and stabilized the steel/biofilm interface, while Sb-mediated sulfidation modified FeS-based SRB-MIC products and hindered the extracellular electron transfer (EET) process. In contrast, excessive Sb (0.10–0.12wt.%) promoted carbide aggregation and interfacial electrochemical heterogeneity, enhancing micro-galvanic coupling, localized anodic dissolution, and EET despite stronger SRB inhibition. These results reveal a dual biological–material effect of Sb, with 0.05wt.% providing the highest SRB-MIC resistance at 690 MPa-grade high-strength steel.

Alumina-based coatings are promising candidates to protect structural materials from lead-bismuth eutectic (LBE) corrosion in advanced nuclear systems. In this study, an Al2O3-TiO2 coating is deposited on FeCrAlY alloy by multi-arc ion plating, and its corrosion behavior was systematically investigated under both static and flowing LBE at 550 degrees C. For comparison, an AlOx coating is also evaluated under static conditions. The results show that the Al2O3-TiO2 coating exhibits superior corrosion resistance and structural stability compared with AlOx coating. This performance is attributed to its amorphous-nanocrystalline structure, which not only improves toughness but also maintains high compositional uniformity and microstructural stability during long-term LBE exposure. Overall, the Al2O3-TiO2 coating shows excellent structure stability and mechanical properties, enabling it to remain intact even under harsh flowing LBE environments, underscoring its potential for advanced reactor applications.

In this paper, the short-term corrosion behavior of the hot-dipped galvanized steel and cold sprayed zinc steel in urban atmosphere was investigated using scanning electron microscope, 3D microscopic and electrochemical measurements. The results showed that the corrosion rate values of hot-dipped galvanized steel decreased from 1.013 μm·y−1 in the first year to 0.891 μm·y−1 after two years of exposure, whereas the corrosion rate values of cold sprayed zinc steel increased from 1.645 μm·y−1 in the first year to 1.882 μm·y−1 after two years of exposure. Electrochemical measurements corroborated these trends, revealing a substantially higher corrosion current density of cold sprayed zinc steel (from 24.46 μA·cm−2 to 47.40 μA·cm−2) compared to hot-dipped galvanized steel (from 10.40 μA·cm−2 to 6.186 μA·cm−2). During the field exposure, the corrosion rate values of the cold sprayed zinc steel were always higher than that of the hot-dipped galvanized steel. The localized corrosion degree for the hot-dipped galvanized steel was relatively high, and the zinc coating was perforated after one year of exposure. General corrosion dominated the surface of the cold sprayed zinc steel, with a low sensitivity of localized corrosion.

An electroless Ni-P-PTFE composite coating was investigated under supercritical COQ (S-CO2) conditions using a newly developed in-situ electrochemical impedance spectroscopy (EIS) technique. The coating exhibited a dense amorphous structure with embedded PTFE particles, effectively suppressing ionic transport and interfacial corrosion. In-situ EIS measurements revealed the high coating resistance value (7.4 & times; 104 Omega & sdot;cm2) demonstrates stable impedance behavior and high corrosion resistance across varying water-phase S-CO2 conditions. Even after 192 h at 80 degrees C, the Ni concentration in corrosion solution was only 100 mg/L, demonstrating the coating's strong protective ability under such extreme conditions.This study provides mechanistic understanding of coating behavior in S-CO2 and establishes in-situ EIS as a robust methodology for evaluating material stability in CCS environments.

M2052 (Mn-20Cu-5Ni-2Fe, at.%) damping alloy was fabricated by laser powder bed fusion (LPBF). Its microstructure, mechanical properties, and damping behavior were investigated after direct aging and solution treatment followed by aging, with the aim of achieving a simultaneous improvement in mechanical performance and damping capacity. The results show that, compared with the as-built condition, direct aging markedly enhances the strength of the alloy, with the ultimate tensile strength reaching approximately 708 MPa, the yield strength increasing to about 469 MPa, and the elongation remaining at 25.7%. Solution treatment significantly improves the ductility of the M2052 alloy, with the elongation reaching as high as about 40.6%. Damping tests indicate that direct aging effectively improves the room-temperature damping performance, with the maximum value increasing by nearly three times. The improvement in mechanical properties and damping capacity is mainly attributed to the beneficial effects of the spinodal structure and twin structures formed during heat treatment. This work provides a theoretical basis for heat-treatment design and property regulation of additively manufactured MnCu based damping alloy components.

This study investigates the failure mechanisms of ASTM 1020 carbon steel elbows from a refinery condensate pipeline, comparing a catastrophically perforated Elbow #1 with a significantly thinned Elbow #2, both after five years of service. Comprehensive failure analysis was performed through macroscopic/metallographic examination, chemical composition verification, mechanical property characterization, and electrochemical test. Results show that flow-accelerated corrosion (FAC) as the predominant wall-thinning mechanism in both elbows. Computational fluid dynamics (CFD) analysis proved that the pressure and radial flow velocity reach their maximum values at the failure location (approximately 45 degrees on the extrados), where material loss was most severe. Microstructural analysis revealed Elbow #1 exhibited banded pearlite-ferrite morphology with elevated pearlite content, whereas Elbow #2 featured dispersed pearlite in ferrite matrix. This microstructural configuration enhanced tensile strength and fracture toughness along the extrusion direction in Elbow #1. However, the banded pearlite structure simultaneously compromised corrosion resistance, accelerating FAC-driven material loss.

This research investigates the synergistic corrosion inhibition effect of a system comprising Styphnolobium japonicum (L.) Schott extract (SE), thiourea (TU), and cetyltrimethylammonium bromide (CTAB) collectively termed STC on mild steel (MS) in H2SO4 solution. The optimal concentration of SE (500 mg/L), TU (100 mg/L), and CTAB (1000 mg/L) yielded a maximum inhibition efficiency of 96.07 % at 313 K and 90.35 % after 8 h immersion. In H2SO4 containing STC, a protective film forms on the MS surface, giving a much higher charge transfer resistance (Rct) than in H2SO4 alone. However, as temperature increases, the film deteriorates, causing a sharp drop in Rct and a consequent decrease in inhibition performance. Tafel analysis indicates that STC acts as a mixed-type inhibitor, reducing both anodic and cathodic reactions. However, increasing temperature raises icorr and lowers inhibition efficiency. Analyses of the radial distribution function (RDF) data confirm that the interaction between STC and MS is chemisorption. In addition, the movement behaviors of H2O, H3O+and SO4 2-are explored using the mean square displacement (MSD) method.

Aiming at the issue of poor corrosion resistance in M2052 alloy and the damping performance degradation as the working temperature increases, this study focuses on enhancing the corrosion resistance of the M2052 damping alloy through a low-temperature (<60 °C) coating preparation method. A uniform Ni-W coating with a thickness of approximately 12 μm and a nanocrystalline structure was successfully obtained under a low current density condition. Compared with the uncoated substrate, the Ni-W-coated samples exhibited significantly enhanced hardness, reduced friction coefficient, and markedly improved wear resistance, with the dominant wear mechanism transitioning from abrasive/oxidative wear to mild adhesive wear. In 3.5 wt.

A comparative investigation was conducted on the corrosion behavior of galvanized coatings under NaCl-containing condensation-drying cycles and full immersion in NaCl solution. The condensation-drying cycle environment significantly accelerated the corrosion damage of galvanized coatings. The cycles induced spatial redistribution of salts, forming high-salinity salt rings that increased the corrosion tendency of the underlying galvanized coatings. Compared with full immersion, the condensation condition promoted the formation of loose corrosion products with weak interatomic bonding and unstable crystal structures, accelerating the diffusion of aggressive species to the steel substrate. As condensation evolved over time, the internal salt concentration increased and the wetting contact angle decreased. Based on the coffee-ring effect, a functional equation was established in this work to correlate the deposition characteristics of salts and corrosion products inside condensate during the drying process with salt concentration and contact angle. Analysis of the function plot revealed that the coupled effects of increasing salt concentration and decreasing contact angle led to localized high salinity, concentrated loose corrosion products, and the formation of electrochemical corrosion couples between the edge and interior of the condensate. Under the synergistic effects of the inherent microstructural inhomogeneity of the galvanized coating, the structural characteristics of corrosion products, and the evolution behavior of the condensation environment, the corrosion damage of galvanized coatings under condensation-drying cycles was ultimately accelerated.

The corrosion fatigue behavior under the coupling effect of multiple factors such as thermal aging-stress-corrosion was studied of Z3CN20.09 M stainless steel (SS) based on the equivalent accelerated thermal aging reached about 64 years, which over the full life span for second-generation pressurized water reactor (PWR) nuclear power plant, by a high-temperature and high-pressure crack growth rate (CGR) testing device, a 3D atom probe tomography (APT) and a transmission electron microscope (TEM). The research results shew that the ferrite phase in Z3CN20.09M SS undergoes spinodal decomposition to form Cr-rich alpha' and iron-rich alpha phase accompanied by the precipitation of the G phase after thermal aging. They became more and more significant as the thermal aging time prolongs, and the intergranular corrosion sensitivity, tensile strength, nano-hardness of the ferrite phase increased while charpy impact and elongation decreased continuously. Correspondingly, the corrosion fatigue CGR at 320 degrees C significantly increases with increasing the aging time at different stress intensity factor (Delta K), which can be attributed to the collaborative deterioration of mechanical and corrosion properties after thermal aging. The quantitative relationship data between thermal aging and corrosion fatigue based on APT study was elucidated.

Austenitizing temperature critically influences martensitic transformation and mechanical properties in martensitic stainless steel, yet its role in variant selection and strengthening–toughening mechanisms remains unclear. Using 1Cr17Ni2 steel, we systematically investigate the effect of austenitizing temperatures from 970 °C to 1060 °C on martensitic crystallography and mechanical performance. Results show that with increasing temperature, prior austenite grains coarsen (22.43 → 31.28 μm), martensite laths widen (256 → 707 nm), and carbides fully dissolve at 1060 °C, accompanied by δ-ferrite precipitation. Variant selection exhibits a non-monotonic evolution, peaking at 1030 °C (CP1 group fraction 45.2%), attributed to the synergistic effect of relaxed spatial constraint after carbide dissolution and enhanced mechanical constraint from peak dislocation density. At 1030 °C, a balanced enhancement of strength and ductility is achieved, originating from solid-solution strengthening, work hardening, and heterogeneous strain fields promoting multi-region plasticity. Impact toughness first decreases then recovers to 51.3 J at 1060 °C, owing to elimination of carbide-induced microcrack sites and high-angle grain boundary networks formed by V1/V3 and V5 variant pairs. This work provides a crystallographic criterion for optimizing strength–ductility–toughness synergy via austenitizing temperature tailoring.

Liquid lead–bismuth eutectic (LBE) corrosion of structural materials is one of the key bottlenecks hindering the engineering application of Generation-IV lead-bismuth cooled reactors. To enhance the long-term LBE corrosion resistance of fuel cladding, oxide dispersion-strengthened (ODS) FeCrAl tubes were surface-modified via low-temperature oxy-nitriding (LTON). After treatment at 430 °C for 8 h, a clearly distinguishable bilayer structure, consisting of an outer Fe–Cr–Al spinel layer and an inner expanded ferrite layer, was fabricated on the tube surface. Long-term corrosion tests of both pristine and LTON-treated ODS FeCrAl specimens were performed in liquid LBE at 550 °C for 2000 h under a low initial dissolved oxygen concentration of about 3.022 × 10-5 wt.%. The results show that the as-received FeCrAl tubes undergo severe liquid metal dissolution corrosion with the formation of discontinuous, non-protective Al2O3 thin film. In comparison, the LTON-modified ODS FeCrAl tube exhibits excellent corrosion resistance in low-oxygen liquid LBE. During 2000 h of LBE corrosion, five distinct layers are identified on the FeCrAl tube from the surface to the matrix: (Ⅰ) magnetite, (Ⅱ) α-Fe, (Ⅲ) N-rich Fe-Cr-Al spinel, (Ⅳ) (N,O)-supersaturated ferrite with Cr2O3 precipitates, and (Ⅴ) N-supersaturated ferrite. The modified layer formed after LTON treatment not only prevents direct contact between LBE and the tube matrix at early stage, but also promotes the formation of the protective oxide scales. In addition, the nitriding layer possesses high hardness, which is expected to simultaneously improve the corrosion resistance and erosion resistance of FeCrAl alloys in LBE.

Vacuum electric arc melting was employed to fabricate yttrium-containing FeCrAl steels and clarify the role of yttrium under liquid-state processing conditions. The effects of yttrium addition on chemical composition, second-phase evolution, microstructure, and room-temperature mechanical properties were systematically investigated. Chemical analysis showed that yttrium was effectively retained and significantly reduced the oxygen content, confirming its melt purification effect. The contents of nitrogen, carbon, and sulfur also changed during vacuum arc melting, indicating coupled residual-element evolution. With increasing yttrium content, Y–O–S-rich particles and Y-rich second phases formed, accompanied by changes in particle size and spatial distribution. Moderate yttrium addition promoted melt purification and controlled second-phase formation, whereas excessive addition caused particle coarsening, Y-rich precipitation, and microstructural heterogeneity. The alloy containing 0.2 wt% yttrium showed a relatively favorable combination of strength and hardness, with an ultimate tensile strength of about 410 MPa and a microhardness of about 190 HV. These results indicate that yttrium mainly affects FeCrAl steels through melt purification, residual-element evolution, and second-phase evolution rather than dense nanoscale oxide dispersion strengthening.

Cold-drawn stainless steel pipes, characterized by high residual stress and high inner wall roughness, are prone to stress corrosion cracking and pitting corrosion. Although the coating is usually deposited to protect steel pipe, it is particularly challenging to deposit coatings on the inner walls of metal pipes with high aspect ratios and complex shapes. In this work, nickel–phosphorus (Ni–P) coatings were successfully applied on the inner walls of 304 stainless steel pipes with a high aspect ratio of 25:1 using electroless plating within a circulated plating solution. The impact of the plating solution flow rate on the microstructure uniformity and microhardness of the deposited coatings was investigated. The coatings produced at a very low flow rate of (0.04 mm/s) or very high flow rate of (> 66 mm/s) showed porous microstructure and reduced hardness. On the contrast, the coating produced at a moderate flow rate of 40 mm/s exhibited dense microstructure with minimal microporosity (1.22 pct), the highly uniform thickness along the axis of pipe, and the highest microhardness (660.2 HV). After the Ni–P coatings prepared at the optimal flow rate were exposed under corrosive hydrochloric acid solution at room temperature for 72 hours, the weight loss of coated steel pipes was only 51.8 pct of that from uncoated counterpart. The coated steel has a higher corrosion potential (− 110.98 mV) and lower corrosion current density (8.75 × 10−6 A/cm2) compared to the uncoated steel. This indicates the successful processing and significant improvement in corrosion resistance of the deposited coatings.

The research was conducted on failed S355 fire tube used for purification of triethylene glycol (TEG) solution, with the matrix materials destructively cracked and deformed after 3 years and 8 months of service. Through integrated experimental analyses (macroscopic/microscopic characterization, chemical composition, mechanical testing, and corrosion product analysis) coupled with finite element analysis (FEA), the failure was attributed to synergistic effects of stress concentration and localized overheating. Results revealed that the right-angle elbow geometry induced severe stress concentration (148.7 MPa via FEA), while reduced gas flow velocity at the elbow promoted localized heating. Thick inner-wall corrosion products (5.70 mm, primarily FeO/ Fe3O4) and external carbon deposits (graphitized carbon with I(D)/I(G) = 2.65) exacerbated thermal resistance, reducing heat transfer efficiency. Material degradation from prolonged hightemperature exposure and wall thinning (from 8.0 to 4.0 mm) further compromised structural integrity. Finally, preventive measures are being suggested to avoid occurrence of such failure of fire tube.

The M2052 alloy (Mn‐20Cu‐5Ni‐2Fe at%) exhibits excellent damping capacity and favorable mechanical strength, making it a promising candidate for vibration damping and energy absorption. However, its potential in lattice structures has not been reported to date. In this article, M2052 alloy lattice structures are fabricated via selective laser melting to evaluate their mechanical properties and energy absorption capabilities. Three lattice architectures with comparable relative densities are designed and manufactured: body‐centered cubic (BCC), BCC with vertical struts (BCCZ), and reinforced hollow BCCZ (RHBCCZ) featuring hollow struts and strengthening ribs. Quasi‐static compression tests and finite element simulations are conducted to analyze their mechanical responses and deformation mechanisms. Furthermore, the effects of heat treatment on the compressive properties and microstructural evolution of BCC lattices are investigated. Results demonstrate that the RHBCCZ structure delivers optimal performance, with a Young's modulus of 1506.3 MPa, yield strength of 18.41 MPa, and maximum energy absorption of 22.69 J cm −3 . Heat treatment enhanced the yield strength and altered the deformation mode of the lattice. This article highlights the potential of M2052 alloy in load‐bearing, energy‐absorbing, and lightweight structural applications.

To tackle the challenge of liquid lead-bismuth eutectic (LBE) corrosion, an aluminum titanate (Al2TiO5, AT) based composite (AT based outer layer and CrAl transition layer) coating was meticulously applied to the surface of FeCrAl alloy via multi-arc ion plating. The coating underwent rigorous thermal shock testing and static LBE corrosion assessment. Remarkably, the AT-based coating demonstrated the ability to endure 6000 h of LBE corrosion at 600 degrees C, which is essentially attributed to the amorphous-nanocrystalline structure of an a-Al2O3, TiO2, and Al2TiO5 (AT) matrix with nanocrystalline gamma-Al2O3 particles distributed randomly. Besides, the composite coating exhibited overall integrity even after 100-cycle thermal shock testing, indicating its superior thermal shock resistance. This is mainly due to both the stable amorphous-nanocrystalline structure of the AT based outer layer with enhanced toughness and the thermal expansion gradient strategy of the FeCrAl substate, CrAl transition layer and AT based outer layer. Our research may shed lights on the development of coatings with corrosive and unstable thermal conditions.

C54-TiSi2 is a promising semiconductor material for integrated circuits due to its excellent electrical properties. However, during the preparation of C54-TiSi2 through electromagnetic directional solidification, the presence of silicon (Si) inclusions can increase resistivity and adversely affect performance. This study investigated the use of sodium hydroxide (NaOH) as a leaching agent to remove Si inclusions from C54-TiSi2 crystals. Thermodynamic analysis and alkali-leaching experiments were conducted, which focused on the morphological characteristics and distribution patterns of Si within C54-TiSi2. The results indicated that the Si impurity content increased with increasing ingot thickness, and the morphology of Si was determined by the pores formed between C54-TiSi2 crystals. Furthermore, NaOH alkaline leaching effectively desilicated the Si without compromising the lattice structure of C54-TiSi2 crystals. Subsequently, with optimal leaching parameters of 15 pct NaOH concentration, a temperature of 70 °C, a leaching time of 20 minutes, and a liquid-to-solid ratio (L/S) of 4:1, the purity of C54-TiSi2 crystals exceeded 99.5 pct, thereby achieving a Si removal rate of 99 pct. After the alkali-leaching and purification process, the resistivity of C54-TiSi2 decreased from 8.35 × 10−5 to 4.75 × 10−5 Ω cm, which was significantly lower compared with the resistivity of commercially available C54-TiSi2, thereby enhancing its electrical properties. This study offered theoretical insight and data support for the purification and performance assessment of C54-TiSi2 crystals.

A novel high-throughput platform enabling high-efficient preparation of droplet microarray and automatic characterization of corrosion morphologies was employed to investigate droplet corrosion on carbon steel. One hundred droplets with different compositions (NaCl and Na2SO4), concentrations (from 0.4 wt.% to 4 wt.%) and pH values (3, 7 and 10) were obtained within 2 h. The average height of accumulated corrosion products (H) in neutral NaCl droplets decreased as NaCl concentration exceeded 2.4 wt.%, while H value in neutral Na2SO4 droplets increased continuously with the increasing Na2SO4 concentration. Finite element modelling confirmed that the high surface coverage of corrosion products in high-concentration NaCl droplets prohibited corrosion products accumulation. The less aggressive SO42− resulted in a low surface coverage thereby enabling continuous corrosion products formation. For the influence of pH values, the corrosion rate in acidic environment (pH=3) was the largest due to the formation of non-protective γ-FeOOH and FeCl2, while the alkaline environment (pH=10) showed the least corrosion rate as more protective α-FeOOH was generated.

Enamel demineralization, the formation of white spot lesions, is a common issue in clinical orthodontic treatment. The appearance of white spot lesions not only affects the texture and health of dental hard tissues but also impacts the health and aesthetics of teeth after orthodontic treatment. The prevention, diagnosis, and treatment of white spot lesions that occur throughout the orthodontic treatment process involve multiple dental specialties. This expert consensus will focus on providing guiding opinions on the management and prevention of white spot lesions during orthodontic treatment, advocating for proactive prevention, early detection, timely treatment, scientific follow-up, and multidisciplinary management of white spot lesions throughout the orthodontic process, thereby maintaining the dental health of patients during orthodontic treatment.