Oxidation of Metals最新文献

{"title":"Oxidation and Hot Corrosion of Al–Si Diffusion-Coated AISI 304 Stainless Steel Exposed to Na2SO4–NaCl–V2O5 Molten Salts","authors":"Ali Reza Tousi,&nbsp;Fatemehsadat Sayyedan","doi":"10.1007/s11085-026-10417-y","DOIUrl":"10.1007/s11085-026-10417-y","url":null,"abstract":"<div><p>A silicon-modified aluminide diffusion coating was developed on AISI 304 stainless steel via a powder-based Al–Si process and vacuum heat treatment at 1050 °C. Oxidation behavior was evaluated in air at 1100 °C for 100 h, and hot corrosion performance was investigated electrochemically in a molten Na₂SO₄–NaCl–V₂O₅ salt mixture at 750 °C. Uncoated AISI 304 exhibited rapid oxidation kinetics with thick, cracked Fe₂O₃/Fe₃O₄ scales and high mass gain. In contrast, the Al-Si diffusion-coated steel showed an order-of-magnitude lower weight gain, associated with the formation of a dense, continuous Al₂O₃-rich scale. Electrochemical measurements revealed a 1.5-fold reduction in corrosion current density for the coated sample, indicating suppressed anodic dissolution in the molten salt. The improved performance is attributed primarily to the protective Al₂O₃ scale; direct evidence of a synergistic role of silicon was not observed. The results demonstrate that Al-Si diffusion coatings offer a cost-effective solution for extending the high-temperature durability of austenitic stainless steels in aggressive molten-salt environments.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148236939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Nb on the Microstructure, Microhardness and Oxidation Behavior of (AlCrFeNi)100-xNbx (x = 0,2,4,6 and 8 at.%) Alloys","authors":"Robson Leopoldino Ferreira,&nbsp;Sebastião Vilas Boas,&nbsp;Bruno Xavier de Freitas,&nbsp;Antonio Augusto Araújo Pinto da Silva","doi":"10.1007/s11085-026-10412-3","DOIUrl":"10.1007/s11085-026-10412-3","url":null,"abstract":"<div><p>This study investigates the effect of niobium addition on the microstructure, high-temperature oxidation behavior, and microhardness of (AlCrFeNi)_100−xNb_x alloys (x = 0, 2, 4, 6, and 8 at.%) produced by arc melting. Thermodynamic calculations predicted the stability of A2 and B2 phases for all compositions and the formation of a C14 Laves phase in Nb-containing alloys, which was experimentally confirmed. The Nb-free alloy exhibited a lamellar A2/B2 microstructure, whereas Nb additions promoted dendritic microstructures with interdendritic regions containing A2, B2, and C14 Laves phases. Isothermal oxidation tests at 1000 °C for up to 96 h revealed a two-stage oxidation behavior, with an initial transient regime followed by slower mass gain kinetics. Although increasing Nb content led to higher mass gains, all alloys developed a continuous and adherent α-Al₂O₃ scale, effectively protecting the base metal. The phase constitution remained unchanged after oxidation, despite microstructural coarsening. Microhardness increased systematically with Nb content due to the higher volume fraction of the C14 Laves phase, whereas high-temperature exposure reduced microhardness as a result of microstructural coarsening. Overall, the results highlight a trade-off between Nb-induced strengthening and oxidation resistance, indicating that controlled Nb additions provide a favorable balance between hardness, wear potential, and oxidation resistance for high-temperature applications.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148172641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidation Behavior of the B2-Phase-Strengthened FBB8 Alloy Under Various Surface Roughness Conditions","authors":"Xu Chen,&nbsp;Ying Wang,&nbsp;Yicheng Luo,&nbsp;Ye Liu,&nbsp;Lin Zhang,&nbsp;Yi Chen,&nbsp;Shuang He,&nbsp;Oleg I. Gorbatov,&nbsp;Xuanhui Qu","doi":"10.1007/s11085-026-10414-1","DOIUrl":"10.1007/s11085-026-10414-1","url":null,"abstract":"<div><p>The effect of surface roughness on the oxidation behavior of the FBB8 (Fe-9.96Ni-10.7Cr-6.49Al-0.25Zr-3.49Mo-0.0094B) alloy in air at 900 °C was investigated in this study. The results indicated that the parabolic rate constants (<i>K</i>_p) for the samples with arithmetic roughness average (Ra) values of 0.2 µm, 1.2 µm and 2.1 µm were 3.68 × 10⁻¹³ g²·cm⁻⁴·s⁻¹, 5.26 × 10⁻¹³ g²·cm⁻⁴ s⁻¹, and 7.91 × 10⁻¹³ g²·cm⁻⁴·s⁻¹, respectively. This positive correlation indicates that increased surface roughness accelerates mass gain during the early oxidation stage. When the substrate Al content was depleted below a critical level, the B2 phase acted as an “aluminum reservoir” to replenish consumed Al. The sample with a Ra value of 0.2 µm exhibited discontinuous external oxide scale and severe internal oxidation, caused by insufficient nucleation sites. In contrast, the ground sample with a Ra value of 2.1 µm reduced internal oxidation by introducing a stress-induced scale at the surface that promoted outward diffusion of Al. The influence of surface roughness on the oxidation behavior of FBB8 alloy was elucidated in this study through its effects on element diffusion and oxide film formation, offering key insights for optimizing surface treatment processes.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148172404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhanced High-Temperature Corrosion Resistance of Laser-Clad Stellite 6 Versus Inconel 625 Coatings in Simulated Waste Incineration Environments","authors":"Duoli Wu,&nbsp;Mustavi Rafid,&nbsp;Nahian Sadid,&nbsp;Hongyu Hu,&nbsp;Xinlong Wei,&nbsp;Erjuan Yang,&nbsp;Yong Li,&nbsp;Chao Zhang","doi":"10.1007/s11085-026-10411-4","DOIUrl":"10.1007/s11085-026-10411-4","url":null,"abstract":"<div><p>The chloride–sulfate-induced hot corrosion of superheater tubes remains a predominant failure mechanism in waste-to-energy (WTE) plants, resulting in significant downtime and maintenance expenditure. This study investigated the high-temperature corrosion performance and failure behavior of laser-clad Stellite 6 (Co-based) and Inconel 625 (Ni-based) coatings deposited on AISI 304 stainless steel substrates. Coatings were produced using optimized laser cladding parameters (laser power: 1.0–2.5 kW; scanning speed: 600–1400 mm/min) to achieve defect-free, metallurgically bonded multilayered structures with minimal dilution. Corrosion resistance was evaluated at 450 °C for 168 h under simulated WTE superheater conditions, including cyclic exposure to KCl–Na₂SO₄ salt deposits and a flowing gas mixture of SO₂, O₂, and H₂O. Post-exposure analysis revealed distinct failure mechanisms between the two coatings. Stellite 6 exhibited superior corrosion resistance, with approximately 52% lower mass gain, attributed to the formation of a predominantly compact and relatively adherent <span>({text{Cr}}_{2} {text{O}}_{{3}} /{text{CoO}})</span>-rich scale that substantially reduced the penetration of corrosive species under the present test conditions. In contrast, Inconel 625 suffered from more severe degradatiosn, including internal oxidation, localized chlorination, and sulfidation, due to the formation of a less protective duplex NiO–Cr₂O₃ scale. The failure mode in Inconel 625 was characterized by scale spallation and accelerated corrosion kinetics consistent with an approximately parabolic rate law <span>(left( {k_{{text{p}}} = 0.464 {text{mg}}^{2} {text{cm}}^{ - 4} h^{ - 1} , R^{2} = 0.89} right))</span> over the 168-h test period. The enhanced durability of Stellite 6 is linked to its higher Cr content and the stabilizing effect of carbide phases, which promote sustained chromia formation. These findings highlight the critical role of coating composition and microstructure in determining corrosion failure mechanisms and support the use of Stellite 6 laser cladding as a robust surface protection strategy to mitigate high-temperature corrosion failures in WTE superheater tubes.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148173227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupled Cellular Automaton and Finite Element Simulations on High-Temperature Oxidation of AlCoCrFeNi High-Entropy Alloy Subjected to Tensile Stress","authors":"Wanlong Peng,&nbsp;Yang Chen,&nbsp;Bing Wang,&nbsp;Weifeng Yuan,&nbsp;Bin Gu","doi":"10.1007/s11085-026-10405-2","DOIUrl":"10.1007/s11085-026-10405-2","url":null,"abstract":"<div><p>This study developed a multi-scale model that integrates cellular automaton and finite element method. The model is used to investigate the oxidation behavior of AlCoCrFeNi high-entropy alloy under coupled high-temperature and tensile stress conditions. The effects of temperature, grain size, and applied stress on oxidation kinetics were investigated. The simulations reveal that oxidation kinetics follows a parabolic law within the temperature range of 1073–1273 K. Elevated temperatures significantly accelerate elemental diffusion and interfacial reactions, leading to a sharp increase in oxidation rates. Grain boundaries act as critical short-circuit diffusion paths, with grain refinement offering additional rapid transport channels for oxygen ions, further accelerating the overall oxidation process. According to the model prediction, elevating the tensile stress from 100 to 400 MPa can amplify the local oxidation rate by a factor of 1.5 to 35 compared to the stress‑free condition, under the current phenomenological assumptions. This enhancement stems from stress concentration, which triggers localized plastic deformation, elevates the chemical activity of metal atoms, and thereby transforms pit roots into active reaction sites. As oxidation progresses inward under increasing stress, initially isolated plastic zones expand and interconnect, inducing more extensive plasticity. This stress-induced mechanochemical coupling is predicted to compromise the formation of a protective oxide scale. It also promotes short-circuit diffusion networks, which may alter the overall oxidation mechanism.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148173648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved High-Temperature Oxidation Resistance of Zirconium Alloy via a Cr Coating on a ZrO2 Interlayer Deposited by Multi-Arc Ion Plating","authors":"Yanhui Zhu,&nbsp;Xiang Liu,&nbsp;Jifu Zhang,&nbsp;Bojie Wang","doi":"10.1007/s11085-026-10406-1","DOIUrl":"10.1007/s11085-026-10406-1","url":null,"abstract":"<div><p>The purpose of this study is to develop a long-term protective coating for zirconium alloy nuclear fuel cladding to enhance its safety under high-temperature accident conditions, such as a loss-of-coolant accident (LOCA). A dense ZrO₂ interlayer was first fabricated on the zirconium alloy substrate via an in situ pre-oxidation method. By optimizing the target current (100, 120, and 150 A) in the multi-arc ion plating process and analysing the resultant coating roughness, hardness, and microstructure, we determined that 100 A was the optimal parameter for depositing a dense and flat Cr overlayer. Accordingly, a ZrO₂/Cr composite coating was constructed. High-temperature oxidation tests at 800–1200 °C demonstrated that the mass gain of the composite coating was significantly lower than that of both the bare zirconium alloy and a single-layer Cr coating. Microscopic analysis revealed that at temperatures of 1000 °C and below, the ZrO₂ interlayer effectively blocked Cr/Zr interdiffusion and oxygen inward diffusion, thereby inhibiting the formation of brittle phases and stabilizing the coating structure. At 1200 °C, although interdiffusion was initiated, the coating exhibited only controlled local oxidation, preventing catastrophic failure. In conclusion, the introduction of a ZrO₂ interlayer significantly improves the high-temperature oxidation resistance of the Cr coating, providing an effective strategy for developing advanced accident-tolerant fuel (ATF) coatings.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148173649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Deformation-Induced Microstructure on Hot Corrosion Behavior of γ'-Strengthened Ni-Based Superalloy IN740H","authors":"P. V. S. Chaithanya,&nbsp;S. K. Pradhan,&nbsp;J. K. Sahu","doi":"10.1007/s11085-026-10410-5","DOIUrl":"10.1007/s11085-026-10410-5","url":null,"abstract":"<div><p>This study investigates the influence of deformation-induced microstructures on the hot corrosion behavior of the γ’-strengthened Ni-based superalloy IN740H. Controlled cold rolling to thickness reductions of 5%, 15%, 30%, and 50% produced systematic microstructural evolution: grain elongation, progressive transformation of CSL boundaries into HAGBs, and increased defect density. A hot corrosion test was conducted at 760 °C for 100 h in simulated flue gas, both with and without a salt deposit (74%Na₂SO₄, 24% K₂SO₄, and 2% NaCl). Contrary to the conventional expectation that increased defect densities would promote protective chromia scale formation in a high-chromium (∼25 wt%) alloy such as IN740H, higher defect densities deteriorated the hot corrosion resistance. The cold-rolled samples exhibited greater mass gain under salt-free conditions and more severe mass loss under salt-deposited conditions. The increased defect density accelerated γ’ dissolution into the γ matrix, promoting extensive subsurface degradation. This was characterized by internal oxidation and sulfidation (i.e., Al₂O₃ and (Cr, Ti)S), accompanied by Ni enrichment and Cr and Al depletion in the subsurface region. Furthermore, the subsurface damage morphology exhibited a clear transition with increasing deformation. At low-to-intermediate deformation levels (5–15%), the subsurface damage region remained limited in extent, but localized percolation of corrosive species along grain boundaries promoted deep intergranular attack. At high strain levels (30–50%), increased defect densities led to extensive subsurface degradation dominated by uniform internal oxidation and sulfidation rather than deep grain boundary percolation.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148173369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure and High-Temperature Chloride Salt Corrosion Behavior of New Ni–Cr–Mo Alloys","authors":"Shuqi Zhu,&nbsp;Xijie Wu,&nbsp;Ao Liu,&nbsp;Zeyuan Sun,&nbsp;Yinghui Tao,&nbsp;Jie Pan,&nbsp;Jun Li,&nbsp;Xueshan Xiao","doi":"10.1007/s11085-026-10413-2","DOIUrl":"10.1007/s11085-026-10413-2","url":null,"abstract":"<div><p>The influence of Mo content on the microstructure, mechanical properties, and high-temperature molten salt corrosion behavior of Ni–Cr–Mo alloys was systematically investigated. After solution treatment, grain refinement was observed with increasing Mo content. Mo-enriched precipitates were observed only in the alloy with 26 wt.% Mo. After exposure to molten NaCl-KCl salt at 700–900 °C, corrosion resistance improved with Mo content up to 24 wt.% but deteriorated at 26 wt.%. All alloys formed a protective oxide scale that consisted of Cr₂O₃, NiO, and NiCr₂O₄. However, its integrity progressively degraded with increasing temperature, transitioning from dense and adherent at 700 °C to porous and cracked at 900 °C. Ni₂(Cr,Mo) phase precipitation was induced during corrosion, and its volume fraction increased with both Mo content and temperature. These Mo-enriched precipitates and abundant Ni₂(Cr,Mo) precipitates may disrupt oxide scale continuity and may initiate localized galvanic corrosion. Ni–15Cr–24Mo showed the most balanced performance among the compositions investigated under the present test conditions. These findings provide important experimental data and theoretical reference for the design of corrosion-resistant alloys for high-temperature chloride environments.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Characteristics of the Oxide Films Formed on the Dilution Zone and Bulk Alloy 52M Cladding in High-Temperature Water","authors":"Binkun Shan,&nbsp;Hongyuan Li,&nbsp;Shugang Zhang,&nbsp;Chengtao Li,&nbsp;Tongming Cui,&nbsp;Yuanjie Tang,&nbsp;Zhanpeng Lu","doi":"10.1007/s11085-026-10408-z","DOIUrl":"10.1007/s11085-026-10408-z","url":null,"abstract":"<div><p>The present work used a weld dilution zone and bulk metal of Alloy 52M weld overlay to conduct an exposure corrosion test in simulated pressurized water reactor (PWR) primary water at 325 °C. The properties of the oxide film formed on the surface of the dilution zone and the bulk metal in Alloy 52M overlay were characterized, and the underlying mechanisms of welding composition dilution on general oxidation and localized oxidation behaviors were analyzed. The results showed that a FeCr₂O₄ or FeCrNiO₄ outer granular oxide and a thicker Cr-rich inner oxide layer, as well as severe local oxidation penetration, were observed on the dilution zone specimen of the Alloy 52M overlay. The needle-like NiCr₂O₄ and NiFe₂O₄ outer layer and a thin compact Cr-rich oxide layer were formed on the bulk metal specimen of the Alloy 52M overlay. The low-Cr and high-Fe contents in the dilution zone enhance the local oxidation kinetics, thus increasing the depth and density of local oxidation penetration at the oxide-matrix interface.</p></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11085-026-10408-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148009832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Fireside Corrosion of Super Austenitic Stainless Steel Sanicro 25 at 750 °C Under Simulated Advanced Ultra Super Critical Fireside Conditions","authors":"C. Anushree,&nbsp;Koustuv Ghosh,&nbsp;E. Vetrivendan,&nbsp;S. Ningshen,&nbsp;Anish Kumar","doi":"10.1007/s11085-026-10407-0","DOIUrl":"10.1007/s11085-026-10407-0","url":null,"abstract":"<div><p>Sanicro 25, a high-Cr austenitic stainless steel (22.5Cr–25Ni–3.4W–3Cu–0.5Nb), is a cost-effective candidate for superheater piping for Advanced Ultra-Supercritical (AUSC) coal thermal power plants. High steam operating temperatures (&gt; 710 °C) and pressures (~ 31 MPa) for enhanced thermal efficiency (&gt; 46%) necessitate materials with superior creep and corrosion resistance. Long operations under unwarranted transients that might undermine the structural integrity of superheater tubes due to increased material degradation caused by fireside corrosion attack (FSC) in real Indian coal ash environments remain underexplored. This study provides the first integrated long-term (2000 h) FSC assessment of Sanicro 25 at 750 °C using Indian coal ash/flue gas, employing the deposit-recoat method to mimic slagging/deslagging at the laboratory scale relevant to the Indian AUSC program. The oxide characteristic and surface characterization by XRD, Raman spectroscopy, and SEM/EDS analysis reveal the initial formation of a Cr₂O₃ passive film, followed by localized fluxing, leading to non-uniform chromia breakdown. The results reveal a distinct time-dependent degradation sequence, creating a stratified oxide scale with a Fe-rich outer layer, a probable mixed spinel layer in the middle, and a chromia inner layer. The penetration depth accelerated after 1500 h, driven by sulfur ingress forming a S-rich band undermining protection. By 2000 h, the inner chromia layer dominates and the total oxide scale ranged from 53 ± 4 to 112 ± 28 μm, as time progressed from 500 to 2000 h. Parabolic kinetic fitting reveals a corrosion rate of ~ 0.27 mm/y at 2000 h. A detailed fireside corrosion mechanism tailored to Indian coal ash is proposed to aid in the design of sulfur-tolerant AUSC superheaters.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture><span>The alternative text for this image may have been generated using AI.</span></div></div></figure></div></div>","PeriodicalId":724,"journal":{"name":"Oxidation of Metals","volume":"103 3","pages":""},"PeriodicalIF":1.5,"publicationDate":"2026-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148010038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}