Exposition of sol‐gel alumina‐coated P92 steel to flue gas: Time‐resolved microstructure evolution, defect tolerance, and repairing of the coating

Wollschläger, Nicole; Nofz, Marianne; Dörfel, I.; Schulz, Wencke; Sojref, Regine; Kranzmann, Axel

doi:10.1002/maco.201709712

Cited by 9 publications

(7 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Alumina coatings, prepared using the sol-gel method, have thicknesses between 10 nm to 10 µm depending on the composition of the sol, conditions of deposition, and the applied heat treatment [33]. Based on previous research using similar sol formulations deposited on P92 steels and heat treated at 650 • C, the alumina coating thickness formed on the steel was approximately 1 µm [34]. To have a uniform coating surface, the average surface roughness (R a ) and sink height (R z ) of the substrate have to be lower than the estimated coating thickness.…”

Section: Effect Of Coating Thicknessmentioning

confidence: 99%

Study of Al2O3 Sol-Gel Coatings on X20Cr13 in Artificial North German Basin Geothermal Water at 150 °C

et al. 2021

Self Cite

View full text Add to dashboard Cite

Al2O3 has been widely used as a coating in industrial applications due to its excellent chemical and thermal resistance. Considering high temperatures and aggressive mediums exist in geothermal systems, Al2O3 can be a potential coating candidate to protect steels in geothermal applications. In this study, γ-Al2O3 was used as a coating on martensitic steels by applying AlOOH sol followed by a heat treatment at 600 °C. To evaluate the coating application process, one-, two-, and three-layer coatings were tested in the artificial North German Basin (NGB), containing 166 g/L Cl−, at 150 °C and 1 MPa for 168 h. To reveal the stability of the Al2O3 coating in NGB solution, three-layer coatings were used in exposure tests for 24, 168, 672, and 1296 h, followed by surface and cross-section characterization. SEM images show that the Al2O3 coating was stable up to 1296 h of exposure, where the outer layer mostly transformed into boehmite AlOOH with needle-like crystals dominating the surface. Closer analysis of cross-sections showed that the interface between each layer was affected in long-term exposure tests, which caused local delamination after 168 h of exposure. In separate experiments, electrochemical impedance spectroscopy (EIS) was performed at 150 °C to evaluate the changes of coatings within the first 24 h. Results showed that the most significant decrease in the impedance is within 6 h, which can be associated with the electrolyte penetration through the coating, followed by the formation of AlOOH. Here, results of both short-term EIS measurements (up to 24 h) and long-term exposure tests (up to 1296 h) are discussed.

show abstract

Section: Effect Of Coating Thicknessmentioning

confidence: 99%

Study of Al2O3 Sol-Gel Coatings on X20Cr13 in Artificial North German Basin Geothermal Water at 150 °C

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…A observação por microscopia ótica (Figura 4-B [14]. Este processo promove como um bloqueio ao transporte de moléculas de gás a través da fissura e oferecem proteção contra a corrosão [13].…”

Section: A B Figura 3 Superfície Do Aço P92 Oxidado Com Gás Oxicombuunclassified

“…Isto favorece a formação de uma fina camada de óxido de cromo (Cr2O3), que mesmo em dimensões nanométricas pode impedir a difusão do ferro e outros elementos da liga para formar óxidos na camada externa. Por outro lado, nas regiões onde a alumina não for continua, é possível a formação de nódulos ou formações de óxido de ferro [14]. Conforme M. Nofzet al [15] a formação de aglomerados de alumina é devido a uma fraca estabilidade do sol de Bohemita; enquanto a formações de nódulos na superfície do revestimento pode decorrer da presença de pequenos agregados nos sóis preparados.…”

Section: A B Figura 3 Superfície Do Aço P92 Oxidado Com Gás Oxicombuunclassified

Avaliação Da Eficácia Da Alumina Como Revestimento Do Aço P92 Na Corrosão Em Altas Temperaturas

Gallo¹,

Rizzo²,

Monteiro³

et al. 2019

ABM Proceedings

Self Cite

View full text Add to dashboard Cite

Resumo Redução na emissão de CO 2 na atmosfera é um dos desafios atuais mais importantes enfrentados por diferentes indústrias no mundo. Tecnologia de oxicombustão, é uma opção utilizada pelas indústrias de carvão de geração de energia para minimizar índices de concentração de CO 2 até emissão ZERO. Tubulações dos trocadores de calor que conformam aquelas plantas de energia, sofrem corrosão em contato com os gases de combustão (H 2 O-CO 2) em altas temperaturas. Para aumentar a vida útil destes materiais, revestimentos protetores são uma alternativa de proteção contra a corrosão. Assim, aço P92 com e sem revestimento foi estudado com o objetivo de avaliar a eficácia de um revestimento de alumina Al 2 O 3 como meio protetor contra a corrosão e o comportamento do revestimento frente a riscos produzidos na superfície da alumina antes de um tratamento de oxidação de (H 2 O, CO 2 ,O 2 ,N 2 ,SO 2) a 650ºC por 2000h. As analises foram realizadas utilizando MEV, EDS e MO. Resultados demostraram uma significativa redução na taxa de corrosão do aço com revestimento em comparação com o aço sem revestimento. A superfície riscada de alumina promoveu á formação de óxidos ricos em Cr abaixo da região danificada e não comprometeu a resistência à corrosão, pois não houve formação de óxido externo.

show abstract

“…However, early studies [10,11] have found that simple aluminide coatings cannot preserve the protection ability in harsh serving environment for a long period. Recently, Wollschläger et al [12,13] prepared a micron-thick porous alumina layer by sol-gel technique on P92 steel against flue gas corrosion. Results have shown that deposition of a thin and porous alumina coating enabled the formation of a dense and protective chromium oxide scale at the interface between coating and steel, which significantly improved the flue gas corrosion resistance.…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Improved Thermal Shock Behaviour of an In Situ Formed Metal-Enamel Interlocking Coating

Wang

Zhang

Jiang

et al. 2021

Acta Metall. Sin. (Engl. Lett.)

View full text Add to dashboard Cite

A novel metal-enamel interlocking coating was designed and prepared in situ by co-deposition of Ni-enamel composite layer and subsequent air spray of enamel with 10 wt% nanoscale Ni. During the firing process, the external enamel layer was melted and jointed with the enamel particles at the upper part of the Ni-plating layer to form the enamel pegs. Thermal shock tests of pure enamel, enamel with 10 wt% Ni composite and metal-enamel interlocking coatings were conducted at 600 °C in water and static air. The results indicated that the metal-enamel interlocking showed superior thermal shock resistance to both pure enamel and enamel with 10 wt% Ni composite coatings. The enhanced performance was mainly attributed to the advantageous effects of mechanical interlocking of the enamel pegs formed at the enamel/Ni-plating interface. Meanwhile, during thermal shock test, big clusters formed by nanoscale Ni agglomerations were oxidised to be a Ni/NiO core-shell structure while small single nanoscale Ni grains were oxidised completely, which both improved the thermal shock resistance of enamel coating significantly.

show abstract

Exposition of sol‐gel alumina‐coated P92 steel to flue gas: Time‐resolved microstructure evolution, defect tolerance, and repairing of the coating

Cited by 9 publications

References 29 publications

Study of Al2O3 Sol-Gel Coatings on X20Cr13 in Artificial North German Basin Geothermal Water at 150 °C

Study of Al2O3 Sol-Gel Coatings on X20Cr13 in Artificial North German Basin Geothermal Water at 150 °C

Avaliação Da Eficácia Da Alumina Como Revestimento Do Aço P92 Na Corrosão Em Altas Temperaturas

Microstructure and Improved Thermal Shock Behaviour of an In Situ Formed Metal-Enamel Interlocking Coating

Contact Info

Product

Resources

About