Corrosion Resistance of Boronized, Aluminized, and Chromized Thermal Diffusion-Coated Steels in Simulated High-Temperature Recovery Boiler Conditions
| Autor: | André McDonald, Gerardo Leal Mendoza, Eugene Medvedovski, Amir Hossein Mahdavi |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Materials science
Carbon steel thermal diffusion coatings Oxide 02 engineering and technology Surface engineering engineering.material Thermal diffusivity 01 natural sciences Corrosion chemistry.chemical_compound 0103 physical sciences Materials Chemistry Recovery boiler Molten salt 010302 applied physics corrosion Metallurgy Surfaces and Interfaces 021001 nanoscience & nanotechnology Surfaces Coatings and Films Cracking recovery boilers chemistry lcsh:TA1-2040 microstructural analysis engineering lcsh:Engineering (General). Civil engineering (General) 0210 nano-technology |
| Zdroj: | Coatings Volume 8 Issue 8 Coatings, Vol 8, Iss 8, p 257 (2018) |
| ISSN: | 2079-6412 |
| DOI: | 10.3390/coatings8080257 |
| Popis: | In this study, the high-temperature molten salt corrosion resistance of bare steels and steels with protective coatings, fabricated by thermal diffusion processes (boronizing, aluminizing and chromizing), were investigated and compared. Surface engineering through thermal diffusion can be used to fabricate protective coatings against corrosion, while alleviating issues around possible cracking and spallation that is typical for conventional thermal-sprayed coatings. In this regard, samples of low carbon steel and 316 stainless steel substrates were boronized, chromized, and aluminized through a proprietary thermal diffusion process, while some of the samples were further coated with additional thin oxide and non-oxide layers to create new surface architectures. In order to simulate the actual corrosion conditions in recovery boilers (e.g., from black liquor combustion), the surfaces of the samples sprayed with a modeling salt solution, were exposed to low-temperature (220 ∘C) and high-temperature (600 ∘C) environments. According to microstructural and X-ray diffraction (XRD) studies and results of hardness determination, the coatings with multilayered architectures, with and without additional oxide layers, showed successful resistance to corrosive attack over bare steels. In particular, the samples with boronized and chromized coatings successfully withstood low-temperature corrosive attack, and the samples with aluminized coatings successfully resisted both low- and high-temperature molten salt corrosive attacks. The results of this study conducted for the first time for the thermal diffusion coatings suggest that these coatings with the obtained architectures may be suitable for surface engineering of large-sized steel components and tubing required for recovery boilers and other production units for pulp and paper processing and power generation. |
| Databáze: | OpenAIRE |
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