Effect of enamel coating on the hot corrosion of 304 stainless steel beneath KCl–ZnCl2 deposits at 450 °C

Hailiang Zhang; Lingxu Yang; Xue Zhang; Qian Wang; Jiangtao Wu; Zhengliang Liu; Chaoliu Zeng; Shenglong Zhu

Journal of Materials Research and Technology (Mar 2023)

Effect of enamel coating on the hot corrosion of 304 stainless steel beneath KCl–ZnCl2 deposits at 450 °C

Hailiang Zhang,
Lingxu Yang,
Xue Zhang,
Qian Wang,
Jiangtao Wu,
Zhengliang Liu,
Chaoliu Zeng,
Shenglong Zhu

Affiliations

Hailiang Zhang: Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
Lingxu Yang: Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China; Corresponding author.
Xue Zhang: Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
Qian Wang: School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, China
Jiangtao Wu: Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
Zhengliang Liu: Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China; Corresponding author.
Chaoliu Zeng: Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China; Corresponding author.
Shenglong Zhu: Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China

Journal volume & issue: Vol. 23
pp. 245 – 257

Abstract

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The hot corrosion behavior of 304 stainless steel (304SS) and the enamel coating in KCl–ZnCl2 salts is studied. The corrosion kinetics of the samples shows that the mass loss of enamel coating is far lower than that of 304SS, indicating that the enamel coating can effectively block the diffusion of Cl element to the enamel coating/alloy interface due to its high chemical stability in chloride salts and low grain boundary density. Fe2O3 and (Fe,Cr)2O3 are mainly formed on the surface of 304SS covered by KCl–10%ZnCl2, whereas no corrosion products are found on the surface of the enamel coating. When the content of ZnCl2 is increased to 55%, Fe2O3 and Cr2O3 are mainly formed on the surface of 304SS, and Zn2SiO4 is formed on the surface of the enamel coating. In the two salts, the corrosion layer of 304SS is composed of Fe-rich oxides (external) and Cr rich oxides (internal). The enrichment of high amounts of Cl element near the interface between the corrosion products and alloy matrix indicate that metal chlorides are formed at the interface. These results are in line with the characteristics of “active oxidation” mechanism.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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