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3809 |
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Wednesday, May 21, 2014, Hall H1 & H2 4:22 PM "Young Professionals" |
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Microstructure and high-temperature oxidation behavior of iron-based wire-arc sprayed coatings |
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Ran Li* / Beijing University of Technology, Beijing Dingyong He/ Beijing University of Technology, China Zheng Zhou/ Beijing University of Technology, China Guohong Wang/ Beijing University of Technology, China Jianmin Jiang/ Beijing University of Technology, China |
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Wire-arc sprayed coatings are increasingly applied for protection against high-temperature oxidation and corrosion of coal fired boilers in thermal power plants. In the present study, Fe-Cr, Fe-Cr-Al and Fe-Cr-Al-B cored wires were used to produce protective coatings for components used in high-temperature environments by wire-arc spraying process. The microstructure, morphology and high-temperature oxidation behavior of the coatings were investigated. The coating produced by boron-containing cored wire exhibited significantly fewer oxide inclusions than the coatings produced by boron-free ones. Thermogravimetric analysis was used to evaluate the high-temperature oxidation behavior of the coatings at a temperature of 650 under cyclic oxidation condition. The results showed that all the coatings exhibited dramatically lower weight gains than the uncoated substrate. The oxidation resistance of the coatings generally improved in the following order: Fe-Cr < Fe-Cr-Al < Fe-Cr-Al-B. With the Al element added into the coatings, the thickness of oxide scales decreased obviously. The addition of boron in cored wire showed an influence on oxidation resistance of the iron-based coating. |