<p>AlCrFeNi medium-entropy alloys (MEA) have attracted considerable attention for high-temperature applications owing to their modifiable mechanical properties and excellent corrosion resistance attributed to their protective oxide scales. A small amount of rare-earth element yttrium (Y) can further improve the resistance of alloys to oxidation/corrosion. In this study, 1 wt.% Y was added to the AlCrFeNi alloy via arc melting, and the effects of the Y addition on the microstructure, mechanical properties, and hot corrosion of the MEA in molten NaCl-KCl salt at 750°C were investigated. To better evaluate the role of Y in enhancing the hot-corrosion resistance, stainless-steel 316 (SS316) was also tested for comparison. It has been demonstrated that the Y addition markedly enhances the mechanical strength and hot-corrosion resistance of the alloy in both air and argon atmospheres. In air, Y improves oxide scale adhesion, and reduces spallation and large void formation in the oxide scale. While, in argon, Y suppresses the outward diffusion of Cr and Al, reduces the formation of volatile chlorides, and inhibits salt penetration into the substrate. This study highlights the beneficial role of Y in improving the hot-corrosion resistance of both AlCrFeNi MEAs and SS316 for applications in hot corrosive environments and at elevated temperatures.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Effects of Rare-Earth Element Yttrium (Y) on the Hot Corrosion of AlCrFeNi Medium-Entropy Alloy in NaCl-KCl Molten Salt at 750°C

  • Zhen Xu,
  • Guijiang Diao,
  • Kaifan Lin,
  • Xin Pang,
  • Jessica Poupore,
  • Wengang Chen,
  • Daolun Chen,
  • D. Y. Li

摘要

AlCrFeNi medium-entropy alloys (MEA) have attracted considerable attention for high-temperature applications owing to their modifiable mechanical properties and excellent corrosion resistance attributed to their protective oxide scales. A small amount of rare-earth element yttrium (Y) can further improve the resistance of alloys to oxidation/corrosion. In this study, 1 wt.% Y was added to the AlCrFeNi alloy via arc melting, and the effects of the Y addition on the microstructure, mechanical properties, and hot corrosion of the MEA in molten NaCl-KCl salt at 750°C were investigated. To better evaluate the role of Y in enhancing the hot-corrosion resistance, stainless-steel 316 (SS316) was also tested for comparison. It has been demonstrated that the Y addition markedly enhances the mechanical strength and hot-corrosion resistance of the alloy in both air and argon atmospheres. In air, Y improves oxide scale adhesion, and reduces spallation and large void formation in the oxide scale. While, in argon, Y suppresses the outward diffusion of Cr and Al, reduces the formation of volatile chlorides, and inhibits salt penetration into the substrate. This study highlights the beneficial role of Y in improving the hot-corrosion resistance of both AlCrFeNi MEAs and SS316 for applications in hot corrosive environments and at elevated temperatures.