Effect of 5%Cr on oxidation of Ni-10Al in 0.1MPa O2 at 900 ℃ and 1 000 ℃
(1.辽宁省沈阳市沈阳大学应用化学系化工技术研究所
2.辽宁省沈阳市科学院腐蚀与防护国家重点实验室
3.College of Applied Chemistry, Shenyang Institute of Chemical Technology, Shenyang 110142, China
4.State Key Laboratory for Corrosion and Protection, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016, China)
2.辽宁省沈阳市科学院腐蚀与防护国家重点实验室
3.College of Applied Chemistry, Shenyang Institute of Chemical Technology, Shenyang 110142, China
4.State Key Laboratory for Corrosion and Protection, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016, China)
Abstract: The effect of 5%Cr(mole fraction) on the scaling behavior of Ni-10Al was investigated at 900 ℃ and 1 000 ℃ with the aim to discuss the third element effect(TEE). The oxidation rate of the ternary alloy containing Cr is much slower than the corresponding binary alloys at both temperatures. A dense external scale of NiO overlying a zone of internal oxide precipitates forms on Ni-10Al, while Ni-5Cr-10Al develops a protective layer. So the addition of Cr promotes the formation of alumina scale. The possible mechanism of Cr on the oxidation of Ni-Al alloy is discussed.
Key words: Ni-Cr-Al alloy; Ni-10Al alloy; oxidation; third-element effect