四元Co-Ni-Cr-Al合金高温氧化模式及其转变机理  

High Temperature Oxidation Mode and Transformation Mechanism of Quaternary Co-Ni-Cr-Al Alloys

作　　者：吕云蕾 任延杰[1,2] 冯抗抗 周梦妮 王文 陈荐[1] 牛焱 LV Yunlei;REN Yanjie;FENG Kangkang;ZHOU Mengni;WANG Wen;CHEN Jian;NIU Yan(College of Energy and Power Engineering,Changsha University of Science and Technology,Changsha 410076,China;School of Mechanical and Energy Engineering,Zhejiang University of Science and Technology,Hangzhou 310023,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]长沙理工大学能源与动力工程学院,长沙410076 [2]浙江科技大学机械与能源工程学院,杭州310023 [3]中国科学院金属研究所,沈阳110016

出　　处：《金属学报》2024年第7期947-956,共10页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.52171066和51771034;湖南省自然科学基金项目No.2020JJ4610;湖南省研究生科研创新项目No.CX20200871。

摘　　要：为深入探究Cr、Al元素对Co-Ni合金高温氧化行为的影响,本工作研究了四元Co-20Ni-8Cr-xAl (x=3、5,质量分数,%)合金在纯氧中800、900、1000和1100℃下的氧化行为。氧化后,2种合金表面均生成了复杂的氧化膜。2种合金在800、900和1000℃下均有不连续Al_(2)O_(3)膜生成,1100℃下仅在Co-20Ni-8Cr-5Al表面生成Al2O3。温度从800℃升到900℃,合金的氧化速率均提高,而温度从1000℃升高到1100℃后,2种合金的氧化速率均下降。合金中Al含量由3%增加到5%,Co-Ni-Cr-Al合金的氧化速率随之下降,但5%的Al含量仍不足以令合金表面生成保护性的Al2O3膜。与Al含量相同的Co-Ni-Al三元合金相比,Cr和Al的同时存在有利于降低四元Co-Ni-Cr-Al合金的氧化速率。The addition of Ni to cobalt-based alloys can form theγ′phase,which can significantly improve their mechanical properties and high-temperature oxidation resistance.The oxidation behavior of quaternary Co-20Ni-8Cr-xAl(x=3 or 5,mass fraction,%)alloys was investigated in 1.013×10^(5)PaO_(2) at 800,900,1000,and 1100℃.Al_(2)O_(3),the effects of Al and/or Cr contents and temperature on the oxidation properties of the alloys were explored by analyzing the oxidation kinetics of the alloys and the crosssectional morphology characteristics of the scales,revealing the oxidation mechanism of these alloys.After oxidation,both the alloys formed complex scales with irregular thickness and composition.Alumina scales were generated for each alloy at 800,900,and 1000℃ and only for Co-20Ni-8Cr-5Al at 1100℃.The increase in temperature from 800℃ to 900℃ has a negative effect on the oxidation resistance,resulting in greatly accelerated oxidation rates.Conversely,that from 1000℃ to 1100℃ has a positive effect on the oxidation of the two alloys,causing a decrease in the oxidation rate.The oxidation rate of the Co-NiCr-Al alloy decreases when the Al content in the alloy is increased from 3%to 5%,but 5%is still not sufficient to form continuous alumina scales.The simultaneous presence of Cr and Al is beneficial to reducing the oxidation rate of the quaternary Co-Ni-Cr-Al alloys compared with the ternary Co-Ni-Al alloy with the same Al content.

关 键 词：Co-Ni-Cr-Al合金 高温氧化 氧化动力学 保护性氧化膜 

分 类 号：TB31[一般工业技术—材料科学与工程]