摘要
用不连续称重法表征了Cr含量(质量分数)分别为20%、24%和28%的Ni-Fe-Cr-Al合金在1200℃空气中氧化后氧化膜的形貌和相组成,研究了这类合金的氧化行为。结果表明:这三种不同Cr含量的Ni-Fe-Cr-Al合金在1200℃氧化100 h后其氧化动力学曲线都符合抛物线规律,氧化速率相近,Cr含量的提高使其抗氧化性能有所提高。这三种Ni-Fe-Cr-Al合金在1200℃氧化1 h后生成的氧化膜均具有两层结构,外层由Cr_(2)O_(3)和少量尖晶石氧化物NiCr_(2)O_(4)组成,内层为Al_(2)O_(3)层;氧化100 h后氧化膜仍为两层结构,与氧化1 h的不同之处是外层主要由混合尖晶石和少量Cr_(2)O_(3)组成,混合尖晶石为NiCr_(2)O_(4)、NiFe_(2)O_(4),内层为连续Al_(2)O_(3)层。这三种合金在氧化过程中均出现明显的内氮化。Cr含量的提高对氧化1 h发生的内氮化有一定的抑制。随着氧化时间的延长(100 h)这三种合金的内氮化深度相近,提高Cr含量对内氮化影响不大。
The oxidation behavior of Ni-Fe-Cr-Al alloys with Cr content of 20%Cr,24%Cr and 28%Cr(mass percentage)respectively at 1200℃ in air for 100 h were studied by intermittent weighing method.The microstructure and phase composition of the alloys and oxide scales were also characterized.The results show that the oxidation kinetics curves of the three alloys all conform to the parabolic law.The oxidation resistance of the alloys is enhanced with the increasing Cr content.A two-layered oxide scale is formed on the surface of the three alloys after oxidation at 1200℃ for 1 h,i.e.the outer layer was composed of Cr_(2)O_(3)and a small amount of spinel oxide NiCr_(2)O_(4),and the inner layer was Al_(2)O_(3)layer.After 100 h oxidation,the oxide scale still has a two-layered structure,which is slightly different from those of the 1 h oxidation,namely,the outer layer is mainly composed of mixed spinel and a small amount of Cr_(2)O_(3),the mixed spinel is NiCr_(2)O_(4)and NiFe_(2)O_(4),and the inner one is continuous Al_(2)O_(3)layer.The three Ni-Fe-Cr-Al alloys with different Cr content showed obvious internal nitriding during air oxidation.When oxidized for 1 h,the increase of Cr content presents a certain inhibitory effect on internal nitriding.With the extension of oxidation time(100 h),the nitriding depth of the three alloys is similar,and the increase of Cr content has little effect on the internal nitriding.
作者
张凯
付广艳
刘恩泽
谭政
宁礼奎
郑志
ZHANG Kai;FU Guangyan;LIU Enze;TAN Zheng;NING Likui;ZHENG Zhi(School of Mechanical and Power Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2024年第10期732-740,共9页
Chinese Journal of Materials Research
基金
国家重点研发计划(2021YFC2202402)。
