摘要
利用磁控钨极电弧炉制备了Ni-16Mo-7Cr-4Fe-xSi (%,质量分数)Hastelloy N合金。采用不连续增重法,研究了不同Si含量的Hastelloy N合金在700℃高温下的恒温氧化行为。利用扫描电镜(SEM)、能谱分析仪(EDS)及X射线衍射仪(XRD)对氧化试样的表面及截面形貌、物相组成进行分析,结果表明:添加Si元素能显著的提高Hastelloy N合金的抗氧化性能。随着Si含量的升高,合金氧化膜厚度减小,表面氧化产物细化且均为尖晶石状氧化物。在700℃下, 5种合金平均氧化速率分别为0.0312, 0.0286, 0.0280, 0.022, 0.0205 g·(m2·h)-1,根据氧化等级评定所有合金均达到完全抗氧化级。添加Si合金氧化速度大幅降低,与无Si合金相比,添加1%Si后增重降低了约38.7%。不同Si含量的合金氧化膜组成基本一致,均未发生氧化层剥落现象,最外层为NiO, NiFe2O4, NiMn2O4,内层为Cr2O3, MoO2等氧化物。当Si含量达到0.5%时,在合金氧化层与基体界面出现SiO2层, SiO2层的出现显著提升了合金的抗氧化性能。
Ni-16 Mo-7 Cr-4 Fe-xSi(%,mass fraction)superalloys were prepared by the magnetic-controlling tungsten electrode arc furnace at high vacuum.The isothermal oxidation behavior of Hastelloy N superalloy with different silicon contents in air at 700℃were investigated by using discontinuous increasing weight method.The phase structure,surface morphology and cross sectional morphology of the oxide products were analyzed by scanning electron microscope(SEM),energy dispersive spectroscope(EDS)and X-ray diffraction(XRD)techniques.Oxidation resistance of the five kinds of alloys at 700℃was used to discuss the oxidation mechanism.The results showed that Si-addition could significantly improve the oxidation resistance of Hastelloy N alloy.With increasing of Si contents,oxide film thickness decreased,and surface spinel oxidation products were refined.The oxidation rate of alloys were 0.0312,0.0286,0.0280,0.022 and 0.0205 g·(m2·h)-1 at 700℃.All alloys mentioned above reached complete antioxidant levels.It was found that the mass gain of alloy with 1%Si contents decreased by 38.7%compared to alloy of free-Si after oxidation for 100 h at 700℃,showing high oxidation resistance of Hastelloy N alloy with Si addition.The oxide film of alloys composition were uniform and no scale spallation were detected.The outer film of alloy mainly consisted of NiO,NiFe2O4,NiMn2O4 and the inner was a mixing layer of Cr2O3,MoO2.When the silicon content reached 0.5%,SiO2 layer appeared at the metal-oxide interface,and the occurrence of SiO2 layer significantly enhanced the oxidation resistance of the alloy.
作者
郭伟杰
张继祥
李建树
陆燕玲
周兴泰
Guo Weijie;Zhang Jixiang;Li Jianshu;Lu Yanling;Zhou Xingtai(School of Mechanotronics&Vehicle Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Department of Nuclear Materials Science and Engineering,Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2019年第5期507-512,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51674237)
重庆市基础与前沿研究计划重点项目(cstc2015jcyjBX0140)资助
作者简介
郭伟杰(1991-),男,山西吕梁人,硕士研究生,研究方向:合金材料性能评估,E-mail:kouaoki@163.com;通信作者:陆燕玲,研究员,电话:021-39191002,E-mail:luyanling@sinap.ac.cn
