热暴露温度对电力用Ti-20Mo高温合金表面氧化的影响  

Influence of Thermal Exposure Temperature on Surface Oxidation of Ti-20Mo Superalloy Used for Electric Power

作　　者：王保华[1] 葛新锋 杨波[3] 胡草笛 WANG Bao-hua;GE Xin-feng;YANG Bo;HU Cao-di(School of Mechanical and Electrical Engineering,Jiaozuo University,Jiaozuo 454000,China;Engineering Technology Center,Xuchang University,Xuchang 461000,China;School of Mechanical and Power Engineering,Henan Polytechnic University,Jiaozuo 454003,China)

机构地区：[1]焦作大学机电工程学院,河南焦作454000 [2]许昌学院工程技术中心,河南许昌461000 [3]河南理工大学机械与动力工程学院,河南焦作454003

出　　处：《稀有金属与硬质合金》2022年第3期34-38,共5页Rare Metals and Cemented Carbides

基　　金：河南省高等学校优秀基层教学组织项目(教高[2017]730号);河南省科技厅科技攻关项目(182102210508)。

摘　　要：为进一步提升Ti-20Mo合金抗氧化能力,研究了不同热暴露温度下电力用Ti-20Mo高温合金表面氧化及组织演变。结果表明:原始合金组织存在等轴α晶粒和大量片状α+β共晶组织。以200℃和400℃温度热暴露时,试样增重均小于6mg;当热暴露温度为600℃时,试样氧化增重近似呈线性增长,最终达16.1mg。热暴露温度上升有助于合金更快完成回复和再结晶转变过程,达到细晶强化的目的。热暴露合金均形成了等轴α晶与片状α+β共晶组织,随着温度的上升,晶粒尺寸也明显增大,晶粒分布更均匀,当热暴露温度为600℃时晶界部位析出大量细小组织。原始Ti-20Mo合金组织包括α相和TiO_(2)相,热暴露温度升高后合金内产生更多TiO_(2)相。当热暴露温度为200℃和400℃时,合金氧化膜内生成了TiO_(2);当温度升到600℃时,合金氧化膜内形成了Al_(2)O_(3)。In order to further improve the oxidation resistance of Ti-20Mo alloy,the surface oxidation and microstructure evolution of Ti-20Mo superalloy used for electric power were studied at different thermal exposure temperatures.The results show that there are equiaxedαgrains and a large number of lamellarα+βeutectic microstructure in the original alloy.When the samples are exposed at 200℃and 400℃,their weight gain is less than 6mg.When the thermal exposure temperature is 600℃,the oxidation weight gain of the sample increases approximately linearly,and finally reaches 16.1mg.The increase of thermal expo-sure temperature can help the alloy to faster complete the recovery and recrystallization transformation process and achieve the purpose of fine grain strengthening.The equiaxedαcrystal grains and the lamellarα+βeutectic microstructure are formed in the thermally exposed alloys.With the increase of temperature,the grain size obviously increases and the grain distribution becomes more uniform.A large number of fine microstructures are precipitated in the grain boundary at 600℃.The microstructure of original Ti-20Mo alloy consists ofαphase and TiO_(2) phase,and more TiO_(2) phase is generated with the increase of thermal exposure temperature.When the thermal exposure temperature is 200℃or 400℃,TiO_(2) is formed in the alloy oxide film.When the temperature rises to 600℃,Al_(2)O_(3) is formed in the alloy oxide film.

关 键 词：Ti-20Mo高温合金 热暴露 温度 氧化动力学 微观组织 

分 类 号：TG132.32[一般工业技术—材料科学与工程]