晶粒细化对Fe-5Cr-5Al合金高温化学稳定性的影响  

Effect of Grain Size on High-Temperature Oxidation Behavior of Fe-5Cr-5Al Alloy

作　　者：孙玥[1] 曹中秋[1] 孙洪津[1] 鲁捷[1] 

机构地区：[1]沈阳师范大学化学与生命科学学院,沈阳110034

出　　处：《沈阳师范大学学报（自然科学版）》2010年第4期517-520,共4页Journal of Shenyang Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(50771068)

摘　　要：采用粉末冶金(PM)和机械合金化(MA)方法通过热压制备了常规尺寸和纳米尺寸的Fe-5Cr-5Al合金,研究了2种合金在900℃,0.1 MPa纯氧中的氧化行为。结果表明,2种合金的氧化动力学曲线均偏离抛物线规律,大体上由三段抛物线所组成,且瞬时抛物线速率常数随时间不规则变化。MAFe-5Cr-5Al合金的氧化速率明显大于PMFe-5Cr-5Al合金,这是由于晶粒细化导致大量晶界的增加,使合金中的活泼组元以更快的速度向外扩散。2种合金表面均未形成保护性的Al2O3膜,其氧化膜组成主要是是Fe的氧化物。Two kinds of Fe-5Cr-5Al alloys were prepared by powders metallurgy（PM） and mechanical alloying（MA） methods through hot pressing technique.Their oxidation behavior was also examined at 900 ℃in 0.1 MPa pure oxygen.Results show that the oxidation kinetic curves of PMFe-5Cr-5Al and MAFe-5Cr-5Al alloys deviate from the parabolic rate law and are composed of three parabolic stages.Their instantaneous parabolic rate constants change irregularly with time.The oxidation rate of MAFe-5Cr-5Al alloy is much greater than that of PMFe-5Cr-5Al alloy,it is because grain refinement caused increase of the grain boundary which leads to the reactive component in the alloy diffuse outward faster.MAFe-5Cr-5Al and PMFe-5Cr-5Al alloys are unable to form the protective Al2O3 oxide scale on the alloy surface.The oxide scales on the alloys are mainly composed of Fe oxides.

关 键 词：Fe-5Cr-5Al合金 晶粒细化 高温氧化 

分 类 号：TG172.82[金属学及工艺—金属表面处理]