摘要
利用机械合金化方法制备了纳米晶(NC)Fe-0.5Si合金(质量百分数,下同),研究了该合金在900℃和1000℃流动纯氧气中的氧化行为,并与相同条件下利用电弧熔炼方法制备的粗晶(CG)Fe-0.5Si合金的氧化行为进行比较。两种Fe-Si合金都形成了类似的混合氧化物层结构(Fe2O3+Fe3O4+FeO+SiO2)。两个试验温度下,NC Fe-0.5Si表现出比CG Fe-0.5Si更快的氧化速度。这是由于NC Fe-0.5Si合金具有更多的晶界,促进了Fe向外扩散和氧向内扩散,从而使氧化速度明显提高。虽然NC Fe-0.5Si较CG Fe-0.5Si形成的混合氧化物层中SiO2的体积分数明显提高,但Fe和氧扩散的绝对速度仍然增大。纳米化降低了Fe-0.5Si合金的抗高温氧化性能。
The oxidation behavior of nanocrystalline（NC） Fe-0.5Si alloy prepared by mechanical alloying was investigated at 900 ℃ and 1 000 ℃ in flowing pure oxygen of 1 atm,and was compared to the oxidation behavior of coarse-grain（CG） Fe-0.5Si alloy prepared by conventional casting under the same treatment condition.At the two temperatures,both Fe-0.5Si samples formed similar complex external scales composed of Fe2O3,Fe3O4,FeO and SiO2.Compared to CG Fe-0.5Si,NC Fe-0.5Si had more grain boundaries,which acted as high-diffusivity paths and promoted the outward diffusion of Fe and the inward diffusion of oxygen,so the oxidation rate was increased significantly.Although the volume percent of SiO2 in the mixed oxides of FeO＋SiO2 of NC Fe-0.5Si was higher than that of CG Fe-0.5Si,the absolute diffusion rates of Fe and oxygen still increased.Nanocrystallization decreased the high-temperature oxidation resistance of Fe-0.5Si alloy.
出处
《腐蚀与防护》
CAS
北大核心
2010年第11期840-843,共4页
Corrosion & Protection
基金
辽宁省高等学校优秀人才支持计划项目(RC-05-15)
关键词
Fe-0.5Si合金
粗晶
纳米晶
高温氧化
晶界扩散
Fe-0.5Si alloy
coarse-grain
nanocrystalline
high-temperature oxidation
grain boundary diffusion
