Fe-Cr-Mn合金在湿润环境中的氧化行为研究  

Oxidation Behavior of Fe-Cr-Mn Alloys in Wet Atmosphere at 800 ℃

作　　者：潘太军[1,2] 陈婧[1] 李杰[1] 胡静[1,2] 

机构地区：[1]常州大学材料科学与工程学院江苏省光伏科学与工程协同创新中心,常州213164 [2]常州大学材料表面科学与技术江苏省重点实验室,常州213164

出　　处：《腐蚀科学与防护技术》2015年第6期537-544,共8页Corrosion Science and Protection Technology

摘　　要：研究比较了Fe-13Cr-x Mn(x=0.5,1,2)系列合金在干燥和湿润空气中800℃下的氧化行为。结果表明,在干燥气氛中合金表现出良好的抗氧化性能,当Mn含量低于1%时有助于合金表面生成阻碍Cr挥发的(Mn,Cr)3O4尖晶石相;而当Mn含量达到2%,合金表面则会产生Mn2O3,从而影响合金的抗高温氧化性能。在含水蒸气气氛中,合金发生了失稳态氧化,表面生成了大量氧化物,合金的氧化速率随Mn含量的增大而减小,主要原因是Mn含量增加导致膜层中形成(Mn,Cr)3O4尖晶石相,从而有效阻碍了水气环境中Cr的挥发,尤其Fe-13Cr-2Mn合金在氧化初期12 h内并没有发生加速腐蚀,Fe-Cr-Mn合金的加速氧化是由表面氧化铬膜与水蒸气发生反应所致。通过SEM,XRD等分析手段深入探讨了合金加速氧化机制以及Mn效应。Fe-Cr-Mn alloys are becoming a promising candidate material for interconnectors of solid oxide fuel cells （SOFC） stacks because of the formation of an conductive scale containing （Mn,Cr）3O4 spinel at intermediate temperature range of 650-800 ℃. To better understand their scal- ing mechanism and evaluate their high temperature performance for SOFC interconnects, the oxida- tion of Fe- 13Cr-xMn alloys with different Mn content （x=0.5, 1, 2） was investigated both in dry and wet air at 800 ℃. The experimental results indicated that all alloys exhibited excellent oxida- tion-resistance in dry atmosphere. The Fe-Cr-Mn alloys with Mn less than 1% could easily form the conductive （Mn, Cr）304 spinel, which can effectively hinder the volatilization of chromium from the surface of the alloys. However, the oxide Mn2O3 presented in the scale after the manga- nese content of the alloy increased up to 2%. These had an impact on the high temperature perfor- mance of the alloy. In the wet atmosphere, the instability oxidation of all alloys occurred and a large amount of oxide products formed on the surface of the alloys, in contrast to that in dry atmo- sphere. The oxidation rates decreased with increasing manganese content, which is mainly attribut- ed to the formation of （Mn, Cr）3O4 spinel with higher Mn content. No accelerated oxidation oc-curred on Fe-13Cr-2Mn alloy within the first 12 h oxidation. The accelerated oxidation of Fe-Cr- Mn alloy was mainly caused by the reaction between the water vapor and chromia scale. The mech- anism of accelerated oxidation and the effect of Mn were reported and elucidated by experimental methods including SEM/EDS and XRD.

关 键 词：Fe-Cr-Mn合金 氧化 Cr挥发 Mn效应 水蒸气 

分 类 号：TG172[金属学及工艺—金属表面处理]