Y_2O_3含量对机械合金化Fe-15Cr合金循环氧化行为的影响

Effect of Y_2O_3 on Cyclic Oxidation Behavior of Mechanical Alloying Fe-15Cr Alloy

采用机械合金化及热压法制备Fe-15Cr、Fe-15Cr-0.8Y_2O_3和Fe-15Cr-3Y_2O_3合金,研究不同Y_2O_3含量对Fe-Cr合金在900℃空气中循环氧化行为的影响.结果表明:Fe-15Cr合金实验1 h氧化膜就有严重的剥落现象,循环氧化9 h后,试样已经几乎完全被氧化;Fe-15Cr-0.8Y_2O_3的氧化质量增量明显大于Fe-15Cr-3Y_2O_3的质量增量,Fe-15Cr-3Y_2O_3的抗高温循环氧化性能最好.Fe-15Cr-0.8Y_2O_3合金的氧化膜主要分为两层,外层主要由Fe_2O_3组成,内层主要由复合氧化物FeCr_2O_4组成,在与基体连接处,存在不连续的Cr_2O_3.Fe-15Cr-3Y_2O_3合金的氧化膜可分为两层,外层主要为Fe_2O_3,厚度较Fe-15Cr-0.8Y_2O_3合金薄;内层比较致密,主要由复合氧化物FeCr_2O_4组成,内层与基体结合良好,结合处零星有富集的Cr_2O_3.Y_2O_3的添加可有效提高Fe-15Cr合金的抗循环氧化能力,其中Fe-15Cr-3Y_2O_3合金好于Fe-15Cr-0.8Y_2O_3合金.

Fe-15Cr,Fe-15Cr-0.8 Y2O3 and Fe-15Cr-3 Y2O3 alloys were prepared by mechanical allo- ying and hot pressing. The effects of different Yz O3 content on cyclic oxidation behavior of mechanical al- loying Fe-Cr alloy at 900 ℃ in air were investigated. The results indicate that, after an hour, the oxide film of Fe-15Cr alloy began to serious spalling, and been almost completely oxidized after 9 hours. The oxida- tion weight-increment of Fe-15Cr-0. 8Y2O3 alloy was higher than Fe-15Cr-3Y2O3. The oxide scales of Fe- 15Cr-0. 8Y2O3 alloy were divided into two layers. The outside layer was mainly. Fe2O3, and the inner was mainly FeCr204, discontinuous Cr2O3 was detected in the junction with the matrix. The oxide scales of Fe- 15Cr-3Y2O3 alloy were divided into two layers. The outside layer was mainly FezO3 ,the inner layer was mainly FeCr204, which is dense and has a good combination with alloy, and little Cr2O3 was detected in the junction. Y2O3 can improve the cyclic oxidation resistance of Fe-15Cr alloy effectively, and the cyclic oxidation resistance of Fe-15Cr-3Y2O3 alloy is slightly better than Fe-15Cr-0.8Y2O3 alloy＇s.