(1. 湘潭大学材料科学与工程学院，湘潭 411105；
2. 湘潭大学材料设计及制备技术湖南省重点实验室，湘潭 411105)
摘 要: 利用扫描电镜、X射线衍射仪等研究Si对FeMo25Cr14Ni10高温耐磨合金组织及其800 ℃氧化行为的影响。结果表明：合金的铸态和退火态组织均为α-Fe (Mo,Cr,Ni) + Laves相(Fe2Mo型)。随Si含量增加，合金中铸态组织形态由魏氏体组织转变为枝晶组织。Si的加入明显改善了合金的抗氧化性能，其作用机理在于提高了基体中Cr的含量，促进了致密Cr2O3氧化膜的形成；而Mo和Si在Laves相中的富集增强了中间相的稳定性，抑制了Mo的氧化与挥发。但当Si含量较低时，低熔点Mo氧化物的挥发不能得到完全抑制，外氧化膜较为疏松，并且会产生剥落现象。Si含量为3%~4%(质量分数)的FeMo25Cr14Ni10合金具有优异的抗氧化性能。
关键字: Si；FeMoCrNi合金；耐磨合金；静态氧化；Laves相
（1. School of Materials Science and Engineering, Xiangtan University, Xiangtan 411105, China;
2. Key Laboratory of Materials Design and Preparation Technology of Hunan Province,
Xiangtan University, Xiangtan 411105, China）
Abstract:The effects of Si on the microstructures of FeMo25Cr14Ni10 high temperature wear-resistance alloys and its oxidation behaviors at 800 ℃ were investigated by scanning electron microscopy (SEM) and X ray diffractometry. The results show that the microstructures of as-cast alloys and annealed alloys are α-Fe (Mo,Cr,Ni) + Laves phase (Fe2Mo type). With the increase of Si content, the as-cast microstructure of alloy changes from Widmanstatten into dendrite. The addition of Si obviously improves the oxidation resistance of the alloys. The action mechanism of Si is that Si can increase the content of Cr in the matrix and promote the formation of dense Cr2O3 film, while the accumulation of Mo and Si in Laves phase increases the stability of the intermediate phase and inhibit oxidation and volatilization of Mo oxides. While when Si content is lower, the volatilization of Mo oxide with low melting point can not be inhibited completely, the outer film is loose, resulting in the spalling of the oxidation film. FeMo25Cr14Ni10 with 3%-4% Si (mass fraction) have excellent oxidation resistance.
Key words: Si; FeMoCrNi alloy; wear-resistance alloy; static oxidation; Laves phase
