(1. 湘潭大學(xué)材料科學(xué)與工程學(xué)院，湘潭 411105；
2. 湘潭大學(xué)材料設(shè)計(jì)及制備技術(shù)湖南省重點(diǎn)實(shí)驗(yàn)室，湘潭 411105)
摘 要: 利用掃描電鏡、X射線衍射儀等研究Si對(duì)FeMo25Cr14Ni10高溫耐磨合金組織及其800 ℃氧化行為的影響。結(jié)果表明：合金的鑄態(tài)和退火態(tài)組織均為α-Fe (Mo,Cr,Ni) + Laves相(Fe2Mo型)。隨Si含量增加，合金中鑄態(tài)組織形態(tài)由魏氏體組織轉(zhuǎn)變?yōu)橹ЫM織。Si的加入明顯改善了合金的抗氧化性能，其作用機(jī)理在于提高了基體中Cr的含量，促進(jìn)了致密Cr2O3氧化膜的形成；而Mo和Si在Laves相中的富集增強(qiáng)了中間相的穩(wěn)定性，抑制了Mo的氧化與揮發(fā)。但當(dāng)Si含量較低時(shí)，低熔點(diǎn)Mo氧化物的揮發(fā)不能得到完全抑制，外氧化膜較為疏松，并且會(huì)產(chǎn)生剝落現(xiàn)象。Si含量為3%~4%(質(zhì)量分?jǐn)?shù))的FeMo25Cr14Ni10合金具有優(yōu)異的抗氧化性能。
關(guān)鍵字: Si；FeMoCrNi合金；耐磨合金；靜態(tài)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
