性能的影響
(福州大學(xué) 材料科學(xué)與工程學(xué)院，福州350002)
摘 要: 采用熔煉法制備出新型高耐磨的Fe-20Ni-xMn-3.5C-2.5Si系固體自潤滑材料，研究稀土元素Ce對(duì)Fe-20Ni-xMn-3.5C-2.5Si系合金中石墨的球化作用及Mn含量對(duì)力學(xué)性能及摩擦磨損性能的影響。結(jié)果表明：隨著Mn含量的增加，合金凝固組織中奧氏體的硬度逐漸增大，特別是Fe-20Ni-xMn-3.5C-2.5Si-0.75Ce系合金在摩擦過程中的表面硬度大幅度提高，呈現(xiàn)出高錳鋼特有的表面加工硬化性質(zhì)，通過TEM可以觀察到磨損表面生成孿晶型馬氏體；添加0.75%(質(zhì)量分?jǐn)?shù))的稀土Ce可以使結(jié)晶的石墨球化，使抗拉強(qiáng)度和抗彎強(qiáng)度大幅度提高，大約比未經(jīng)球化處理的提高3~5.8倍；稀土Ce的加入可以促進(jìn)Fe1.1Mn3.9C2型碳化物的生成，使材料的耐磨性進(jìn)一步提高，其中Fe-20Ni-16Mn-3.5C-2.5Si-0.75Ce合金的磨損率最低，大約是QT500球墨鑄鐵的1/13。
關(guān)鍵字: Fe-Ni-Mn-C-Si-Ce合金；高錳奧氏體；MnCe；加工硬化； 摩擦；磨損
properties of Fe-Ni-Mn-C-Si-Ce alloys
（College of Materials Science and Engineering, Fuzhou University, Fuzhou 350002, China）
Abstract:Fe-20Ni-xMn-3.5C-2.5Si solid self-lubricating materials with property of high-wearing were prepared by melting method. The spheroidization effect of rare earth Ce on graphite and the effect of Mn addition on mechanical properties and tribological performances of Fe-20Ni-xMn-3.5C-2.5Si alloys were studied. The results show that the austenite hardness of solidifying structures increases as the manganese content increases. The surface hardness of Fe-20Ni-xMn-3.5C-2.5Si-0.75Ce alloy increases widely after being worn and it appears the work-hardening of surface as like the high manganese-containing steel. The type of compound twin martensite on surface can be observed by TEM. The spheroidization effect of 0.75%(in mass fraction)of rare earth cerium on the graphite during crystallization is effective. The spheroidized alloy has higher tensile strength and flexural strength which is about 3−5.8 times higher than those of the non-spheroidized alloy. With the addition of rare earth Ce, the second phase Fe1.1Mn3.9C2, which makes the wear resisting property further increase, appears in matrix. Fe-20Ni-12Mn-3.5C-2.5Si -0.75Ce alloy has the lowest wear rate which is about 13 times lower than that of the spheroidal cast iron.
Key words: Fe-Ni-Mn-C-Si-Ce alloy; high manganese austenite; Mn; Ce; work-hardening; friction; wear
