性能的影响
(福州大学 材料科学与工程学院，福州350002)
摘 要: 采用熔炼法制备出新型高耐磨的Fe-20Ni-xMn-3.5C-2.5Si系固体自润滑材料，研究稀土元素Ce对Fe-20Ni-xMn-3.5C-2.5Si系合金中石墨的球化作用及Mn含量对力学性能及摩擦磨损性能的影响。结果表明：随着Mn含量的增加，合金凝固组织中奥氏体的硬度逐渐增大，特别是Fe-20Ni-xMn-3.5C-2.5Si-0.75Ce系合金在摩擦过程中的表面硬度大幅度提高，呈现出高锰钢特有的表面加工硬化性质，通过TEM可以观察到磨损表面生成孪晶型马氏体；添加0.75%(质量分数)的稀土Ce可以使结晶的石墨球化，使抗拉强度和抗弯强度大幅度提高，大约比未经球化处理的提高3~5.8倍；稀土Ce的加入可以促进Fe1.1Mn3.9C2型碳化物的生成，使材料的耐磨性进一步提高，其中Fe-20Ni-16Mn-3.5C-2.5Si-0.75Ce合金的磨损率最低，大约是QT500球墨铸铁的1/13。
关键字: Fe-Ni-Mn-C-Si-Ce合金；高锰奥氏体；MnCe；加工硬化； 摩擦；磨损
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
