合金化及热处理对Fe_3Al合金组织和性能影响

研究了不同的热处理条件及添加Mn,Mo,Nb,Cr,V,RE（La-Ce）等合金元素对Fe3Al合金组织和性能的影响。结果表明,Fe3Al合金在B2相区间保温淬火后的硬度值较小,在DO3相区短时间回火硬度值大幅增加,随回火时间延长硬度值呈降低趋势,在本实验的最长回火时间内（50h）硬度稍有提高;TEM分析表明,这与回火过程中DO3畴的尺寸变化有关;合金化后Cr和V的加入降低合金硬度,其它几种元素都提高了合金的硬度;SEM分析表明合金元素的作用机理不同：Cr软化了合金,Mo主要产生固溶强化,Mn、V、Nb加入后有第二相析出,RE元素主要偏析在晶界,细晶强化。

The effects of alloying and heat treatment on the structures and performances of Fe3Al alloys

In this paper,the effects of different heat treatment and addition of alloy elements such as manganese（Mn）,molybdenum（Mo）,niobium（Nb）,chromium（Cr）,vanadium（V） and RE（lanthanum-cerium） on the structure and performance of Fe3Al-based alloys are studied.The results indicates that the hardness values of Fe3Al alloys are low in B2 phase regions after insulation quenching while the values are increased substantially in DO3 phase regions after short time tempering,and the values get lower as the tempering time increases,with the hardness increased slightly in the longest time（50h） tempering.TEM results show that this depends on the change of the size of DO3 domains during the tempering.The hardness of alloys decreases with the addition of Cr and V,while it increases with the addition of other elements.SEM results show that different alloying elements have different mechanism： Cr reduces the hardness of alloys;Mo produces solution strengthening;the second phase is formed with the addition of Mn,V and Nb;RE is mainly segregated in the grain boundary which produces grain refinement strengthening.