电铝热多期法制备FeV80合金的偏析研究

Segregation of FeV80 Alloy by Electro-Aluminothermic Multi-Period Process

利用扫描电镜、能谱分析、FactSage热力学计算等方法,研究了FeV80合金的微观形貌及元素分布情况,结果表明:FeV80合金主要由浅灰色的基体相(σ相)和深灰色的针状、颗粒状第二相(BCC-A2相)组成,且杂质元素Si更倾向于在σ相中析出。结合现场试验,对FeV80合金的宏观偏析进行了研究,受元素熔点、密度、凝固性等影响,合金各元素均存在不同程度的偏析,浇铸有利于合金元素的均质,但必须同时减缓冷却速度才能更显著地改善偏析,此时合金主元素V的极差、标准差最大,分别为1.510%和0.4714%,杂质元素S的极差、标准差最小,分别为0.004%和0.0017%。

The microstructure and elemental distributions of FeV80 alloy were studied by SEM-EDS and FactSage software.The results show that the FeV80 alloy consists of the light grey basic phase(σphase)and dark gray granular or acicular secondary phase(BCC-A2 phase).And silicon as the impurity tends to precipitate inσphase.Based on the industrial experiments,the macrosegregation of FeV80 alloy was also studied.All the alloy elements have different degrees of segregation affected by the melting point,density and solidification of the elements.Casting is in favor of the homogeneity of elements,and reducing cooling rate simultaneously is necessary to improve the macrosegregation significantly,with the major element vanadium having the maximum range and standard deviation respectively at 1.510%and 0.4714%,and sulfur(impurity element)having the minimum range and standard deviation respectively at 0.004%and 0.0017%.