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测定了Ｆｅ－１５Ｃｒ－４Ａｌ合金在５００℃的时效脆化动力学，利用内耗，ＴＥＭ，ＥＰＭＡ和ＳＥＭ等手段研究了合金在时效后的组织变化和断裂行为．结果表明，时效脆化第一阶段（０－１００ｈ）主要是碳化物在α相晶界析出的作用，它损害界面结合，降低断裂应力，使塑性在时效０．２５ｈ后消失；第二阶段（１００－１０００ｈ）主要是富Ｃｒ－α＇相均匀析出的作用，它通过强化基体引起二次脆化．含０．２和０．４％Ｙ的Ｆｅ－１５Ｃｒ－４Ａｌ－Ｙ合金在固溶态下无Ｓｎｏｅｋ内耗峰，碳在α相中的浓度低于０．０００７％，这是碳原子被Ｙ_２Ｆｅ_（１７）相俘获的结果．因此，含钇合金在５００℃时效时不发生晶界碳化物析出，时效１０００ｈ后塑性无明显变化．
The aging embrittlement kinetics of Fe-15Cr-4Al alloy at 500 ℃ was measured. The microstructure and fracture behavior of the alloy after aging were studied by means of internal friction, TEM, EPMA and SEM. The results show that the first stage of aging embrittlement (0-100h) is mainly the precipitation of carbides on the α phase grain boundary, which interferes with the interfacial bonding and reduces the fracture stress, and the plasticity disappears after 0.25h aging. In the second stage ( 100-1000h) is mainly Cr-α ’rich phase of the role of uniform precipitation, which through the matrix to cause secondary embrittlement. The Fe-15Cr-4Al-Y alloy containing 0.2 and 0.4% Y has no Snoek internal friction peak in the solid solution state, and the concentration of carbon in the α phase is less than 0.0007%. This is because the carbon atom is replaced by Y 2 Fe_ ( 17) phase capture results. Therefore, the alloy containing yttrium does not occur at 500 ℃ aging grain boundary carbide precipitation, aging after 1000h no significant change in plasticity.