【摘要】 １１００℃预处理的Ｆｅ－１５Ｃｒ－４Ａｌ合金在５００℃时效后迅速脆化，８００℃预处理的合金则无脆化倾向。高温处理的合金有明显的Ｓｎｏｅｋ内耗峰，α相中碳、氮的浓度较高。时效后Ｓｎｏｅｋ峰降低，在主峰的高温侧还分裂出一小峰。这表明４７５℃脆化包括碳、氮析出和α＇相析出两个过程。前者在时效初期有极强的脆化作用，后者在时效数百小时后才显示出微弱的影响。中温预处理的合金无Ｓｎｏｅｋ峰，碳、氮已充分析出，它们不再发生时效析出。含０．２和０．４ｗｔ％Ｙ的合金不出现４７５℃脆性。内耗无Ｓｎｏｅｋ峰，合金中碳化物、氮化物极少。Ｙ－Ｆｅ相俘获杂质原子，消除碳、氮的时效析出，是钇抑制４７５℃脆性的原因。更多还原

【Abstract】 Fe-15Cr-4Al alloy became brittle after aging at 500℃ for 0. 25～1h. An obviours Snoek internal friction peak of carbon atoms was found ,which decreased after the aging. It was considered that the brittleness in the brittleness in the first stage of 475℃ embrirtlement was due to a carbide precipitation. The embrittlement can be reduced by lowering pretreatment temperature. No snoek peak was detected in the alloys with yttrium because carbon atoms have been captured by Y-Fe particks. Therefove ,the 475℃ embrittlement was inhibited.更多还原