Fe-24Al-1Cr合金固溶时效处理的组织和力学性能
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摘要
利用金相法、XRD和TEM研究了Fe-24Al-1Cr合金800、900和1050℃固溶和625、565和520℃时效处理的微观组织,研究了Fe-24Al-1Cr合金固溶时效后的压缩断裂强度、压缩屈服强度及压缩率等。结果表明,Cr合金化Fe-24Al合金经固溶时效处理后仍然析出有序相B2和DO3相。Fe-24Al-1Cr合金固溶时效处理后产生富Cr的Fe-Al-Cr相,沿晶界、位错线析出,也在晶内产生。Fe-24Al-1Cr合金固溶时效处理后位错主要以位错列的形式存在,呈现平面滑移的特征,位错间距较大,达数十纳米至100 nm。出现较多位错对、位错偶极子;也存在位错攀移"弓出"、位错"弯折"等衬度特征和蜷线位错组态,说明Cr的加入增大位错对及位错之间距离以及形变位错的可动性。Cr合金化Fe-24Al合金综合力学性能优于Fe-24Al合金。经1050℃×0.5 h固溶520℃×1 h时效处理后的Fe-24Al-1Cr合金表现出最佳的力学性能,压缩断裂强度为1270 MPa,压缩屈服强度为750 MPa,压缩率为21%。
Microstructure of Fe-24Al-1Cr alloy treated by solid solution(at 800,900 and 1050 ℃) and aging(at 625,565 and 520 ℃) were investigated using metallography,XRD and TEM.And the mechanical properties such as compression fracture strength,compression yield strength and compression rate were also studied.The results show that B2 and DO3 phases precipitate during solution and aging for Cr-alloyed Fe-24Al alloy.And Cr-rich precipitation phases generate during this process,which distribute along dislocation lines and grain boundary,also in the grains.The dislocations after solution and aging mainly show dislocation arrays,showing planar sliding characteristics.And the dislocation spacings are larger to 10-100 nm.At the same time,many dislocation dipoles,dislocation pairs appear.Some dislocation climbing "bowing out","kink" contrast characteristics and spiral dislocations can be seen.All these show that the introduction of Cr increases the dislocation spacings and enhances the mobility of dislocation.The Cr-alloyed Fe-24Al alloy shows a higher mechanical property than Fe-24Al alloy.The technology of 1050 ℃×0.5 h solution,520 ℃×1 h aging gives the optimum mechanical properties with 1270 MPa of compression fracture strength,750 MPa of compression yield strength and 21% of compression rate.
Microstructure of Fe-24Al-1Cr alloy treated by solid solution(at 800,900 and 1050 ℃) and aging(at 625,565 and 520 ℃) were investigated using metallography,XRD and TEM.And the mechanical properties such as compression fracture strength,compression yield strength and compression rate were also studied.The results show that B2 and DO3 phases precipitate during solution and aging for Cr-alloyed Fe-24Al alloy.And Cr-rich precipitation phases generate during this process,which distribute along dislocation lines and grain boundary,also in the grains.The dislocations after solution and aging mainly show dislocation arrays,showing planar sliding characteristics.And the dislocation spacings are larger to 10-100 nm.At the same time,many dislocation dipoles,dislocation pairs appear.Some dislocation climbing "bowing out","kink" contrast characteristics and spiral dislocations can be seen.All these show that the introduction of Cr increases the dislocation spacings and enhances the mobility of dislocation.The Cr-alloyed Fe-24Al alloy shows a higher mechanical property than Fe-24Al alloy.The technology of 1050 ℃×0.5 h solution,520 ℃×1 h aging gives the optimum mechanical properties with 1270 MPa of compression fracture strength,750 MPa of compression yield strength and 21% of compression rate.
引文
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[5]高小玫,钱祥荣.Cr对Fe3Al的韧化作用[J].金属学报,1994,30(7):307-311.
[6]姚正军,苏宏华,向定汉.合金元素的添加对Fe3Al基合金有序转变温度的影响[J].南京航空航天大学学报,2002,34(3):230-234.
[7]李飞.Fe-Al合金中调幅分解与有序化共存相变行为的研究[D].哈尔滨:哈尔滨工业大学,2010.
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