【摘要】 使用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对比分析了617B镍基合金在750℃持久试样和时效态试样的组织结构和析出相。结果表明:在蠕变和时效过程中在晶内和晶界都析出复杂面心立方结构的M23C6,晶内析出有序立方结构γ′相,前者为多边形或条形,后者为粒状;随着试验时间的延长析出物的颗粒尺寸出现长大的趋势;应力对γ′相的生长影响不明显,但是对晶界碳化物有明显的影响;在长时间应力条件下,M23C6碳化物聚集长大。更多还原

【Abstract】 The microstructure and precipitates of the creep-ruptured and aged alloy 617 B at 750 oC were characterized by means of scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The polygonal(or strip-type) M23C6 particles with a complex face-centered cubic(fcc) structure locate along grain boundaries and inside grains, and granular γ ′ phase particles with an ordered fccstructure inside grains were observed during creep and aging. The precipitates grown up with test time.The comparative observation of the aged and creep-ruptured alloy samples revealed that the applied stress did not affect the growth of γ ′ phase obviously, but affect the precipitation of carbides at grain boundaries greatly. The stress leads to the sharp growth and agglomation of M23C6 particles after a long time creep test.更多还原