【摘要】 为了揭示高合金化难变形GH742高温合金铸锭偏析规律及随后均匀化处理过程中元素分布规律,采用微观组织分析手段分析研究了该合金铸态和均匀化态的显微组织和元素的偏析情况;根据实验中偏析元素Nb,Ti的分布,讨论了偏析指数与工艺参数和材料参数的关系。研究结果认为:偏析指数的变化量Δδ在枝晶间距为80μm～120μm时减小量最大,并且在枝晶间距为120μm的条件下,合金在1160℃退火8h和16h的Nb元素的δ计算值与实验值较符合。更多还原

【Abstract】 The microstructure of as cast GH742 and the distributions of the alloying elements during homogenizing treatment were studied by optical microscope,scanning electron microscopy and EDAX.Meanwhile,the relationship of segregation parameter δ and several processing parameters was also studied on the basis of Nb,Ti distribution.The results show that the variety of segregation parameter is the highest when dendritic distance is 80 μm～120 μm,and the calculated and experimented result of segregation index δ has a good agreement for Nb annealing at 1160 ℃ for 8 h and 16 h.更多还原