论文部分内容阅读
采用熔体超温处理方法,通过改变熔体超温处理时间研究定向凝固镍基高温合金DZ125凝固组织的演化规律。结果表明:熔体超温处理时间由15min延长到30min可以细化枝晶、减小偏析。然而,进一步延长熔体超温处理时间至60min,枝晶却略微粗化。熔体超温处理15min时,碳化物形貌为草书体,而熔体超温处理时间大于30min时碳化物则主要为非连续性棒状和块状。造成这种现象的主要原因是熔体超温处理时间的变化影响到熔体状态,进而影响到凝固组织。
The evolution of solidification microstructures of directional solidified Ni-based superalloy DZ125 was studied by melt over-temperature treatment by changing the melt over-temperature treatment time. The results show that the extension of melt temperature from 15min to 30min can refine the dendrite and reduce the segregation. However, further prolonging the temperature of the melt over 60 minutes, the dendrites slightly roughened. When the melt is over-heated for 15 min, the morphology of the carbide is cursive, while the carbide is mainly non-continuous rod-like and massive when the melt is over-heated for more than 30 min. The main reason for this phenomenon is that the change of the melt over-temperature treatment time affects the melt state, which in turn affects the solidified structure.