熔体过热处理对FGH4096镍基高温合金纯净化行为及凝固组织的影响

Effect of Melt Overheating Treatment on Pure Purification Behavior and Solidification Microstructure of FGH4096 Nickel-Based Superalloy

在不同熔体过热温度(1415,1463,1523℃)和过热时间(10,20,30 min)下对FGH4096镍基高温合金进行熔体过热处理,研究了熔体过热对合金纯净化行为及凝固组织的影响。结果表明:随着熔体过热温度的升高或过热时间的延长,二次枝晶间距逐渐减小;随着过热温度的升高,合金中元素的偏析程度降低,过热时间对元素偏析程度的影响不大;当过热温度为1415~1463℃时,熔体主要发生碳-氧反应,吸氮反应较弱,合金中氧含量和氮含量均较低;当熔体过热温度为1463~1523℃时,熔体主要发生MgO坩埚分解反应和吸氮反应,因此合金中的氧含量和氮含量均较高。

FGH4096 alloy was treated by melt overheating process under different melt overheating temperatures(1415,1463,1523℃)and overheating times(10,20,30 min).The influence of melt overheating on the purification behavior and solidification microstructure of the alloy was studied.The results show that with increasing melt overheating temperature or prolonging overheating time,the secondary dendrite spacing decreased gradually.With increasing overheating temperature,the segregation degree of the elements in the alloy decreased,but the influence of the overheating time on the segregation degree was not significant.When the overheating temperature was 1415-1463℃,carbon-oxygen reaction mainly occurred in the melt,and the nitrogen absorption reaction was weak,resulting in low oxygen and nitrogen content.When the melt overheating temperature was 1463-1523℃,MgO crucible decomposition reaction and absorbed nitrogen reaction occurred,resulting in high oxygen and nitrogen content in the alloy.