The Metallurgical Mechanisms of Inclusions in the FGH4096 Alloy during Electron Beam Refining

Abstract

The effect of different electron beam refining parameters on the type， quantity and size distribution of inclusions during melt solidification was studied. The content of O and N in FGH4096 alloy and the type， quantity and size distribution of inclusions after different power refining were statistically analyzed， and the mechanism of influence of power on inclusions growth during electron beam refining was revealed in combination with the growth kinetics of inclusions. The number density of carbon and nitrogen compounds and complex phase inclusions in FGH4096 alloys prepared by electron beam refining was the largest， and the proportion of both was 95.53%. In the carbon nitrogen compounds and complex phase inclusions， TiN-TiC， TiN-（Ti，M）C and Al2O3-TiN-（Ti，M）C occupied a large proportion. The inclusions growth kinetics calculations showed that when the power increased from 9 kW to 12 kW， the increased power improved the removal effect of the inclusions forming elements， limited the elemental content required for the growth of inclusions， reduced the formation temperature of inclusions and thus reduced its growth temperature range， and led to a reduced growth time and size of inclusions due to the small change in the cooling rate additionally.However， when the power 12 kW increased to 15 kW， the O and N content decreased less while the melt cooling rate decreased larger， resulting in an increased growth time of the inclusion.It reduced the effect of the removal of impurity element content， with an increase in the size of inclusions.

Keywords

• electron beam refining； fgh4096； inclusion； kinetics