摘要
The distribution of phosphorus in IN706 alloy was studied,with particular emphasis on the as-cast microstructure and homogenization treatment.It is found that phosphorus is segregated in Laves phase and markedly influences the as-cast microstructure of IN706 alloy.Phosphorus retards the formation of Laves phase with the eutectic form,but promotes the Laves formation with the blocky form.Phosphorus refines the dendritic structure and noticeably enlarges the interdendritic area.The reason for phosphorus influencing the as-cast microstructure is attributed to its extremely low solubility in γ matrix and great retarding effect on γ matrix solidification.In addition,phosphorus slightly decreases the melting temperature of Laves phase,and retards the dissolution of Laves phase and the element diffusion between dendrite core and interdendritic area during the homogenization treatment.And it is thought that phosphorus delays the homogenization process by inhibiting the element diffusion.
研究磷偏聚对IN706合金铸态组织及均匀化处理的影响。结果表明,磷偏聚于Laves相中,显著影响合金的铸态组织。磷抑制Laves相以共晶形态析出,但促进Laves相以块状形态析出。磷细化枝晶组织,并且扩大枝晶间面积。磷对铸态组织的影响是由于其在γ基体的低溶解度和对γ基体凝固的阻碍作用引起的。此外,磷稍微降低Laves相的熔点,在均匀化过程中,磷阻碍Laves相溶解以及枝晶干与枝晶间的元素扩散。磷通过阻碍元素扩散来推迟均匀化过程。
