热变形工艺对FGH96高温合金PPB析出相及组织的影响

Effect of Hot Deformation on PPB Precipitations and Microstructure in P/M Superalloy FGH96

以AA粉制备的HIP态FGH96高温合金为研究对象,研究不同热变形工艺前后FGH96高温合金PPB析出物及组织状态的变化。结果表明:HIP态FGH96高温合金可见呈圆形分布的PPB析出物,粗大的长条状γ′相呈圆形链状分布是PPB的主要特征之一;经热变形后,FGH96高温合金PPB变形、破碎,再结晶晶粒细化、扭转,晶粒取向差变小;随着热变形温度升高、变形量增大、变形速率减小,PPB析出物变形和破碎程度越显著,粗大的初生γ′相和二次γ′相残留越少、尺寸越小;热变形温度升高、变形量增大以及变形速率减小有利于PPB的减轻甚至消除。

HIPed FGH96 superalloy prepared by AA powder was used as the research object, and the PPB precipitations and microstructures before and after different hot deformations were studied. The results show that PPB precipitates with circular distribution can be seen in HIPed FGH96 superalloy, and the coarse strip prime γ′ phase with circular chain distribution is one of the main characters of PPB. After hot deformation, the PPB in FGH96 superalloy is deformed and broken, the recrystallization grains are refined and twisted, and the grain misorientation becomes smaller. With the increase of deformation temperature and hot deformation, and the decrease of deformation rate, the deformation and fragmentation of PPB precipitates are more significant, the size of the primary residual γ′ phase becomes smaller, and the volume becomes less. The increase of deformation temperature and hot deformation, and the decrease of deformation rate are beneficial to reduce or even eliminate PPB precipitations.