GH5188高温合金组织特征及冷热加工过程组织演变

Microstructure evolution during hot and cold working process and microstructure characteristics of GH5188 superalloy

摘要:

为了给控制生产工艺、优化性能提供理论参考，利用SEM、EDS和Thermo-Calc热力学软件研究了GH5188钴基高温合金生产加工过程中的组织演变及热处理工艺。结果表明：GH5188合金主要相组成为γ相、M6C和 M23C6，采用1200°C/20h的均匀化制度可明显消除铸态组织偏析；热轧态组织晶粒细小且有大量碳化物沿着轧向平行析出；冷轧态组织晶粒扭曲变形严重，颗粒状M6C为主要析出相，当退火温度高于1170℃，晶界处的二次碳化物基本回溶，再结晶晶粒能够正常长大。

Abstract:

In order to provide theoretical guidance for production process contorl and performance optimization, the microstructure evolution and heat treatment process in the production procecss of GH5188 cobalt-base superalloy were investigated by SEM, EDS and Thermo-Calc software. The result indicates that the main phases of GH5188 alloy include γ, M6C and M23C6. The 1200°C/20h could reduce segregation of as-cast microstructure. Hot-rolled microstructure have a fine grain size, and a large number of aligned carbides precipitate along rolling direction. In the cold-rolled microstructure with serious grain deformation, granular M6C was found to be predominant phase. when the annealing temperature is higher than 1170°C, secondary carbides at the grain boundaries dissolved back into γ and recrystallized grain can grow in normal way.