对Inconel 783合金铸锭先进行扩散退火处理, 再进行热锻、固溶、时效处理, 分析了扩散退火对该合金最终显微组织(主要是析出相)及力学性能的影响。结果表明: 未经扩散退火处理的合金, 最终显微组织中会生成较大尺寸的带状或枝晶状晶界β相及大块状的含铌碳化物, 而经扩散退火处理合金中的析出相主要由细小且弥散分布的γ′相、颗粒状晶内β相和短棒状晶界β相组成; 经扩散退火处理合金的室温屈服和抗拉强度分别比未扩散退火合金的提高近100 MPa, 伸长率提高近30%, 650 ℃时的拉伸强度显著增加, 塑性提高1倍多, 这主要归因于扩散退火处理后显微组织中均匀弥散分布的细小析出相。

Inconel 783 ingot casting alloy was treated by diffusion annealing, then hot forged and treated by solution and aging treatment. The effects of diffusion annealing on the final microstructure (mainly precipitates) and mechanical properties of the alloy were analyzed. The results show that the band-shaped or dendrite-like β phase with relatively large sizes at grain boundaries and large block-like Nb-carbides were formed in the final microstructures of the alloy without diffusion annealing, while the precipitates in the alloy with diffusion annealing were composed of fine and dispersed γ′ phase, granular β phase and short rod-like grain boundary β phase. Comparing to the alloy without diffusion annealing, the yield and ultimate tensile strength of the alloy with diffusion annealing increased by about 100 MPa and the elongation by about 30%; the tensile strength at 650 ℃ increased significantly and the ductility was improved by more than one time, which were mainly attributed to the uniformly dispersed fine precipitates in the microstructures by the diffusion annealing treatment.