Effect of Aging Heat Treatment on the Microstructure and Creep Properties of the Cast Ni-Based Superalloy at Low Temperature

• 来源期刊: 金属学报（英文版）
• 年，卷（期）: 2019,（5）
• 页码范围: 651-658
• 页数: 8页
• 语种: 英文

摘要

Effect of aging heat treatment on the grain boundary microstructure and creep properties of a cast Ni-based superalloy was investigated.With increasing aging temperature from 750 to 1000 ℃,M23C6 carbides along the grain boundaries evolve from fine distributed block,continuous film into the coarse discrete block.Moreover,the M23C6 carbides are mainly enveloped within γ'layers along grain boundaries during 1000 ℃ aging.Creep rupture lifetime and elongation at 760 ℃ and 645 MPa are improved with increasing the aging temperature.In particular,the creep rupture lifetime of the specimens aging at 1000 ℃ is one order of magnitude higher than that of the specimens aging at 750 ℃.The enhancement of ductility induced by the γ'envelopes plays a significant role in the improvement of creep rupture lifetime.