中温形变热处理对新型镍基高温合金组织和力学行为的影响
Effect of Medium Temperature Deformation Heat Treatment on Microstructure and Mechanical Behaviour of a Novel Ni-based Superalloy
甄炳 1孔维俊 1高钰璧 1王兴茂 1丁雨田1
作者信息
- 1. 兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州 730050;兰州理工大学材料科学与工程学院,甘肃兰州 730050
- 折叠
摘要
采用EBSD、SEM和准静态室温单轴拉伸试验研究了不同中温形变热处理工艺与新型镍基高温合金微观组织和室温力学性能之间的关系.结果表明,新型镍基高温合金经中温形变热处理后可明显提高退火孪晶的长度分数,最高可达40.6％.退火孪晶的形成主要以晶粒的"生长意外"机制为主.同时,相比于固溶+双级时效处理试样的力学性能(屈服强度σy=1018 MPa,延伸率εf=17.44％),合金在750 ℃轧制变形30％后在1120 ℃退火30 min并经双级时效处理,其σy可提高499 MPa,为1517 MPa,而其εf仅降低了 4.69％.在750 ℃轧制变形50％后在1120 ℃退火30 min并经双级时效处理,其σy可提高352 MPa,为1370 MPa,而其εf基本保持不变.这种强度的升高主要归因于晶粒细化和退火孪晶的共同作用,这为高性能镍基高温合金提供一种新的强化策略.
Abstract
The relationship between different medium-temperature deformation heat treatment processes and the microstructure and room-temperature mechanical properties of a novel Ni-based superalloy was investigated using EBSD,SEM and quasi-static room-temperature uniaxial tensile tests.Results show that the length fraction of annealed twins of the novel Ni-based superalloy can be significantly increased up to 40.6％after the medium temperature deformation heat treatment.The formation of annealed twins is mainly based on the"growth accident"mechanism of the grains.At the same time,compared with the mechanical properties of the specimens with solid solution+double-stage aging(σy=1018 MPa,εf=17.44％),the alloy annealed at 1120 ℃ for 30 min after 30％roll deformation at 750 ℃ and double-aging,the σy increased by 499 MPa to 1517 MPa,while its εf is decreased by only 4.69％.After rolling at 750 ℃ for 50％deformation followed by annealing at 1120 ℃ for 30 min with double-stage aging,the σy increases by 352 MPa to 1370 MPa,while the εf remains essentially unchanged.This increase in strength is mainly attributed to the combined effect of grain refinement and annealing twinning,which provides a new strengthening strategy for high performance Ni-based superalloys.
关键词
新型镍基高温合金/中温形变热处理/力学性能/退火孪晶Key words
novel Ni-based superalloy/medium-temperature deformation heat treatment/mechanical properties/annealed twins引用本文复制引用
基金项目
国家重点研发计划(2017YFA0700703)
兰州理工大学红柳优秀青年人才支持计划()
出版年
2024
NETL
NSTL
万方数据