摘要
对锆合金(Zr705)在液氮和室温条件下进行了不同变形量的轧制变形以及后续不同温度的真空退火处理。采用扫描电镜(SEM)、透射电镜(TEM)、显微硬度计及压缩实验等分析了轧制以及退火温度对Zr705合金微观组织及力学性能的影响。结果表明,Zr705合金由等轴的初生α相+(α+β)两相区组成,(α+β)两相区内的α与β相呈片层状。在轧制过程中,合金的(α+β)两相区内片状组织的取向发生旋转,且随变形量增大逐渐平行于轧制方向。随着退火温度的升高,Zr705合金的硬度与强度先升高后降低,先升高的原因主要是因为析出了细小弥散的ω粒子,后降低的原因主要是发生了回复与再结晶。在相同变形量与退火温度条件下,液氮轧制变形态以及峰值时效态的强度与硬度要高于室温轧制样品,这可能是液氮温度有效地抑制了轧制变形过程中的动态回复,保留的位错密度更高,导致β→ω转变驱动力更大,致使退火过程中析出了更多的ω粒子所致。
The zirconium alloy(Zr705) was subjected to rolling deformation with different amount of deformation at liquid nitrogen and room temperature and subsequent vacuum annealing at different temperatures. The effects of rolling and annealing temperature on microstructure and mechanical properties of Zr705 alloy were analyzed by means of scanning electron microscopy(SEM), transmission electron microscopy(TEM), microhardness test and compression experiments. The results show that the Zr705 alloy is composed of the equiaxed primary α phase +(α+β) two-phase region, and the α and β phases in the(α+β) two-phase region are lamellar. During the rolling process, the orientation of the α and β lamellar in the(α+β) two-phase region of the alloy rotates and gradually parallel to the rolling direction with the increase of the deformation amount. With the increase of annealing temperature, the hardness and strength of the Zr705 alloy increase first and then decrease, the reason of the first increase is mainly due to the precipitation of fine dispersed ω particles, and the reason of the later decrease is mainly due to the occurrence of recovery and recrystallization. Under the same deformation amount and annealing temperature, the strength and hardness of the alloy rolled at liquid nitrogen temperature are higher than those of the sample rolled at room temperature, this may be caused by liquid nitrogen temperature effectively inhibiting the dynamic recovery during rolling deformation, retaining higher dislocation density, resulting in greater transformation driving force of the β→ω transformation, resulting in more ω particles precipitated during annealing.
作者
唐维维
何维均
周正
刘庆
TANG Wei-wei;HE Wei-jun;ZHOU Zheng;LIU Qing(College of Materials Science and Engineering,Chongqing University,Chongqing 400044,China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2019年第12期85-92,共8页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金(51971041,51601023,51401011)
关键词
锆合金
热处理
轧制变形
微观组织
力学性能
zirconium alloy
heat treatment
rolling deformation
microstructure
mechanical property
