摘要
分析了不同预变形量时退火态Zr-4合金的显微组织,研究了预变形量对退火态Zr-4合金室温和350℃下拉伸性能的作用规律,并通过扫描电子显微镜(SEM)及透射电子显微镜(TEM)对不同预变形量试样的显微形貌、位错组态及其分布情况进行了分析。拉伸试验结果表明:随着预变形量的增加退火态Zr-4合金在室温和高温下的屈服强度和抗拉强度均显著提高,断面收缩率和延伸率有一定的降低。对不同预变形量试样的显微形貌及位错分布情况的分析表明,Zr-4合金随着预变形量的逐步增加,晶粒会逐渐发生扭转与拉长;第二相析出物(SPPs)有在晶界上聚集的趋势,且随着预变形量的增加分布越来越不均匀;在晶粒内产生高密度位错,且位错之间相互缠结。高密度位错在晶界和第二相的阻碍作用下容易发生塞积,这种高密度位错塞积引起粗大晶粒的破碎或产生亚晶,从而提高Zr-4合金的拉伸强度;晶粒的细化和第二相的偏聚还会使Zr-4合金保持良好的塑性。适当的预变形加工在不损害退火态锆合金塑性的前提下,可以有效的提高其抗拉强度和屈服强度。
Microstructure analysis of Zircaloy-4 alloy under different pre-deformation was performed and the effects of pre-deformation on tensile properties of Zircaloy-4 alloy at room temperature and 350 ℃ were studied. Furthermore, microstructures, dislocations mor- phologies and distributions of different pre-deformation samples were investigated through scanning electron microscopy （SEM） and transmission electron microscopy （TEM）. Tension test showed that, with the increase of pre-deformation, both the yield strength and tensile strength of annealed state Zirealoy-4 alloy increased significantly and percentage reduction of area and elongation decreased. The analysis on the microstructure and dislocation of different pre-deformation samples showed that grain torsion and elongation would occur owing to the increase of pre-deformation. In addition, the secondary phase particles （SPPs） tended to congregate in the grain bounda- ry, and inhomogeneous distribution with pre-deformations increasing. High density and highly intertwist dislocations formed in these conditions. High density dislocations stuffed up to dislocation pile-up. These dislocation pile-up would cause bulky grain crushing or produce subgrain which could improve the tensile strength of Zirealoy-4 alloy. Moreover, grains fining and SPPs segregation could help to keep good plasticity of the Zirealoy-4 alloy. Therefore, it can be concluded that proper pre-deformation processing could effectively improve the tensile strength and yield strength of annealed state zirconium alloy without any loss of plasticity.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2013年第6期857-862,共6页
Chinese Journal of Rare Metals
基金
国家科技部重点基础研究发展计划项目(2007CB613803)资助
关键词
锆合金
预变形
拉伸性能
zirconium alloy
pre-deformed
tensile property
作者简介
王旭（1986-），男，新疆石河子人，硕士，工程师；研究方向：锆合金与高温钛合金材料
通讯联系人（E-mail：caojingxia@sina．com）
