摘要
M5合金是一种适用于高燃耗组件的新型锆合金,主要用作燃料棒包壳、端塞、导向管和定位格架材料。采用棒材试样,对M5合金在375℃温度下进行了5个应变水平的低周疲劳实验,应变比R=-1。对合金的循环响应特征进行了分析,并根据实验数据拟合出了疲劳寿命曲线和方程。用扫描电镜分析了低周疲劳样品的断口,讨论了合金的低周疲劳断裂特征。结果表明,在循环变形过程中,M5合金表现出了明显的硬化、饱和、软化阶段,其中饱和阶段所占比例较大,而硬化和软化阶段所占比例较小;其循环应变寿命特性遵循Coffin-manson关系;疲劳裂纹均起源于试样表面,且存在有多个裂纹源,断裂区布满发达的韧窝,属于明显的韧性断裂。
M5 alloy was a new zirconium alloy used in high burn up assembly such as fuel cladding, end plug, guide tube and grid spring and so on. In this paper, rod samples were adopted and low cycle fatigue tests were finished under the conditions of strain ratio being - 1 and 5 kinds strain levels at 375 ℃. The character of cycle response was analyzed and the curve was fitted and its function was obtained for strain-cycle life based on the experimental data. Fracture surface of low cycle fatigue sample was analyzed with SEM. Further more, the crack character of low cycle fatigue was discussed. The results indicated that the stages of hardening, softening and saturation demonstrated obvi- ously during cycle deformation of the alloy, and the proportion of saturation stage was larger than that of hardening and softening ones. The peculiarity of cycle strain-life followed Coffin-manson relationship. And all fatigue cracks took their source at the sample surface where there were many sources. Fracture of the samples showed dimpled fracture which obviously belonged in tough rupture.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2008年第6期694-697,共4页
Chinese Journal of Rare Metals
关键词
锆合金
M5合金
低周疲劳
zirconium alloy
M5 alloy
low cycle fatigue
作者简介
田锋（1973-），男，陕西人，学士，工程师；研究方向：锆及锆合金研究.通讯联系人（E-mail：tianfengnin@163．com）
