摘要
为了定量描述锆-4合金低周疲劳断口的疲劳特性,利用小波变换,研究了断口能量在三维空间的变化特征以及试样状态和加载方向对合金疲劳寿命的影响。结果表明在裂纹扩展期,沿裂纹扩展方向上,能量曲线都具有明显的阶段性;断口表面的形貌随裂纹扩展过程变化较大,在裂纹扩展的初始阶段断口形貌最粗糙,而在扩展期后期则比较平坦、光滑;在与裂纹扩展过程垂直的方向上,裂纹的能量远比周边基体能量大,表明锆-4合金疲劳裂纹的形貌明显比周边区域陡峭。进一步研究还发现,相同加载方向,渗氢试样的能量曲线位于无氢试样的上方,说明氢能改善Zr-4合金的疲劳性能,提高合金的疲劳寿命;对非渗氢态试样,根据能量曲线,R试样的低周疲劳寿命应大于T试样。但实验结果与之不符,说明仅仅根据能量曲线判别寿命长短还有一定的局限性。
In order to describe quantitatively the fatigue characteristic of the alloy Zr -4＇ s low-cycle （Zircaloy-4）, based on wavelet decomposition technology, the change of fracture energy in 3D effect of sample state and loading direction to fatigue life were studied. The obvious stages of energy covered along the crack expanding direction in the propagation zone. There were large changes in ance of fatigue fracture along the crack expanding direction. The most roughness segment is in the fatigue fracture space and the curve were dis- the 3D appearprimary stage, and then the 3 D appearance of fatigue fracture was becoming smoother. The energy of crack was far larger than that of the ambient body in vertical direction of the crack propagation. It was showed that the 3D appearance of crack is steeper than that of ambient areas. The energy curve of hydrogenation is above the curve of hydrogen-free in the same loading direction. Therefore, hydrogen can improve the fatigue characteristic of Zircaloy -4. According to energy curve, low-cycle fatigue life of R sample is larger than that of T sample. However, the result of experiment isn＇t coincident. It showed that there is a definite localization to differentiate the fracture life only using energy curve.
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
北大核心
2007年第4期94-97,共4页
Journal of Sichuan University (Engineering Science Edition)
基金
四川省杰出青年学科带头人培养基金资助项目(03ZQ026-051)
关键词
锆-4合金
能量曲线
渗氢
加载方向
Zircaloy- 4
energy curve
hydrogenation
loading direction
