摘要
锆合金带材是核电中常用结构材料,影响其冲压成形性的因素有很多。本文采用有限元模拟的方法,结合典型的冲压件结构,重点研究材料性能参数对锆合金带材冲压成形的影响。结果表明,工件接近底面圆角处厚度最小,减薄最多,为最容易开裂位置;冲压过程有限元模拟预测裂纹位置与实际相符,在凸模圆角处为双向拉伸;在凹模圆角处介于纯剪切与单向拉伸之间;在近凸模圆角位置为单向拉伸而后转为平面状态,到达破裂区。当材料各向异性参数r值一定时,随着硬化指数n值增大,壁厚减薄越少,壁厚分布更均匀;n值一定时,塑性应变比各向异性度Δr较小的带材冲压时破裂倾向也较小。所以控制带材的硬化能力和各向异性行为可改善带材冲制性能。
Zirconium alloy is widely used in nuclear industry such as cladding tubes,pressure tubes,structural components etc.In this paper,the effect of hardening exponent n value and Lankford coefficient r value on formability of zirconium alloy is studied with finite element simulation method.The results show that the maximum thinning of the workpiece occurs around punch corner which is similar to the fracture occurred in sheet forming test.Element located near punch radius follows a biaxial stretching strain path;Element located close to punch radius follows at first a uniaxial tension path,changing next to a strain path close to plane strain condition;Element located around die radius follows a strain path between shear and uniaxial tension path.When the same Lankford coefficient is used in numerical simulation,the thickness distribution is more uniform with the increase of hardening exponent n.With the same n value,the fracture tendency of the sheet with smaller Δr value decreases.Therefore,controlling the hardening ability and anisotropic behavior of the sheet can improve the formability of zirconium alloy.
作者
李烨琪
刘劲松
邓偲瀛
宋鸿武
张士宏
杨志刚
LI Yeqi;LIU Jinsong;DENG Siying;SONG Hongwu;ZHANG Shihong;YANG Zhigang(Shenyang Ligong University,Shenyang 110159,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China;School of Materials Science and Engineering,University of Science and Technology of China,Hefei 230026,China;Shenyang research institute of Foundry,Shenyang 110041)
出处
《沈阳理工大学学报》
CAS
2020年第3期30-35,共6页
Journal of Shenyang Ligong University
关键词
板材成形
锆合金
各向异性
硬化指数
数值模拟
sheet forming
zirconium alloy
anisotropy
hardening index
numerical simulation
