摘要
Zr-4合金广泛用作大多数压水堆和反应堆的燃料包壳材料,因此针对其焊接的研究有非常重要的现实意义。论文采用数值模拟方式研究Zr-4合金电子束焊接的瞬态过程,采用双椭球热源模型,结合接触及辐射等边界条件,采用变密度六面体网格,耦合温度场和应力场,建立了Zr-4合金管电子束焊接的有限元瞬态数学模型,采用自适应时间步,计算了Zr-4合金管真空电子束焊接的三维瞬态温度场和应力场。数值模拟结果表明:在电子束功率相对较小的条件下,焊缝深宽比较小,采用双椭球热源模型进行数值模拟,所获熔池形状与实验所得焊缝成形吻合良好,证明了该数学模型的合理性,从而可为制定实际焊接工艺提供理论指导。在所设定的计算条件下,筒盖和筒体均变形均匀,主要表现形式为沿径向突出,且筒盖变形大于筒体,和实际焊接现象基本一致;焊后最大整体变形约0.02 mm。
Zr-4 alloy was widely used in most of the fuel cladding materials for pressurized water reactors and reactors, and it had very important practical significance in studying the welding process. Coupling the temperature and stress fields, the transient finite ele- ment model of Zr-4 alloy tube＇s electron beam welding with the double ellipsoid source model was set up, in which the contact and radi- ation boundary condition and variable density hexahedral mesh were used, and then the three-dimensional transient temperature and stress fields in Zr-4 alloy tube＇s vacuum electron beam welding were obtained with adaptive time step. The simulation results showed that, the shape of molten pool obtained by using double ellipsoid source model to carry through numerical simulation agreed well with the experimental weld formation, when the power of the electron beam and depth-to-width ratio were comparatively small, and then the rationality of model was proved, so that it could provide theoretical guidance to formulate actual welding process. Under the setting con- dition, the distortion of the tube body and cover was well-proportioned with the radial outshoot as the main style, and the distortion of cover was bigger than the body, which was basically the same with real welding phenomenon. The maximum overall defoimation after welding was about 0.02 mm.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2016年第7期660-665,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(91226023)资助
关键词
ZR-4合金
电子束焊接
温度场
应力场
Zr-4 alloy
electron beam welding
temperature field
stress field
