2219铝合金电子束堆焊凝固缺陷的模拟预测

Prediction of shrinkage defects in 2219 Al alloy electron beam overlaying welds

关键词:  电子束堆焊  热源模型  根部缩孔  判据程序

Key words:  electron beam overlaying weld  heat source model  root shrinkage cavity  criterion program

摘要:

铝合金电子束堆焊焊缝根部缩孔是一种特种焊接缺陷,它会导致应力集中诱发裂纹产生,显著降低焊件承载能力,必须给予足够重视.文中主要借助于ANSYS有限元软件的APDL二次开发编程语言,将匙孔模式焊接热源模型与枝晶间渗流理论和Niyama判据相结合,提出了一套基于温度场的凝固收缩判据程序,并应用它成功模拟预测了非熔透2219铝合金电子束堆焊件的根部缩孔缺陷.结果表明,通过模拟手段得到的缩孔缺陷沿焊缝熔深方向误差为8.76%,沿焊缝熔宽方向误差为13.28%,与试验对比件基本吻合,验证了缺陷判据程序的正确性和实用性.

Abstract:

Root shrinkage cavity in Al alloy electron beam welds is one special kind of welding defect, which results in stress concentration, induces the occurrence of crack and remarkablely decreases the carrying capacity, so it must be paid great attention. With the help of ANSYS APDL, by combining keyhole mode welding heat source model and interdendriticflowing theory as well as Niyama criterion, a set of defect criterion program based on temperature field was proposed to predict the root shrinkage cavity in 2219 Al alloy non-penetration electron beam overlaying weld. The results indicated that the simulated welding penetration has an error of 8.76%, the erros of simulated welding width is 13.28%, which werebasically in accordance with experimental samples. These results validated the exactness and feasibility of the defect criterion program developed in this paper.