作　　者： ; ; ;

机构地区： 北京航空航天大学

出　　处： 《稀有金属材料与工程》 2013年第S2期33-37,共5页

摘　　要： 根据实际的焊缝形状,选择了组合热源模型,并分析了脉冲束流下热源模型的能量密度分布。脉冲热源的能量密度分布不仅与空间位置有关,还与热源作用的时刻有关。建立了304不锈钢的脉冲电子束焊接三维数学模型,分别模拟了脉冲电子束和普通连续电子束焊接的温度场,得到了不同参数下的温度场分布云图和热循环曲线。结果表明:与普通连续电子束焊接相比,脉冲电子束焊接得到的热循环曲线呈现波动的上升和下降,曲线上同时存在多个波峰和波谷,焊缝中心区的温度场波动幅度较大,而远离焊缝区的温度场几乎不受脉冲束流的影响;在相同平均束流作用下,脉冲电子束焊接得到焊缝中心的峰值温度要比连续电子束的高;将模拟预测的焊缝与实际的焊缝对比,结果较为吻合,验证了模型的准确性。 According to the experimental weld shape,the energy density distribution of the heat source model under pulsed beam was analyzed and the combined heat source model was selected.Energy density distribution of pulsed heat source depends on the spatial position of nodes and the moment heat source loaded.A three-dimensional finite element model for temperature field simulation of pulsed EBW(electron beam welding) on 304 stainless steel was set up based on ANSYS.The temperature field of pulsed EBW and continuous EBW were simulated,respectively,and the temperature field contours and thermal cycle curves were obtained under different parameters.The simulation results show that,there exists violent fluctuation for the temperature field of pulsed EBW.The multiple peaks & troughs can be found in the thermal cycle curves.The fluctuation range of the temperature field is significant in the weld center region,whereas the temperature distribution away from the weld area is little affected by the pulse beam.With the same average beam current,the peak temperature each node reached under the pulsed EBW is higher than that under the continuous EBW.The predicted weld is consistent to the experimental weld,which verifies the accuracy of the model.

关 键 词： 脉冲电子束焊接 热源模型 温度场 数值模拟

领　　域： [金属学及工艺]