【摘要】：為有效地控制電子束焊接后的焊縫成形,得到符合要求的焊接結(jié)構(gòu),本文基于電子束焊接熔池物理過程的分析,使用有限體積法(FVM)數(shù)值模擬軟件Fluent,對(duì)2mm厚的2219鋁合金電子束穿透焊的溫度場(chǎng)和流場(chǎng)進(jìn)行數(shù)值模擬,研究了電子束穿透焊時(shí)熔池的流動(dòng)行為及規(guī)律.模擬結(jié)果表明,電子束焊接形成穿透型匙孔時(shí),熔池中液態(tài)金屬的流速大小和方向迅速發(fā)生改變,最大流速可以達(dá)到10 m/s;產(chǎn)生的金屬蒸汽反沖壓力會(huì)使熔池劇烈震蕩,熔池中遠(yuǎn)離匙孔的液態(tài)金屬在Marangoni對(duì)流的驅(qū)動(dòng)下,使熔池上、下兩部分形成了較中間部分更長(zhǎng)、更不穩(wěn)定的拖尾,同時(shí)促進(jìn)了熔池寬度的增加;熔池寬度和熔池拖尾長(zhǎng)度分別在35 ms、90 ms左右達(dá)到了穩(wěn)定.模擬焊接熔池凝固后,正面焊縫有一定的余高,背面焊縫有一定的收縮,其表面焊縫形態(tài)與實(shí)際焊縫形態(tài)吻合良好.此外,通過對(duì)熔池中液態(tài)金屬的流速分析,還可以得出結(jié)論:金屬蒸汽反沖壓力對(duì)熔池的驅(qū)動(dòng)作用遠(yuǎn)大于重力和表面張力的影響.
[Abstract]:In order to effectively control the weld formation after electron beam welding and obtain the welding structure that meets the requirements, based on the analysis of the physical process of electron beam welding molten pool, the finite volume method (FVM) numerical simulation software Fluent, is used in this paper. The temperature field and flow field of electron beam penetration welding (EBW) of 2219 aluminum alloy with 2mm thickness were numerically simulated. The simulation results show that the velocity and direction of liquid metal in the molten pool change rapidly when the electron beam welding forms the penetrating keyhole, and the maximum velocity can reach 10 Ms. The resulting recoil pressure of the metal vapor can cause a sharp oscillation in the molten pool, where liquid metal far from the keyhole is driven by the Marangoni convection, resulting in the formation of a longer, more unstable tail on the bottom of the pool than the middle part. At the same time, the width of the molten pool is increased. The width of the weld pool and the tail length of the weld pool are stable at about 35 ms,90 ms. After simulated weld pool solidification, the front weld has a certain excess height, the back weld has a certain shrinkage, and the surface weld shape is in good agreement with the actual weld shape. In addition, by analyzing the flow rate of liquid metal in the molten pool, it can be concluded that the effect of metal vapor recoil pressure on the driving effect of molten pool is much greater than that of gravity and surface tension.
【作者單位】： 先進(jìn)焊接與連接國(guó)家重點(diǎn)實(shí)驗(yàn)室(哈爾濱工業(yè)大學(xué));
【分類號(hào)】：TG456.3

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本文編號(hào)：2378479