【摘要】：基于磁流體動力學(xué)及Maxwell方程組,建立了變極性等離子電弧的三維瞬態(tài)計算模型,依據(jù)變極性等離子弧焊對鋁合金板材穿孔焊接過程的物理特性,提出了隨電弧極性變化的分時導(dǎo)電模型,通過計算得到了變極性等離子電弧的溫度場、流場、電流密度和電弧壓力的分布情況,以及電弧壓力隨時間的變化過程。通過實驗測量了工件表面電弧中心壓力,得到了不同極性時的電弧形態(tài)。結(jié)果表明:相同電流條件下,正極性時電弧溫度場分布比反極性時更加分散,但正極性時電弧最高溫度范圍小于反極性時;反極性電弧壓力和電流密度在電弧中心處均大于正極性,在徑向距電弧中心一定距離處,2種極性時的電弧壓力和電流密度的大小出現(xiàn)反轉(zhuǎn);電弧壓力對焊接電流響應(yīng)迅速,正極性電弧壓力小于反極性電弧壓力,焊接電流過零時,電弧壓力會降低到較低的值,電流增加時電弧壓力變化存在"過沖"現(xiàn)象;對實驗與計算得到的變極性等離子電弧正反極性時電弧圖像和工件表面電弧中心壓力進行了對比,結(jié)果吻合良好。
[Abstract]:Based on magnetohydrodynamics and Maxwell equations, a three-dimensional transient calculation model of variable polarity plasma arc is established. According to the physical characteristics of the process of variable polarity plasma arc welding for aluminum alloy sheet perforation welding, the three dimensional transient calculation model of variable polarity plasma arc welding is established. A time-sharing conduction model with arc polarity is proposed. The temperature field, current density and arc pressure distribution of the plasma arc with variable polarity are calculated, as well as the variation process of arc pressure with time. The arc central pressure on the surface of the workpiece was measured experimentally, and the arc shape was obtained with different polarity. The results show that the distribution of arc temperature field in the positive polarity is more dispersed than that in the reverse polarity under the same current condition, but the maximum temperature range of the arc in the positive polarity is smaller than that in the reverse polarity. The reverse arc pressure and current density are larger than the positive electrode at the center of the arc. At a certain distance from the center of the arc, the arc pressure and current density of the two polarities are reversed, and the arc pressure has a rapid response to the welding current. The positive arc pressure is smaller than the reverse arc pressure. When the welding current is over 00:00, the arc pressure will be reduced to a lower value, and the arc pressure will overshoot when the current increases. The arc images obtained by experiments and calculations for the positive and negative polarity of variable polarity plasma arc are compared with the arc central pressure on the surface of the workpiece. The results are in good agreement with each other.
【作者單位】： 北京工業(yè)大學(xué)機電學(xué)院汽車結(jié)構(gòu)部件先進制造技術(shù)教育部工程研究中心;
【基金】：國家自然科學(xué)基金項目No.51505008 國家科技重大專項項目No.2014ZX04001-171~~
【分類號】：TG456.2

【參考文獻】

相關(guān)期刊論文 前10條

1 樊丁;黃自成;黃健康;王新鑫;黃勇;;考慮金屬蒸汽的鎢極惰性氣體保護焊電弧與熔池交互作用三維數(shù)值分析[J];物理學(xué)報;2015年10期

2 王新鑫;樊丁;黃健康;黃勇;;雙鎢極TIG電弧-熔池傳熱與流動數(shù)值模擬[J];金屬學(xué)報;2015年02期

3 王新鑫;樊丁;黃健康;黃勇;;雙鎢極耦合電弧數(shù)值模擬[J];物理學(xué)報;2013年22期

4 石s，

本文編號：2284913