發(fā)布時(shí)間：2018-06-10 02:35

  本文選題：三絲 + 間接電弧　； 參考：《大連理工大學(xué)》2017年博士論文

【摘要】：現(xiàn)代工業(yè)的發(fā)展對(duì)高效焊接技術(shù)的需求愈來愈迫切,尤其是大型結(jié)構(gòu)件產(chǎn)品的制造對(duì)高熔敷率焊接技術(shù)的需求越來越多。但是采用傳統(tǒng)電弧焊接時(shí),如果增加焊接電流來提高熔敷率,母材熱輸入勢(shì)必增加,容易導(dǎo)致焊縫性能下降等問題。為了增加熔敷率的同時(shí)減少熱輸入,雙絲間接電弧焊是一種很好的方法。在雙絲間接電弧焊的基礎(chǔ)上,本文引入第三根焊絲,首次提出了三絲間接電弧焊,通過第三根焊絲產(chǎn)生的磁場(chǎng)控制電弧形態(tài),解決了大電流時(shí)雙絲間接電弧形態(tài)發(fā)散導(dǎo)致熱輸入過小的問題。對(duì)三絲間接電弧焊的穩(wěn)定性、電弧形態(tài)、熔滴過渡、電弧特性、熔敷率等進(jìn)行了研究和分析。首次利用三絲間接電弧,開發(fā)了窄間隙氣體保護(hù)三絲間接電弧焊工藝,并對(duì)該工藝側(cè)壁熔合和多層焊層間熔合進(jìn)行了重點(diǎn)探討。本文的主要研究內(nèi)容如下:(1)研究了氣體保護(hù)三絲間接電弧特性。三絲間接電弧的主絲電流大于邊絲電流,能夠?qū)﹄娀⌒螒B(tài)起到約束作用,由電弧挺度原理,三絲間接電弧受到主絲磁場(chǎng)作用,整體沿著主絲延長線方向,避免了電弧形態(tài)發(fā)散。另外,三絲間接電弧焊有多種焊絲分布方式,其影響磁場(chǎng)分布狀態(tài),因此可以利用焊絲分布對(duì)三絲間接電弧形態(tài)進(jìn)行調(diào)控,即對(duì)間接電弧熱量分布進(jìn)行調(diào)控。(2)研究了氣體保護(hù)三絲間接電弧熔滴過渡特性。三根焊絲之間的相互電磁力對(duì)熔滴過渡產(chǎn)生了較大的影響,由于邊絲電磁力對(duì)主絲熔滴過渡起促進(jìn)作用,試驗(yàn)條件下,主絲一直為射流過度,并沿著主絲延長線。由于主絲電磁力對(duì)邊絲的排斥作用,使得邊絲熔滴過渡被排斥離開主絲。(3)研究了氣體保護(hù)三絲間接電弧焊熔敷率特性。由于電源的連接方式發(fā)生改變,與同樣有兩個(gè)焊接電源的傳統(tǒng)雙絲焊相比,三絲間接電弧焊時(shí),用于熔化焊絲的電弧熱量多,而用于熔化母材的電弧熱量少。如試驗(yàn)條件下,三絲間接電弧的母材熔化效率2.09%～12.43%,焊絲熔化效率61.09%～90.31%;傳統(tǒng)雙絲電弧的母材熔化效率22.15%～27.44%,焊絲熔化效率37.69%～46.84%。根據(jù)實(shí)際試驗(yàn)和查閱相關(guān)資料,與傳統(tǒng)雙絲焊相比,如480 A時(shí),傳統(tǒng)雙絲焊的熔敷率為8.04 Kg/h,而三絲間接電弧焊的熔敷率為25.5 Kg/h,三絲間接電弧焊提高熔敷率200%以上。與雙絲間接電弧焊相比,由于可用參數(shù)范圍提高,三絲間接電弧提高了熔敷率可用上限。(4)開發(fā)了窄間隙氣體保護(hù)三絲間接電弧焊工藝。利用焊絲分布對(duì)三絲間接電弧和熔滴過渡進(jìn)行調(diào)控,使得電弧熱量集中到母材側(cè)壁上,實(shí)現(xiàn)了窄間隙三絲間接電弧焊?jìng)?cè)壁熔合。當(dāng)主絲為豎直向下時(shí),熔池積累在主絲之下,電弧的位置不能進(jìn)一步降低,電弧的熱量無法作用到焊縫根部,焊縫根部未能熔合。而當(dāng)主絲傾斜后,熔池積累在主絲之后,焊槍高度可以進(jìn)一步降低,使得電弧熱量能夠到達(dá)焊縫根部,焊縫根部熔合。(5)提出了后置鎢極電弧的方法,改善了窄間隙氣體保護(hù)三絲間接電弧焊焊縫成形。由于三絲間接電弧主絲的熔敷金屬在焊縫中央大量積累,沒有其它輔助的情況下,窄間隙三絲間接電弧焊的焊縫表面呈凸起狀。窄間隙多層焊接時(shí),凸起狀焊縫成形使得焊槍高度無法降低,電弧熱量無法作用到焊縫根部,容易造成焊縫根部未熔合和層間熔合困難。針對(duì)此問題,根據(jù)鎢極電弧壓力使焊縫表面下凹的現(xiàn)象,提出了在三絲間接電弧后添加鎢極電弧的方法,改善了焊縫成形。后置鎢極電弧后,窄間隙三絲間接電弧焊的焊縫表面變?yōu)榘紶?且隨著鎢極電流的增大,鎢極電弧壓力增加,焊縫表面下凹程度明顯增加。
[Abstract]:The demand for high efficiency welding technology is becoming more and more urgent in the development of modern industry, especially for the manufacture of large structure parts. The demand for high melting rate welding technology is more and more. However, when the traditional arc welding is used, if the welding current is added to improve the melting rate, the heat input of the base material will be increased and the weld performance will be reduced easily. In order to increase the melting rate and reduce the heat input at the same time, double wire indirect arc welding is a good method. On the basis of double wire indirect arc welding, third wires are introduced in this paper. Three wire indirect arc welding is proposed for the first time. The electric arc state is controlled by the magnetic field produced by third wires, and the shape hair of double wire indirect arc is solved when the current is large. The problem of heat input is too small. The stability of the three wire indirect arc welding, the shape of the arc, the droplet transition, the characteristics of the arc and the melting rate are studied and analyzed. The indirect arc welding process of the narrow gap gas protection three wire is developed for the first time using three wire indirect arc, and the fusion of the side wall and the interlayer fusion of the multi layer welding process is also carried out. The main contents of this paper are as follows: (1) the characteristics of indirect arc of three wire in gas protection are studied. The main wire current of three wire indirect arc is larger than the edge wire current, it can play a restraining effect on the shape of the arc. The principle of arc stiffness, the indirect arc of the three wire is affected by the magnetic field of the main wire, the whole direction of the wire is extended along the main wire, and the arc is avoided. Form divergence. In addition, three wire indirect arc welding has a variety of wire distribution mode, which affects the distribution of magnetic field. Therefore, the distribution of welding wire can be used to regulate the form of indirect arc of three wires, that is, the indirect arc heat distribution is regulated. (2) the characteristics of the droplet transition between the three wire arc welding arc welding and the interaction between the three wires are studied. The electromagnetic force has a great influence on the droplet transition, because the edge wire electromagnetic force plays an important role in the transition of the main wire droplet transition. Under the test conditions, the main wire has been overflowing the jet and extending the wire along the main wire. Due to the repellent effect of the main wire electromagnetic force to the edge wire, the side wire is excluded from the main wire. (3) the gas protection three wire is studied. Compared with the traditional double wire welding with the same two welding power, three wire indirect arc welding has more arc heat than the traditional double wire welding with the same two welding power, and the arc heat used to melt the material is less than that of the three wire indirect arc welding. For example, the melting efficiency of the three wire indirect arc is 2.09% ~ 12.43. The melting efficiency of welding wire is 61.09% ~ 90.31%, the melting efficiency of the traditional double wire arc is 22.15% ~ 27.44%, the melting efficiency of welding wire is 37.69% ~ 46.84%., according to the actual test and the related data, compared with the traditional double wire welding, such as 480 A, the penetration rate of the traditional double wire welding is 8.04 Kg/h, and the deposition rate of the three wire indirect arc welding is 25.5 Kg/h, three wire. Indirect arc welding increases the deposition rate of more than 200%. Compared with double wire indirect arc welding, the three wire indirect arc improves the application rate of the welding rate, as compared with the double wire indirect arc welding. (4) the indirect arc welding process of the narrow gap gas protection three wire is developed. The arc heat can be controlled by the distribution of wire on the indirect arc and droplet transition of the three wire. When the main wire is vertical downward, the weld pool accumulates under the main wire, the position of the arc can not be further reduced, the heat of the arc can not be applied to the weld root, and the weld root is not fused. When the main wire is inclined, the weld pool is accumulated after the main wire and the welding gun is high after the main wire is inclined. The degree can be further reduced, so that the arc heat can reach the weld root and the weld root fusion. (5) the method of the rear tungsten arc is put forward to improve the formation of the three wire indirect arc welding seam forming in the narrow gap gas protection. Because the deposited metal of the three wire indirect arc main wire accumulates in the center of the weld, there is no other auxiliary condition. The weld surface of the three wire indirect arc welding has a convex shape. When the narrow gap is multi-layer welding, the height of the welding gun can not be reduced and the heat of the arc can not be used to the root of the weld. It is easy to cause the weld root to be not fused and the interlayer fusion is difficult. The method of adding tungsten pole arc after three wire indirect arc is proposed to improve the weld formation. After the rear tungsten arc, the weld surface of the narrow gap three wire indirect arc welding becomes concave, and with the increase of the tungsten current, the pressure of the tungsten arc increases and the concave degree of the weld surface increases obviously.
【學(xué)位授予單位】：大連理工大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG444.72

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相關(guān)期刊論文 前10條

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本文編號(hào)：2001682