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目前市面(mian)上(shang)的(de)工業風扇葉(xie)片都是以鋁(lv)合金(jin)為主，這(zhe)是因為鋁(lv)合金(jin)材料的(de)密度低且強度高，熱電(dian)導率高，耐腐蝕的(de)能力強，擁有較好的(de)物理特性及(ji)力學方面(mian)性能。

      但是因(yin)為(wei)焊(han)(han)接(jie)方法(fa)和(he)焊(han)(han)接(jie)工藝(yi)參數選取不當，會導致葉片焊(han)(han)接(jie)以后(hou)因(yin)力(li)過于(yu)集中化而(er)產生(sheng)嚴重的(de)機械變形，或者(zhe)因(yin)焊(han)(han)縫氣孔、夾渣(zha)和(he)未(wei)焊(han)(han)透等等不足，致使焊(han)(han)縫金屬(shu)裂紋或者(zhe)材質疏松，從而(er)嚴重的(de)影響產品質量與性能。

      鋁為銀白色輕金(jin)屬，有良好的(de)可塑性(xing)(xing)，比較高(gao)的(de)導(dao)(dao)電性(xing)(xing)、導(dao)(dao)熱性(xing)(xing)，還(huan)具有抗氧(yang)(yang)化及抗腐蝕性(xing)(xing)能。鋁極易(yi)氧(yang)(yang)化產出(chu)三氧(yang)(yang)化二鋁薄膜，在焊縫中生(sheng)出(chu)夾雜物，而破壞金(jin)屬的(de)連續性(xing)(xing)及其均勻性(xing)(xing)能，降低它(ta)的(de)機械(xie)性(xing)(xing)能及耐腐蝕的(de)性(xing)(xing)能。

      這是(shi)在焊(han)接鋁(lv)合金是(shi)很難避免的事，所(suo)以我(wo)們(men)需(xu)要了(le)解鋁(lv)合金焊(han)接時應(ying)該注意的地方(fang)。

      （1）易被氧(yang)化(hua)。空氣中，鋁易和氧(yang)化(hua)合(he)(he)，產生致密的(de)三氧(yang)化(hua)二鋁薄膜（厚度約0.1-0.2mm），熔(rong)點很高(gao)（約2050°C），大大地超(chao)過鋁及鋁合(he)(he)金的(de)熔(rong)點（約600°C左右(you)）。

      （2）容(rong)易產生(sheng)氣(qi)孔(kong)。鋁(lv)及(ji)鋁(lv)合金(jin)焊在(zai)接時(shi)生(sheng)出氣(qi)孔(kong)主(zhu)要因素是氫，由于液(ye)態鋁(lv)可溶解大量氫，但固態的(de)鋁(lv)基本不會(hui)溶解氫，所以當熔池溫度快速冷卻與(yu)凝(ning)固的(de)時(shi)候(hou)，氫來不及(ji)逸出，易在(zai)焊縫(feng)里面形(xing)成氣(qi)孔(kong)。氫氣(qi)孔(kong)當前難完全免除，氫的(de)來源有(you)很多，

      （3）焊(han)縫時(shi)候(hou)變形(xing)及(ji)形(xing)成裂紋(wen)的(de)(de)(de)傾向較(jiao)大。鋁線(xian)膨脹系數及(ji)結晶收縮(suo)率都約(yue)比鋼要(yao)大出兩(liang)倍，易生(sheng)成比較(jiao)大的(de)(de)(de)焊(han)接變形(xing)內應力，剛性較(jiao)大的(de)(de)(de)結構將會加速熱(re)裂紋(wen)的(de)(de)(de)生(sheng)成。

      （4）合(he)金元素的(de)蒸發(fa)的(de)燒(shao)損。鋁合(he)金中含有低沸點的(de)元素（如(ru)鎂(mei)、鋅、錳等(deng)），在(zai)高溫電(dian)弧作用下，極易(yi)蒸發(fa)燒(shao)損，從而(er)改變焊縫金屬(shu)的(de)化學成分，使焊縫性(xing)能(neng)下降。

      （5）溫強度和(he)塑性低。高溫時(shi)鋁的(de)強度和(he)塑性很低，破壞了焊(han)縫金屬(shu)的(de)成(cheng)形，有時(shi)還容易造成(cheng)焊(han)縫金屬(shu)塌落(luo)和(he)焊(han)穿現(xian)象。

      當然(ran)這只是焊接(jie)時(shi)應該注意的問題，這些(xie)了解(jie)后，我們需要明白(bai)工業風(feng)扇葉片焊接(jie)工藝方法。

      （1）焊(han)前的準(zhun)備

      運用化學和機械(xie)的方法，嚴格的清(qing)理(li)焊縫坡口(kou)兩側的表面氧化性(xing)膜。

      （2）確定(ding)裝配(pei)間(jian)隙(xi)和(he)定(ding)位(wei)焊間(jian)距(ju)

      施焊(han)(han)的(de)過程(cheng)中(zhong)，鋁板受熱膨脹，使(shi)焊(han)(han)縫坡(po)口(kou)間(jian)隙減小，焊(han)(han)前裝配間(jian)隙若(ruo)留得太(tai)小，焊(han)(han)接過程(cheng)中(zhong)便會引(yin)起兩板坡(po)口(kou)的(de)重疊，增加焊(han)(han)后板面(mian)不平度(du)及(ji)變形(xing)量裝。配間(jian)隙若(ruo)過大(da)，施焊(han)(han)困難，并有燒(shao)穿的(de)可能(neng)性。一(yi)定的(de)定位焊(han)(han)間(jian)距可保證所需要的(de)定位焊(han)(han)間(jian)隙，選擇合適的(de)裝配間(jian)隙和定位焊(han)(han)間(jian)距，為(wei)減少變形(xing)的(de)有效措(cuo)施。

      （3）選擇焊(han)接的設備

      當前市場上焊(han)接產品種(zhong)類較多(duo)，通常(chang)更好用交(jiao)流鎢極(ji)(ji)氬弧焊(han)（即TIG焊(han)）。它為在氬氣保護作用下，利用鎢電極(ji)(ji)及(ji)工件問產生的電弧熱熔化母材及(ji)填充(chong)焊(han)絲的一種(zhong)焊(han)接方法(fa)。

      （4）選(xuan)擇焊(han)絲(si)通常(chang)選(xuan)用(yong)301純(chun)鋁(lv)焊(han)絲(si)及311鋁(lv)硅(gui)焊(han)絲(si)。

      （5）選取(qu)焊(han)(han)(han)(han)(han)接方(fang)(fang)法(fa)參數通常以左(zuo)焊(han)(han)(han)(han)(han)法(fa)進(jin)(jin)行(xing)，焊(han)(han)(han)(han)(han)炬和工(gong)件(jian)會成60°角。焊(han)(han)(han)(han)(han)接厚(hou)(hou)度(du)15mm時，用右(you)焊(han)(han)(han)(han)(han)法(fa)進(jin)(jin)行(xing)，焊(han)(han)(han)(han)(han)炬與工(gong)件(jian)會成90°角。焊(han)(han)(han)(han)(han)接的(de)(de)(de)壁(bi)厚(hou)(hou)在3mm以上的(de)(de)(de)時候(hou)，開V形坡口(kou)，夾角是60°～70°，間隙不(bu)可大于1mm，用多層焊(han)(han)(han)(han)(han)的(de)(de)(de)方(fang)(fang)法(fa)去完成。壁(bi)厚(hou)(hou)在1．5mm以下的(de)(de)(de)時候(hou)，不(bu)開坡口(kou)，也不(bu)留(liu)間隙，也不(bu)會加填充(chong)(chong)絲。焊(han)(han)(han)(han)(han)固定管子(zi)對接接頭(tou)的(de)(de)(de)時候(hou)，若管徑為(wei)200mm，壁(bi)厚(hou)(hou)為(wei)6mm的(de)(de)(de)時候(hou)，宜采(cai)用直徑為(wei)3～4mm的(de)(de)(de)鎢極(ji)，用220～240A的(de)(de)(de)焊(han)(han)(han)(han)(han)接電流(liu)，直徑為(wei)4mm的(de)(de)(de)填充(chong)(chong)焊(han)(han)(han)(han)(han)絲，用1～2層焊(han)(han)(han)(han)(han)完。

At present, the industrial fan blades on the market are mainly made of aluminum alloy, because of its low density and high strength, high thermal conductivity, strong corrosion resistance, and good physical and mechanical properties. However, improper selection of welding method and welding process parameters will lead to serious mechanical deformation of Blade due to over-concentration of welding force, or due to insufficient weld porosity, Slag Inclusion and incomplete penetration, etc. The quality and performance of the products are seriously affected by the weld metal crack or material porosity. Aluminum is a silver-white light metal with good plasticity, high conductivity, thermal conductivity, oxidation resistance and corrosion resistance. Aluminum is highly oxidised to produce aluminium oxide films, which produce inclusions in welds, which damage the metal's continuity and uniformity, reducing its mechanical properties and corrosion resistance. This is in the welding of aluminum alloy is very difficult to avoid, so we need to understand the aluminum alloy welding should pay attention to the place (1) easy to be oxidized. In the air, aluminum easily oxidizes, resulting in a dense aluminium oxide film (thickness about 0.1-0.2 mm) with a very high melting point (about 2050 °c) , which greatly exceeds the melting point of aluminum and its alloys (about 600 °c) (2) prone to blowhole. Hydrogen is the main factor for the formation of pores in aluminum and aluminum alloys during welding. Because liquid aluminum can dissolve a large amount of hydrogen, but solid aluminum can hardly dissolve hydrogen, so when the bath temperature is rapidly cooled and solidified, hydrogen can not escape POROSITY is easily formed in the weld. At present, it is difficult to completely eliminate the hydrogen hole, the hydrogen source has many, (3) when the weld deformation and the forming crack tendency is big. Aluminum Linear Expansion Coefficient and crystallization shrinkage are about twice larger than steel, easy to generate greater welding deformation stress, rigid structure will accelerate the formation of hot cracks (4) burning of the alloy elements by evaporation. Aluminum alloys contain low boiling point elements (such as magnesium, zinc, manganese, etc.) . Under the action of high temperature arc, it is easy to evaporate and lose, thus changing the chemical composition of the Weld metal and reducing the weld performance (5) low temperature strength and plasticity. The strength and plasticity of aluminum is very low at high temperature, which destroys the formation of weld metal and sometimes causes the collapse and wear of weld metal. Of course, this is only welding should pay attention to the problem, these understanding, we need to understand the industrial fan blade welding process (1) the preparation before welding, the use of chemical and mechanical methods, Strictly Clean The weld groove on both sides of the surface oxide film (2) to determine the assembly gap and the positioning welding distance. During the welding process, the aluminum plate is expanded by heat, which reduces the gap between the welding seams and the groove. If the pre-welding assembly gap is too small, the overlap of the groove between the two plates will occur during the welding process Increase the flatness and deformation of the welded plate. If the clearance is too large, it is difficult to weld, and there is the possibility of burning through. A certain distance between the two welds can ensure the required distance between the two welds, and the suitable distance between the two welds can be selected as an effective measure to reduce deformation (3) choose welding equipment, there are many kinds of welding products in the market, usually it is best to use AC TIG (TIG welding) . The utility model relates to a welding method for welding a base metal and a filling welding wire by using an electric arc generated by a tungsten electrode and a workpiece under the protection of Argon Gas (4)301 pure aluminum wire and 311 aluminum-silicon wire are usually used for selecting welding wire (5) welding method parameters are usually selected by left welding method, welding torch and workpiece will be 60 angle. When the thickness of welding is 15mm, the right welding method is used, and the welding torch and the workpiece will form a 90 angle. When the thickness of the welding wall is more than 3mm, open the V-groove, the angle is 60 ~ 70, the gap can not be more than 1mm, with multi-layer welding method to complete. When the wall thickness is less than 1.5 mm, there is no groove, no gap and no filling wire. When welding the butt joint of fixed pipe, if the pipe diameter is 200mm, the wall thickness is 6mm, should use the tungsten electrode with the diameter of 3 ~ 4mm, the welding current of 220 ~ 240A, the filler wire with the diameter of 4mm, and use 1 ~ 2 layers to weld.