電弧是什么

電(dian)(dian)弧(hu)(hu)是(shi)(shi)一束高溫電(dian)(dian)離氣(qi)體，是(shi)(shi)一種氣(qi)體放(fang)電(dian)(dian)現象(xiang)，是(shi)(shi)氣(qi)體放(fang)電(dian)(dian)中最(zui)強(qiang)烈的一種自持放(fang)電(dian)(dian)，也(ye)是(shi)(shi)一種等(deng)離子體。當電(dian)(dian)流(liu)通過某些絕緣(yuan)介質(zhi)（例(li)如(ru)空氣(qi)）所產生的瞬間火花，就(jiu)是(shi)(shi)電(dian)(dian)弧(hu)(hu)，電(dian)(dian)弧(hu)(hu)放(fang)電(dian)(dian)最(zui)顯著的外觀特征是(shi)(shi)明亮的弧(hu)(hu)光(guang)柱和電(dian)(dian)極斑點，通常可分(fen)為長(chang)(chang)弧(hu)(hu)和短弧(hu)(hu)兩類。長(chang)(chang)弧(hu)(hu)中弧(hu)(hu)柱起重要作(zuo)用，短弧(hu)(hu)長(chang)(chang)度在(zai)幾(ji)毫米以下，陰極區和陽極區起主要作(zuo)用。

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電(dian)(dian)(dian)弧(hu)(hu)在(zai)外(wai)力作用(yong)(yong)下，如氣流，外(wai)界磁(ci)場甚至(zhi)電(dian)(dian)(dian)弧(hu)(hu)本身產生(sheng)的(de)(de)磁(ci)場作用(yong)(yong)下會(hui)迅速移(yi)動(dong)（每秒可達幾百米），拉(la)長、卷曲形成十分復雜的(de)(de)形狀，電(dian)(dian)(dian)弧(hu)(hu)在(zai)電(dian)(dian)(dian)極上(shang)的(de)(de)孳生(sheng)點(dian)也會(hui)快(kuai)速移(yi)動(dong)或跳(tiao)動(dong)。電(dian)(dian)(dian)弧(hu)(hu)放(fang)電(dian)(dian)(dian)可用(yong)(yong)于焊接、冶(ye)煉、照(zhao)明、噴涂等，主要(yao)是利(li)(li)用(yong)(yong)電(dian)(dian)(dian)弧(hu)(hu)的(de)(de)高溫、高能量密度、易控制等特點(dian)，在(zai)這些應用(yong)(yong)中，都(dou)需使電(dian)(dian)(dian)弧(hu)(hu)穩定放(fang)電(dian)(dian)(dian)。注意(yi)電(dian)(dian)(dian)弧(hu)(hu)具有超強(qiang)的(de)(de)電(dian)(dian)(dian)力，能瞬間使心臟(zang)停跳(tiao)，所以，利(li)(li)用(yong)(yong)電(dian)(dian)(dian)弧(hu)(hu)而工作的(de)(de)人們需要(yao)小心。

電(dian)(dian)(dian)(dian)弧(hu)焊接是(shi)工業生(sheng)產中(zhong)應(ying)用(yong)最(zui)廣泛(fan)的(de)(de)(de)(de)(de)焊接方法，將要焊接的(de)(de)(de)(de)(de)金屬作(zuo)為一極(ji)，焊條作(zuo)為另一極(ji)，兩(liang)極(ji)接近時產生(sheng)電(dian)(dian)(dian)(dian)弧(hu)，利(li)用(yong)電(dian)(dian)(dian)(dian)弧(hu)放電(dian)(dian)(dian)(dian)所產生(sheng)的(de)(de)(de)(de)(de)熱(re)(re)量將焊條與工件互相熔化(hua)(hua)并(bing)在(zai)冷凝后(hou)形(xing)(xing)成(cheng)(cheng)焊縫(feng)，從而獲得牢固接頭的(de)(de)(de)(de)(de)焊接過程。電(dian)(dian)(dian)(dian)弧(hu)焊接的(de)(de)(de)(de)(de)實質是(shi)氣體(ti)導電(dian)(dian)(dian)(dian)，即(ji)電(dian)(dian)(dian)(dian)弧(hu)所在(zai)的(de)(de)(de)(de)(de)空間中(zhong)的(de)(de)(de)(de)(de)中(zhong)性氣體(ti)在(zai)一定電(dian)(dian)(dian)(dian)壓(ya)作(zuo)用(yong)下分(fen)解成(cheng)(cheng)帶正電(dian)(dian)(dian)(dian)荷的(de)(de)(de)(de)(de)正離(li)子和帶負電(dian)(dian)(dian)(dian)荷的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)子，稱為電(dian)(dian)(dian)(dian)離(li)，這(zhe)兩(liang)種帶電(dian)(dian)(dian)(dian)質點分(fen)別向(xiang)兩(liang)極(ji)方向(xiang)運(yun)動，使局(ju)部氣體(ti)導電(dian)(dian)(dian)(dian)形(xing)(xing)成(cheng)(cheng)電(dian)(dian)(dian)(dian)弧(hu)。電(dian)(dian)(dian)(dian)弧(hu)把(ba)電(dian)(dian)(dian)(dian)能轉換成(cheng)(cheng)熱(re)(re)能，加熱(re)(re)和熔化(hua)(hua)金屬，形(xing)(xing)成(cheng)(cheng)焊接接頭。

電弧焊接方法有哪些

1、手工電弧焊

手(shou)工電弧(hu)焊(han)(han)是(shi)(shi)通過帶藥(yao)皮的(de)焊(han)(han)條(tiao)和(he)被(bei)焊(han)(han)金(jin)(jin)屬(shu)(shu)間(jian)的(de)電弧(hu)將(jiang)被(bei)焊(han)(han)金(jin)(jin)屬(shu)(shu)加熱，從而達(da)到焊(han)(han)接的(de)目的(de)。焊(han)(han)條(tiao)和(he)工件的(de)電弧(hu)是(shi)(shi)由電流引(yin)起的(de)，它提(ti)供熱能(neng)并將(jiang)母材、填充金(jin)(jin)屬(shu)(shu)以(yi)及藥(yao)皮融(rong)化，隨著電弧(hu)向右移動(dong)，焊(han)(han)接金(jin)(jin)屬(shu)(shu)得以(yi)凝固并在表(biao)面形成(cheng)一層焊(han)(han)渣(zha)。手(shou)工電弧(hu)焊(han)(han)中最主要的(de)要素是(shi)(shi)焊(han)(han)條(tiao)本(ben)身，它是(shi)(shi)由金(jin)(jin)屬(shu)(shu)芯外(wai)覆一層粒狀焊(han)(han)劑(ji)和(he)某種粘接劑(ji)制作而成(cheng)的(de)。所有的(de)碳鋼和(he)低(di)合(he)金(jin)(jin)鋼焊(han)(han)條(tiao)基本(ben)上都用低(di)碳鋼絲(si)做(zuo)芯，而合(he)金(jin)(jin)元素則來自于藥(yao)皮，這也(ye)是(shi)(shi)較(jiao)為經濟的(de)一種合(he)金(jin)(jin)化方(fang)法(fa)。

2、氣體保護電弧焊

氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)保護(hu)電(dian)弧焊(han)(han)是通過焊(han)(han)槍連續不斷的(de)送絲(si)(si)(si)，由焊(han)(han)絲(si)(si)(si)和工件之間產生的(de)電(dian)弧的(de)熱量將母材和焊(han)(han)絲(si)(si)(si)熔化(hua)，從而(er)達到(dao)焊(han)(han)接的(de)目的(de)。氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)保護(hu)電(dian)弧焊(han)(han)很重要的(de)一個特(te)點(dian)是焊(han)(han)接過程的(de)保護(hu)氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)也是由焊(han)(han)槍輸送，這些氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)有惰性(xing)的(de)，也有非惰性(xing)的(de)。惰性(xing)氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)如氬、氦可(ke)(ke)用(yong)于(yu)某些焊(han)(han)接當(dang)中，它(ta)(ta)們可(ke)(ke)單(dan)獨(du)使(shi)用(yong)，也可(ke)(ke)混合(he)使(shi)用(yong)，或(huo)與其它(ta)(ta)非惰性(xing)氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)如氮氣(qi)(qi)(qi)、氧(yang)氣(qi)(qi)(qi)或(huo)二(er)氧(yang)化(hua)碳混合(he)使(shi)用(yong)。多數(shu)氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)保護(hu)電(dian)弧焊(han)(han)使(shi)用(yong)二(er)氧(yang)化(hua)碳作為保護(hu)氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)，因為與惰性(xing)氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)相比，它(ta)(ta)價格較為便宜。氣(qi)(qi)(qi)體(ti)(ti)(ti)(ti)保護(hu)電(dian)弧焊(han)(han)的(de)電(dian)極是實芯(xin)焊(han)(han)絲(si)(si)(si)。

3、藥芯焊絲電弧焊

藥(yao)(yao)芯(xin)焊(han)(han)(han)(han)(han)(han)絲(si)(si)電(dian)弧(hu)焊(han)(han)(han)(han)(han)(han)與(yu)氣(qi)體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)(han)非常(chang)相似，差別在于(yu)藥(yao)(yao)芯(xin)焊(han)(han)(han)(han)(han)(han)絲(si)(si)焊(han)(han)(han)(han)(han)(han)采(cai)用(yong)(yong)的(de)(de)是管(guan)狀(zhuang)(zhuang)焊(han)(han)(han)(han)(han)(han)絲(si)(si)，其中(zhong)裝有(you)粒狀(zhuang)(zhuang)的(de)(de)焊(han)(han)(han)(han)(han)(han)劑(ji)(ji)，而不(bu)是氣(qi)體(ti)(ti)保(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)(han)所(suo)(suo)用(yong)(yong)的(de)(de)實芯(xin)焊(han)(han)(han)(han)(han)(han)絲(si)(si)。管(guan)狀(zhuang)(zhuang)的(de)(de)焊(han)(han)(han)(han)(han)(han)絲(si)(si)通過焊(han)(han)(han)(han)(han)(han)槍中(zhong)的(de)(de)導電(dian)嘴送進，并在焊(han)(han)(han)(han)(han)(han)絲(si)(si)和工(gong)件之間產生電(dian)弧(hu)。隨著向前焊(han)(han)(han)(han)(han)(han)接而熔敷焊(han)(han)(han)(han)(han)(han)縫金屬，和手工(gong)電(dian)弧(hu)焊(han)(han)(han)(han)(han)(han)一樣，在焊(han)(han)(han)(han)(han)(han)縫金屬上覆蓋著一層(ceng)焊(han)(han)(han)(han)(han)(han)渣。根據使用(yong)(yong)的(de)(de)焊(han)(han)(han)(han)(han)(han)絲(si)(si)類(lei)型不(bu)同，可(ke)以(yi)對(dui)藥(yao)(yao)芯(xin)焊(han)(han)(han)(han)(han)(han)附帶或不(bu)附帶額外的(de)(de)保(bao)(bao)護(hu)氣(qi)體(ti)(ti)。有(you)些焊(han)(han)(han)(han)(han)(han)絲(si)(si)被設計成靠(kao)內(nei)部焊(han)(han)(han)(han)(han)(han)劑(ji)(ji)提(ti)供所(suo)(suo)有(you)需要的(de)(de)保(bao)(bao)護(hu)，它們(men)被稱為(wei)自保(bao)(bao)護(hu)性。其它的(de)(de)焊(han)(han)(han)(han)(han)(han)絲(si)(si)要求附加的(de)(de)保(bao)(bao)護(hu)氣(qi)體(ti)(ti)提(ti)供附加的(de)(de)保(bao)(bao)護(hu)。

4、鎢極氣體保護電弧焊

鎢(wu)極(ji)(ji)(ji)(ji)氣體保護電(dian)弧焊(han)(han)最(zui)重要的(de)特性是電(dian)極(ji)(ji)(ji)(ji)在焊(han)(han)接(jie)(jie)過程中(zhong)不會消耗。它采用(yong)純鎢(wu)或(huo)(huo)鎢(wu)合金制造，具(ju)有(you)(you)承受高溫(wen)的(de)能(neng)力(li)，甚至是電(dian)弧的(de)高溫(wen)。因(yin)(yin)而，當電(dian)流通過時，就在鎢(wu)極(ji)(ji)(ji)(ji)和(he)工(gong)件之間建立起電(dian)弧。當需要填(tian)充金屬時，必須(xu)額外添(tian)加，通常采用(yong)手(shou)工(gong)方式，或(huo)(huo)采用(yong)機械送絲系統。電(dian)弧和(he)金屬采用(yong)惰(duo)性氣體保護，這些氣體從包圍著(zhu)鎢(wu)極(ji)(ji)(ji)(ji)的(de)噴嘴中(zhong)流出。因(yin)(yin)為(wei)沒有(you)(you)使(shi)用(yong)焊(han)(han)劑(ji)，熔(rong)敷金屬不需要清(qing)渣(zha)。鎢(wu)極(ji)(ji)(ji)(ji)氣體保護電(dian)弧焊(han)(han)在許多工(gong)業領域有(you)(you)著(zhu)廣泛的(de)應(ying)用(yong)，它能(neng)焊(han)(han)接(jie)(jie)幾乎所有(you)(you)的(de)材料，因(yin)(yin)為(wei)電(dian)極(ji)(ji)(ji)(ji)在焊(han)(han)接(jie)(jie)過程沒有(you)(you)熔(rong)化，具(ju)有(you)(you)在極(ji)(ji)(ji)(ji)低電(dian)流情況下焊(han)(han)接(jie)(jie)的(de)能(neng)力(li)，使(shi)得(de)鎢(wu)極(ji)(ji)(ji)(ji)氬(ya)弧焊(han)(han)可(ke)用(yong)于極(ji)(ji)(ji)(ji)薄(bo)材料的(de)焊(han)(han)接(jie)(jie)。它特有(you)(you)的(de)清(qing)潔(jie)和(he)操作可(ke)控特性，使(shi)它成為(wei)苛刻(ke)條件下應(ying)用(yong)的(de)首選(xuan)，這些應(ying)用(yong)如太空、食品(pin)和(he)藥品(pin)加工(gong)，石化和(he)動力(li)管(guan)道(dao)工(gong)業。

5、埋弧焊

埋弧焊(han)(han)通過用實芯焊(han)(han)絲連(lian)續送進，焊(han)(han)絲產生的電弧完全被(bei)顆(ke)粒狀的焊(han)(han)劑層(ceng)所覆(fu)蓋(gai)，因(yin)而被(bei)命名(ming)成(cheng)“埋弧”焊(han)(han)，這(zhe)種方法是目(mu)前所提及(ji)的在(zai)焊(han)(han)縫金屬熔敷效(xiao)率上最高(gao)的一種典型(xing)焊(han)(han)接(jie)方法。對(dui)于埋弧焊(han)(han)工藝，顆(ke)粒狀焊(han)(han)劑被(bei)置于焊(han)(han)絲的前部或(huo)周圍來實現(xian)對(dui)熔化金屬的保護。在(zai)焊(han)(han)接(jie)過程中，在(zai)焊(han)(han)道上有一層(ceng)焊(han)(han)渣和(he)仍然為顆(ke)粒狀的焊(han)(han)劑。