電弧是什么
電(dian)(dian)(dian)弧(hu)(hu)是一束高溫電(dian)(dian)(dian)離氣體,是一種氣體放電(dian)(dian)(dian)現(xian)象,是氣體放電(dian)(dian)(dian)中(zhong)(zhong)最(zui)強烈的一種自持放電(dian)(dian)(dian),也是一種等(deng)離子體。當電(dian)(dian)(dian)流通過某些絕緣介質(例如(ru)空氣)所產生的瞬間火花,就是電(dian)(dian)(dian)弧(hu)(hu),電(dian)(dian)(dian)弧(hu)(hu)放電(dian)(dian)(dian)最(zui)顯著的外(wai)觀特征是明亮的弧(hu)(hu)光柱和(he)電(dian)(dian)(dian)極斑(ban)點(dian),通常(chang)可分為長(chang)弧(hu)(hu)和(he)短(duan)弧(hu)(hu)兩類。長(chang)弧(hu)(hu)中(zhong)(zhong)弧(hu)(hu)柱起重要作用(yong),短(duan)弧(hu)(hu)長(chang)度(du)在幾毫米以下,陰極區和(he)陽極區起主要作用(yong)。
電(dian)(dian)(dian)弧在外力(li)(li)作用下,如氣流,外界(jie)磁場甚至電(dian)(dian)(dian)弧本身產生(sheng)的(de)(de)(de)磁場作用下會(hui)迅速移動(每秒可達幾百米),拉長、卷曲形成(cheng)十(shi)分復(fu)雜的(de)(de)(de)形狀(zhuang),電(dian)(dian)(dian)弧在電(dian)(dian)(dian)極上(shang)的(de)(de)(de)孳生(sheng)點也會(hui)快(kuai)速移動或(huo)跳動。電(dian)(dian)(dian)弧放電(dian)(dian)(dian)可用于焊接(jie)、冶煉、照(zhao)明、噴涂(tu)等,主要(yao)是利用電(dian)(dian)(dian)弧的(de)(de)(de)高溫、高能量密度、易控制等特點,在這(zhe)些應用中,都需(xu)使(shi)電(dian)(dian)(dian)弧穩定放電(dian)(dian)(dian)。注意電(dian)(dian)(dian)弧具有(you)超強的(de)(de)(de)電(dian)(dian)(dian)力(li)(li),能瞬間使(shi)心臟停跳,所以(yi),利用電(dian)(dian)(dian)弧而(er)工(gong)作的(de)(de)(de)人們需(xu)要(yao)小(xiao)心。
電(dian)(dian)(dian)弧(hu)(hu)焊(han)接(jie)是工(gong)(gong)業生產(chan)中(zhong)應用(yong)最廣泛(fan)的(de)(de)(de)焊(han)接(jie)方法,將要焊(han)接(jie)的(de)(de)(de)金(jin)屬作(zuo)為(wei)(wei)一極,焊(han)條作(zuo)為(wei)(wei)另(ling)一極,兩(liang)極接(jie)近時(shi)產(chan)生電(dian)(dian)(dian)弧(hu)(hu),利用(yong)電(dian)(dian)(dian)弧(hu)(hu)放電(dian)(dian)(dian)所產(chan)生的(de)(de)(de)熱(re)(re)量將焊(han)條與工(gong)(gong)件互(hu)相(xiang)熔化并(bing)在冷凝后形(xing)成焊(han)縫,從而獲(huo)得牢固接(jie)頭(tou)(tou)的(de)(de)(de)焊(han)接(jie)過(guo)程。電(dian)(dian)(dian)弧(hu)(hu)焊(han)接(jie)的(de)(de)(de)實質(zhi)是氣體導(dao)電(dian)(dian)(dian),即電(dian)(dian)(dian)弧(hu)(hu)所在的(de)(de)(de)空間中(zhong)的(de)(de)(de)中(zhong)性氣體在一定電(dian)(dian)(dian)壓(ya)作(zuo)用(yong)下分解成帶(dai)正(zheng)電(dian)(dian)(dian)荷的(de)(de)(de)正(zheng)離(li)子和(he)帶(dai)負電(dian)(dian)(dian)荷的(de)(de)(de)電(dian)(dian)(dian)子,稱為(wei)(wei)電(dian)(dian)(dian)離(li),這兩(liang)種帶(dai)電(dian)(dian)(dian)質(zhi)點分別向兩(liang)極方向運動,使局部氣體導(dao)電(dian)(dian)(dian)形(xing)成電(dian)(dian)(dian)弧(hu)(hu)。電(dian)(dian)(dian)弧(hu)(hu)把電(dian)(dian)(dian)能轉換成熱(re)(re)能,加熱(re)(re)和(he)熔化金(jin)屬,形(xing)成焊(han)接(jie)接(jie)頭(tou)(tou)。
電弧焊接方法有哪些
1、手工電弧焊
手(shou)工(gong)電(dian)(dian)(dian)弧(hu)(hu)焊(han)(han)是(shi)通過帶藥(yao)皮的(de)焊(han)(han)條(tiao)和(he)被(bei)(bei)焊(han)(han)金(jin)(jin)(jin)屬間的(de)電(dian)(dian)(dian)弧(hu)(hu)將(jiang)被(bei)(bei)焊(han)(han)金(jin)(jin)(jin)屬加熱(re),從而達到焊(han)(han)接的(de)目(mu)的(de)。焊(han)(han)條(tiao)和(he)工(gong)件(jian)的(de)電(dian)(dian)(dian)弧(hu)(hu)是(shi)由電(dian)(dian)(dian)流引(yin)起的(de),它提(ti)供熱(re)能并將(jiang)母材、填充金(jin)(jin)(jin)屬以及(ji)藥(yao)皮融(rong)化(hua),隨(sui)著電(dian)(dian)(dian)弧(hu)(hu)向右移(yi)動,焊(han)(han)接金(jin)(jin)(jin)屬得以凝固(gu)并在表(biao)面形成一(yi)(yi)層(ceng)焊(han)(han)渣。手(shou)工(gong)電(dian)(dian)(dian)弧(hu)(hu)焊(han)(han)中最主(zhu)要(yao)的(de)要(yao)素是(shi)焊(han)(han)條(tiao)本(ben)身,它是(shi)由金(jin)(jin)(jin)屬芯外覆一(yi)(yi)層(ceng)粒狀焊(han)(han)劑和(he)某種粘接劑制作而成的(de)。所(suo)有(you)的(de)碳鋼(gang)和(he)低(di)合金(jin)(jin)(jin)鋼(gang)焊(han)(han)條(tiao)基本(ben)上都用低(di)碳鋼(gang)絲做芯,而合金(jin)(jin)(jin)元素則來自于藥(yao)皮,這也是(shi)較為經濟的(de)一(yi)(yi)種合金(jin)(jin)(jin)化(hua)方(fang)法。
2、氣體保護電弧焊
氣(qi)(qi)(qi)體(ti)(ti)(ti)保(bao)護(hu)(hu)電(dian)弧(hu)(hu)焊(han)(han)(han)是(shi)通過(guo)(guo)焊(han)(han)(han)槍(qiang)連續不斷的(de)(de)(de)送絲(si),由焊(han)(han)(han)絲(si)和工件之間(jian)產生的(de)(de)(de)電(dian)弧(hu)(hu)的(de)(de)(de)熱量將母材和焊(han)(han)(han)絲(si)熔化,從而達到焊(han)(han)(han)接的(de)(de)(de)目的(de)(de)(de)。氣(qi)(qi)(qi)體(ti)(ti)(ti)保(bao)護(hu)(hu)電(dian)弧(hu)(hu)焊(han)(han)(han)很重要的(de)(de)(de)一(yi)個特點是(shi)焊(han)(han)(han)接過(guo)(guo)程的(de)(de)(de)保(bao)護(hu)(hu)氣(qi)(qi)(qi)體(ti)(ti)(ti)也是(shi)由焊(han)(han)(han)槍(qiang)輸送,這些氣(qi)(qi)(qi)體(ti)(ti)(ti)有惰性(xing)(xing)的(de)(de)(de),也有非(fei)惰性(xing)(xing)的(de)(de)(de)。惰性(xing)(xing)氣(qi)(qi)(qi)體(ti)(ti)(ti)如氬、氦可用(yong)于某些焊(han)(han)(han)接當中,它們可單獨使(shi)(shi)用(yong),也可混合(he)使(shi)(shi)用(yong),或(huo)與(yu)(yu)其它非(fei)惰性(xing)(xing)氣(qi)(qi)(qi)體(ti)(ti)(ti)如氮氣(qi)(qi)(qi)、氧氣(qi)(qi)(qi)或(huo)二氧化碳(tan)(tan)混合(he)使(shi)(shi)用(yong)。多數氣(qi)(qi)(qi)體(ti)(ti)(ti)保(bao)護(hu)(hu)電(dian)弧(hu)(hu)焊(han)(han)(han)使(shi)(shi)用(yong)二氧化碳(tan)(tan)作為(wei)保(bao)護(hu)(hu)氣(qi)(qi)(qi)體(ti)(ti)(ti),因為(wei)與(yu)(yu)惰性(xing)(xing)氣(qi)(qi)(qi)體(ti)(ti)(ti)相比(bi),它價格較為(wei)便宜。氣(qi)(qi)(qi)體(ti)(ti)(ti)保(bao)護(hu)(hu)電(dian)弧(hu)(hu)焊(han)(han)(han)的(de)(de)(de)電(dian)極是(shi)實芯焊(han)(han)(han)絲(si)。
3、藥芯焊絲電弧焊
藥(yao)芯(xin)(xin)焊(han)(han)(han)(han)(han)絲(si)電(dian)弧(hu)焊(han)(han)(han)(han)(han)與氣(qi)(qi)體(ti)保(bao)(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)非常相似,差別(bie)在(zai)于藥(yao)芯(xin)(xin)焊(han)(han)(han)(han)(han)絲(si)焊(han)(han)(han)(han)(han)采用(yong)(yong)的(de)(de)(de)(de)(de)(de)是管狀(zhuang)焊(han)(han)(han)(han)(han)絲(si),其中裝有粒狀(zhuang)的(de)(de)(de)(de)(de)(de)焊(han)(han)(han)(han)(han)劑(ji),而(er)不(bu)(bu)(bu)是氣(qi)(qi)體(ti)保(bao)(bao)(bao)護(hu)焊(han)(han)(han)(han)(han)所(suo)用(yong)(yong)的(de)(de)(de)(de)(de)(de)實芯(xin)(xin)焊(han)(han)(han)(han)(han)絲(si)。管狀(zhuang)的(de)(de)(de)(de)(de)(de)焊(han)(han)(han)(han)(han)絲(si)通過焊(han)(han)(han)(han)(han)槍中的(de)(de)(de)(de)(de)(de)導電(dian)嘴送進(jin),并在(zai)焊(han)(han)(han)(han)(han)絲(si)和(he)工件之間產(chan)生電(dian)弧(hu)。隨(sui)著向前焊(han)(han)(han)(han)(han)接(jie)而(er)熔敷焊(han)(han)(han)(han)(han)縫金屬(shu),和(he)手工電(dian)弧(hu)焊(han)(han)(han)(han)(han)一樣(yang),在(zai)焊(han)(han)(han)(han)(han)縫金屬(shu)上覆蓋著一層焊(han)(han)(han)(han)(han)渣。根據(ju)使用(yong)(yong)的(de)(de)(de)(de)(de)(de)焊(han)(han)(han)(han)(han)絲(si)類型不(bu)(bu)(bu)同,可以對藥(yao)芯(xin)(xin)焊(han)(han)(han)(han)(han)附帶或不(bu)(bu)(bu)附帶額外的(de)(de)(de)(de)(de)(de)保(bao)(bao)(bao)護(hu)氣(qi)(qi)體(ti)。有些焊(han)(han)(han)(han)(han)絲(si)被設計成靠內部焊(han)(han)(han)(han)(han)劑(ji)提供所(suo)有需(xu)要的(de)(de)(de)(de)(de)(de)保(bao)(bao)(bao)護(hu),它(ta)們(men)被稱(cheng)為自保(bao)(bao)(bao)護(hu)性(xing)。其它(ta)的(de)(de)(de)(de)(de)(de)焊(han)(han)(han)(han)(han)絲(si)要求附加(jia)的(de)(de)(de)(de)(de)(de)保(bao)(bao)(bao)護(hu)氣(qi)(qi)體(ti)提供附加(jia)的(de)(de)(de)(de)(de)(de)保(bao)(bao)(bao)護(hu)。
4、鎢極氣體保護電弧焊
鎢(wu)(wu)極(ji)(ji)氣(qi)(qi)體(ti)(ti)保護電弧(hu)焊(han)最(zui)重要(yao)的(de)(de)(de)(de)特(te)性是電極(ji)(ji)在(zai)焊(han)接(jie)過程中(zhong)(zhong)不(bu)會消耗。它(ta)采用(yong)純鎢(wu)(wu)或(huo)鎢(wu)(wu)合金(jin)制造,具(ju)有(you)(you)(you)承受高溫的(de)(de)(de)(de)能力(li),甚(shen)至(zhi)是電弧(hu)的(de)(de)(de)(de)高溫。因(yin)(yin)而(er),當(dang)電流(liu)通(tong)(tong)過時,就在(zai)鎢(wu)(wu)極(ji)(ji)和(he)工(gong)件之(zhi)間(jian)建立起電弧(hu)。當(dang)需要(yao)填充(chong)金(jin)屬(shu)時,必(bi)須額外添加,通(tong)(tong)常采用(yong)手工(gong)方式,或(huo)采用(yong)機械送絲系統。電弧(hu)和(he)金(jin)屬(shu)采用(yong)惰性氣(qi)(qi)體(ti)(ti)保護,這些(xie)氣(qi)(qi)體(ti)(ti)從包圍著鎢(wu)(wu)極(ji)(ji)的(de)(de)(de)(de)噴嘴中(zhong)(zhong)流(liu)出。因(yin)(yin)為(wei)沒有(you)(you)(you)使用(yong)焊(han)劑,熔(rong)敷金(jin)屬(shu)不(bu)需要(yao)清渣。鎢(wu)(wu)極(ji)(ji)氣(qi)(qi)體(ti)(ti)保護電弧(hu)焊(han)在(zai)許多工(gong)業領域有(you)(you)(you)著廣(guang)泛的(de)(de)(de)(de)應(ying)用(yong),它(ta)能焊(han)接(jie)幾(ji)乎所有(you)(you)(you)的(de)(de)(de)(de)材料,因(yin)(yin)為(wei)電極(ji)(ji)在(zai)焊(han)接(jie)過程沒有(you)(you)(you)熔(rong)化,具(ju)有(you)(you)(you)在(zai)極(ji)(ji)低電流(liu)情況下(xia)(xia)焊(han)接(jie)的(de)(de)(de)(de)能力(li),使得(de)鎢(wu)(wu)極(ji)(ji)氬弧(hu)焊(han)可(ke)用(yong)于極(ji)(ji)薄材料的(de)(de)(de)(de)焊(han)接(jie)。它(ta)特(te)有(you)(you)(you)的(de)(de)(de)(de)清潔和(he)操作可(ke)控特(te)性,使它(ta)成為(wei)苛刻條(tiao)件下(xia)(xia)應(ying)用(yong)的(de)(de)(de)(de)首(shou)選,這些(xie)應(ying)用(yong)如太空(kong)、食品和(he)藥品加工(gong),石化和(he)動(dong)力(li)管道工(gong)業。
5、埋弧焊
埋弧(hu)焊(han)(han)通過用實芯焊(han)(han)絲(si)(si)連續送(song)進,焊(han)(han)絲(si)(si)產生的電弧(hu)完全被顆粒狀(zhuang)的焊(han)(han)劑(ji)層(ceng)所覆(fu)蓋,因而被命名成(cheng)“埋弧(hu)”焊(han)(han),這種方法(fa)是目前(qian)所提(ti)及的在(zai)焊(han)(han)縫(feng)金(jin)屬熔(rong)敷效率上最高的一種典型(xing)焊(han)(han)接(jie)方法(fa)。對于埋弧(hu)焊(han)(han)工藝,顆粒狀(zhuang)焊(han)(han)劑(ji)被置于焊(han)(han)絲(si)(si)的前(qian)部或周圍來(lai)實現(xian)對熔(rong)化金(jin)屬的保(bao)護。在(zai)焊(han)(han)接(jie)過程(cheng)中,在(zai)焊(han)(han)道(dao)上有一層(ceng)焊(han)(han)渣和仍然為顆粒狀(zhuang)的焊(han)(han)劑(ji)。