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來源:行(xing)業動態 閱(yue)讀:109251 發布(bu)時間(jian):2019-07-05
導讀:由(you)于生(sheng)產銅(tong)(tong)桿(gan)(gan)的兩(liang)者的工藝不(bu)同(tong),所生(sheng)產的銅(tong)(tong)桿(gan)(gan)中的含氧量及外(wai)觀(guan)就不(bu)同(tong)。上(shang)(shang)引(yin)生(sheng)產的銅(tong)(tong)桿(gan)(gan),工藝得當氧含量在10ppm以(yi)下(xia),叫無氧銅(tong)(tong)桿(gan)(gan);連鑄連鑄生(sheng)產的銅(tong)(tong)桿(gan)(gan) 是在保護條件下(xia)的熱軋,氧含量在200-500ppm范圍內,但有時也高達(da)700ppm以(yi)上(shang)(shang),一般(ban)情況下(xia),此種方法生(sheng)產的銅(tong)(tong)外(wai)表光亮,低(di)氧銅(tong)(tong)桿(gan)(gan),有時也叫光桿(gan)(gan)。
銅桿是(shi)(shi)電纜行(xing)(xing)業(ye)的主(zhu)要原料,生(sheng)產(chan)(chan)的方式主(zhu)要有兩種——連鑄(zhu)(zhu)(zhu)(zhu)連軋法(fa)和(he)上引連鑄(zhu)(zhu)(zhu)(zhu)法(fa)。連鑄(zhu)(zhu)(zhu)(zhu)連軋低氧(yang)銅桿的生(sheng)產(chan)(chan)方法(fa)較多(duo),其特點是(shi)(shi)金屬(shu)在(zai)豎(shu)爐(lu)中融化后(hou)(hou)(hou),銅液通(tong)過保(bao)溫爐(lu)、溜槽、中間(jian)包,從(cong)澆(jiao)管(guan)進(jin)入(ru)封(feng)閉的模腔(qiang)內(nei),采用較大的冷(leng)卻(que)強(qiang)度進(jin)行(xing)(xing)冷(leng)卻(que),形成鑄(zhu)(zhu)(zhu)(zhu)坯,然后(hou)(hou)(hou)進(jin)行(xing)(xing)多(duo)道次軋制,生(sheng)產(chan)(chan)的低氧(yang)銅桿為(wei)熱加工(gong)組(zu)(zu)織(zhi),原來的鑄(zhu)(zhu)(zhu)(zhu)造(zao)組(zu)(zu)織(zhi)已經破碎,含氧(yang)量(liang)一般為(wei)200~400ppm之(zhi)間(jian)。無(wu)氧(yang)銅桿國內(nei)基(ji)本全部采用上引連鑄(zhu)(zhu)(zhu)(zhu)法(fa)生(sheng)產(chan)(chan),金屬(shu)在(zai)感(gan)應(ying)電爐(lu)中融化后(hou)(hou)(hou)通(tong)過石墨模進(jin)行(xing)(xing)上引連續鑄(zhu)(zhu)(zhu)(zhu)造(zao),之(zhi)后(hou)(hou)(hou)進(jin)行(xing)(xing)冷(leng)軋或冷(leng)加工(gong),生(sheng)產(chan)(chan)的無(wu)氧(yang)銅桿為(wei)鑄(zhu)(zhu)(zhu)(zhu)造(zao)組(zu)(zu)織(zhi),含氧(yang)量(liang)一般在(zai)20ppm以(yi)下。由(you)于制造(zao)工(gong)藝的不同,所以(yi)在(zai)組(zu)(zu)織(zhi)結構、氧(yang)含量(liang)分布(bu)、雜質的形式及分布(bu)等諸多(duo)方面有較大差別。
一、拉制性能
銅桿的(de)(de)拉制(zhi)(zhi)(zhi)性(xing)能跟很多因(yin)素有關,如雜質(zhi)的(de)(de)含量(liang)、氧含量(liang)及(ji)分布、工(gong)藝(yi)控制(zhi)(zhi)(zhi)等。下面分別從以(yi)上幾個方(fang)面對銅桿的(de)(de)拉制(zhi)(zhi)(zhi)性(xing)能進行分析。
1、熔化方(fang)式對S等雜質的影響
連(lian)鑄(zhu)連(lian)軋生產銅(tong)(tong)桿(gan)主要是(shi)通(tong)過氣體的燃燒使(shi)銅(tong)(tong)桿(gan)熔化(hua),在燃燒的過程中,通(tong)過氧(yang)化(hua)和(he)揮發作用,可(ke)一定程度減少部分雜質進入(ru)銅(tong)(tong)液,因此(ci)連(lian)鑄(zhu)連(lian)軋法(fa)對(dui)原(yuan)料要求相對(dui)低(di)一些。上引(yin)連(lian)鑄(zhu)生產無氧(yang)銅(tong)(tong)桿(gan),由于是(shi)用感應電(dian)爐熔化(hua),電(dian)解銅(tong)(tong)表面的“銅(tong)(tong)綠”“銅(tong)(tong)豆”基本都(dou)熔入(ru)到(dao)銅(tong)(tong)液中。其中熔入(ru)的S對(dui)無氧(yang)銅(tong)(tong)桿(gan)塑(su)性影響(xiang)極大,會增加拉絲斷(duan)線率。
2、鑄造過程中(zhong)雜質(zhi)的(de)進(jin)入
在生產(chan)過(guo)(guo)程中(zhong),連(lian)(lian)鑄連(lian)(lian)軋工(gong)(gong)藝(yi)需(xu)通過(guo)(guo)保溫爐、溜(liu)槽(cao)、中(zhong)間包(bao)轉(zhuan)運銅(tong)液,相對(dui)容易造成(cheng)耐(nai)火(huo)(huo)材料的(de)(de)(de)剝落,在軋制(zhi)過(guo)(guo)程中(zhong)需(xu)要通過(guo)(guo)軋輥,造成(cheng)鐵質的(de)(de)(de)脫落,會(hui)(hui)給銅(tong)桿造成(cheng)外部夾雜。而熱軋中(zhong)皮(pi)上(shang)(shang)和皮(pi)下氧(yang)化物的(de)(de)(de)軋入(ru),會(hui)(hui)給低氧(yang)桿的(de)(de)(de)拉絲(si)造成(cheng)不(bu)利的(de)(de)(de)影(ying)響(xiang)。上(shang)(shang)引連(lian)(lian)鑄法(fa)生產(chan)工(gong)(gong)藝(yi)流程較短,銅(tong)液是通過(guo)(guo)聯體爐內潛流式完成(cheng),對(dui)耐(nai)火(huo)(huo)材料的(de)(de)(de)沖擊不(bu)大,結晶是通過(guo)(guo)石(shi)墨(mo)模內進行,所(suo)以過(guo)(guo)程中(zhong)可能產(chan)生的(de)(de)(de)污染源(yuan)較少,雜質進入(ru)的(de)(de)(de)機(ji)會(hui)(hui)較少。
O、S、P是(shi)與(yu)銅會生產化(hua)合物的(de)元素。在熔態(tai)銅中(zhong),氧可以溶(rong)解一部(bu)分,但(dan)當銅冷凝時,氧幾乎(hu)不溶(rong)解于銅中(zhong)。熔態(tai)時所溶(rong)解的(de)氧,以銅=氧化(hua)亞銅共(gong)(gong)晶(jing)體(ti)析出(chu),分布在晶(jing)粒(li)晶(jing)界處。銅-氧化(hua)亞銅共(gong)(gong)晶(jing)體(ti)的(de)出(chu)現,顯著降低(di)了銅的(de)塑性(xing)。
硫可(ke)以(yi)溶解在(zai)(zai)熔體(ti)的銅(tong)中,但在(zai)(zai)室溫下(xia),其溶解度幾(ji)乎(hu)降(jiang)低(di)(di)到零(ling),它以(yi)硫化亞銅(tong)的形式出現在(zai)(zai)晶粒晶界處,會(hui)顯(xian)著(zhu)降(jiang)低(di)(di)銅(tong)的塑性。
3、氧(yang)(yang)(yang)在低氧(yang)(yang)(yang)銅(tong)桿和無氧(yang)(yang)(yang)銅(tong)桿中分布形式及(ji)其影(ying)響
氧含(han)量對低氧銅桿的(de)(de)(de)拉(la)線(xian)性能有(you)著(zhu)明顯的(de)(de)(de)影響。當氧含(han)量增加到最佳值(zhi)時,銅桿的(de)(de)(de)斷線(xian)率最低。這是因為(wei)(wei)氧在(zai)與大(da)部分雜質反(fan)應的(de)(de)(de)過(guo)程中都起到了(le)清除器(qi)的(de)(de)(de)作用。適(shi)度的(de)(de)(de)氧還有(you)利于去(qu)除銅液中的(de)(de)(de)氫,生成(cheng)水蒸氣溢出,減少氣孔的(de)(de)(de)形(xing)成(cheng)。最佳的(de)(de)(de)氧含(han)量為(wei)(wei)拉(la)線(xian)工藝提供了(le)最好的(de)(de)(de)條件。
低氧(yang)(yang)銅(tong)桿氧(yang)(yang)化(hua)物的分(fen)(fen)布:在連續(xu)澆鑄中(zhong)凝固(gu)的最初階(jie)段(duan),散熱速率和均(jun)勻冷卻(que)是決定(ding)銅(tong)桿氧(yang)(yang)化(hua)物分(fen)(fen)布的主要因(yin)素(su)。不均(jun)勻冷卻(que)會(hui)引起銅(tong)桿內部(bu)結構(gou)本(ben)質上的差異,但后續(xu)的熱加工,柱狀晶通常會(hui)遭到破壞,使氧(yang)(yang)化(hua)亞銅(tong)顆(ke)粒細微化(hua)和均(jun)勻分(fen)(fen)布。氧(yang)(yang)化(hua)物顆(ke)粒聚集(ji)而產生的典型(xing)情況是中(zhong)心爆裂。除氧(yang)(yang)化(hua)物顆(ke)粒分(fen)(fen)布的影響(xiang)外,具(ju)有較(jiao)小(xiao)氧(yang)(yang)化(hua)物顆(ke)粒的銅(tong)桿顯示出較(jiao)好的拉線特性,較(jiao)大的Cu2O顆(ke)粒容(rong)易造成應力集(ji)中(zhong)點(dian)而斷裂。
無氧(yang)(yang)銅(tong)(tong)(tong)含氧(yang)(yang)量超標,銅(tong)(tong)(tong)桿變脆,延伸(shen)(shen)率下降(jiang),拉伸(shen)(shen)式樣端口顯暗紅色,結晶(jing)組織(zhi)疏松。當氧(yang)(yang)含量超出8ppm時(shi),工(gong)藝性(xing)能(neng)變差(cha),表現為鑄造及(ji)拉伸(shen)(shen)過(guo)程(cheng)中斷(duan)桿及(ji)斷(duan)線率極具增高(gao)。這(zhe)是由于氧(yang)(yang)能(neng)與(yu)銅(tong)(tong)(tong)生成(cheng)氧(yang)(yang)化亞銅(tong)(tong)(tong)脆性(xing)相(xiang),形(xing)成(cheng)銅(tong)(tong)(tong)-氧(yang)(yang)化亞銅(tong)(tong)(tong)共晶(jing)體(ti),以網狀組織(zhi)分布在境界上。這(zhe)種脆性(xing)相(xiang)硬(ying)度(du)高(gao),在冷變形(xing)時(shi)將會與(yu)銅(tong)(tong)(tong)機(ji)體(ti)脫離,導(dao)致(zhi)(zhi)銅(tong)(tong)(tong)桿的機(ji)械(xie)性(xing)能(neng)下降(jiang),在后續加工(gong)中容易造成(cheng)斷(duan)裂(lie)現象(xiang)。氧(yang)(yang)含量高(gao)還能(neng)導(dao)致(zhi)(zhi)無氧(yang)(yang)銅(tong)(tong)(tong)桿導(dao)電率下降(jiang)。因此,必須嚴格控制(zhi)上引(yin)連(lian)鑄工(gong)藝及(ji)產(chan)品(pin)質量。
4、氫的影響
在(zai)上引連鑄中(zhong),氧含量控制較低,氧化物的(de)副作用唄**降低,但氫的(de)影響成為較顯著的(de)問題(ti)。吸氣后(hou)熔體中(zhong)存在(zai)平衡反應:H2O(g)=[O]+2[H];
氣(qi)(qi)體(ti)及疏松是在結晶(jing)(jing)的(de)(de)(de)過程(cheng)中,氫從過飽(bao)和的(de)(de)(de)溶液(ye)中析(xi)出并(bing)聚集(ji)而形(xing)成的(de)(de)(de)。在結晶(jing)(jing)前(qian)析(xi)出的(de)(de)(de)氫又(you)可還原氧化亞銅而生成水氣(qi)(qi)泡。由于上(shang)引鑄造的(de)(de)(de)特點是銅液(ye)自(zi)上(shang)而下的(de)(de)(de)結晶(jing)(jing),形(xing)成的(de)(de)(de)液(ye)**形(xing)狀近似錐型。銅液(ye)結晶(jing)(jing)前(qian)析(xi)出的(de)(de)(de)氣(qi)(qi)體(ti)在上(shang)浮過程(cheng)中被堵(du)在凝固組織內,結晶(jing)(jing)時(shi)在鑄桿內形(xing)成氣(qi)(qi)孔(kong)。上(shang)引的(de)(de)(de)含氣(qi)(qi)量(liang)少時(shi),析(xi)出的(de)(de)(de)氫存(cun)在于晶(jing)(jing)界(jie)處,形(xing)成疏松;含氣(qi)(qi)量(liang)多時(shi),則聚集(ji)成氣(qi)(qi)孔(kong),因(yin)此,氣(qi)(qi)孔(kong)和疏松是氫氣(qi)(qi)和水蒸氣(qi)(qi)兩者形(xing)成的(de)(de)(de)。
氫來(lai)源于(yu)上引生產過程中的各個工藝環節,如原(yuan)料電解銅的“銅綠”、輔料木炭(tan)**、氣候環境**、石墨結晶器未干燥等。因(yin)此(ci),熔化爐中的銅液表面應覆蓋(gai)經烘烤的木炭(tan),電解銅應盡(jin)量(liang)去(qu)除(chu)“銅綠”、“銅豆”“耳朵”,對提高無氧銅桿質量(liang)非(fei)常重要。
在連鑄(zhu)連軋工藝(yi)中,往往采用適度控(kong)制氧含量來控(kong)制氫。Cu2O+ H2= 2Cu+ H2O
由于銅液(ye)在鑄造過(guo)程(cheng)中是自(zi)下(xia)而上結晶,銅液(ye)中的(de)氧和氫所產(chan)生(sheng)的(de)水蒸氣很容易上浮(fu)跑出(chu),銅液(ye)中的(de)氫大部分能(neng)被有效去(qu)除(chu),因(yin)而對(dui)銅桿的(de)影響(xiang)較小(xiao)。
二、表面質量
在生產電磁線等產品(pin)的(de)過程中,對銅(tong)(tong)桿的(de)表面(mian)質量也需提(ti)出要(yao)(yao)求。需要(yao)(yao)拉(la)制后(hou)的(de)銅(tong)(tong)絲表面(mian)無毛刺、銅(tong)(tong)粉少、無油污。并通過扭轉(zhuan)試驗測量表面(mian)銅(tong)(tong)粉的(de)質量和扭轉(zhuan)后(hou)觀察銅(tong)(tong)桿的(de)復原情況來(lai)判定其好壞。
在連(lian)鑄(zhu)(zhu)連(lian)軋(ya)過(guo)程(cheng)中,從鑄(zhu)(zhu)造到軋(ya)制(zhi)前,溫度高,完全暴露于(yu)(yu)空氣中,使(shi)鑄(zhu)(zhu)坯表面形成較(jiao)厚(hou)的氧化(hua)(hua)(hua)層,在軋(ya)制(zhi)過(guo)程(cheng)中,隨著軋(ya)輥的轉動,氧化(hua)(hua)(hua)物顆粒軋(ya)入銅(tong)線表面。由于(yu)(yu)氧化(hua)(hua)(hua)亞(ya)銅(tong)是(shi)高熔點(dian)脆性化(hua)(hua)(hua)合物,對于(yu)(yu)軋(ya)入較(jiao)深的氧化(hua)(hua)(hua)亞(ya)銅(tong),當成條狀的聚集物遇模(mo)具拉伸時(shi),就會(hui)是(shi)銅(tong)桿(gan)外表面產(chan)生毛刺(ci),給后續(xu)的涂漆造成麻煩。
而上引連(lian)鑄工藝制造的無(wu)(wu)氧銅桿(gan),由于鑄造和冷卻(que)完全與氧隔絕,后續亦無(wu)(wu)熱軋(ya)過程,銅桿(gan)表面無(wu)(wu)軋(ya)入表面的氧化物(wu),質量較好,拉(la)制后銅粉(fen)少(shao),上述問(wen)題(ti)較少(shao)存在。
無(wu)氧銅(tong)桿也分(fen)進(jin)口設(she)(she)備(bei)做的(de)(de)(de)和國(guo)(guo)產(chan)設(she)(she)備(bei)做的(de)(de)(de),但(dan)目前進(jin)口產(chan)品已無(wu)明顯優勢(shi),銅(tong)桿產(chan)品出(chu)來后區別不是很大,只要(yao)銅(tong)板(ban)選的(de)(de)(de)好,生(sheng)(sheng)產(chan)控制比較穩定(ding),國(guo)(guo)產(chan)設(she)(she)備(bei)也能產(chan)出(chu)可(ke)拉伸0.05的(de)(de)(de)銅(tong)桿.進(jin)口設(she)(she)備(bei)一般(ban)是芬蘭奧托(tuo)昆(kun)普的(de)(de)(de)設(she)(she)備(bei),國(guo)(guo)產(chan)設(she)(she)備(bei)最好的(de)(de)(de)應該(gai)是上海的(de)(de)(de)海軍廠(chang)的(de)(de)(de)了,生(sheng)(sheng)產(chan)時(shi)間(jian)最長,軍工企(qi)業(ye),質量可(ke)靠。
低氧銅桿進口設備國際主要有兩種(zhong)(zhong),一種(zhong)(zhong)是美國南線設備,英文是SOUTHWIRE,國內廠家是南京(jing)華新,江西銅業(ye),另一種(zhong)(zhong)是德(de)國CONTIROD設備,國內廠家是常(chang)州金源,天津大無縫。
無(wu)氧(yang)(yang)(yang)(yang)及低(di)氧(yang)(yang)(yang)(yang)桿(gan)從含(han)(han)氧(yang)(yang)(yang)(yang)量上容(rong)易區(qu)別,無(wu)氧(yang)(yang)(yang)(yang)銅是(shi)含(han)(han)氧(yang)(yang)(yang)(yang)量在10-20個(ge)PPM以下(xia)(xia),但(dan)目(mu)前有(you)的(de)(de)(de)(de)廠家(jia)只能(neng)(neng)做到50個(ge)PPM以下(xia)(xia).低(di)氧(yang)(yang)(yang)(yang)銅桿(gan)在 200-400個(ge)PPM,好(hao)的(de)(de)(de)(de)桿(gan)子(zi)一般(ban)(ban)含(han)(han)氧(yang)(yang)(yang)(yang)量控制在250個(ge)PPM左(zuo)右(you),無(wu)氧(yang)(yang)(yang)(yang)桿(gan)一般(ban)(ban)采取(qu)的(de)(de)(de)(de)是(shi)上引法,低(di)氧(yang)(yang)(yang)(yang)桿(gan)是(shi)連鑄連軋,兩種產(chan)品相(xiang)對(dui)而(er)言低(di)氧(yang)(yang)(yang)(yang)桿(gan)對(dui)漆包線(xian)性(xing) 能(neng)(neng)更適應些,如(ru)柔軟(ruan)性(xing),回彈角(jiao),繞線(xian)性(xing)能(neng)(neng).但(dan)低(di)氧(yang)(yang)(yang)(yang)桿(gan)對(dui)拉絲(si)條(tiao)件相(xiang)對(dui)要苛刻些,同樣拉伸(shen)0.2的(de)(de)(de)(de)細絲(si),如(ru)果伸(shen)線(xian)條(tiao)件不(bu)(bu)(bu)好(hao),普(pu)(pu)通的(de)(de)(de)(de)無(wu)氧(yang)(yang)(yang)(yang)桿(gan)可拉而(er)好(hao)的(de)(de)(de)(de)低(di)氧(yang)(yang)(yang)(yang)桿(gan)就斷 線(xian),但(dan)如(ru)果放在好(hao)的(de)(de)(de)(de)伸(shen)線(xian)條(tiao)件,同樣的(de)(de)(de)(de)桿(gan)子(zi),低(di)氧(yang)(yang)(yang)(yang)桿(gan)說(shuo)不(bu)(bu)(bu)定就能(neng)(neng)拉到雙(shuang)(shuang)零(ling)五,而(er)普(pu)(pu)通無(wu)氧(yang)(yang)(yang)(yang)桿(gan)最多(duo)只能(neng)(neng)拉伸(shen)到0.1而(er)已,當然做的(de)(de)(de)(de)最細的(de)(de)(de)(de)如(ru)雙(shuang)(shuang)零(ling)二(er)卻非得(de)依靠進口的(de)(de)(de)(de) 無(wu)氧(yang)(yang)(yang)(yang)銅桿(gan)了.目(mu)前有(you)企(qi)業(ye)嘗試用剝皮(pi)的(de)(de)(de)(de)方式來處理低(di)氧(yang)(yang)(yang)(yang)桿(gan)來伸(shen)0.03線(xian).但(dan)有(you)關這方面的(de)(de)(de)(de)內容(rong)我還(huan)不(bu)(bu)(bu)是(shi)很清楚。
音響線一(yi)般反而喜歡用無氧(yang)桿(gan),這(zhe)和(he)無氧(yang)桿(gan)是(shi)單晶(jing)銅,低氧(yang)桿(gan)是(shi)多晶(jing)銅有關。
氧銅桿(gan)和(he)無氧銅桿(gan)由于制造方(fang)法的不(bu)同,致使存在差別,具有各自(zi)的特點。
一(yi)、關(guan)于氧的吸入和脫(tuo)去以及它的存在狀(zhuang)態
生產銅(tong)(tong)(tong)(tong)桿(gan)的(de)陰極(ji)銅(tong)(tong)(tong)(tong)的(de)含氧(yang)(yang)(yang)(yang)量一般(ban)在10—50ppm,在常溫下(xia)(xia)氧(yang)(yang)(yang)(yang)在銅(tong)(tong)(tong)(tong)中(zhong)(zhong)的(de)固溶(rong)度約2ppm。低(di)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)桿(gan)的(de)含氧(yang)(yang)(yang)(yang)量一般(ban)在200(175)—400(450)ppm,因此(ci)氧(yang)(yang)(yang)(yang)的(de)進入是(shi)(shi)在銅(tong)(tong)(tong)(tong)的(de)液態(tai)下(xia)(xia)吸入的(de),而(er)上引法無(wu)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)桿(gan)則相反,氧(yang)(yang)(yang)(yang)在液態(tai)銅(tong)(tong)(tong)(tong)下(xia)(xia)保(bao)持相當時間后,被還原而(er)脫去,通常這(zhe)種(zhong)桿(gan)的(de)含氧(yang)(yang)(yang)(yang)量都在10—50ppm以(yi)下(xia)(xia),最低(di)可達1-2ppm,從(cong)組(zu)織上看,低(di)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)中(zhong)(zhong)的(de)氧(yang)(yang)(yang)(yang),以(yi)氧(yang)(yang)(yang)(yang)化銅(tong)(tong)(tong)(tong)狀(zhuang)態(tai),存在于晶粒邊界附近,這(zhe)對(dui)低(di)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)桿(gan)而(er)言可以(yi)說(shuo)是(shi)(shi)常見的(de)但對(dui)無(wu)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)桿(gan)則很(hen)少見。氧(yang)(yang)(yang)(yang)化銅(tong)(tong)(tong)(tong)以(yi)夾雜形式在晶界出現對(dui)材料的(de)韌性(xing)產生負(fu)面影響。而(er)無(wu)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)中(zhong)(zhong)的(de)氧(yang)(yang)(yang)(yang)很(hen)低(di),所以(yi)這(zhe)種(zhong)銅(tong)(tong)(tong)(tong)的(de)組(zu)織是(shi)(shi)均勻的(de)單(dan)相組(zu)織對(dui)韌性(xing)有利。在無(wu)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)桿(gan)中(zhong)(zhong)的(de)多孔性(xing)是(shi)(shi)不(bu)常見的(de),而(er)在低(di)氧(yang)(yang)(yang)(yang)銅(tong)(tong)(tong)(tong)桿(gan)中(zhong)(zhong)則是(shi)(shi)常見的(de)一種(zhong)缺(que)陷。
二、熱軋組織(zhi)和鑄造組織(zhi)的(de)區別
低氧(yang)銅桿由于經(jing)(jing)過熱(re)軋,所以(yi)其(qi)組(zu)織(zhi)(zhi)屬熱(re)加工組(zu)織(zhi)(zhi),原來(lai)的(de)(de)鑄(zhu)造(zao)組(zu)織(zhi)(zhi)已(yi)經(jing)(jing)破(po)碎,在8mm的(de)(de)桿時(shi)已(yi)有再(zai)結(jie)(jie)晶(jing)的(de)(de)形式出現,而(er)(er)無(wu)氧(yang)銅桿屬鑄(zhu)造(zao)組(zu)織(zhi)(zhi),晶(jing)粒(li)粗(cu)大,這(zhe)是為什么(me),無(wu)氧(yang)銅的(de)(de)再(zai)結(jie)(jie)晶(jing)溫(wen)度較(jiao)高(gao)(gao)(gao),需要較(jiao)高(gao)(gao)(gao)退火溫(wen)度的(de)(de)固有原因。這(zhe)是因為,再(zai)結(jie)(jie)晶(jing)發(fa)生在晶(jing)粒(li)邊(bian)界(jie)(jie)附近(jin),無(wu)氧(yang)銅桿組(zu)織(zhi)(zhi)晶(jing)粒(li)粗(cu)大,晶(jing)粒(li)尺寸(cun)甚至能達(da)幾個(ge)毫米(mi),因而(er)(er)晶(jing)粒(li)邊(bian)界(jie)(jie)少(shao)(shao),即使通過拉制變形,但(dan)晶(jing)粒(li)邊(bian)界(jie)(jie)相(xiang)對(dui)低氧(yang)銅桿還是較(jiao)少(shao)(shao),所以(yi)需要較(jiao)高(gao)(gao)(gao)的(de)(de)退火功率(lv)(lv)。對(dui)無(wu)氧(yang)銅成(cheng)功的(de)(de)退火要求(qiu)是:由桿經(jing)(jing)拉制,但(dan)尚未鑄(zhu)造(zao)組(zu)織(zhi)(zhi)的(de)(de)線時(shi)的(de)(de)第一次退火,其(qi)退火功率(lv)(lv)應比同(tong)(tong)樣情況(kuang)的(de)(de)低氧(yang)銅高(gao)(gao)(gao)10——15%。經(jing)(jing)繼續拉制,在以(yi)后(hou)階段的(de)(de)退火功率(lv)(lv)應留有足夠的(de)(de)余量和(he)對(dui)低氧(yang)銅和(he)無(wu)氧(yang)銅切(qie)實(shi)區別執行不同(tong)(tong)的(de)(de)退火工藝,以(yi)保證在制品(pin)和(he)成(cheng)品(pin)導線的(de)(de)柔軟性。
三(san)、夾雜,氧含量波動(dong),表面氧化物和可能(neng)存在的(de)熱軋缺(que)陷的(de)差別
無氧銅桿(gan)(gan)的(de)可拉性(xing)在(zai)所有線(xian)徑里與(yu)低氧銅桿(gan)(gan)相比都是優越的(de),除上述(shu)組織原(yuan)因外,無氧銅桿(gan)(gan)夾(jia)雜(za)少,含氧量穩定(ding)(ding),無熱軋可能產(chan)生的(de)缺陷(xian),桿(gan)(gan)表(biao)氧化物(wu)厚度可達≤15A。在(zai)連鑄連軋生產(chan)過(guo)程中如果工藝不(bu)穩定(ding)(ding),對氧監控(kong)不(bu)嚴,含氧量不(bu)穩定(ding)(ding)將(jiang)直(zhi)接(jie)影響(xiang)桿(gan)(gan)的(de)性(xing)能。如果桿(gan)(gan)的(de)表(biao)面氧化物(wu)能在(zai)后工序的(de)連續清(qing)洗中得以彌補外,但比較麻煩的(de)是有相當多(duo)的(de)氧化物(wu)存(cun)在(zai)于(yu)“皮(pi)下(xia)”,對拉線(xian)斷(duan)線(xian)影響(xiang)更直(zhi)接(jie),故(gu)而在(zai)拉制微(wei)細線(xian),超微(wei)細線(xian)時,為了減少斷(duan)線(xian),有時要對銅桿(gan)(gan)采(cai)取不(bu)得已(yi)的(de)辦法(fa)——剝(bo)皮(pi),甚至二次剝(bo)皮(pi)的(de)原(yuan)因所在(zai),目的(de)要除去皮(pi)下(xia)氧化物(wu)。
四(si)、低氧銅桿和(he)無氧銅桿的(de)韌性有差別
兩者都(dou)可以拉到0.015mm,但在低(di)溫(wen)超導線中的低(di)溫(wen)級無(wu)氧銅,其細(xi)絲間(jian)(jian)的間(jian)(jian)距只有0.001mm.
五、從制桿的原材料到(dao)制線的經濟(ji)性(xing)有差(cha)別。
制(zhi)造無(wu)氧銅(tong)桿要求質量較高(gao)的(de)原材料。一般(ban),拉制(zhi)直(zhi)徑>1mm的(de)銅(tong)線(xian)時,低氧銅(tong)桿的(de)優點比(bi)較明(ming)顯,而(er)無(wu)氧銅(tong)桿顯得更為優越(yue)的(de)是(shi)拉制(zhi)直(zhi)徑<0.5mm的(de)銅(tong)線(xian)。
六、低氧(yang)銅(tong)(tong)桿(gan)的(de)(de)制線(xian)工藝與無(wu)氧(yang)銅(tong)(tong)桿(gan)的(de)(de)有所(suo)不(bu)同(tong)。
低氧銅(tong)桿的(de)(de)(de)制(zhi)線工(gong)藝不能(neng)照搬到無氧銅(tong)桿的(de)(de)(de)制(zhi)線工(gong)藝上來,至少兩者的(de)(de)(de)退(tui)火工(gong)藝是不同的(de)(de)(de)。因為線的(de)(de)(de)柔軟性深(shen)受材料成(cheng)份和制(zhi)桿,制(zhi)線和退(tui)火工(gong)藝的(de)(de)(de)影響,不能(neng)簡單地說(shuo)低氧銅(tong)或無氧銅(tong)誰軟誰硬。
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