穿孔是不銹鋼管生產的重要工序之一,對不銹鋼管的管坯成本、品種規格及成品質量有很大影響。根據穿孔機的結構和穿孔過程變形特點的不同,穿孔機可分為兩大類:一類為斜軋穿孔機,又根據軋輥形狀及導衛裝置的不同而演變出多種類型,如曼乃斯曼穿孔機、狄塞爾穿孔機等;另一類是壓力擠孔機和推軋穿孔機(PPM穿孔機)。目前應用最廣的是二輥斜軋穿孔機。


一、斜軋穿孔


  自(zi)1885年發(fa)明(ming)二輥斜(xie)軋(ya)穿(chuan)孔(kong)(kong)機(ji)(ji)(ji)(ji)(ji)以來,斜(xie)軋(ya)穿(chuan)孔(kong)(kong)至今仍是(shi)最廣泛應用的穿(chuan)孔(kong)(kong)設備。主要斜(xie)軋(ya)穿(chuan)孔(kong)(kong)機(ji)(ji)(ji)(ji)(ji)的類型有:桶形輥穿(chuan)孔(kong)(kong)機(ji)(ji)(ji)(ji)(ji)、狄塞爾穿(chuan)孔(kong)(kong)機(ji)(ji)(ji)(ji)(ji)、錐形輥穿(chuan)孔(kong)(kong)機(ji)(ji)(ji)(ji)(ji)及三(san)輥穿(chuan)孔(kong)(kong)機(ji)(ji)(ji)(ji)(ji)。


1. 桶形(xing)輥穿(chuan)孔機


   二輥(gun)(gun)(gun)斜軋(ya)(ya)穿(chuan)孔機(ji)由德(de)國的(de)(de)曼乃斯曼(R.&M.Mannesmann)兄弟(di)發明,經瑞士工程(cheng)師(shi)斯蒂弗(fu)爾(R.C Stiefeil)加以完善。它的(de)(de)工作運動情況(kuang)如圖3-1所示,左右(you)兩個(ge)軋(ya)(ya)輥(gun)(gun)(gun)同向旋轉,上(shang)下垂直(zhi)布(bu)置(zhi)的(de)(de)兩個(ge)導板固定不(bu)(bu)動,中(zhong)間(jian)一(yi)個(ge)隨動頂頭,軋(ya)(ya)輥(gun)(gun)(gun)軸(zhou)線(xian)和軋(ya)(ya)制線(xian)相交成一(yi)個(ge)傾斜角(jiao)。軋(ya)(ya)輥(gun)(gun)(gun)左右(you)布(bu)置(zhi),導板上(shang)下布(bu)置(zhi)的(de)(de)為(wei)臥(wo)式穿(chuan)孔機(ji),相反(fan)為(wei)立式穿(chuan)孔機(ji)。二輥(gun)(gun)(gun)斜軋(ya)(ya)穿(chuan)孔方(fang)法(fa)的(de)(de)優(you)點(dian)是對心性好(hao),毛管(guan)(guan)(guan)的(de)(de)壁厚(hou)較均勻;一(yi)次延伸(shen)系數(shu)較大,一(yi)般在(zai)(zai)1.25~4.5之(zhi)間(jian),可(ke)以直(zhi)接從實心圓(yuan)坯(pi)穿(chuan)制成較薄的(de)(de)毛管(guan)(guan)(guan)。主(zhu)要缺(que)點(dian)是這種(zhong)(zhong)加工方(fang)法(fa)變形(xing)復雜,容易在(zai)(zai)毛管(guan)(guan)(guan)內外表面產生和擴大缺(que)陷,所以對管(guan)(guan)(guan)坯(pi)質量要求(qiu)較高(gao),一(yi)般皆采用鍛、軋(ya)(ya)坯(pi)。由于對鋼(gang)管(guan)(guan)(guan)表面質量要求(qiu)的(de)(de)不(bu)(bu)斷提高(gao),合金鋼(gang)比(bi)重的(de)(de)不(bu)(bu)斷增長,尤其是連鑄圓(yuan)坯(pi)的(de)(de)推廣使用,現(xian)在(zai)(zai)這種(zhong)(zhong)喂入角(jiao)小于13°的(de)(de)二輥(gun)(gun)(gun)斜軋(ya)(ya)機(ji),已(yi)不(bu)(bu)能滿足不(bu)(bu)銹鋼(gang)管(guan)(guan)(guan)生產中(zhong)對生產率(lv)和鋼(gang)管(guan)(guan)(guan)質量的(de)(de)要求(qiu),因而新結構的(de)(de)斜軋(ya)(ya)穿(chuan)孔機(ji)相繼(ji)出現(xian)。


圖 1.jpg


 2. 狄塞爾穿孔機


  狄塞爾(er)穿(chuan)孔機是主動旋轉導盤二輥桶形輥斜軋穿孔機,如圖3-2所示,1972年開始見于聯邦德國,是在二輥桶形輥穿孔機基礎上演變而來的。軋輥上下布置,每個軋輥由單獨的主電機通過萬向連接軸直接驅動;左右兩側的導板被兩主動旋轉導盤所替代,因導盤是傳動的,導盤旋轉的切線速度在變形區壓縮帶比軋輥切線速度在軋制軸線上的分量大20%~25%,給軋件施加一個軸向送進力,以減少軋件的軸向阻力。孔喉橢圓度可調近1.0,這樣使最大延伸系數達到5.0,軸向金屬滑動系數增加,毛管內外表面質量大為改善,從而提高了生產率,降低了單位能耗。狄塞爾穿孔機出口速度達1.2m/s,導盤磨損小,使用壽命長,不必經常更換,有利于作業率的提高。


圖 2.jpg


  圍(wei)繞提高穿(chuan)孔(kong)效(xiao)率和穿(chuan)孔(kong)毛管精(jing)度,進行(xing)了一系列的(de)技術改進。如頂桿采用(yong)線外循環(huan)冷卻,在機架出口,向一側循環(huan)運(yun)送冷卻,冷卻后(hou)送回穿(chuan)孔(kong)軋制線,由于是線外脫出穿(chuan)孔(kong)毛管送往下道(dao)工序,避免了頂桿小(xiao)車的(de)往復運(yun)動,縮短穿(chuan)孔(kong)周(zhou)期,提高了效(xiao)率。如機后(hou)采用(yong)多組定(ding)(ding)心抱(bao)輥(gun),增加頂桿的(de)穩(wen)定(ding)(ding)性(xing),提高壁厚精(jing)度。


3. 錐形輥穿孔機


  20世紀80年(nian)代又在狄塞爾穿孔(kong)(kong)機(ji)(ji)結構特點的(de)基礎上(shang)(shang)(shang),出現(xian)了(le)(le)主動(dong)旋轉導(dao)(dao)盤、大喂入角(jiao)的(de)錐形(xing)(xing)(xing)(xing)輥(gun)(gun)兩輥(gun)(gun)斜軋(ya)(ya)(ya)(ya)穿孔(kong)(kong)機(ji)(ji),如(ru)圖3-3所(suo)示。它與狄塞爾穿孔(kong)(kong)機(ji)(ji)最大的(de)不同(tong)是(shi)軋(ya)(ya)(ya)(ya)輥(gun)(gun)的(de)形(xing)(xing)(xing)(xing)狀由桶(tong)(tong)形(xing)(xing)(xing)(xing)改為錐形(xing)(xing)(xing)(xing),這(zhe)種(zhong)(zhong)輥(gun)(gun)形(xing)(xing)(xing)(xing)對斜軋(ya)(ya)(ya)(ya)穿孔(kong)(kong)機(ji)(ji)的(de)適應性(xing)來(lai)說,優于桶(tong)(tong)形(xing)(xing)(xing)(xing)輥(gun)(gun)。因為在這(zhe)種(zhong)(zhong)穿孔(kong)(kong)機(ji)(ji)上(shang)(shang)(shang),錐形(xing)(xing)(xing)(xing)輥(gun)(gun)的(de)直徑沿(yan)穿孔(kong)(kong)變(bian)(bian)形(xing)(xing)(xing)(xing)區(qu)是(shi)逐(zhu)漸增加的(de),因此,在很大程度(du)(du)上(shang)(shang)(shang)減少(shao)管(guan)(guan)坯(pi)變(bian)(bian)形(xing)(xing)(xing)(xing)過程中(zhong)的(de)切向(xiang)剪切應力(li),抑制旋轉橫(heng)鍛效應,改善了(le)(le)毛(mao)管(guan)(guan)內外表面質(zhi)量,使得許多難穿的(de)高合金鋼管(guan)(guan)坯(pi)都可(ke)(ke)以在這(zhe)種(zhong)(zhong)軋(ya)(ya)(ya)(ya)機(ji)(ji)上(shang)(shang)(shang)順利軋(ya)(ya)(ya)(ya)制。錐形(xing)(xing)(xing)(xing)輥(gun)(gun)穿孔(kong)(kong)機(ji)(ji)穿孔(kong)(kong)效率高,有報道稱最大出口速度(du)(du)可(ke)(ke)達1.5m/s,有利于高生(sheng)產(chan)(chan)率機(ji)(ji)組選用;軋(ya)(ya)(ya)(ya)輥(gun)(gun)軸線與軋(ya)(ya)(ya)(ya)制線間除了(le)(le)有10°左右的(de)喂入角(jiao)α外,還有一個15°左右的(de)輾軋(ya)(ya)(ya)(ya)角(jiao)γ,這(zhe)樣可(ke)(ke)使該類型穿孔(kong)(kong)軸向(xiang)滑動(dong)系數(shu)達到了(le)(le)0.9,最大延伸系數(shu)可(ke)(ke)達6.0,在變(bian)(bian)形(xing)(xing)(xing)(xing)量的(de)分配(pei)上(shang)(shang)(shang),可(ke)(ke)承擔較(jiao)大變(bian)(bian)形(xing)(xing)(xing)(xing),從而(er)減少(shao)了(le)(le)軋(ya)(ya)(ya)(ya)管(guan)(guan)機(ji)(ji)的(de)變(bian)(bian)形(xing)(xing)(xing)(xing);穿孔(kong)(kong)擴徑量達到30%~40%,這(zhe)就(jiu)不僅可(ke)(ke)提供(gong)薄壁毛(mao)管(guan)(guan),還可(ke)(ke)以減少(shao)管(guan)(guan)坯(pi)規(gui)格范圍,簡化生(sheng)產(chan)(chan)管(guan)(guan)理。錐形(xing)(xing)(xing)(xing)輥(gun)(gun)穿孔(kong)(kong)機(ji)(ji)既有配(pei)備導(dao)(dao)盤的(de),也有配(pei)備導(dao)(dao)板的(de),目(mu)前已建(jian)、在建(jian)新(xin)的(de)軋(ya)(ya)(ya)(ya)管(guan)(guan)機(ji)(ji)組上(shang)(shang)(shang)兩種(zhong)(zhong)配(pei)置均有使用。


圖 3.jpg


 狄塞(sai)爾穿(chuan)孔(kong)機(ji)和(he)錐形(xing)輥穿(chuan)孔(kong)機(ji)都是(shi)當代(dai)廣為采用的新(xin)型穿(chuan)孔(kong)機(ji),穿(chuan)孔(kong)效率高及產品精(jing)度(du)高,適于連(lian)鑄坯穿(chuan)孔(kong)。其中錐形(xing)輥穿(chuan)孔(kong)機(ji)具有(you)更(geng)大的發展前(qian)途(tu)。



二(er)、壓力(li)穿孔


  不(bu)銹鋼(gang)管坯壓力穿孔常在立式水壓機或液壓機(穿孔機)上進行,圖3-4為壓力穿孔(也稱壓力沖孔)操作過程示意圖。壓力穿孔于1891年問世,它是將方形或多邊形鋼錠放在擠壓缸中,擠成中空杯體,延伸系數為1.0~1.1,穿孔比(空心坯長度與內徑比)不大于7~10。


圖 4.jpg


  與二輥斜軋相比,這種加(jia)工(gong)(gong)方法的(de)坯(pi)料中心(xin)處(chu)于不(bu)(bu)等軸全(quan)向壓應力狀態,外(wai)表面(mian)承受著較(jiao)大(da)(da)的(de)徑向壓力,因(yin)內、外(wai)表面(mian)在加(jia)工(gong)(gong)過程中不(bu)(bu)會產生缺陷,對來料沒(mei)有(you)苛(ke)刻(ke)要求,可用(yong)于鋼錠、連鑄(zhu)方坯(pi)和(he)低(di)塑性材料的(de)穿(chuan)孔(kong)。此(ci)法加(jia)工(gong)(gong)主(zhu)要是中心(xin)變(bian)形(xing),特(te)別有(you)利(li)于鋼錠中心(xin)的(de)粗大(da)(da)疏松組織致密(mi)化,雖(sui)然最大(da)(da)延(yan)伸系(xi)數只(zhi)有(you)1.1,但中心(xin)部(bu)分的(de)變(bian)形(xing)效果(guo)(guo)相當于外(wai)部(bu)加(jia)工(gong)(gong)效果(guo)(guo)的(de)5倍(bei)。主(zhu)要缺點是生產率低(di),成材率低(di),偏心(xin)率較(jiao)大(da)(da)。



三、對(dui)穿孔毛(mao)管的質(zhi)量要求


 1. 對穿孔(kong)工藝(yi)要求(qiu)


   不銹(xiu)鋼管(guan)(guan)(guan)坯穿(chuan)(chuan)孔(kong)(kong)是熱(re)軋無縫鋼管(guan)(guan)(guan)生(sheng)產(chan)中最重要(yao)(yao)的(de)(de)變形工序(xu)之一(yi),它將實心(xin)(xin)的(de)(de)管(guan)(guan)(guan)坯變為(wei)(wei)空心(xin)(xin)坯,穿(chuan)(chuan)孔(kong)(kong)后(hou)的(de)(de)空心(xin)(xin)坯通(tong)常被稱作毛(mao)管(guan)(guan)(guan)。我們可以(yi)視穿(chuan)(chuan)孔(kong)(kong)工序(xu)為(wei)(wei)定(ding)型工序(xu),即將軋件(jian)的(de)(de)橫截面(mian)定(ding)為(wei)(wei)圓環狀的(de)(de)工序(xu)。穿(chuan)(chuan)孔(kong)(kong)后(hou)毛(mao)管(guan)(guan)(guan)質量(liang)的(de)(de)好壞直接關系到下道工序(xu)的(de)(de)工藝是否能正常執行以(yi)及(ji)最終(zhong)產(chan)品質量(liang)的(de)(de)高(gao)低。為(wei)(wei)此對(dui)穿(chuan)(chuan)孔(kong)(kong)工藝提出如下幾點(dian)要(yao)(yao)求:首先要(yao)(yao)保證穿(chuan)(chuan)制(zhi)的(de)(de)毛(mao)管(guan)(guan)(guan)壁厚(hou)均勻,螺旋線較(jiao)淺、橢圓度小(xiao),幾何尺寸精度高(gao),當毛(mao)管(guan)(guan)(guan)尺寸偏小(xiao)、芯棒同毛(mao)管(guan)(guan)(guan)間隙過(guo)小(xiao)時(shi),毛(mao)管(guan)(guan)(guan)的(de)(de)溫降快,軋制(zhi)過(guo)程(cheng)中容易產(chan)生(sheng)壁厚(hou)不均、拉凹、孔(kong)(kong)洞等缺陷;其次,毛(mao)管(guan)(guan)(guan)的(de)(de)內外表面(mian)要(yao)(yao)光滑,不得有結疤、折疊、劃傷、裂紋、凹凸不平等缺陷;最后(hou)要(yao)(yao)有相應(ying)的(de)(de)穿(chuan)(chuan)孔(kong)(kong)速度和軋制(zhi)周期,以(yi)適應(ying)整(zheng)個(ge)機組的(de)(de)生(sheng)產(chan)節奏,使毛(mao)管(guan)(guan)(guan)溫度比(bi)較(jiao)均勻、終(zhong)軋溫度能夠滿足(zu)軋管(guan)(guan)(guan)機的(de)(de)工藝要(yao)(yao)求。


 2. 確保(bao)毛管質(zhi)量的技(ji)術措施(shi)


 為了(le)滿足上述工(gong)(gong)藝要(yao)求,除了(le)確定正確的穿孔工(gong)(gong)藝參數(包(bao)括管坯(pi)加熱溫(wen)度(du)、穿孔溫(wen)度(du)、穿孔速(su)度(du)、軋輥轉速(su)和喂入角的大小(xiao))及調整參數(輥距(ju)、導板/導盤距(ju)、頂(ding)頭(tou)前伸(shen)量)外,穿孔機組(zu)還應用了(le)如下技術:


   a. 穿孔機架:軋輥垂直(zhi)布置(zhi),使(shi)得更換和檢查(cha)導(dao)盤/導(dao)板的時間很短,可確保毛管外表面質量;


   b. 出口部分(fen):頂頭(tou)(tou)(tou)/頂桿從(cong)毛(mao)管(guan)中(zhong)抽出后頂頭(tou)(tou)(tou)或頂頭(tou)(tou)(tou)/頂桿的冷(leng)卻(que)在線外(wai)(wai)進(jin)行。設置(zhi)頂頭(tou)(tou)(tou)或頂頭(tou)(tou)(tou)/頂桿線外(wai)(wai)冷(leng)卻(que)循環系統(tong),可(ke)縮短周(zhou)期(qi)時間(jian),更容易檢(jian)查、更換(huan)頂頭(tou)(tou)(tou),另(ling)外(wai)(wai)如采用線外(wai)(wai)用回轉式冷(leng)卻(que)裝置(zhi)進(jin)行頂桿(帶頂頭(tou)(tou)(tou))冷(leng)卻(que),還(huan)可(ke)確保(bao)頂桿的直度較好(hao),為毛(mao)管(guan)的壁厚均勻提供了保(bao)證(zheng)(zheng);頂頭(tou)(tou)(tou)的循環使(shi)用,因冷(leng)卻(que)時間(jian)充分(fen),使(shi)冷(leng)卻(que)效果得到(dao)保(bao)證(zheng)(zheng),從(cong)而可(ke)以(yi)提高頂頭(tou)(tou)(tou)的使(shi)用壽命,確保(bao)毛(mao)管(guan)內表面的光滑;


  c. 頂(ding)桿(gan)及毛(mao)管導(dao)向:有多(duo)組(zu)定心(xin)輥,第一(yi)組(zu)定心(xin)輥裝在機架內,使(shi)其盡量靠近穿(chuan)(chuan)(chuan)孔變形區,以減(jian)小頂(ding)頭/頂(ding)桿(gan)的懸臂長度(du)、提高(gao)頂(ding)桿(gan)的剛度(du),可(ke)更好(hao)地限制頂(ding)桿(gan)/頂(ding)頭及軋件在穿(chuan)(chuan)(chuan)孔過(guo)程中(zhong)的徑向抖動,確(que)保穿(chuan)(chuan)(chuan)出(chu)的毛(mao)管壁厚均(jun)勻;


  d. 采用頂(ding)桿預旋(xuan)轉技術,頂(ding)頭能自動對正管坯的(de)中心,以提(ti)高毛管頭部的(de)壁厚(hou)精(jing)度,并可降低二(er)次咬(yao)入(ru)時(shi)因頂(ding)頭/頂(ding)桿轉動慣(guan)量的(de)阻力轉矩(ju)而(er)發生不咬(yao)入(ru)(前卡)故(gu)障的(de)概率。


3. 特殊(shu)的工藝要求


  為滿足(zu)連軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)工藝(yi)的(de)(de)(de)特殊性,對于(yu)專供連續軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)機使用(yong)的(de)(de)(de)毛(mao)管(guan)(guan)(guan)(guan),還有兩(liang)項重(zhong)要的(de)(de)(de)質量指標(biao)要求(qiu)(qiu):一(yi)(yi)是(shi)毛(mao)管(guan)(guan)(guan)(guan)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)的(de)(de)(de)橢圓(yuan)度(du)要小,因為毛(mao)管(guan)(guan)(guan)(guan)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)橢圓(yuan)度(du)過(guo)(guo)大將(jiang)(jiang)影響軋(ya)(ya)(ya)管(guan)(guan)(guan)(guan)前穿(chuan)芯(xin)(xin)棒(bang)的(de)(de)(de)順(shun)利(li)進(jin)行,輕者刮掉(diao)芯(xin)(xin)棒(bang)表面的(de)(de)(de)潤滑劑(ji),使軋(ya)(ya)(ya)制過(guo)(guo)程中震(zhen)動較大,降低荒管(guan)(guan)(guan)(guan)的(de)(de)(de)壁厚精度(du)和芯(xin)(xin)棒(bang)的(de)(de)(de)使用(yong)壽命(ming)并損傷(shang)設備,重(zhong)者芯(xin)(xin)棒(bang)可能會頂彎(wan)毛(mao)管(guan)(guan)(guan)(guan),致(zhi)使生(sheng)產中斷,這(zhe)就要求(qiu)(qiu)在(zai)調整時注意保(bao)證穿(chuan)孔過(guo)(guo)程即將(jiang)(jiang)結(jie)束時,毛(mao)管(guan)(guan)(guan)(guan)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)的(de)(de)(de)歸圓(yuan)效果;二(er)是(shi)毛(mao)管(guan)(guan)(guan)(guan)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)不得存在(zai)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)鐮(lian)刀(非環狀連續體(ti)部(bu)(bu)(bu)(bu)分(fen)的(de)(de)(de)俗稱,見圖3-5)缺(que)陷,當毛(mao)管(guan)(guan)(guan)(guan)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)存在(zai)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)鐮(lian)刀缺(que)陷時,穿(chuan)芯(xin)(xin)棒(bang)過(guo)(guo)程中容易將(jiang)(jiang)毛(mao)管(guan)(guan)(guan)(guan)尾(wei)(wei)(wei)部(bu)(bu)(bu)(bu)不連續的(de)(de)(de)部(bu)(bu)(bu)(bu)分(fen)金屬碰掉(diao),一(yi)(yi)旦這(zhe)些溫度(du)較低的(de)(de)(de)金屬被帶到毛(mao)管(guan)(guan)(guan)(guan)中,軋(ya)(ya)(ya)制時將(jiang)(jiang)硌傷(shang)軋(ya)(ya)(ya)件而(er)產生(sheng)孔洞管(guan)(guan)(guan)(guan),若這(zhe)些較硬的(de)(de)(de)金屬掉(diao)在(zai)軋(ya)(ya)(ya)輥上,將(jiang)(jiang)硌傷(shang)軋(ya)(ya)(ya)輥輥面而(er)造成鋼管(guan)(guan)(guan)(guan)外表面缺(que)陷等嚴重(zhong)的(de)(de)(de)質量事故(gu)。


圖 5.jpg


  如果是向(xiang)(xiang)限動(dong)(dong)芯棒連續軋管(guan)(guan)(guan)(guan)(guan)(guan)機提供(gong)毛管(guan)(guan)(guan)(guan)(guan)(guan),還(huan)須向(xiang)(xiang)毛管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)噴(pen)吹氮氣(qi)和硼(peng)砂,以(yi)起到(dao)去除毛管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)表面(mian)(mian)的(de)(de)(de)(de)(de)(de)氧(yang)化(hua)鐵皮(pi)、減(jian)小芯棒與軋件間的(de)(de)(de)(de)(de)(de)摩(mo)擦力、防止(zhi)軋制過程中(zhong)抖動(dong)(dong)的(de)(de)(de)(de)(de)(de)作(zuo)用(yong)。其過程為:抽出頂(ding)桿(gan)后的(de)(de)(de)(de)(de)(de)毛管(guan)(guan)(guan)(guan)(guan)(guan),送到(dao)吹硼(peng)砂站(zhan),由一特制的(de)(de)(de)(de)(de)(de)噴(pen)嘴向(xiang)(xiang)毛管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)部噴(pen)入硼(peng)砂和氮氣(qi),吹掉毛管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)部的(de)(de)(de)(de)(de)(de)氧(yang)化(hua)鐵皮(pi),清(qing)除原來的(de)(de)(de)(de)(de)(de)氧(yang)化(hua)物(硼(peng)砂使(shi)管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)壁的(de)(de)(de)(de)(de)(de)氧(yang)化(hua)層脫氧(yang),高溫(wen)下(xia)的(de)(de)(de)(de)(de)(de)硼(peng)砂呈熔融(rong)態,均勻地附(fu)著在毛管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)表面(mian)(mian)上可起到(dao)潤滑劑的(de)(de)(de)(de)(de)(de)作(zuo)用(yong),氮氣(qi)能(neng)(neng)保(bao)持(chi)毛管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)表面(mian)(mian)不再被氧(yang)化(hua));另外,硼(peng)砂在高溫(wen)狀態下(xia)生(sheng)(sheng)成霧狀氣(qi)體(ti),充(chong)滿(man)管(guan)(guan)(guan)(guan)(guan)(guan)內(nei),以(yi)防止(zhi)在隨(sui)后的(de)(de)(de)(de)(de)(de)運(yun)動(dong)(dong)中(zhong)空氣(qi)進入,減(jian)少內(nei)表面(mian)(mian)產生(sheng)(sheng)二次(ci)(ci)氧(yang)化(hua)的(de)(de)(de)(de)(de)(de)可能(neng)(neng)。這(zhe)就要求軋管(guan)(guan)(guan)(guan)(guan)(guan)前盡量避免毛管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)(de)(de)軸向(xiang)(xiang)移(yi)動(dong)(dong),以(yi)防止(zhi)毛管(guan)(guan)(guan)(guan)(guan)(guan)內(nei)表面(mian)(mian)產生(sheng)(sheng)二次(ci)(ci)氧(yang)化(hua),從(cong)而確(que)保(bao)軋制過程的(de)(de)(de)(de)(de)(de)穩定和軋出荒管(guan)(guan)(guan)(guan)(guan)(guan)的(de)(de)(de)(de)(de)(de)質量。


  限動芯棒連續軋(ya)管(guan)機組是否能(neng)正常運轉,是否能(neng)生產出高(gao)質(zhi)量的(de)(de)(de)不(bu)銹鋼管(guan),與(yu)毛(mao)管(guan)的(de)(de)(de)各項質(zhi)量指標(包括(kuo)溫度的(de)(de)(de)均勻性、外徑(jing)/壁(bi)厚幾(ji)何尺寸(cun)的(de)(de)(de)精度、內(nei)外表(biao)面的(de)(de)(de)光滑程(cheng)度等)有很大關(guan)(guan)系特別(bie)是與(yu)毛(mao)管(guan)尾(wei)部的(de)(de)(de)質(zhi)量狀況(kuang)(內(nei)徑(jing)尺寸(cun)偏差和是否存在尾(wei)部鐮刀(dao))以及為清除(chu)毛(mao)管(guan)內(nei)表(biao)面氧化物、防止毛(mao)管(guan)內(nei)表(biao)面二次氧化所(suo)采取的(de)(de)(de)上述工藝措施的(de)(de)(de)效果是密切相關(guan)(guan)的(de)(de)(de)。