【精(jing)密鋼管】精(jing)密鋼管的生產流程(cheng) 精(jing)密鋼管優點
精密鋼管基本用途
精密鋼管廣泛用于汽車、摩托車、電動車、石化、電力、船只、航天、軸承、氣動元件、中低壓鍋爐無(wu)縫(feng)鋼(gang)管(guan)等(deng)范疇,也可適(shi)用于鋼(gang)筋(jin)套筒、軸承、液壓、機械加工等(deng)領域!
精密鋼管生產流程
精密鋼管的生(sheng)產(chan)流(liu)程(cheng)(cheng)和(he)普通(tong)的無縫管一樣,就(jiu)是(shi)多(duo)了道最后酸洗冷軋的程(cheng)(cheng)序(xu)。
精密鋼管工藝流程
管坯——檢(jian)驗(yan)——剝皮——檢(jian)驗(yan)——加熱——穿孔——酸(suan)洗(xi)鈍化(hua)——修磨(mo)——潤滑風干——冷軋——去(qu)油——切(qie)頭——檢(jian)驗(yan)——標識——成(cheng)品包(bao)裝
鋼管區別
1、無(wu)縫鋼管主要特點是無(wu)焊接縫,可承(cheng)受較大的(de)(de)壓力。產品可以是很粗糙的(de)(de)鑄態或(huo)冷(leng)撥件。
2、精密鋼管(guan)是(shi)近(jin)幾(ji)年出現的產品,主要(yao)是(shi)內孔、外壁尺寸有嚴格的公差及(ji)粗(cu)糙(cao)度。
精密鋼管特點
1.外徑更小。
2.精度高可做小(xiao)批量生。
3.冷拔成品精度(du)高(gao),表面質量好。
4.鋼管橫面積更復(fu)雜(za)。
5.鋼管(guan)性能更(geng)優越,金屬比較密(mi)。
3.冷拔成品精度高(gao),表面質量好。
4.鋼管橫面積(ji)更(geng)復雜。
5.鋼管性能更(geng)優越,金(jin)屬(shu)比較密。
精密鋼管計算公式(shi)::[(外徑(jing)-壁厚)*壁厚]*0.02466=kg/米(每米的重量)
熱處理工藝
前奏
真空(kong)退(tui)火優質彈(dan)簧鋼(gang)(gang)、工具鋼(gang)(gang)、精密鋼(gang)(gang)管(guan)的絲(si)材(cai),不銹(xiu)鋼(gang)(gang)制品及鈦(tai)合金(jin)材(cai),作光亮退(tui)火均可(ke)采用(yong)真空(kong)處理。退(tui)火溫度(du)愈(yu)低,則要求真空(kong)度(du)愈(yu)高(gao)。為防止鉻(ge)的蒸發(fa)及加速(su)熱傳導,一般采用(yong)載氣加熱(保溫)法,并注意對不銹(xiu)鋼(gang)(gang)和鈦(tai)合金(jin)不宜用(yong)氮而應(ying)采用(yong)氬氣。
過程
真(zhen)空(kong)(kong)淬(cui)(cui)(cui)(cui)火(huo)(huo)真(zhen)空(kong)(kong)淬(cui)(cui)(cui)(cui)火(huo)(huo)爐按冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)卻(que)方(fang)法(fa)分為油(you)淬(cui)(cui)(cui)(cui)和(he)氣(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)兩類(lei),按工(gong)(gong)位(wei)(wei)數分為單(dan)室(shi)(shi)(shi)式(shi)和(he)雙(shuang)室(shi)(shi)(shi)式(shi),904山畏(wei)嘲均屬周(zhou)期(qi)式(shi)作(zuo)業爐。真(zhen)空(kong)(kong)油(you)淬(cui)(cui)(cui)(cui)爐都是雙(shuang)室(shi)(shi)(shi)的(de)(de)(de),后(hou)室(shi)(shi)(shi)置電加(jia)熱(re)(re)元件,前室(shi)(shi)(shi)的(de)(de)(de)下(xia)方(fang)置油(you)槽。工(gong)(gong)件完成(cheng)加(jia)熱(re)(re)、保溫后(hou)移入(ru)前室(shi)(shi)(shi),關閉中(zhong)門(men)后(hou)向前室(shi)(shi)(shi)充入(ru)惰性氣(qi)(qi)(qi)至大(da)約2.66%26times;lO~1.01%26times;10 Pa(200~760mm汞(gong)柱(zhu)),入(ru)油(you)。油(you)淬(cui)(cui)(cui)(cui)易引起工(gong)(gong)件表面變質。由于(yu)(yu)表面活性大(da),在短暫(zan)的(de)(de)(de)高(gao)(gao)溫油(you)膜作(zuo)用(yong)(yong)下(xia)即可發(fa)生(sheng)顯著(zhu)薄層滲碳,此(ci)外,碳黑和(he)油(you)在表面的(de)(de)(de)粘附對(dui)簡化熱(re)(re)處(chu)(chu)理(li)流(liu)(liu)程很不(bu)利。真(zhen)空(kong)(kong)淬(cui)(cui)(cui)(cui)火(huo)(huo)技術的(de)(de)(de)發(fa)展(zhan)主要在于(yu)(yu)研制性能(neng)優良、工(gong)(gong)位(wei)(wei)單(dan)一(yi)的(de)(de)(de)氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)淬(cui)(cui)(cui)(cui)火(huo)(huo)爐。前述雙(shuang)室(shi)(shi)(shi)式(shi)爐亦可用(yong)(yong)于(yu)(yu)氣(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(在前室(shi)(shi)(shi)噴(pen)氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)卻(que)),但雙(shuang)工(gong)(gong)位(wei)(wei)式(shi)的(de)(de)(de)操作(zuo)使(shi)(shi)大(da)批量裝爐的(de)(de)(de)生(sheng)產(chan)發(fa)生(sheng)困難(nan),也(ye)易在高(gao)(gao)溫移動中(zhong)引起工(gong)(gong)件變形或改變工(gong)(gong)件方(fang)位(wei)(wei)增加(jia)淬(cui)(cui)(cui)(cui)火(huo)(huo)變形。單(dan)一(yi)工(gong)(gong)位(wei)(wei)的(de)(de)(de)氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)淬(cui)(cui)(cui)(cui)火(huo)(huo)爐是在加(jia)熱(re)(re)保溫完成(cheng)后(hou)在加(jia)熱(re)(re)室(shi)(shi)(shi)內噴(pen)氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)卻(que)。氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)的(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)速不(bu)如(ru)油(you)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)快,也(ye)低于(yu)(yu)傳統淬(cui)(cui)(cui)(cui)火(huo)(huo)法(fa)中(zhong)的(de)(de)(de)熔鹽等溫、分級淬(cui)(cui)(cui)(cui)火(huo)(huo)。因而,不(bu)斷提高(gao)(gao)噴(pen)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)室(shi)(shi)(shi)壓(ya)力(li),增大(da)流(liu)(liu)量,以(yi)及采用(yong)(yong)摩爾質量比氮(dan)和(he)氬小(xiao)的(de)(de)(de)惰性氣(qi)(qi)(qi)體氦和(he)氫(qing),是當今(jin)真(zhen)空(kong)(kong)淬(cui)(cui)(cui)(cui)火(huo)(huo)技術發(fa)展(zhan)的(de)(de)(de)主流(liu)(liu)。70年(nian)代(dai)后(hou)期(qi)將(jiang)氮(dan)氣(qi)(qi)(qi)噴(pen)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)的(de)(de)(de)壓(ya)力(li)從(cong)(1~2)%26times;10Pa提高(gao)(gao)到(5~6)%26times;10Pa,使(shi)(shi)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)卻(que)能(neng)力(li)接(jie)近于(yu)(yu)常壓(ya)下(xia)的(de)(de)(de)油(you)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)。80年(nian)代(dai)中(zhong)期(qi)出現超高(gao)(gao)壓(ya)氣(qi)(qi)(qi)淬(cui)(cui)(cui)(cui),用(yong)(yong)(10~20)%26times;10Pa的(de)(de)(de)氦,冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)卻(que)能(neng)力(li)等于(yu)(yu)或略高(gao)(gao)于(yu)(yu)油(you)淬(cui)(cui)(cui)(cui),已進入(ru)工(gong)(gong)業實用(yong)(yong)。90年(nian)代(dai)初采用(yong)(yong)40%26times;10Pa的(de)(de)(de)氫(qing)氣(qi)(qi)(qi),接(jie)近水淬(cui)(cui)(cui)(cui)的(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)(leng)(leng)卻(que)能(neng)力(li),尚(shang)處(chu)(chu)于(yu)(yu)起步階(jie)段。工(gong)(gong)業發(fa)達(da)國家(jia)已進展(zhan)到以(yi)高(gao)(gao)壓(ya)(5~6)%26times;10。Pa氣(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)為主體,而中(zhong)國產(chan)氣(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)一(yi)些金屬的(de)(de)(de)蒸(zheng)氣(qi)(qi)(qi)壓(ya)(理(li)論值)與溫度(du)的(de)(de)(de)關系則尚(shang)處(chu)(chu)于(yu)(yu)一(yi)般(ban)加(jia)壓(ya)氣(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(2%26times;10Pa)型階(jie)段。
結果真空滲(shen)碳(tan)(tan)(tan)為真空滲(shen)碳(tan)(tan)(tan)一(yi)淬(cui)火(huo)工(gong)藝曲線。在真空中加熱(re)到(dao)滲(shen)碳(tan)(tan)(tan)溫(wen)度并保溫(wen)使表面凈化、活(huo)化之(zhi)后,通(tong)入(ru)稀薄滲(shen)碳(tan)(tan)(tan)富化氣(qi)(見控(kong)制氣(qi)氛熱(re)處理),在大約(yue)1330Pa(10T0rr)負壓下(xia)進行滲(shen)入(ru),然(ran)后停(ting)氣(qi)(降壓)進行擴(kuo)散(san)。滲(shen)碳(tan)(tan)(tan)后的(de)精密鋼管淬(cui)火(huo)采(cai)用一(yi)次淬(cui)火(huo)法,即(ji)先(xian)停(ting)電,通(tong)氮冷(leng)卻工(gong)件至(zhi)臨界點A,、以下(xia),使內部發(fa)生相(xiang)變(bian),再停(ting)氣(qi)、開泵,升溫(wen)到(dao)Ac1,~Accm之(zhi)間。淬(cui)冷(leng)方法可(ke)采(cai)用氣(qi)冷(leng)或油冷(leng)。后者為奧氏體(ti)化后移(yi)入(ru)前室(shi),充氮至(zhi)常壓,入(ru)油。真空滲(shen)碳(tan)(tan)(tan)的(de)溫(wen)度一(yi)般(ban)高(gao)于普通(tong)氣(qi)體(ti)滲(shen)碳(tan)(tan)(tan),常采(cai)用920~1040℃滲(shen)入(ru)和(he)擴(kuo)散(san)可(ke)按所示分兩階(jie)段,也可(ke)用脈沖(chong)式(shi)通(tong)氣(qi)、停(ting)氣(qi),多段式(shi)的(de)滲(shen)一(yi)擴(kuo)相(xiang)間,效果更好。由于溫(wen)度高(gao),尤其表面潔凈、有活(huo)性,真空滲(shen)碳(tan)(tan)(tan)層形成(cheng)速度比(bi)普通(tong)氣(qi)體(ti)、液(ye)體(ti)和(he)固(gu)體(ti)滲(shen)碳(tan)(tan)(tan)快,如要求滲(shen)層為1mm時,在927℃只需(xu)5h,而1033℃僅需(xu)1h。