20#精密鋼管批發零售

　　現貨充足,定制加工各種規格20#精密鋼管,發(fa)貨快(kuai),報價低,全(quan)國可發(fa),我司專業(ye)生產,歡迎咨(zi)詢~

　　20#精密鋼管熱處理工(gong)藝

　　精密鋼管前奏

　　真空退火優(you)質彈簧鋼(gang)(gang)、工具(ju)鋼(gang)(gang)、精密鋼(gang)(gang)管(guan)的絲材，不銹(xiu)鋼(gang)(gang)制品及鈦合(he)金(jin)材，作光亮退火均可采(cai)(cai)用(yong)(yong)真空處理。退火溫(wen)(wen)度愈低(di)，則要求真空度愈高。為(wei)防(fang)止鉻的蒸發(fa)及加速熱傳(chuan)導，一般采(cai)(cai)用(yong)(yong)載氣(qi)加熱(保溫(wen)(wen))法，并注意對不銹(xiu)鋼(gang)(gang)和鈦合(he)金(jin)不宜用(yong)(yong)氮而應采(cai)(cai)用(yong)(yong)氬氣(qi)。

　　精密鋼管過程

　　真(zhen)空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)真(zhen)空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)爐(lu)(lu)(lu)按冷(leng)(leng)(leng)(leng)(leng)卻方法(fa)分(fen)為(wei)油淬(cui)(cui)(cui)和(he)氣(qi)淬(cui)(cui)(cui)兩類(lei)，按工(gong)位(wei)數分(fen)為(wei)單室(shi)(shi)式和(he)雙室(shi)(shi)式，904山\畏嘲均屬(shu)周期(qi)式作(zuo)(zuo)業爐(lu)(lu)(lu)。真(zhen)空(kong)油淬(cui)(cui)(cui)爐(lu)(lu)(lu)都是雙室(shi)(shi)的(de)(de)(de)(de)(de)(de)，后(hou)室(shi)(shi)置電加(jia)熱元件，前(qian)(qian)室(shi)(shi)的(de)(de)(de)(de)(de)(de)下方置油槽。工(gong)件完(wan)成加(jia)熱、保溫(wen)(wen)后(hou)移入前(qian)(qian)室(shi)(shi)，關閉中門后(hou)向前(qian)(qian)室(shi)(shi)充(chong)入惰(duo)性(xing)氣(qi)至(zhi)大(da)約2.66%26times;lO ～1.01%26times;10 Pa(200～760mm汞柱)，入油。油淬(cui)(cui)(cui)易引起(qi)工(gong)件表(biao)面變(bian)(bian)質(zhi)。由于(yu)表(biao)面活性(xing)大(da)，在短暫的(de)(de)(de)(de)(de)(de)高(gao)溫(wen)(wen)油膜作(zuo)(zuo)用(yong)(yong)下即(ji)可發生顯(xian)著薄(bo)層滲碳(tan)，此(ci)外(wai)，碳(tan)黑(hei)和(he)油在表(biao)面的(de)(de)(de)(de)(de)(de)粘附對簡(jian)化熱處理(li)流程很不利。真(zhen)空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)技(ji)術的(de)(de)(de)(de)(de)(de)發展主要在于(yu)研制(zhi)性(xing)能(neng)優良、工(gong)位(wei)單一的(de)(de)(de)(de)(de)(de)氣(qi)冷(leng)(leng)(leng)(leng)(leng)淬(cui)(cui)(cui)火(huo)(huo)(huo)爐(lu)(lu)(lu)。前(qian)(qian)述雙室(shi)(shi)式爐(lu)(lu)(lu)亦可用(yong)(yong)于(yu)氣(qi)淬(cui)(cui)(cui)(在前(qian)(qian)室(shi)(shi)噴(pen)(pen)氣(qi)冷(leng)(leng)(leng)(leng)(leng)卻)，但雙工(gong)位(wei)式的(de)(de)(de)(de)(de)(de)操作(zuo)(zuo)使(shi)大(da)批量裝爐(lu)(lu)(lu)的(de)(de)(de)(de)(de)(de)生產發生困(kun)難(nan)，也(ye)易在高(gao)溫(wen)(wen)移動中引起(qi)工(gong)件變(bian)(bian)形(xing)或改變(bian)(bian)工(gong)件方位(wei)增加(jia)淬(cui)(cui)(cui)火(huo)(huo)(huo)變(bian)(bian)形(xing)。單一工(gong)位(wei)的(de)(de)(de)(de)(de)(de)氣(qi)冷(leng)(leng)(leng)(leng)(leng)淬(cui)(cui)(cui)火(huo)(huo)(huo)爐(lu)(lu)(lu)是在加(jia)熱保溫(wen)(wen)完(wan)成后(hou)在加(jia)熱室(shi)(shi)內噴(pen)(pen)氣(qi)冷(leng)(leng)(leng)(leng)(leng)卻。氣(qi)冷(leng)(leng)(leng)(leng)(leng)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)速(su)不如油冷(leng)(leng)(leng)(leng)(leng)快，也(ye)低于(yu)傳統淬(cui)(cui)(cui)火(huo)(huo)(huo)法(fa)中的(de)(de)(de)(de)(de)(de)熔(rong)鹽等溫(wen)(wen)、分(fen)級淬(cui)(cui)(cui)火(huo)(huo)(huo)。因而，不斷提高(gao)噴(pen)(pen)冷(leng)(leng)(leng)(leng)(leng)室(shi)(shi)壓(ya)(ya)力，增大(da)流量，以及采用(yong)(yong)摩(mo)爾質(zhi)量比氮(dan)和(he)氬小的(de)(de)(de)(de)(de)(de)惰(duo)性(xing)氣(qi)體(ti)氦和(he)氫(qing)，是當今(jin)真(zhen)空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)技(ji)術發展的(de)(de)(de)(de)(de)(de)主流。70年(nian)(nian)代(dai)后(hou)期(qi)將氮(dan)氣(qi)噴(pen)(pen)冷(leng)(leng)(leng)(leng)(leng)的(de)(de)(de)(de)(de)(de)壓(ya)(ya)力從(1～2)%26times;10Pa提高(gao)到(5～6)%26times;10Pa，使(shi)冷(leng)(leng)(leng)(leng)(leng)卻能(neng)力接近于(yu)常(chang)壓(ya)(ya)下的(de)(de)(de)(de)(de)(de)油冷(leng)(leng)(leng)(leng)(leng)。80年(nian)(nian)代(dai)中期(qi)出(chu)現超高(gao)壓(ya)(ya)氣(qi)淬(cui)(cui)(cui)，用(yong)(yong)(10～20)%26times;10Pa的(de)(de)(de)(de)(de)(de)氦，冷(leng)(leng)(leng)(leng)(leng)卻能(neng)力等于(yu)或略高(gao)于(yu)油淬(cui)(cui)(cui)，已進(jin)入工(gong)業實用(yong)(yong)。90年(nian)(nian)代(dai)初(chu)采用(yong)(yong)40%26times;10Pa的(de)(de)(de)(de)(de)(de)氫(qing)氣(qi)，接近水(shui)淬(cui)(cui)(cui)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)卻能(neng)力，尚處于(yu)起(qi)步階段。工(gong)業發達(da)國(guo)(guo)家已進(jin)展到以高(gao)壓(ya)(ya)(5～6)%26times;10。Pa氣(qi)淬(cui)(cui)(cui)為(wei)主體(ti)，而中國(guo)(guo)產氣(qi)淬(cui)(cui)(cui)一些(xie)金屬(shu)的(de)(de)(de)(de)(de)(de)蒸氣(qi)壓(ya)(ya)(理(li)論(lun)值(zhi))與溫(wen)(wen)度的(de)(de)(de)(de)(de)(de)關系則(ze)尚處于(yu)一般加(jia)壓(ya)(ya)氣(qi)淬(cui)(cui)(cui)(2%26times;10Pa)型階段。

　　結果真(zhen)(zhen)空(kong)滲(shen)(shen)(shen)碳(tan)為真(zhen)(zhen)空(kong)滲(shen)(shen)(shen)碳(tan)一(yi)淬火工藝曲線。在真(zhen)(zhen)空(kong)中加熱(re)到滲(shen)(shen)(shen)碳(tan)溫(wen)度(du)并保溫(wen)使(shi)表面(mian)凈化、活化之(zhi)后(hou)(hou)，通(tong)(tong)入稀薄滲(shen)(shen)(shen)碳(tan)富化氣(qi)(qi)(qi)(qi)(qi)(見控(kong)制氣(qi)(qi)(qi)(qi)(qi)氛熱(re)處理)，在大(da)約1330Pa(10T0rr)負壓下進行滲(shen)(shen)(shen)入，然后(hou)(hou)停(ting)氣(qi)(qi)(qi)(qi)(qi)(降壓)進行擴(kuo)散。滲(shen)(shen)(shen)碳(tan)后(hou)(hou)的(de)精密鋼管淬火采(cai)(cai)用(yong)(yong)一(yi)次淬火法，即先停(ting)電，通(tong)(tong)氮冷(leng)卻工件至(zhi)臨界點A，、以(yi)下，使(shi)內部(bu)發生相變，再停(ting)氣(qi)(qi)(qi)(qi)(qi)、開泵，升溫(wen)到Ac1，～Accm之(zhi)間(jian)。淬冷(leng)方法可采(cai)(cai)用(yong)(yong)氣(qi)(qi)(qi)(qi)(qi)冷(leng)或(huo)油(you)冷(leng)。后(hou)(hou)者為奧(ao)氏體(ti)化后(hou)(hou)移入前室，充(chong)氮至(zhi)常壓，入油(you)。真(zhen)(zhen)空(kong)滲(shen)(shen)(shen)碳(tan)的(de)溫(wen)度(du)一(yi)般高(gao)于普通(tong)(tong)氣(qi)(qi)(qi)(qi)(qi)體(ti)滲(shen)(shen)(shen)碳(tan)，常采(cai)(cai)用(yong)(yong)920～1040℃滲(shen)(shen)(shen)入和擴(kuo)散可按所示分(fen)兩階(jie)段，也可用(yong)(yong)脈沖式通(tong)(tong)氣(qi)(qi)(qi)(qi)(qi)、停(ting)氣(qi)(qi)(qi)(qi)(qi)，多(duo)段式的(de)滲(shen)(shen)(shen)一(yi)擴(kuo)相間(jian)，效果更好。由(you)于溫(wen)度(du)高(gao)，尤(you)其表面(mian)潔(jie)凈、有活性，真(zhen)(zhen)空(kong)滲(shen)(shen)(shen)碳(tan)層形(xing)成速度(du)比普通(tong)(tong)氣(qi)(qi)(qi)(qi)(qi)體(ti)、液體(ti)和固體(ti)滲(shen)(shen)(shen)碳(tan)快，如要求滲(shen)(shen)(shen)層為1mm時，在927℃只需5h，而1033℃僅需1h。

　　精密鋼管硬度與變形

　　取(qu)兩塊(kuai)式(shi)樣，一(yi)塊(kuai)用于研究(jiu)不(bu)同形變程度(du)對硬度(du)的影響，另一(yi)塊(kuai)研究(jiu)不(bu)同溫(wen)度(du)對性能的影響。

　　冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)(qiang)(qiang)化在(zai)實際(ji)生(sheng)產中具有重(zhong)要的(de)(de)(de)意義。首(shou)先這是一(yi)種重(zhong)要的(de)(de)(de)強(qiang)(qiang)(qiang)(qiang)(qiang)化材(cai)料的(de)(de)(de)手段，尤(you)其(qi)對用熱處理不(bu)能強(qiang)(qiang)(qiang)(qiang)(qiang)化的(de)(de)(de)材(cai)料來(lai)說，顯得更為重(zhong)要。其(qi)次(ci)，冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)(qiang)(qiang)化有利于金屬的(de)(de)(de)變(bian)(bian)(bian)形(xing)(xing)(xing)均勻(yun)。因為精密(mi)(mi)鋼管的(de)(de)(de)變(bian)(bian)(bian)形(xing)(xing)(xing)部分(fen)產生(sheng)硬(ying)化，將使變(bian)(bian)(bian)形(xing)(xing)(xing)向未變(bian)(bian)(bian)形(xing)(xing)(xing)或變(bian)(bian)(bian)形(xing)(xing)(xing)較少的(de)(de)(de)部分(fen)繼(ji)續發展。第三，冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)(qiang)(qiang)化可以提高(gao)構(gou)件在(zai)使用過程中的(de)(de)(de)安全(quan)性，構(gou)件一(yi)旦(dan)超(chao)載，產生(sheng)塑性變(bian)(bian)(bian)形(xing)(xing)(xing)，由于強(qiang)(qiang)(qiang)(qiang)(qiang)化作用，可防止構(gou)件突然斷裂(lie)。但是，冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)(qiang)(qiang)化也給(gei)精密(mi)(mi)鋼管的(de)(de)(de)繼(ji)續變(bian)(bian)(bian)形(xing)(xing)(xing)帶來(lai)困(kun)難，甚至(zhi)出(chu)現裂(lie)紋。因此(ci)，在(zai)精密(mi)(mi)鋼管變(bian)(bian)(bian)形(xing)(xing)(xing)和加工過程中常進行"中間(jian)退(tui)火"，以消除它的(de)(de)(de)不(bu)利影響。