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(huo)快,報價(jia)低,全國可發(fa),我司專業生產,歡迎咨(zi)詢~

　　20#精密鋼管(guan)熱(re)處理工(gong)藝

　　精密鋼管前奏

　　真空退火(huo)優質(zhi)彈簧鋼(gang)(gang)、工(gong)具鋼(gang)(gang)、精密鋼(gang)(gang)管的(de)絲材，不(bu)銹鋼(gang)(gang)制(zhi)品及(ji)(ji)鈦合金(jin)材，作光亮(liang)退火(huo)均可采(cai)用真空處理。退火(huo)溫度愈低(di)，則要求(qiu)真空度愈高。為防止鉻的(de)蒸發及(ji)(ji)加速熱(re)傳導，一般采(cai)用載氣加熱(re)(保溫)法，并注意對不(bu)銹鋼(gang)(gang)和鈦合金(jin)不(bu)宜用氮(dan)而(er)應采(cai)用氬氣。

　　精密鋼管過程

　　真空(kong)淬(cui)(cui)(cui)火(huo)真空(kong)淬(cui)(cui)(cui)火(huo)爐(lu)按冷(leng)(leng)(leng)卻(que)方(fang)法分(fen)為油淬(cui)(cui)(cui)和(he)氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)兩類，按工(gong)(gong)位(wei)數分(fen)為單(dan)室(shi)(shi)(shi)式(shi)和(he)雙室(shi)(shi)(shi)式(shi)，904山\畏(wei)嘲均屬(shu)周期(qi)式(shi)作(zuo)業(ye)爐(lu)。真空(kong)油淬(cui)(cui)(cui)爐(lu)都是(shi)雙室(shi)(shi)(shi)的(de)(de)，后(hou)(hou)室(shi)(shi)(shi)置電加(jia)(jia)熱(re)(re)元(yuan)件(jian)(jian)(jian)(jian)(jian)，前(qian)室(shi)(shi)(shi)的(de)(de)下(xia)方(fang)置油槽。工(gong)(gong)件(jian)(jian)(jian)(jian)(jian)完成加(jia)(jia)熱(re)(re)、保(bao)溫(wen)后(hou)(hou)移入前(qian)室(shi)(shi)(shi)，關閉中(zhong)門(men)后(hou)(hou)向前(qian)室(shi)(shi)(shi)充入惰(duo)性氣(qi)(qi)(qi)(qi)(qi)至大約(yue)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)(gong)件(jian)(jian)(jian)(jian)(jian)表(biao)(biao)面變質(zhi)(zhi)。由于(yu)(yu)表(biao)(biao)面活性大，在(zai)短暫的(de)(de)高(gao)(gao)溫(wen)油膜(mo)作(zuo)用下(xia)即可發(fa)(fa)生顯著薄層(ceng)滲碳，此(ci)外，碳黑和(he)油在(zai)表(biao)(biao)面的(de)(de)粘附對簡化熱(re)(re)處理流程(cheng)很不利。真空(kong)淬(cui)(cui)(cui)火(huo)技術(shu)的(de)(de)發(fa)(fa)展(zhan)(zhan)主要在(zai)于(yu)(yu)研制(zhi)性能優(you)良、工(gong)(gong)位(wei)單(dan)一(yi)的(de)(de)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)(leng)淬(cui)(cui)(cui)火(huo)爐(lu)。前(qian)述雙室(shi)(shi)(shi)式(shi)爐(lu)亦(yi)可用于(yu)(yu)氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(在(zai)前(qian)室(shi)(shi)(shi)噴(pen)(pen)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)(leng)卻(que))，但雙工(gong)(gong)位(wei)式(shi)的(de)(de)操(cao)作(zuo)使(shi)大批量(liang)(liang)裝爐(lu)的(de)(de)生產發(fa)(fa)生困難，也(ye)(ye)易在(zai)高(gao)(gao)溫(wen)移動中(zhong)引起(qi)工(gong)(gong)件(jian)(jian)(jian)(jian)(jian)變形或(huo)(huo)改(gai)變工(gong)(gong)件(jian)(jian)(jian)(jian)(jian)方(fang)位(wei)增加(jia)(jia)淬(cui)(cui)(cui)火(huo)變形。單(dan)一(yi)工(gong)(gong)位(wei)的(de)(de)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)(leng)淬(cui)(cui)(cui)火(huo)爐(lu)是(shi)在(zai)加(jia)(jia)熱(re)(re)保(bao)溫(wen)完成后(hou)(hou)在(zai)加(jia)(jia)熱(re)(re)室(shi)(shi)(shi)內噴(pen)(pen)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)(leng)卻(que)。氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)(leng)的(de)(de)冷(leng)(leng)(leng)速不如油冷(leng)(leng)(leng)快(kuai)，也(ye)(ye)低于(yu)(yu)傳統淬(cui)(cui)(cui)火(huo)法中(zhong)的(de)(de)熔(rong)鹽(yan)等(deng)溫(wen)、分(fen)級淬(cui)(cui)(cui)火(huo)。因(yin)而，不斷(duan)提(ti)高(gao)(gao)噴(pen)(pen)冷(leng)(leng)(leng)室(shi)(shi)(shi)壓(ya)(ya)(ya)力(li)(li)(li)，增大流量(liang)(liang)，以(yi)及采用摩爾質(zhi)(zhi)量(liang)(liang)比氮(dan)(dan)和(he)氬小(xiao)的(de)(de)惰(duo)性氣(qi)(qi)(qi)(qi)(qi)體氦(hai)和(he)氫(qing)，是(shi)當(dang)今(jin)真空(kong)淬(cui)(cui)(cui)火(huo)技術(shu)發(fa)(fa)展(zhan)(zhan)的(de)(de)主流。70年代后(hou)(hou)期(qi)將氮(dan)(dan)氣(qi)(qi)(qi)(qi)(qi)噴(pen)(pen)冷(leng)(leng)(leng)的(de)(de)壓(ya)(ya)(ya)力(li)(li)(li)從(1～2)%26times;10Pa提(ti)高(gao)(gao)到(dao)(5～6)%26times;10Pa，使(shi)冷(leng)(leng)(leng)卻(que)能力(li)(li)(li)接近于(yu)(yu)常(chang)壓(ya)(ya)(ya)下(xia)的(de)(de)油冷(leng)(leng)(leng)。80年代中(zhong)期(qi)出現(xian)超高(gao)(gao)壓(ya)(ya)(ya)氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)，用(10～20)%26times;10Pa的(de)(de)氦(hai)，冷(leng)(leng)(leng)卻(que)能力(li)(li)(li)等(deng)于(yu)(yu)或(huo)(huo)略高(gao)(gao)于(yu)(yu)油淬(cui)(cui)(cui)，已進入工(gong)(gong)業(ye)實用。90年代初(chu)采用40%26times;10Pa的(de)(de)氫(qing)氣(qi)(qi)(qi)(qi)(qi)，接近水淬(cui)(cui)(cui)的(de)(de)冷(leng)(leng)(leng)卻(que)能力(li)(li)(li)，尚(shang)(shang)處于(yu)(yu)起(qi)步階段(duan)。工(gong)(gong)業(ye)發(fa)(fa)達國家已進展(zhan)(zhan)到(dao)以(yi)高(gao)(gao)壓(ya)(ya)(ya)(5～6)%26times;10。Pa氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)為主體，而中(zhong)國產氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)一(yi)些金屬(shu)的(de)(de)蒸氣(qi)(qi)(qi)(qi)(qi)壓(ya)(ya)(ya)(理論值)與溫(wen)度的(de)(de)關系(xi)則尚(shang)(shang)處于(yu)(yu)一(yi)般加(jia)(jia)壓(ya)(ya)(ya)氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(2%26times;10Pa)型階段(duan)。

　　結果(guo)真(zhen)空(kong)滲(shen)碳(tan)(tan)(tan)為(wei)(wei)真(zhen)空(kong)滲(shen)碳(tan)(tan)(tan)一(yi)(yi)淬(cui)(cui)火工藝(yi)曲線。在(zai)(zai)真(zhen)空(kong)中(zhong)加熱到滲(shen)碳(tan)(tan)(tan)溫度(du)并保溫使表面凈化(hua)、活化(hua)之(zhi)后(hou)，通(tong)(tong)入(ru)稀薄(bo)滲(shen)碳(tan)(tan)(tan)富化(hua)氣(qi)(見(jian)控(kong)制(zhi)氣(qi)氛熱處理)，在(zai)(zai)大約1330Pa(10T0rr)負(fu)壓下進行滲(shen)入(ru)，然后(hou)停(ting)氣(qi)(降壓)進行擴散(san)。滲(shen)碳(tan)(tan)(tan)后(hou)的精(jing)密鋼管淬(cui)(cui)火采用一(yi)(yi)次(ci)淬(cui)(cui)火法(fa)，即先停(ting)電，通(tong)(tong)氮冷(leng)卻工件(jian)至(zhi)臨界點A，、以下，使內部發生相(xiang)變，再停(ting)氣(qi)、開(kai)泵，升溫到Ac1，～Accm之(zhi)間。淬(cui)(cui)冷(leng)方法(fa)可采用氣(qi)冷(leng)或油冷(leng)。后(hou)者為(wei)(wei)奧氏(shi)體(ti)化(hua)后(hou)移入(ru)前室，充(chong)氮至(zhi)常壓，入(ru)油。真(zhen)空(kong)滲(shen)碳(tan)(tan)(tan)的溫度(du)一(yi)(yi)般高(gao)于普(pu)通(tong)(tong)氣(qi)體(ti)滲(shen)碳(tan)(tan)(tan)，常采用920～1040℃滲(shen)入(ru)和擴散(san)可按所(suo)示分兩(liang)階段(duan)，也可用脈(mo)沖(chong)式通(tong)(tong)氣(qi)、停(ting)氣(qi)，多段(duan)式的滲(shen)一(yi)(yi)擴相(xiang)間，效(xiao)果(guo)更好。由于溫度(du)高(gao)，尤其表面潔凈、有活性，真(zhen)空(kong)滲(shen)碳(tan)(tan)(tan)層形成速度(du)比普(pu)通(tong)(tong)氣(qi)體(ti)、液體(ti)和固體(ti)滲(shen)碳(tan)(tan)(tan)快，如要求(qiu)滲(shen)層為(wei)(wei)1mm時(shi)，在(zai)(zai)927℃只需5h，而1033℃僅需1h。

　　精密(mi)鋼管(guan)硬度與變形

　　取兩塊(kuai)式(shi)樣，一塊(kuai)用于(yu)研究不同(tong)形(xing)變程度(du)對硬度(du)的影響(xiang)，另一塊(kuai)研究不同(tong)溫度(du)對性能(neng)的影響(xiang)。

　　冷變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)強(qiang)(qiang)化(hua)(hua)在(zai)實(shi)際(ji)生產(chan)中(zhong)具有重(zhong)要的(de)(de)(de)意義。首先這是(shi)(shi)一種(zhong)重(zhong)要的(de)(de)(de)強(qiang)(qiang)化(hua)(hua)材(cai)料的(de)(de)(de)手段，尤其對(dui)用熱處理不能強(qiang)(qiang)化(hua)(hua)的(de)(de)(de)材(cai)料來說，顯得更為重(zhong)要。其次，冷變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)強(qiang)(qiang)化(hua)(hua)有利(li)于金屬(shu)的(de)(de)(de)變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)均勻。因為精(jing)密鋼(gang)管(guan)(guan)的(de)(de)(de)變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)部分產(chan)生硬化(hua)(hua)，將使變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)向未變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)或變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)較少的(de)(de)(de)部分繼(ji)續(xu)發展。第三，冷變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)強(qiang)(qiang)化(hua)(hua)可以提(ti)高構件在(zai)使用過程中(zhong)的(de)(de)(de)安全性(xing)，構件一旦超載，產(chan)生塑性(xing)變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)，由于強(qiang)(qiang)化(hua)(hua)作用，可防止構件突(tu)然斷(duan)裂(lie)。但是(shi)(shi)，冷變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)強(qiang)(qiang)化(hua)(hua)也給精(jing)密鋼(gang)管(guan)(guan)的(de)(de)(de)繼(ji)續(xu)變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)帶來困(kun)難，甚至出現裂(lie)紋。因此，在(zai)精(jing)密鋼(gang)管(guan)(guan)變(bian)(bian)形(xing)(xing)(xing)(xing)(xing)和加(jia)工過程中(zhong)常進(jin)行(xing)"中(zhong)間退火"，以消(xiao)除(chu)它的(de)(de)(de)不利(li)影響(xiang)。