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,發貨快(kuai),報(bao)價低,全(quan)國可發,我司專業生產,歡迎咨詢~

　　20#精密鋼管熱(re)處理工藝

　　精密鋼管前奏

　　真空退(tui)火(huo)優質彈簧鋼、工(gong)具鋼、精密(mi)鋼管的絲材，不銹(xiu)鋼制品及鈦合金(jin)材，作(zuo)光亮退(tui)火(huo)均可采用(yong)真空處理。退(tui)火(huo)溫度愈低，則要求(qiu)真空度愈高。為防止鉻的蒸發及加速熱(re)傳導，一般采用(yong)載氣加熱(re)(保溫)法(fa)，并注意對不銹(xiu)鋼和鈦合金(jin)不宜(yi)用(yong)氮而應采用(yong)氬氣。

　　精密鋼管過程

　　真(zhen)空(kong)淬火(huo)真(zhen)空(kong)淬火(huo)爐(lu)(lu)按冷(leng)(leng)(leng)(leng)(leng)卻(que)方(fang)(fang)法分為(wei)油(you)淬和(he)氣(qi)(qi)(qi)淬兩(liang)類，按工(gong)(gong)(gong)位數分為(wei)單(dan)室式和(he)雙室式，904山\畏嘲均(jun)屬周(zhou)期(qi)式作業爐(lu)(lu)。真(zhen)空(kong)油(you)淬爐(lu)(lu)都是雙室的(de)(de)(de)(de)(de)(de)(de)，后(hou)(hou)室置(zhi)電加熱(re)元(yuan)件(jian)，前室的(de)(de)(de)(de)(de)(de)(de)下(xia)(xia)方(fang)(fang)置(zhi)油(you)槽(cao)。工(gong)(gong)(gong)件(jian)完成(cheng)加熱(re)、保(bao)溫后(hou)(hou)移(yi)(yi)入前室，關(guan)閉(bi)中(zhong)門后(hou)(hou)向前室充入惰(duo)(duo)性氣(qi)(qi)(qi)至(zhi)大約2.66%26times;lO ～1.01%26times;10 Pa(200～760mm汞柱)，入油(you)。油(you)淬易引起(qi)工(gong)(gong)(gong)件(jian)表(biao)面變質。由(you)于(yu)(yu)表(biao)面活性大，在(zai)(zai)(zai)短暫的(de)(de)(de)(de)(de)(de)(de)高(gao)(gao)(gao)溫油(you)膜作用(yong)(yong)(yong)下(xia)(xia)即可發(fa)生顯著薄層滲碳(tan)，此(ci)外，碳(tan)黑和(he)油(you)在(zai)(zai)(zai)表(biao)面的(de)(de)(de)(de)(de)(de)(de)粘(zhan)附對簡(jian)化熱(re)處理流程(cheng)很不利。真(zhen)空(kong)淬火(huo)技術(shu)的(de)(de)(de)(de)(de)(de)(de)發(fa)展主(zhu)要在(zai)(zai)(zai)于(yu)(yu)研制性能(neng)優良(liang)、工(gong)(gong)(gong)位單(dan)一(yi)(yi)的(de)(de)(de)(de)(de)(de)(de)氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)淬火(huo)爐(lu)(lu)。前述雙室式爐(lu)(lu)亦可用(yong)(yong)(yong)于(yu)(yu)氣(qi)(qi)(qi)淬(在(zai)(zai)(zai)前室噴氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)卻(que))，但雙工(gong)(gong)(gong)位式的(de)(de)(de)(de)(de)(de)(de)操(cao)作使大批量(liang)(liang)裝爐(lu)(lu)的(de)(de)(de)(de)(de)(de)(de)生產發(fa)生困難，也(ye)易在(zai)(zai)(zai)高(gao)(gao)(gao)溫移(yi)(yi)動中(zhong)引起(qi)工(gong)(gong)(gong)件(jian)變形或改變工(gong)(gong)(gong)件(jian)方(fang)(fang)位增加淬火(huo)變形。單(dan)一(yi)(yi)工(gong)(gong)(gong)位的(de)(de)(de)(de)(de)(de)(de)氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)淬火(huo)爐(lu)(lu)是在(zai)(zai)(zai)加熱(re)保(bao)溫完成(cheng)后(hou)(hou)在(zai)(zai)(zai)加熱(re)室內噴氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)卻(que)。氣(qi)(qi)(qi)冷(leng)(leng)(leng)(leng)(leng)的(de)(de)(de)(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)速不如油(you)冷(leng)(leng)(leng)(leng)(leng)快，也(ye)低(di)于(yu)(yu)傳統淬火(huo)法中(zhong)的(de)(de)(de)(de)(de)(de)(de)熔鹽等(deng)溫、分級淬火(huo)。因而，不斷提(ti)高(gao)(gao)(gao)噴冷(leng)(leng)(leng)(leng)(leng)室壓(ya)(ya)力，增大流量(liang)(liang)，以及采(cai)用(yong)(yong)(yong)摩爾質量(liang)(liang)比氮和(he)氬小的(de)(de)(de)(de)(de)(de)(de)惰(duo)(duo)性氣(qi)(qi)(qi)體氦(hai)和(he)氫，是當今(jin)真(zhen)空(kong)淬火(huo)技術(shu)發(fa)展的(de)(de)(de)(de)(de)(de)(de)主(zhu)流。70年(nian)代后(hou)(hou)期(qi)將氮氣(qi)(qi)(qi)噴冷(leng)(leng)(leng)(leng)(leng)的(de)(de)(de)(de)(de)(de)(de)壓(ya)(ya)力從(1～2)%26times;10Pa提(ti)高(gao)(gao)(gao)到(dao)(5～6)%26times;10Pa，使冷(leng)(leng)(leng)(leng)(leng)卻(que)能(neng)力接(jie)近于(yu)(yu)常壓(ya)(ya)下(xia)(xia)的(de)(de)(de)(de)(de)(de)(de)油(you)冷(leng)(leng)(leng)(leng)(leng)。80年(nian)代中(zhong)期(qi)出(chu)現超高(gao)(gao)(gao)壓(ya)(ya)氣(qi)(qi)(qi)淬，用(yong)(yong)(yong)(10～20)%26times;10Pa的(de)(de)(de)(de)(de)(de)(de)氦(hai)，冷(leng)(leng)(leng)(leng)(leng)卻(que)能(neng)力等(deng)于(yu)(yu)或略高(gao)(gao)(gao)于(yu)(yu)油(you)淬，已(yi)進入工(gong)(gong)(gong)業實(shi)用(yong)(yong)(yong)。90年(nian)代初(chu)采(cai)用(yong)(yong)(yong)40%26times;10Pa的(de)(de)(de)(de)(de)(de)(de)氫氣(qi)(qi)(qi)，接(jie)近水淬的(de)(de)(de)(de)(de)(de)(de)冷(leng)(leng)(leng)(leng)(leng)卻(que)能(neng)力，尚(shang)處于(yu)(yu)起(qi)步階段(duan)(duan)。工(gong)(gong)(gong)業發(fa)達國(guo)家已(yi)進展到(dao)以高(gao)(gao)(gao)壓(ya)(ya)(5～6)%26times;10。Pa氣(qi)(qi)(qi)淬為(wei)主(zhu)體，而中(zhong)國(guo)產氣(qi)(qi)(qi)淬一(yi)(yi)些金屬的(de)(de)(de)(de)(de)(de)(de)蒸氣(qi)(qi)(qi)壓(ya)(ya)(理論(lun)值)與溫度的(de)(de)(de)(de)(de)(de)(de)關(guan)系則尚(shang)處于(yu)(yu)一(yi)(yi)般加壓(ya)(ya)氣(qi)(qi)(qi)淬(2%26times;10Pa)型階段(duan)(duan)。

　　結果真(zhen)(zhen)空(kong)(kong)(kong)(kong)滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)為(wei)真(zhen)(zhen)空(kong)(kong)(kong)(kong)滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)一(yi)(yi)淬火(huo)工(gong)藝曲線。在(zai)真(zhen)(zhen)空(kong)(kong)(kong)(kong)中(zhong)加熱到(dao)滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)溫(wen)度(du)并(bing)保(bao)溫(wen)使(shi)表面凈化(hua)、活(huo)化(hua)之(zhi)后，通入(ru)(ru)(ru)(ru)稀(xi)薄滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)富化(hua)氣(qi)(qi)(qi)(見控(kong)制(zhi)氣(qi)(qi)(qi)氛熱處理(li))，在(zai)大約1330Pa(10T0rr)負壓(ya)(ya)下進(jin)行滲(shen)(shen)(shen)(shen)入(ru)(ru)(ru)(ru)，然后停(ting)(ting)氣(qi)(qi)(qi)(降壓(ya)(ya))進(jin)行擴(kuo)散(san)(san)。滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)后的精(jing)密鋼管淬火(huo)采用一(yi)(yi)次淬火(huo)法(fa)，即先(xian)停(ting)(ting)電(dian)，通氮冷卻工(gong)件至臨界(jie)點A，、以下，使(shi)內部(bu)發生相變，再停(ting)(ting)氣(qi)(qi)(qi)、開泵(beng)，升(sheng)溫(wen)到(dao)Ac1，～Accm之(zhi)間(jian)。淬冷方法(fa)可(ke)采用氣(qi)(qi)(qi)冷或油冷。后者為(wei)奧氏體化(hua)后移入(ru)(ru)(ru)(ru)前室，充氮至常壓(ya)(ya)，入(ru)(ru)(ru)(ru)油。真(zhen)(zhen)空(kong)(kong)(kong)(kong)滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)的溫(wen)度(du)一(yi)(yi)般高于(yu)普通氣(qi)(qi)(qi)體滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)，常采用920～1040℃滲(shen)(shen)(shen)(shen)入(ru)(ru)(ru)(ru)和擴(kuo)散(san)(san)可(ke)按所示分兩階(jie)段(duan)，也可(ke)用脈沖式通氣(qi)(qi)(qi)、停(ting)(ting)氣(qi)(qi)(qi)，多段(duan)式的滲(shen)(shen)(shen)(shen)一(yi)(yi)擴(kuo)相間(jian)，效(xiao)果更好。由(you)于(yu)溫(wen)度(du)高，尤其表面潔凈、有活(huo)性，真(zhen)(zhen)空(kong)(kong)(kong)(kong)滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)層(ceng)形成速(su)度(du)比普通氣(qi)(qi)(qi)體、液(ye)體和固(gu)體滲(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)快，如要求(qiu)滲(shen)(shen)(shen)(shen)層(ceng)為(wei)1mm時，在(zai)927℃只需(xu)5h，而1033℃僅(jin)需(xu)1h。

　　精(jing)密鋼(gang)管硬度與(yu)變(bian)形

　　取(qu)兩(liang)塊(kuai)式樣，一塊(kuai)用于研(yan)究不同形變程度(du)對(dui)硬度(du)的(de)影響(xiang)，另一塊(kuai)研(yan)究不同溫度(du)對(dui)性能的(de)影響(xiang)。

　　冷變(bian)形(xing)(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)在實際生(sheng)(sheng)產(chan)中(zhong)(zhong)具有重(zhong)要的(de)(de)(de)意(yi)義。首先(xian)這(zhe)是一種重(zhong)要的(de)(de)(de)強(qiang)(qiang)(qiang)化(hua)(hua)材料(liao)的(de)(de)(de)手段，尤(you)其(qi)對用(yong)熱處理(li)不能強(qiang)(qiang)(qiang)化(hua)(hua)的(de)(de)(de)材料(liao)來(lai)說，顯(xian)得更(geng)為(wei)重(zhong)要。其(qi)次，冷變(bian)形(xing)(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)有利(li)于金屬的(de)(de)(de)變(bian)形(xing)(xing)(xing)(xing)均勻。因(yin)(yin)為(wei)精密(mi)鋼(gang)管的(de)(de)(de)變(bian)形(xing)(xing)(xing)(xing)部分(fen)產(chan)生(sheng)(sheng)硬化(hua)(hua)，將使變(bian)形(xing)(xing)(xing)(xing)向未(wei)變(bian)形(xing)(xing)(xing)(xing)或變(bian)形(xing)(xing)(xing)(xing)較少的(de)(de)(de)部分(fen)繼(ji)續(xu)發展(zhan)。第三，冷變(bian)形(xing)(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)可(ke)以提高構件(jian)在使用(yong)過(guo)程(cheng)中(zhong)(zhong)的(de)(de)(de)安全性，構件(jian)一旦超載，產(chan)生(sheng)(sheng)塑性變(bian)形(xing)(xing)(xing)(xing)，由于強(qiang)(qiang)(qiang)化(hua)(hua)作(zuo)用(yong)，可(ke)防止(zhi)構件(jian)突然斷裂。但是，冷變(bian)形(xing)(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)也給(gei)精密(mi)鋼(gang)管的(de)(de)(de)繼(ji)續(xu)變(bian)形(xing)(xing)(xing)(xing)帶來(lai)困難，甚至出(chu)現裂紋。因(yin)(yin)此，在精密(mi)鋼(gang)管變(bian)形(xing)(xing)(xing)(xing)和加(jia)工(gong)過(guo)程(cheng)中(zhong)(zhong)常進(jin)行"中(zhong)(zhong)間退火"，以消除它(ta)的(de)(de)(de)不利(li)影響。