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,報價低(di),全(quan)國可發(fa),我司專(zhuan)業生產,歡(huan)迎咨詢(xun)~

　　20#精密(mi)鋼管熱(re)處理工藝

　　精密鋼管前奏

　　真(zhen)空退(tui)火優質彈簧鋼(gang)、工具鋼(gang)、精密鋼(gang)管的絲材，不(bu)(bu)銹(xiu)鋼(gang)制品(pin)及(ji)鈦(tai)合(he)金材，作光亮退(tui)火均可采(cai)用真(zhen)空處理。退(tui)火溫(wen)(wen)度愈低，則要求真(zhen)空度愈高。為防止鉻的蒸發及(ji)加速熱(re)傳導，一(yi)般(ban)采(cai)用載氣加熱(re)(保溫(wen)(wen))法，并注(zhu)意(yi)對不(bu)(bu)銹(xiu)鋼(gang)和鈦(tai)合(he)金不(bu)(bu)宜用氮而應采(cai)用氬氣。

　　精密鋼管過程

　　真(zhen)(zhen)空(kong)淬(cui)(cui)火(huo)(huo)(huo)真(zhen)(zhen)空(kong)淬(cui)(cui)火(huo)(huo)(huo)爐按(an)冷(leng)(leng)卻(que)方法分為油(you)(you)(you)(you)淬(cui)(cui)和氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)兩類，按(an)工(gong)(gong)(gong)位數分為單(dan)室(shi)(shi)式(shi)和雙(shuang)(shuang)室(shi)(shi)式(shi)，904山(shan)\畏嘲均屬周期式(shi)作業爐。真(zhen)(zhen)空(kong)油(you)(you)(you)(you)淬(cui)(cui)爐都是(shi)(shi)雙(shuang)(shuang)室(shi)(shi)的(de)(de)(de)(de)(de)，后(hou)(hou)(hou)(hou)室(shi)(shi)置電加(jia)(jia)熱(re)(re)(re)元件(jian)(jian)，前(qian)室(shi)(shi)的(de)(de)(de)(de)(de)下(xia)方置油(you)(you)(you)(you)槽。工(gong)(gong)(gong)件(jian)(jian)完(wan)成加(jia)(jia)熱(re)(re)(re)、保溫(wen)(wen)后(hou)(hou)(hou)(hou)移入前(qian)室(shi)(shi)，關閉中(zhong)(zhong)門后(hou)(hou)(hou)(hou)向前(qian)室(shi)(shi)充入惰(duo)(duo)性(xing)氣(qi)(qi)(qi)(qi)(qi)(qi)至大約(yue)2.66%26times;lO ～1.01%26times;10 Pa(200～760mm汞(gong)柱)，入油(you)(you)(you)(you)。油(you)(you)(you)(you)淬(cui)(cui)易引起工(gong)(gong)(gong)件(jian)(jian)表面變(bian)質。由于表面活性(xing)大，在(zai)(zai)短暫的(de)(de)(de)(de)(de)高溫(wen)(wen)油(you)(you)(you)(you)膜作用(yong)下(xia)即可發生(sheng)顯著薄層滲碳，此外(wai)，碳黑和油(you)(you)(you)(you)在(zai)(zai)表面的(de)(de)(de)(de)(de)粘附(fu)對簡化熱(re)(re)(re)處(chu)理流(liu)程很不(bu)利(li)。真(zhen)(zhen)空(kong)淬(cui)(cui)火(huo)(huo)(huo)技術(shu)的(de)(de)(de)(de)(de)發展(zhan)主(zhu)要在(zai)(zai)于研(yan)制性(xing)能(neng)(neng)優良(liang)、工(gong)(gong)(gong)位單(dan)一(yi)的(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)淬(cui)(cui)火(huo)(huo)(huo)爐。前(qian)述雙(shuang)(shuang)室(shi)(shi)式(shi)爐亦可用(yong)于氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(在(zai)(zai)前(qian)室(shi)(shi)噴(pen)氣(qi)(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)卻(que))，但雙(shuang)(shuang)工(gong)(gong)(gong)位式(shi)的(de)(de)(de)(de)(de)操作使大批量裝爐的(de)(de)(de)(de)(de)生(sheng)產發生(sheng)困難，也易在(zai)(zai)高溫(wen)(wen)移動中(zhong)(zhong)引起工(gong)(gong)(gong)件(jian)(jian)變(bian)形或改變(bian)工(gong)(gong)(gong)件(jian)(jian)方位增(zeng)(zeng)加(jia)(jia)淬(cui)(cui)火(huo)(huo)(huo)變(bian)形。單(dan)一(yi)工(gong)(gong)(gong)位的(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)淬(cui)(cui)火(huo)(huo)(huo)爐是(shi)(shi)在(zai)(zai)加(jia)(jia)熱(re)(re)(re)保溫(wen)(wen)完(wan)成后(hou)(hou)(hou)(hou)在(zai)(zai)加(jia)(jia)熱(re)(re)(re)室(shi)(shi)內噴(pen)氣(qi)(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)卻(que)。氣(qi)(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)的(de)(de)(de)(de)(de)冷(leng)(leng)速不(bu)如油(you)(you)(you)(you)冷(leng)(leng)快(kuai)，也低于傳統淬(cui)(cui)火(huo)(huo)(huo)法中(zhong)(zhong)的(de)(de)(de)(de)(de)熔鹽等(deng)溫(wen)(wen)、分級淬(cui)(cui)火(huo)(huo)(huo)。因而，不(bu)斷提高噴(pen)冷(leng)(leng)室(shi)(shi)壓(ya)(ya)力(li)，增(zeng)(zeng)大流(liu)量，以及采用(yong)摩爾質量比氮和氬小的(de)(de)(de)(de)(de)惰(duo)(duo)性(xing)氣(qi)(qi)(qi)(qi)(qi)(qi)體氦和氫，是(shi)(shi)當(dang)今真(zhen)(zhen)空(kong)淬(cui)(cui)火(huo)(huo)(huo)技術(shu)發展(zhan)的(de)(de)(de)(de)(de)主(zhu)流(liu)。70年(nian)代后(hou)(hou)(hou)(hou)期將氮氣(qi)(qi)(qi)(qi)(qi)(qi)噴(pen)冷(leng)(leng)的(de)(de)(de)(de)(de)壓(ya)(ya)力(li)從(1～2)%26times;10Pa提高到(dao)(5～6)%26times;10Pa，使冷(leng)(leng)卻(que)能(neng)(neng)力(li)接近(jin)于常壓(ya)(ya)下(xia)的(de)(de)(de)(de)(de)油(you)(you)(you)(you)冷(leng)(leng)。80年(nian)代中(zhong)(zhong)期出現超高壓(ya)(ya)氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)，用(yong)(10～20)%26times;10Pa的(de)(de)(de)(de)(de)氦，冷(leng)(leng)卻(que)能(neng)(neng)力(li)等(deng)于或略高于油(you)(you)(you)(you)淬(cui)(cui)，已進入工(gong)(gong)(gong)業實用(yong)。90年(nian)代初(chu)采用(yong)40%26times;10Pa的(de)(de)(de)(de)(de)氫氣(qi)(qi)(qi)(qi)(qi)(qi)，接近(jin)水淬(cui)(cui)的(de)(de)(de)(de)(de)冷(leng)(leng)卻(que)能(neng)(neng)力(li)，尚處(chu)于起步(bu)階段。工(gong)(gong)(gong)業發達國家已進展(zhan)到(dao)以高壓(ya)(ya)(5～6)%26times;10。Pa氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)為主(zhu)體，而中(zhong)(zhong)國產氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)一(yi)些金(jin)屬的(de)(de)(de)(de)(de)蒸氣(qi)(qi)(qi)(qi)(qi)(qi)壓(ya)(ya)(理論(lun)值)與(yu)溫(wen)(wen)度的(de)(de)(de)(de)(de)關系則尚處(chu)于一(yi)般(ban)加(jia)(jia)壓(ya)(ya)氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(2%26times;10Pa)型階段。

　　結(jie)果(guo)真(zhen)空滲(shen)(shen)碳為真(zhen)空滲(shen)(shen)碳一淬(cui)火(huo)工藝曲線。在(zai)真(zhen)空中加(jia)熱到滲(shen)(shen)碳溫(wen)(wen)度并保溫(wen)(wen)使表面(mian)凈化(hua)、活化(hua)之(zhi)后，通(tong)入稀薄(bo)滲(shen)(shen)碳富(fu)化(hua)氣(qi)(見控制氣(qi)氛熱處理)，在(zai)大約(yue)1330Pa(10T0rr)負壓下(xia)進行滲(shen)(shen)入，然(ran)后停氣(qi)(降壓)進行擴(kuo)(kuo)散。滲(shen)(shen)碳后的精密鋼管淬(cui)火(huo)采(cai)(cai)用(yong)(yong)一次淬(cui)火(huo)法(fa)，即先停電(dian)，通(tong)氮冷(leng)卻(que)工件(jian)至(zhi)臨界點A，、以下(xia)，使內部發生相(xiang)變，再(zai)停氣(qi)、開泵，升溫(wen)(wen)到Ac1，～Accm之(zhi)間。淬(cui)冷(leng)方法(fa)可(ke)采(cai)(cai)用(yong)(yong)氣(qi)冷(leng)或油冷(leng)。后者為奧氏體化(hua)后移入前室，充氮至(zhi)常(chang)壓，入油。真(zhen)空滲(shen)(shen)碳的溫(wen)(wen)度一般高于(yu)普通(tong)氣(qi)體滲(shen)(shen)碳，常(chang)采(cai)(cai)用(yong)(yong)920～1040℃滲(shen)(shen)入和擴(kuo)(kuo)散可(ke)按所示分(fen)兩(liang)階段(duan)，也可(ke)用(yong)(yong)脈(mo)沖式通(tong)氣(qi)、停氣(qi)，多段(duan)式的滲(shen)(shen)一擴(kuo)(kuo)相(xiang)間，效果(guo)更(geng)好。由于(yu)溫(wen)(wen)度高，尤其(qi)表面(mian)潔凈、有(you)活性(xing)，真(zhen)空滲(shen)(shen)碳層(ceng)形(xing)成速度比普通(tong)氣(qi)體、液體和固體滲(shen)(shen)碳快，如要(yao)求滲(shen)(shen)層(ceng)為1mm時，在(zai)927℃只需5h，而1033℃僅需1h。

　　精密鋼管硬度與變形

　　取兩塊(kuai)式樣，一塊(kuai)用于研(yan)究(jiu)不(bu)同(tong)形變程度(du)對(dui)(dui)硬度(du)的影(ying)響，另一塊(kuai)研(yan)究(jiu)不(bu)同(tong)溫度(du)對(dui)(dui)性能的影(ying)響。

　　冷(leng)變(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)在實際生(sheng)產中(zhong)具有重要的(de)意義。首先這是(shi)一(yi)種重要的(de)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)材(cai)料的(de)手段，尤其(qi)對(dui)用(yong)熱處理不(bu)能強(qiang)(qiang)(qiang)化(hua)(hua)(hua)的(de)材(cai)料來說，顯得更為(wei)(wei)重要。其(qi)次，冷(leng)變(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)有利(li)于金屬(shu)的(de)變(bian)形(xing)(xing)(xing)均勻。因為(wei)(wei)精(jing)密鋼(gang)管的(de)變(bian)形(xing)(xing)(xing)部分產生(sheng)硬化(hua)(hua)(hua)，將(jiang)使(shi)變(bian)形(xing)(xing)(xing)向(xiang)未變(bian)形(xing)(xing)(xing)或變(bian)形(xing)(xing)(xing)較少的(de)部分繼(ji)續發(fa)展。第(di)三，冷(leng)變(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)可(ke)以提高構件(jian)在使(shi)用(yong)過(guo)(guo)程中(zhong)的(de)安全(quan)性，構件(jian)一(yi)旦超載，產生(sheng)塑性變(bian)形(xing)(xing)(xing)，由(you)于強(qiang)(qiang)(qiang)化(hua)(hua)(hua)作(zuo)用(yong)，可(ke)防止構件(jian)突然斷裂。但是(shi)，冷(leng)變(bian)形(xing)(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)也給精(jing)密鋼(gang)管的(de)繼(ji)續變(bian)形(xing)(xing)(xing)帶來困難，甚至出現(xian)裂紋(wen)。因此，在精(jing)密鋼(gang)管變(bian)形(xing)(xing)(xing)和加工過(guo)(guo)程中(zhong)常(chang)進行"中(zhong)間退火"，以消除它的(de)不(bu)利(li)影響。