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(zhuan)業生產,歡迎(ying)咨(zi)詢~

　　20#精密鋼管熱(re)處理工藝

　　精密鋼管前奏

　　真空退火優質彈簧(huang)鋼(gang)、工(gong)具(ju)鋼(gang)、精(jing)密鋼(gang)管的(de)絲材，不銹鋼(gang)制品及(ji)鈦(tai)合金(jin)材，作(zuo)光亮(liang)退火均(jun)可(ke)采用(yong)真空處理(li)。退火溫度愈低，則(ze)要求真空度愈高。為防(fang)止鉻(ge)的(de)蒸發及(ji)加速(su)熱(re)傳導，一(yi)般采用(yong)載氣加熱(re)(保溫)法，并注意對不銹鋼(gang)和鈦(tai)合金(jin)不宜(yi)用(yong)氮而應采用(yong)氬氣。

　　精密鋼管過程

　　真空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)真空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)爐(lu)按(an)冷卻(que)方(fang)法分(fen)為油(you)(you)(you)淬(cui)(cui)(cui)和氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)兩(liang)類(lei)，按(an)工(gong)位(wei)(wei)數分(fen)為單室(shi)式(shi)和雙室(shi)式(shi)，904山\畏(wei)嘲均屬(shu)周(zhou)期(qi)式(shi)作業爐(lu)。真空(kong)油(you)(you)(you)淬(cui)(cui)(cui)爐(lu)都(dou)是雙室(shi)的(de)(de)(de)(de)(de)，后(hou)室(shi)置電加(jia)熱(re)元(yuan)件(jian)，前室(shi)的(de)(de)(de)(de)(de)下(xia)方(fang)置油(you)(you)(you)槽(cao)。工(gong)件(jian)完(wan)成(cheng)(cheng)加(jia)熱(re)、保溫(wen)(wen)后(hou)移(yi)入(ru)前室(shi)，關(guan)閉中(zhong)門后(hou)向前室(shi)充(chong)入(ru)惰性(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(ru)油(you)(you)(you)。油(you)(you)(you)淬(cui)(cui)(cui)易引(yin)起工(gong)件(jian)表面(mian)變質(zhi)。由于(yu)(yu)(yu)表面(mian)活性(xing)大，在(zai)短暫(zan)的(de)(de)(de)(de)(de)高溫(wen)(wen)油(you)(you)(you)膜作用(yong)下(xia)即可(ke)發(fa)生(sheng)顯(xian)著薄(bo)層滲碳，此外(wai)，碳黑和油(you)(you)(you)在(zai)表面(mian)的(de)(de)(de)(de)(de)粘附對簡(jian)化熱(re)處(chu)(chu)理(li)流(liu)程很不利。真空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)技(ji)術(shu)的(de)(de)(de)(de)(de)發(fa)展主要在(zai)于(yu)(yu)(yu)研制性(xing)能優(you)良(liang)、工(gong)位(wei)(wei)單一(yi)的(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)(qi)(qi)冷淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)爐(lu)。前述雙室(shi)式(shi)爐(lu)亦可(ke)用(yong)于(yu)(yu)(yu)氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(在(zai)前室(shi)噴氣(qi)(qi)(qi)(qi)(qi)(qi)冷卻(que))，但雙工(gong)位(wei)(wei)式(shi)的(de)(de)(de)(de)(de)操作使(shi)大批(pi)量裝爐(lu)的(de)(de)(de)(de)(de)生(sheng)產發(fa)生(sheng)困難，也易在(zai)高溫(wen)(wen)移(yi)動中(zhong)引(yin)起工(gong)件(jian)變形或(huo)改變工(gong)件(jian)方(fang)位(wei)(wei)增(zeng)加(jia)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)變形。單一(yi)工(gong)位(wei)(wei)的(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)(qi)(qi)冷淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)爐(lu)是在(zai)加(jia)熱(re)保溫(wen)(wen)完(wan)成(cheng)(cheng)后(hou)在(zai)加(jia)熱(re)室(shi)內噴氣(qi)(qi)(qi)(qi)(qi)(qi)冷卻(que)。氣(qi)(qi)(qi)(qi)(qi)(qi)冷的(de)(de)(de)(de)(de)冷速不如油(you)(you)(you)冷快，也低于(yu)(yu)(yu)傳統淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)法中(zhong)的(de)(de)(de)(de)(de)熔鹽(yan)等溫(wen)(wen)、分(fen)級淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)。因而，不斷提(ti)高噴冷室(shi)壓力，增(zeng)大流(liu)量，以(yi)及采用(yong)摩爾質(zhi)量比氮(dan)和氬(ya)小的(de)(de)(de)(de)(de)惰性(xing)氣(qi)(qi)(qi)(qi)(qi)(qi)體(ti)氦(hai)和氫(qing)，是當今真空(kong)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)技(ji)術(shu)發(fa)展的(de)(de)(de)(de)(de)主流(liu)。70年(nian)代(dai)后(hou)期(qi)將氮(dan)氣(qi)(qi)(qi)(qi)(qi)(qi)噴冷的(de)(de)(de)(de)(de)壓力從(1～2)%26times;10Pa提(ti)高到(5～6)%26times;10Pa，使(shi)冷卻(que)能力接(jie)近于(yu)(yu)(yu)常壓下(xia)的(de)(de)(de)(de)(de)油(you)(you)(you)冷。80年(nian)代(dai)中(zhong)期(qi)出現超高壓氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)，用(yong)(10～20)%26times;10Pa的(de)(de)(de)(de)(de)氦(hai)，冷卻(que)能力等于(yu)(yu)(yu)或(huo)略高于(yu)(yu)(yu)油(you)(you)(you)淬(cui)(cui)(cui)，已(yi)進(jin)(jin)入(ru)工(gong)業實用(yong)。90年(nian)代(dai)初采用(yong)40%26times;10Pa的(de)(de)(de)(de)(de)氫(qing)氣(qi)(qi)(qi)(qi)(qi)(qi)，接(jie)近水淬(cui)(cui)(cui)的(de)(de)(de)(de)(de)冷卻(que)能力，尚處(chu)(chu)于(yu)(yu)(yu)起步階(jie)段。工(gong)業發(fa)達國(guo)家(jia)已(yi)進(jin)(jin)展到以(yi)高壓(5～6)%26times;10。Pa氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)為主體(ti)，而中(zhong)國(guo)產氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)一(yi)些金屬(shu)的(de)(de)(de)(de)(de)蒸(zheng)氣(qi)(qi)(qi)(qi)(qi)(qi)壓(理(li)論值(zhi))與溫(wen)(wen)度的(de)(de)(de)(de)(de)關(guan)系則尚處(chu)(chu)于(yu)(yu)(yu)一(yi)般加(jia)壓氣(qi)(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(2%26times;10Pa)型(xing)階(jie)段。

　　結果真空滲(shen)(shen)碳為真空滲(shen)(shen)碳一(yi)淬火(huo)工藝(yi)曲(qu)線。在真空中加熱(re)到(dao)滲(shen)(shen)碳溫度(du)并保溫使表面(mian)凈(jing)化(hua)、活化(hua)之后(hou)(hou)，通(tong)入稀薄滲(shen)(shen)碳富化(hua)氣(qi)(qi)(qi)(qi)(qi)(見控制氣(qi)(qi)(qi)(qi)(qi)氛熱(re)處理)，在大(da)約(yue)1330Pa(10T0rr)負壓下進行(xing)滲(shen)(shen)入，然后(hou)(hou)停(ting)(ting)(ting)氣(qi)(qi)(qi)(qi)(qi)(降壓)進行(xing)擴(kuo)散。滲(shen)(shen)碳后(hou)(hou)的(de)精密鋼(gang)管淬火(huo)采(cai)用(yong)(yong)(yong)一(yi)次淬火(huo)法，即先停(ting)(ting)(ting)電，通(tong)氮(dan)冷(leng)卻工件(jian)至臨界點A，、以(yi)下，使內部發(fa)生相(xiang)變，再停(ting)(ting)(ting)氣(qi)(qi)(qi)(qi)(qi)、開泵，升溫到(dao)Ac1，～Accm之間(jian)。淬冷(leng)方法可采(cai)用(yong)(yong)(yong)氣(qi)(qi)(qi)(qi)(qi)冷(leng)或油(you)冷(leng)。后(hou)(hou)者(zhe)為奧(ao)氏體(ti)化(hua)后(hou)(hou)移入前室，充氮(dan)至常壓，入油(you)。真空滲(shen)(shen)碳的(de)溫度(du)一(yi)般高于(yu)(yu)普通(tong)氣(qi)(qi)(qi)(qi)(qi)體(ti)滲(shen)(shen)碳，常采(cai)用(yong)(yong)(yong)920～1040℃滲(shen)(shen)入和擴(kuo)散可按所示分(fen)兩階段，也可用(yong)(yong)(yong)脈沖式(shi)通(tong)氣(qi)(qi)(qi)(qi)(qi)、停(ting)(ting)(ting)氣(qi)(qi)(qi)(qi)(qi)，多段式(shi)的(de)滲(shen)(shen)一(yi)擴(kuo)相(xiang)間(jian)，效果更好。由(you)于(yu)(yu)溫度(du)高，尤其(qi)表面(mian)潔凈(jing)、有活性，真空滲(shen)(shen)碳層(ceng)形成速度(du)比普通(tong)氣(qi)(qi)(qi)(qi)(qi)體(ti)、液體(ti)和固體(ti)滲(shen)(shen)碳快，如(ru)要求滲(shen)(shen)層(ceng)為1mm時，在927℃只需5h，而1033℃僅需1h。

　　精(jing)密(mi)鋼管(guan)硬度與(yu)變形

　　取兩塊式樣(yang)，一塊用于研究不(bu)同(tong)形變程度對(dui)硬(ying)度的影(ying)響，另一塊研究不(bu)同(tong)溫度對(dui)性能的影(ying)響。

　　冷變(bian)(bian)(bian)形(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)在(zai)實際生(sheng)產中(zhong)具有重要(yao)的(de)(de)(de)(de)意義。首(shou)先(xian)這(zhe)是(shi)一(yi)種(zhong)重要(yao)的(de)(de)(de)(de)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)材料(liao)的(de)(de)(de)(de)手段，尤其對用(yong)熱處理不能強(qiang)(qiang)(qiang)化(hua)(hua)(hua)的(de)(de)(de)(de)材料(liao)來說(shuo)，顯得(de)更為重要(yao)。其次，冷變(bian)(bian)(bian)形(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)有利(li)(li)于(yu)金屬的(de)(de)(de)(de)變(bian)(bian)(bian)形(xing)(xing)均勻。因(yin)為精密(mi)鋼管的(de)(de)(de)(de)變(bian)(bian)(bian)形(xing)(xing)部(bu)分產生(sheng)硬化(hua)(hua)(hua)，將使變(bian)(bian)(bian)形(xing)(xing)向未(wei)變(bian)(bian)(bian)形(xing)(xing)或(huo)變(bian)(bian)(bian)形(xing)(xing)較少的(de)(de)(de)(de)部(bu)分繼(ji)續發展。第三，冷變(bian)(bian)(bian)形(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)可以提(ti)高構件(jian)在(zai)使用(yong)過(guo)程中(zhong)的(de)(de)(de)(de)安全(quan)性，構件(jian)一(yi)旦超載(zai)，產生(sheng)塑(su)性變(bian)(bian)(bian)形(xing)(xing)，由于(yu)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)作(zuo)用(yong)，可防止(zhi)構件(jian)突然斷裂(lie)。但是(shi)，冷變(bian)(bian)(bian)形(xing)(xing)強(qiang)(qiang)(qiang)化(hua)(hua)(hua)也給精密(mi)鋼管的(de)(de)(de)(de)繼(ji)續變(bian)(bian)(bian)形(xing)(xing)帶來困難，甚(shen)至(zhi)出現裂(lie)紋。因(yin)此，在(zai)精密(mi)鋼管變(bian)(bian)(bian)形(xing)(xing)和加工(gong)過(guo)程中(zhong)常進(jin)行"中(zhong)間退火"，以消除(chu)它的(de)(de)(de)(de)不利(li)(li)影響。