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,報價低,全(quan)國可發(fa),我司專(zhuan)業(ye)生產,歡迎(ying)咨(zi)詢~

　　20#精密鋼(gang)管熱處(chu)理工藝

　　精密鋼管前奏

　　真空(kong)退火(huo)優(you)質彈簧鋼、工(gong)具鋼、精密鋼管的(de)絲材，不銹鋼制品及(ji)鈦合(he)金材，作光亮退火(huo)均可采(cai)用(yong)真空(kong)處理。退火(huo)溫度(du)愈低，則要求(qiu)真空(kong)度(du)愈高。為防止鉻的(de)蒸發及(ji)加速熱傳(chuan)導，一般采(cai)用(yong)載(zai)氣加熱(保溫)法(fa)，并注意對不銹鋼和鈦合(he)金不宜用(yong)氮而應(ying)采(cai)用(yong)氬(ya)氣。

　　精密鋼管過程

　　真空淬(cui)(cui)(cui)(cui)火(huo)(huo)真空淬(cui)(cui)(cui)(cui)火(huo)(huo)爐(lu)按(an)冷(leng)(leng)卻(que)方(fang)法(fa)分(fen)為油淬(cui)(cui)(cui)(cui)和(he)氣(qi)(qi)淬(cui)(cui)(cui)(cui)兩類，按(an)工(gong)位(wei)數分(fen)為單(dan)室(shi)(shi)(shi)(shi)(shi)式(shi)(shi)(shi)和(he)雙室(shi)(shi)(shi)(shi)(shi)式(shi)(shi)(shi)，904山\畏嘲均屬(shu)周期式(shi)(shi)(shi)作業(ye)(ye)爐(lu)。真空油淬(cui)(cui)(cui)(cui)爐(lu)都(dou)是(shi)雙室(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)，后室(shi)(shi)(shi)(shi)(shi)置電加熱元(yuan)件，前(qian)室(shi)(shi)(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)下方(fang)置油槽。工(gong)件完(wan)成加熱、保溫(wen)后移(yi)入(ru)前(qian)室(shi)(shi)(shi)(shi)(shi)，關(guan)閉(bi)中(zhong)門(men)后向前(qian)室(shi)(shi)(shi)(shi)(shi)充入(ru)惰(duo)性氣(qi)(qi)至(zhi)大約2.66%26times;lO ～1.01%26times;10 Pa(200～760mm汞柱)，入(ru)油。油淬(cui)(cui)(cui)(cui)易引(yin)起工(gong)件表(biao)(biao)面變(bian)質(zhi)。由于(yu)(yu)表(biao)(biao)面活性大，在(zai)短暫的(de)(de)(de)(de)(de)(de)高(gao)溫(wen)油膜作用(yong)(yong)下即可(ke)(ke)發(fa)生(sheng)顯著薄層滲碳，此外(wai)，碳黑(hei)和(he)油在(zai)表(biao)(biao)面的(de)(de)(de)(de)(de)(de)粘(zhan)附(fu)對簡化熱處理流程(cheng)很(hen)不(bu)利。真空淬(cui)(cui)(cui)(cui)火(huo)(huo)技(ji)術的(de)(de)(de)(de)(de)(de)發(fa)展(zhan)(zhan)主(zhu)要(yao)在(zai)于(yu)(yu)研(yan)制性能優良、工(gong)位(wei)單(dan)一(yi)的(de)(de)(de)(de)(de)(de)氣(qi)(qi)冷(leng)(leng)淬(cui)(cui)(cui)(cui)火(huo)(huo)爐(lu)。前(qian)述雙室(shi)(shi)(shi)(shi)(shi)式(shi)(shi)(shi)爐(lu)亦可(ke)(ke)用(yong)(yong)于(yu)(yu)氣(qi)(qi)淬(cui)(cui)(cui)(cui)(在(zai)前(qian)室(shi)(shi)(shi)(shi)(shi)噴(pen)氣(qi)(qi)冷(leng)(leng)卻(que))，但雙工(gong)位(wei)式(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)操作使大批量裝爐(lu)的(de)(de)(de)(de)(de)(de)生(sheng)產發(fa)生(sheng)困難(nan)，也易在(zai)高(gao)溫(wen)移(yi)動(dong)中(zhong)引(yin)起工(gong)件變(bian)形(xing)或改變(bian)工(gong)件方(fang)位(wei)增加淬(cui)(cui)(cui)(cui)火(huo)(huo)變(bian)形(xing)。單(dan)一(yi)工(gong)位(wei)的(de)(de)(de)(de)(de)(de)氣(qi)(qi)冷(leng)(leng)淬(cui)(cui)(cui)(cui)火(huo)(huo)爐(lu)是(shi)在(zai)加熱保溫(wen)完(wan)成后在(zai)加熱室(shi)(shi)(shi)(shi)(shi)內(nei)噴(pen)氣(qi)(qi)冷(leng)(leng)卻(que)。氣(qi)(qi)冷(leng)(leng)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)速(su)不(bu)如油冷(leng)(leng)快，也低于(yu)(yu)傳統淬(cui)(cui)(cui)(cui)火(huo)(huo)法(fa)中(zhong)的(de)(de)(de)(de)(de)(de)熔(rong)鹽等溫(wen)、分(fen)級(ji)淬(cui)(cui)(cui)(cui)火(huo)(huo)。因而(er)，不(bu)斷提高(gao)噴(pen)冷(leng)(leng)室(shi)(shi)(shi)(shi)(shi)壓(ya)力，增大流量，以(yi)及采(cai)用(yong)(yong)摩爾質(zhi)量比氮(dan)和(he)氬小的(de)(de)(de)(de)(de)(de)惰(duo)性氣(qi)(qi)體氦(hai)和(he)氫(qing)，是(shi)當今真空淬(cui)(cui)(cui)(cui)火(huo)(huo)技(ji)術發(fa)展(zhan)(zhan)的(de)(de)(de)(de)(de)(de)主(zhu)流。70年(nian)(nian)代(dai)(dai)后期將氮(dan)氣(qi)(qi)噴(pen)冷(leng)(leng)的(de)(de)(de)(de)(de)(de)壓(ya)力從(1～2)%26times;10Pa提高(gao)到(5～6)%26times;10Pa，使冷(leng)(leng)卻(que)能力接近于(yu)(yu)常壓(ya)下的(de)(de)(de)(de)(de)(de)油冷(leng)(leng)。80年(nian)(nian)代(dai)(dai)中(zhong)期出現超(chao)高(gao)壓(ya)氣(qi)(qi)淬(cui)(cui)(cui)(cui)，用(yong)(yong)(10～20)%26times;10Pa的(de)(de)(de)(de)(de)(de)氦(hai)，冷(leng)(leng)卻(que)能力等于(yu)(yu)或略高(gao)于(yu)(yu)油淬(cui)(cui)(cui)(cui)，已進入(ru)工(gong)業(ye)(ye)實用(yong)(yong)。90年(nian)(nian)代(dai)(dai)初采(cai)用(yong)(yong)40%26times;10Pa的(de)(de)(de)(de)(de)(de)氫(qing)氣(qi)(qi)，接近水淬(cui)(cui)(cui)(cui)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)卻(que)能力，尚處于(yu)(yu)起步階段。工(gong)業(ye)(ye)發(fa)達(da)國(guo)家已進展(zhan)(zhan)到以(yi)高(gao)壓(ya)(5～6)%26times;10。Pa氣(qi)(qi)淬(cui)(cui)(cui)(cui)為主(zhu)體，而(er)中(zhong)國(guo)產氣(qi)(qi)淬(cui)(cui)(cui)(cui)一(yi)些金屬(shu)的(de)(de)(de)(de)(de)(de)蒸氣(qi)(qi)壓(ya)(理論值)與(yu)溫(wen)度的(de)(de)(de)(de)(de)(de)關(guan)系則尚處于(yu)(yu)一(yi)般(ban)加壓(ya)氣(qi)(qi)淬(cui)(cui)(cui)(cui)(2%26times;10Pa)型階段。

　　結果真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)為真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)一淬(cui)火(huo)(huo)工(gong)(gong)藝曲線。在真(zhen)(zhen)空中(zhong)加熱(re)到(dao)滲(shen)(shen)(shen)(shen)碳(tan)溫(wen)度(du)并保(bao)溫(wen)使表面(mian)凈化(hua)(hua)、活(huo)(huo)化(hua)(hua)之后(hou)，通(tong)入(ru)稀薄滲(shen)(shen)(shen)(shen)碳(tan)富(fu)化(hua)(hua)氣(qi)(見控制氣(qi)氛熱(re)處理)，在大(da)約1330Pa(10T0rr)負壓下(xia)進(jin)行(xing)滲(shen)(shen)(shen)(shen)入(ru)，然(ran)后(hou)停(ting)氣(qi)(降(jiang)壓)進(jin)行(xing)擴(kuo)散。滲(shen)(shen)(shen)(shen)碳(tan)后(hou)的精密鋼管淬(cui)火(huo)(huo)采用(yong)(yong)一次淬(cui)火(huo)(huo)法，即(ji)先停(ting)電(dian)，通(tong)氮冷(leng)卻(que)工(gong)(gong)件(jian)至臨(lin)界(jie)點A，、以下(xia)，使內部發生(sheng)相(xiang)變，再停(ting)氣(qi)、開(kai)泵，升溫(wen)到(dao)Ac1，～Accm之間(jian)。淬(cui)冷(leng)方法可采用(yong)(yong)氣(qi)冷(leng)或油(you)冷(leng)。后(hou)者(zhe)為奧(ao)氏體(ti)化(hua)(hua)后(hou)移入(ru)前室，充氮至常(chang)壓，入(ru)油(you)。真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)的溫(wen)度(du)一般高于普(pu)通(tong)氣(qi)體(ti)滲(shen)(shen)(shen)(shen)碳(tan)，常(chang)采用(yong)(yong)920～1040℃滲(shen)(shen)(shen)(shen)入(ru)和(he)擴(kuo)散可按(an)所(suo)示(shi)分兩階段(duan)，也可用(yong)(yong)脈沖(chong)式通(tong)氣(qi)、停(ting)氣(qi)，多段(duan)式的滲(shen)(shen)(shen)(shen)一擴(kuo)相(xiang)間(jian)，效果更(geng)好。由(you)于溫(wen)度(du)高，尤其表面(mian)潔凈、有活(huo)(huo)性，真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)層(ceng)形成速度(du)比普(pu)通(tong)氣(qi)體(ti)、液體(ti)和(he)固體(ti)滲(shen)(shen)(shen)(shen)碳(tan)快，如要求(qiu)滲(shen)(shen)(shen)(shen)層(ceng)為1mm時，在927℃只(zhi)需(xu)5h，而1033℃僅(jin)需(xu)1h。

　　精密鋼(gang)管(guan)硬度與變形

　　取兩塊(kuai)式樣(yang)，一塊(kuai)用于研(yan)究(jiu)不(bu)同(tong)形(xing)變程度(du)對硬度(du)的影響，另(ling)一塊(kuai)研(yan)究(jiu)不(bu)同(tong)溫度(du)對性能的影響。

　　冷變(bian)形(xing)強化(hua)(hua)在(zai)實際生產中(zhong)具有(you)(you)重要(yao)的意義。首先(xian)這是(shi)一(yi)種重要(yao)的強化(hua)(hua)材料(liao)的手段(duan)，尤(you)其(qi)對用熱處理不能強化(hua)(hua)的材料(liao)來(lai)說，顯得更(geng)為(wei)重要(yao)。其(qi)次，冷變(bian)形(xing)強化(hua)(hua)有(you)(you)利(li)于金屬(shu)的變(bian)形(xing)均勻(yun)。因為(wei)精密(mi)(mi)鋼管的變(bian)形(xing)部分(fen)產生硬(ying)化(hua)(hua)，將使變(bian)形(xing)向未變(bian)形(xing)或變(bian)形(xing)較少的部分(fen)繼續發展。第三，冷變(bian)形(xing)強化(hua)(hua)可(ke)以提(ti)高構(gou)件(jian)在(zai)使用過程中(zhong)的安全性，構(gou)件(jian)一(yi)旦超載，產生塑性變(bian)形(xing)，由于強化(hua)(hua)作(zuo)用，可(ke)防(fang)止構(gou)件(jian)突(tu)然斷裂。但是(shi)，冷變(bian)形(xing)強化(hua)(hua)也給精密(mi)(mi)鋼管的繼續變(bian)形(xing)帶來(lai)困(kun)難，甚至出現裂紋(wen)。因此，在(zai)精密(mi)(mi)鋼管變(bian)形(xing)和加(jia)工過程中(zhong)常進(jin)行"中(zhong)間退火"，以消除它的不利(li)影(ying)響。