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,報價低,全國可發,我司專業(ye)生產,歡(huan)迎咨詢~

　　20#精密鋼(gang)管熱處理(li)工藝

　　精密鋼管前奏

　　真空退(tui)火優(you)質彈簧鋼、工具(ju)鋼、精密鋼管的絲材，不銹鋼制品及鈦(tai)合(he)金材，作光亮退(tui)火均可采(cai)(cai)用(yong)真空處理。退(tui)火溫度愈低，則(ze)要求真空度愈高。為防止鉻(ge)的蒸發(fa)及加速熱(re)傳導(dao)，一般采(cai)(cai)用(yong)載氣(qi)加熱(re)(保溫)法，并注意(yi)對不銹鋼和鈦(tai)合(he)金不宜用(yong)氮(dan)而應采(cai)(cai)用(yong)氬(ya)氣(qi)。

　　精密鋼管過程

　　真空(kong)淬(cui)(cui)(cui)(cui)火真空(kong)淬(cui)(cui)(cui)(cui)火爐(lu)(lu)(lu)(lu)(lu)按(an)冷(leng)(leng)卻方法分為(wei)油(you)(you)淬(cui)(cui)(cui)(cui)和氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)兩類(lei)，按(an)工(gong)(gong)(gong)位(wei)數(shu)分為(wei)單室(shi)(shi)(shi)式和雙室(shi)(shi)(shi)式，904山\畏嘲均屬周(zhou)期式作業爐(lu)(lu)(lu)(lu)(lu)。真空(kong)油(you)(you)淬(cui)(cui)(cui)(cui)爐(lu)(lu)(lu)(lu)(lu)都是(shi)雙室(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)，后室(shi)(shi)(shi)置(zhi)電加熱(re)元件，前室(shi)(shi)(shi)的(de)(de)(de)(de)(de)(de)下(xia)方置(zhi)油(you)(you)槽(cao)。工(gong)(gong)(gong)件完成(cheng)加熱(re)、保溫(wen)后移入(ru)前室(shi)(shi)(shi)，關閉中(zhong)門后向前室(shi)(shi)(shi)充入(ru)惰性(xing)氣(qi)(qi)(qi)(qi)(qi)至(zhi)大(da)約2.66%26times;lO ～1.01%26times;10 Pa(200～760mm汞柱)，入(ru)油(you)(you)。油(you)(you)淬(cui)(cui)(cui)(cui)易引(yin)起工(gong)(gong)(gong)件表面(mian)(mian)變(bian)(bian)質。由(you)于(yu)(yu)表面(mian)(mian)活性(xing)大(da)，在(zai)(zai)短暫(zan)的(de)(de)(de)(de)(de)(de)高(gao)(gao)溫(wen)油(you)(you)膜作用(yong)(yong)(yong)下(xia)即可發(fa)生顯著(zhu)薄層(ceng)滲碳，此(ci)外，碳黑和油(you)(you)在(zai)(zai)表面(mian)(mian)的(de)(de)(de)(de)(de)(de)粘附對簡化熱(re)處理(li)流程(cheng)很(hen)不利。真空(kong)淬(cui)(cui)(cui)(cui)火技(ji)(ji)術(shu)的(de)(de)(de)(de)(de)(de)發(fa)展(zhan)主要在(zai)(zai)于(yu)(yu)研制性(xing)能優良、工(gong)(gong)(gong)位(wei)單一(yi)的(de)(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)淬(cui)(cui)(cui)(cui)火爐(lu)(lu)(lu)(lu)(lu)。前述雙室(shi)(shi)(shi)式爐(lu)(lu)(lu)(lu)(lu)亦可用(yong)(yong)(yong)于(yu)(yu)氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(在(zai)(zai)前室(shi)(shi)(shi)噴(pen)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)卻)，但雙工(gong)(gong)(gong)位(wei)式的(de)(de)(de)(de)(de)(de)操(cao)作使大(da)批量裝爐(lu)(lu)(lu)(lu)(lu)的(de)(de)(de)(de)(de)(de)生產發(fa)生困(kun)難(nan)，也易在(zai)(zai)高(gao)(gao)溫(wen)移動中(zhong)引(yin)起工(gong)(gong)(gong)件變(bian)(bian)形(xing)或(huo)改變(bian)(bian)工(gong)(gong)(gong)件方位(wei)增(zeng)加淬(cui)(cui)(cui)(cui)火變(bian)(bian)形(xing)。單一(yi)工(gong)(gong)(gong)位(wei)的(de)(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)淬(cui)(cui)(cui)(cui)火爐(lu)(lu)(lu)(lu)(lu)是(shi)在(zai)(zai)加熱(re)保溫(wen)完成(cheng)后在(zai)(zai)加熱(re)室(shi)(shi)(shi)內噴(pen)氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)卻。氣(qi)(qi)(qi)(qi)(qi)冷(leng)(leng)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)速不如(ru)油(you)(you)冷(leng)(leng)快，也低于(yu)(yu)傳統(tong)淬(cui)(cui)(cui)(cui)火法中(zhong)的(de)(de)(de)(de)(de)(de)熔鹽等(deng)溫(wen)、分級淬(cui)(cui)(cui)(cui)火。因而，不斷提高(gao)(gao)噴(pen)冷(leng)(leng)室(shi)(shi)(shi)壓(ya)力，增(zeng)大(da)流量，以(yi)及采(cai)(cai)用(yong)(yong)(yong)摩(mo)爾(er)質量比氮和氬小的(de)(de)(de)(de)(de)(de)惰性(xing)氣(qi)(qi)(qi)(qi)(qi)體氦和氫，是(shi)當(dang)今真空(kong)淬(cui)(cui)(cui)(cui)火技(ji)(ji)術(shu)發(fa)展(zhan)的(de)(de)(de)(de)(de)(de)主流。70年代(dai)后期將氮氣(qi)(qi)(qi)(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)(gao)到(dao)(5～6)%26times;10Pa，使冷(leng)(leng)卻能力接(jie)近于(yu)(yu)常壓(ya)下(xia)的(de)(de)(de)(de)(de)(de)油(you)(you)冷(leng)(leng)。80年代(dai)中(zhong)期出(chu)現超(chao)高(gao)(gao)壓(ya)氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)，用(yong)(yong)(yong)(10～20)%26times;10Pa的(de)(de)(de)(de)(de)(de)氦，冷(leng)(leng)卻能力等(deng)于(yu)(yu)或(huo)略高(gao)(gao)于(yu)(yu)油(you)(you)淬(cui)(cui)(cui)(cui)，已進入(ru)工(gong)(gong)(gong)業實用(yong)(yong)(yong)。90年代(dai)初采(cai)(cai)用(yong)(yong)(yong)40%26times;10Pa的(de)(de)(de)(de)(de)(de)氫氣(qi)(qi)(qi)(qi)(qi)，接(jie)近水淬(cui)(cui)(cui)(cui)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)卻能力，尚處于(yu)(yu)起步(bu)階(jie)段。工(gong)(gong)(gong)業發(fa)達國(guo)家已進展(zhan)到(dao)以(yi)高(gao)(gao)壓(ya)(5～6)%26times;10。Pa氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)為(wei)主體，而中(zhong)國(guo)產氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)一(yi)些金屬的(de)(de)(de)(de)(de)(de)蒸氣(qi)(qi)(qi)(qi)(qi)壓(ya)(理(li)論值(zhi))與溫(wen)度的(de)(de)(de)(de)(de)(de)關系則(ze)尚處于(yu)(yu)一(yi)般加壓(ya)氣(qi)(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(2%26times;10Pa)型階(jie)段。

　　結果真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)為(wei)(wei)真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)一(yi)淬(cui)火工(gong)藝(yi)曲線。在真(zhen)(zhen)空中加熱到滲(shen)(shen)(shen)(shen)碳(tan)溫(wen)度(du)(du)并保溫(wen)使表(biao)面(mian)凈化(hua)(hua)、活化(hua)(hua)之(zhi)后(hou)，通(tong)入(ru)(ru)稀薄滲(shen)(shen)(shen)(shen)碳(tan)富化(hua)(hua)氣(見(jian)控制(zhi)氣氛熱處理)，在大約1330Pa(10T0rr)負壓(ya)下進行滲(shen)(shen)(shen)(shen)入(ru)(ru)，然后(hou)停(ting)氣(降(jiang)壓(ya))進行擴(kuo)散。滲(shen)(shen)(shen)(shen)碳(tan)后(hou)的(de)精密(mi)鋼管淬(cui)火采用(yong)一(yi)次淬(cui)火法，即先停(ting)電(dian)，通(tong)氮(dan)(dan)冷(leng)卻(que)工(gong)件(jian)至(zhi)臨界點A，、以(yi)下，使內部發生(sheng)相變，再停(ting)氣、開(kai)泵，升溫(wen)到Ac1，～Accm之(zhi)間。淬(cui)冷(leng)方法可(ke)采用(yong)氣冷(leng)或油(you)冷(leng)。后(hou)者為(wei)(wei)奧氏體(ti)(ti)化(hua)(hua)后(hou)移入(ru)(ru)前(qian)室，充氮(dan)(dan)至(zhi)常(chang)壓(ya)，入(ru)(ru)油(you)。真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)的(de)溫(wen)度(du)(du)一(yi)般高(gao)于普通(tong)氣體(ti)(ti)滲(shen)(shen)(shen)(shen)碳(tan)，常(chang)采用(yong)920～1040℃滲(shen)(shen)(shen)(shen)入(ru)(ru)和(he)(he)擴(kuo)散可(ke)按(an)所示分(fen)兩階段(duan)，也可(ke)用(yong)脈沖式通(tong)氣、停(ting)氣，多段(duan)式的(de)滲(shen)(shen)(shen)(shen)一(yi)擴(kuo)相間，效(xiao)果更好(hao)。由于溫(wen)度(du)(du)高(gao)，尤其表(biao)面(mian)潔凈、有活性，真(zhen)(zhen)空滲(shen)(shen)(shen)(shen)碳(tan)層形成速(su)度(du)(du)比(bi)普通(tong)氣體(ti)(ti)、液體(ti)(ti)和(he)(he)固體(ti)(ti)滲(shen)(shen)(shen)(shen)碳(tan)快(kuai)，如要求滲(shen)(shen)(shen)(shen)層為(wei)(wei)1mm時，在927℃只(zhi)需(xu)(xu)5h，而1033℃僅(jin)需(xu)(xu)1h。

　　精(jing)密鋼管硬度與變形

　　取兩塊式(shi)樣，一塊用于研究(jiu)不(bu)同形變程度(du)對硬度(du)的影響(xiang)，另一塊研究(jiu)不(bu)同溫(wen)度(du)對性能的影響(xiang)。

　　冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)強(qiang)化(hua)在(zai)實際生(sheng)產中(zhong)(zhong)具有(you)重(zhong)要的(de)意義。首(shou)先這是一種重(zhong)要的(de)強(qiang)化(hua)材料的(de)手段(duan)，尤其(qi)對用熱處(chu)理不能強(qiang)化(hua)的(de)材料來(lai)說，顯得更為重(zhong)要。其(qi)次，冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)強(qiang)化(hua)有(you)利于金屬(shu)的(de)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)均勻。因(yin)為精(jing)密(mi)(mi)鋼管的(de)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)部分產生(sheng)硬(ying)化(hua)，將使(shi)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)向未變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)或(huo)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)較少的(de)部分繼續(xu)發展。第(di)三，冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)強(qiang)化(hua)可以提高構件(jian)(jian)在(zai)使(shi)用過(guo)程中(zhong)(zhong)的(de)安(an)全性(xing)，構件(jian)(jian)一旦超(chao)載，產生(sheng)塑性(xing)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)，由于強(qiang)化(hua)作(zuo)用，可防止構件(jian)(jian)突然(ran)斷(duan)裂。但是，冷(leng)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)強(qiang)化(hua)也給(gei)精(jing)密(mi)(mi)鋼管的(de)繼續(xu)變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)帶來(lai)困難，甚(shen)至出(chu)現裂紋。因(yin)此(ci)，在(zai)精(jing)密(mi)(mi)鋼管變(bian)(bian)(bian)形(xing)(xing)(xing)(xing)和(he)加工過(guo)程中(zhong)(zhong)常進行(xing)"中(zhong)(zhong)間退(tui)火"，以消除它的(de)不利影(ying)響。