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,全國可發(fa),我司專業(ye)生產,歡迎咨(zi)詢~
牌號 | 化學成分% | |||||
C | Si | Mn | S | P | Cr | |
10 | 0.07-0.13 | 0.17-0.37 | 0.35-0.65 | ≤0.035 | ≤0.035 | |
20 | 0.17-0.23 | 0.17-0.37 | 0.35-0.65 | ≤0.035 | ≤0.035 | |
35 | 0.32-0.39 | 0.17-0.37 | 0.35-0.65 | ≤0.035 | ≤0.035 | |
45 | 0.42-0.50 | 0.17-0.37 | 0.50-0.80 | ≤0.035 | ≤0.035 | |
40Cr | 0.37-0.44 | 0.17-0.37 | 0.50-0.80 | ≤0.035 | ≤0.035 | 0.08-1.10 |
25Mn | 0.22-0.29 | 0.17-0.37 | 0.70-1.00 | ≤0.035 | ≤0.035 | ≤0.25 |
37Mn5 | 0.30-0.39 | 0.15-0.30 | 1.20-1.50 | ≤0.015 | ≤0.020 |
20#精密鋼管熱處理工(gong)藝
精密鋼管前奏
真(zhen)空退(tui)火優質彈簧(huang)鋼(gang)、工具鋼(gang)、精(jing)密(mi)鋼(gang)管的絲材(cai),不銹(xiu)鋼(gang)制品及鈦合(he)金材(cai),作光亮(liang)退(tui)火均(jun)可采(cai)(cai)用真(zhen)空處理(li)。退(tui)火溫度愈低,則要求真(zhen)空度愈高。為防止鉻的蒸發及加(jia)(jia)速熱傳導,一般采(cai)(cai)用載氣加(jia)(jia)熱(保溫)法(fa),并注意對(dui)不銹(xiu)鋼(gang)和鈦合(he)金不宜用氮而應采(cai)(cai)用氬氣。
精密鋼管過程
真(zhen)空淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)真(zhen)空淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)爐(lu)按冷(leng)(leng)卻(que)方法(fa)分為(wei)(wei)油(you)(you)淬(cui)(cui)(cui)(cui)(cui)(cui)和(he)氣(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(cui)(cui)兩類,按工(gong)位(wei)(wei)數分為(wei)(wei)單(dan)室式(shi)(shi)和(he)雙(shuang)(shuang)室式(shi)(shi),904山(shan)\畏嘲均(jun)屬周期(qi)(qi)式(shi)(shi)作業(ye)爐(lu)。真(zhen)空油(you)(you)淬(cui)(cui)(cui)(cui)(cui)(cui)爐(lu)都是雙(shuang)(shuang)室的(de)(de)(de)(de)(de)(de),后(hou)(hou)室置電(dian)加(jia)(jia)(jia)熱元件(jian)(jian),前(qian)室的(de)(de)(de)(de)(de)(de)下方置油(you)(you)槽。工(gong)件(jian)(jian)完成(cheng)加(jia)(jia)(jia)熱、保溫(wen)(wen)后(hou)(hou)移入(ru)(ru)前(qian)室,關閉中門后(hou)(hou)向(xiang)前(qian)室充入(ru)(ru)惰性(xing)(xing)氣(qi)(qi)(qi)(qi)至大約(yue)2.66%26times;lO ~1.01%26times;10 Pa(200~760mm汞柱),入(ru)(ru)油(you)(you)。油(you)(you)淬(cui)(cui)(cui)(cui)(cui)(cui)易引(yin)起(qi)工(gong)件(jian)(jian)表面變質(zhi)。由于(yu)表面活性(xing)(xing)大,在(zai)(zai)短暫的(de)(de)(de)(de)(de)(de)高(gao)(gao)(gao)溫(wen)(wen)油(you)(you)膜作用下即(ji)可發(fa)(fa)生(sheng)顯著(zhu)薄(bo)層滲碳(tan),此(ci)外,碳(tan)黑和(he)油(you)(you)在(zai)(zai)表面的(de)(de)(de)(de)(de)(de)粘(zhan)附對(dui)簡化熱處(chu)理(li)流(liu)(liu)程很不利。真(zhen)空淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)技術的(de)(de)(de)(de)(de)(de)發(fa)(fa)展(zhan)主要在(zai)(zai)于(yu)研制(zhi)性(xing)(xing)能優良、工(gong)位(wei)(wei)單(dan)一的(de)(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)冷(leng)(leng)淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)爐(lu)。前(qian)述雙(shuang)(shuang)室式(shi)(shi)爐(lu)亦可用于(yu)氣(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(cui)(cui)(在(zai)(zai)前(qian)室噴(pen)氣(qi)(qi)(qi)(qi)冷(leng)(leng)卻(que)),但雙(shuang)(shuang)工(gong)位(wei)(wei)式(shi)(shi)的(de)(de)(de)(de)(de)(de)操作使(shi)大批量裝爐(lu)的(de)(de)(de)(de)(de)(de)生(sheng)產(chan)發(fa)(fa)生(sheng)困(kun)難,也易在(zai)(zai)高(gao)(gao)(gao)溫(wen)(wen)移動中引(yin)起(qi)工(gong)件(jian)(jian)變形或改變工(gong)件(jian)(jian)方位(wei)(wei)增加(jia)(jia)(jia)淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)變形。單(dan)一工(gong)位(wei)(wei)的(de)(de)(de)(de)(de)(de)氣(qi)(qi)(qi)(qi)冷(leng)(leng)淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)爐(lu)是在(zai)(zai)加(jia)(jia)(jia)熱保溫(wen)(wen)完成(cheng)后(hou)(hou)在(zai)(zai)加(jia)(jia)(jia)熱室內噴(pen)氣(qi)(qi)(qi)(qi)冷(leng)(leng)卻(que)。氣(qi)(qi)(qi)(qi)冷(leng)(leng)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)速不如油(you)(you)冷(leng)(leng)快,也低于(yu)傳統淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)法(fa)中的(de)(de)(de)(de)(de)(de)熔鹽(yan)等(deng)溫(wen)(wen)、分級淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)。因而,不斷(duan)提高(gao)(gao)(gao)噴(pen)冷(leng)(leng)室壓(ya)力(li)(li),增大流(liu)(liu)量,以及采(cai)用摩爾質(zhi)量比氮(dan)和(he)氬小(xiao)的(de)(de)(de)(de)(de)(de)惰性(xing)(xing)氣(qi)(qi)(qi)(qi)體(ti)氦和(he)氫(qing),是當今真(zhen)空淬(cui)(cui)(cui)(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)技術發(fa)(fa)展(zhan)的(de)(de)(de)(de)(de)(de)主流(liu)(liu)。70年(nian)代后(hou)(hou)期(qi)(qi)將氮(dan)氣(qi)(qi)(qi)(qi)噴(pen)冷(leng)(leng)的(de)(de)(de)(de)(de)(de)壓(ya)力(li)(li)從(1~2)%26times;10Pa提高(gao)(gao)(gao)到(5~6)%26times;10Pa,使(shi)冷(leng)(leng)卻(que)能力(li)(li)接近(jin)于(yu)常(chang)壓(ya)下的(de)(de)(de)(de)(de)(de)油(you)(you)冷(leng)(leng)。80年(nian)代中期(qi)(qi)出現超高(gao)(gao)(gao)壓(ya)氣(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(cui)(cui),用(10~20)%26times;10Pa的(de)(de)(de)(de)(de)(de)氦,冷(leng)(leng)卻(que)能力(li)(li)等(deng)于(yu)或略高(gao)(gao)(gao)于(yu)油(you)(you)淬(cui)(cui)(cui)(cui)(cui)(cui),已進入(ru)(ru)工(gong)業(ye)實用。90年(nian)代初采(cai)用40%26times;10Pa的(de)(de)(de)(de)(de)(de)氫(qing)氣(qi)(qi)(qi)(qi),接近(jin)水淬(cui)(cui)(cui)(cui)(cui)(cui)的(de)(de)(de)(de)(de)(de)冷(leng)(leng)卻(que)能力(li)(li),尚處(chu)于(yu)起(qi)步階(jie)段。工(gong)業(ye)發(fa)(fa)達(da)國家已進展(zhan)到以高(gao)(gao)(gao)壓(ya)(5~6)%26times;10。Pa氣(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(cui)(cui)為(wei)(wei)主體(ti),而中國產(chan)氣(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(cui)(cui)一些金屬的(de)(de)(de)(de)(de)(de)蒸氣(qi)(qi)(qi)(qi)壓(ya)(理(li)論(lun)值)與溫(wen)(wen)度的(de)(de)(de)(de)(de)(de)關系則尚處(chu)于(yu)一般加(jia)(jia)(jia)壓(ya)氣(qi)(qi)(qi)(qi)淬(cui)(cui)(cui)(cui)(cui)(cui)(2%26times;10Pa)型階(jie)段。
結(jie)果(guo)真空(kong)(kong)滲(shen)碳(tan)(tan)為真空(kong)(kong)滲(shen)碳(tan)(tan)一(yi)淬(cui)火工藝(yi)曲線(xian)。在真空(kong)(kong)中加熱(re)到滲(shen)碳(tan)(tan)溫度并保(bao)溫使表面凈化(hua)、活化(hua)之后(hou),通入稀(xi)薄(bo)滲(shen)碳(tan)(tan)富(fu)化(hua)氣(見控制氣氛熱(re)處理),在大約(yue)1330Pa(10T0rr)負壓下進(jin)(jin)行滲(shen)入,然后(hou)停氣(降(jiang)壓)進(jin)(jin)行擴散(san)。滲(shen)碳(tan)(tan)后(hou)的精密(mi)鋼(gang)管淬(cui)火采用一(yi)次淬(cui)火法,即先停電(dian),通氮冷卻工件(jian)至臨界(jie)點A,、以下,使內部發(fa)生相變,再停氣、開泵,升溫到Ac1,~Accm之間。淬(cui)冷方(fang)法可采用氣冷或油(you)冷。后(hou)者(zhe)為奧氏體(ti)化(hua)后(hou)移入前室,充氮至常壓,入油(you)。真空(kong)(kong)滲(shen)碳(tan)(tan)的溫度一(yi)般高于普(pu)通氣體(ti)滲(shen)碳(tan)(tan),常采用920~1040℃滲(shen)入和(he)擴散(san)可按所示分兩階段,也可用脈沖式通氣、停氣,多段式的滲(shen)一(yi)擴相間,效果(guo)更好(hao)。由(you)于溫度高,尤其表面潔凈、有活性(xing),真空(kong)(kong)滲(shen)碳(tan)(tan)層形成速度比普(pu)通氣體(ti)、液體(ti)和(he)固體(ti)滲(shen)碳(tan)(tan)快,如(ru)要求滲(shen)層為1mm時,在927℃只需(xu)(xu)5h,而1033℃僅需(xu)(xu)1h。
精密(mi)鋼(gang)管硬度與變形
取兩塊(kuai)(kuai)式(shi)樣(yang),一(yi)塊(kuai)(kuai)用于研(yan)究不同形變(bian)程度對硬度的(de)影響,另(ling)一(yi)塊(kuai)(kuai)研(yan)究不同溫度對性能的(de)影響。
冷(leng)變(bian)(bian)(bian)形(xing)強化(hua)在(zai)實際生產中(zhong)具有(you)重(zhong)要(yao)(yao)的(de)(de)(de)(de)意義。首先(xian)這是一種重(zhong)要(yao)(yao)的(de)(de)(de)(de)強化(hua)材料的(de)(de)(de)(de)手段,尤其對用熱處理不能強化(hua)的(de)(de)(de)(de)材料來說,顯得更為(wei)重(zhong)要(yao)(yao)。其次,冷(leng)變(bian)(bian)(bian)形(xing)強化(hua)有(you)利(li)于金屬的(de)(de)(de)(de)變(bian)(bian)(bian)形(xing)均(jun)勻(yun)。因(yin)為(wei)精(jing)(jing)密(mi)鋼管的(de)(de)(de)(de)變(bian)(bian)(bian)形(xing)部分產生硬化(hua),將使變(bian)(bian)(bian)形(xing)向未變(bian)(bian)(bian)形(xing)或(huo)變(bian)(bian)(bian)形(xing)較少的(de)(de)(de)(de)部分繼續發展。第三,冷(leng)變(bian)(bian)(bian)形(xing)強化(hua)可以提高構(gou)件(jian)在(zai)使用過(guo)程中(zhong)的(de)(de)(de)(de)安(an)全性,構(gou)件(jian)一旦超載,產生塑性變(bian)(bian)(bian)形(xing),由于強化(hua)作用,可防止構(gou)件(jian)突然斷(duan)裂。但(dan)是,冷(leng)變(bian)(bian)(bian)形(xing)強化(hua)也(ye)給精(jing)(jing)密(mi)鋼管的(de)(de)(de)(de)繼續變(bian)(bian)(bian)形(xing)帶(dai)來困難,甚至出現裂紋(wen)。因(yin)此,在(zai)精(jing)(jing)密(mi)鋼管變(bian)(bian)(bian)形(xing)和加工過(guo)程中(zhong)常(chang)進行"中(zhong)間(jian)退火",以消除它的(de)(de)(de)(de)不利(li)影(ying)響。