淮安碳氫清洗機滲碳溫度 930℃、滲碳時間 80min，滲碳淬火結 束后，測試了不同部位滲碳層的碳含量和硬度，測試 結果如圖 3 所示。 可以看出， 隨著距表面距離的增 大，碳的質量分數不斷降低，而硬度呈現出先上升后 下降的趨勢。一般而言，供應碳氫清洗機鋼(gang)中(zhong)碳(tan)(tan)(tan)含(han)(han)量(liang)是決定淬火后馬 氏(shi)(shi)體(ti)(ti)硬(ying)(ying)度(du)的最主(zhu)要(yao)因素(su)，馬氏(shi)(shi)體(ti)(ti)中(zhong)碳(tan)(tan)(tan)含(han)(han)量(liang)越高，其(qi)硬(ying)(ying) 度(du)也越大(da)，這是導致鋼(gang)淬火后變(bian)硬(ying)(ying)的最主(zhu)要(yao)的因素(su)。 與此同(tong)時，由鋼(gang)的馬氏(shi)(shi)體(ti)(ti)轉變(bian)的特點可知，鋼(gang)淬火后 不會完全得到馬氏(shi)(shi)體(ti)(ti)組(zu)織(zhi)，會有殘余奧氏(shi)(shi)體(ti)(ti)的存在。 隨著(zhu)鋼(gang)中(zhong)碳(tan)(tan)(tan)含(han)(han)量(liang)的增大(da)，殘余奧氏(shi)(shi)體(ti)(ti)含(han)(han)量(liang)增加，從而(er) 降低滲(shen)(shen)碳(tan)(tan)(tan)層的硬(ying)(ying)度(du)。兩方面(mian)的作用(yong)(yong)疊加，導致隨著(zhu)碳(tan)(tan)(tan) 的質(zhi)量(liang)分數的下降， 硬(ying)(ying)度(du)呈現出先(xian)上升后下降的趨 勢。從圖 3 中(zhong)可知，距表面(mian)距離 0.5mm 時，硬(ying)(ying)度(du)值達 到最大(da) 862HV，對應的碳(tan)(tan)(tan)含(han)(han)量(liang)為 0.78%。現在我(wo)們(men)(men)(men)已經知道了我(wo)們(men)(men)(men)使(shi)用(yong)(yong)低壓真(zhen)空(kong)滲(shen)(shen)碳(tan)(tan)(tan)爐的時候(hou)影(ying)響硬(ying)(ying)度(du)的原因是什么，那么這樣的話在我(wo)們(men)(men)(men)進行(xing)使(shi)用(yong)(yong)的時候(hou)就會更(geng)加的方便(bian)和便(bian)捷了，所以說無論是低壓真(zhen)空(kong)滲(shen)(shen)碳(tan)(tan)(tan)爐還是其(qi)他的產品，我(wo)們(men)(men)(men)最好都要(yao)了解他的他點和影(ying)響因素(su)之后再去進行(xing)使(shi)用(yong)(yong)。

給大(da)家介(jie)紹下常用(yong)(yong)(yong)(yong)熱(re)處(chu)理(li)(li)多(duo)用(yong)(yong)(yong)(yong)爐(lu)(lu)爐(lu)(lu)型(xing)的(de)(de)(de)(de)(de)(de)選擇(ze)：1．對(dui)于不(bu)能成(cheng)(cheng)批(pi)定(ding)型(xing)生(sheng)產的(de)(de)(de)(de)(de)(de)，工(gong)件(jian)(jian)(jian)(jian)大(da)小(xiao)(xiao)不(bu)相(xiang)等(deng)的(de)(de)(de)(de)(de)(de)，種類較(jiao)多(duo)的(de)(de)(de)(de)(de)(de)，要(yao)求工(gong)藝上具有通用(yong)(yong)(yong)(yong)性、多(duo)用(yong)(yong)(yong)(yong)性的(de)(de)(de)(de)(de)(de)，可(ke)(ke)(ke)選用(yong)(yong)(yong)(yong)箱式(shi)多(duo)用(yong)(yong)(yong)(yong)爐(lu)(lu)。2．加(jia)熱(re)長(chang)軸(zhou)類及長(chang)的(de)(de)(de)(de)(de)(de)絲桿(gan)，管(guan)子等(deng)工(gong)件(jian)(jian)(jian)(jian)時(shi)，可(ke)(ke)(ke)選用(yong)(yong)(yong)(yong)深(shen)井(jing)式(shi)電爐(lu)(lu)。3．小(xiao)(xiao)批(pi)量(liang)的(de)(de)(de)(de)(de)(de)滲碳(tan)零(ling)件(jian)(jian)(jian)(jian)，可(ke)(ke)(ke)選用(yong)(yong)(yong)(yong)井(jing)式(shi)氣(qi)體滲碳(tan)爐(lu)(lu)。4．對(dui)于大(da)批(pi)量(liang)的(de)(de)(de)(de)(de)(de)汽(qi)車、拖拉機(ji)(ji)齒輪等(deng)零(ling)件(jian)(jian)(jian)(jian)的(de)(de)(de)(de)(de)(de)生(sheng)產可(ke)(ke)(ke)選連(lian)續式(shi)滲碳(tan)生(sheng)產線或(huo)箱式(shi)多(duo)用(yong)(yong)(yong)(yong)爐(lu)(lu)。5．對(dui)沖壓件(jian)(jian)(jian)(jian)板材(cai)坯料的(de)(de)(de)(de)(de)(de)加(jia)熱(re)大(da)批(pi)量(liang)生(sheng)產時(shi)，最(zui)好選用(yong)(yong)(yong)(yong)滾動爐(lu)(lu)，輥底爐(lu)(lu)。6．對(dui)成(cheng)(cheng)批(pi)的(de)(de)(de)(de)(de)(de)定(ding)型(xing)零(ling)件(jian)(jian)(jian)(jian)，生(sheng)產上可(ke)(ke)(ke)選用(yong)(yong)(yong)(yong)推桿(gan)式(shi)或(huo)傳送帶(dai)式(shi)電阻爐(lu)(lu)（推桿(gan)爐(lu)(lu)或(huo)鑄帶(dai)爐(lu)(lu)）7．小(xiao)(xiao)型(xing)機(ji)(ji)械零(ling)件(jian)(jian)(jian)(jian)如：螺釘(ding)，螺母(mu)等(deng)可(ke)(ke)(ke)選用(yong)(yong)(yong)(yong)振底式(shi)爐(lu)(lu)或(huo)網(wang)帶(dai)式(shi)爐(lu)(lu)。8．鋼(gang)球(qiu)及滾柱熱(re)處(chu)理(li)(li)可(ke)(ke)(ke)選用(yong)(yong)(yong)(yong)內螺旋的(de)(de)(de)(de)(de)(de)回轉(zhuan)管(guan)爐(lu)(lu)。9．有色(se)金屬(shu)錠坯在大(da)批(pi)量(liang)生(sheng)產時(shi)可(ke)(ke)(ke)用(yong)(yong)(yong)(yong)推桿(gan)式(shi)爐(lu)(lu)，而對(dui)有色(se)金屬(shu)小(xiao)(xiao)零(ling)件(jian)(jian)(jian)(jian)及材(cai)料可(ke)(ke)(ke)用(yong)(yong)(yong)(yong)空氣(qi)循環加(jia)熱(re)爐(lu)(lu)。

的(de)(de)(de)結構組成特點(dian)：井(jing)(jing)(jing)式(shi)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)爐(lu)(lu)(lu)爐(lu)(lu)(lu)殼由型鋼及(ji)優質(zhi)(zhi)(zhi)鋼板組焊(han)而(er)成，井(jing)(jing)(jing)式(shi)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)爐(lu)(lu)(lu)可實現(xian)爐(lu)(lu)(lu)蓋(gai)和爐(lu)(lu)(lu)體之間的(de)(de)(de)密封，并(bing)在(zai)爐(lu)(lu)(lu)殼上(shang)部(bu)設置排煙(yan)裝(zhuang)置。井(jing)(jing)(jing)式(shi)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)爐(lu)(lu)(lu)爐(lu)(lu)(lu)底襯(chen)由輕質(zhi)(zhi)(zhi)粘(zhan)土磚和重質(zhi)(zhi)(zhi)抗滲(shen)碳砌筑而(er)成，爐(lu)(lu)(lu)墻襯(chen)為復合(he)爐(lu)(lu)(lu)襯(chen)結構，耐火層(ceng)(ceng)采用(yong)輕質(zhi)(zhi)(zhi)粘(zhan)土磚，保(bao)溫(wen)層(ceng)(ceng)用(yong)陶瓷纖維棉或粘(zhan)土磚，各層(ceng)(ceng)經過優化(hua)設計。在(zai)耐火層(ceng)(ceng)內預制了不銹鋼掛鉤(gou)，用(yong)于電阻絲帶的(de)(de)(de)安裝(zhuang)。井(jing)(jing)(jing)式(shi)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)爐(lu)(lu)(lu)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)裝(zhuang)置均(jun)勻(yun)布置在(zai)爐(lu)(lu)(lu)襯(chen)墻體的(de)(de)(de)周圍，該(gai)井(jing)(jing)(jing)式(shi)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)爐(lu)(lu)(lu)由高(gao)溫(wen)電熱(re)合(he)金帶繞(rao)制成波紋狀，分布在(zai)各個加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)區(qu)內，安裝(zhuang)方(fang)式(shi)確保(bao)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)均(jun)勻(yun)性和使用(yong)壽命(ming)以(yi)及(ji)高(gao)的(de)(de)(de)可靠(kao)性，安裝(zhuang)、維修方(fang)便。井(jing)(jing)(jing)式(shi)加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)爐(lu)(lu)(lu)每一個加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)區(qu)都設有(you)測溫(wen)和超溫(wen)報警熱(re)偶(ou)。每一區(qu)的(de)(de)(de)每一組加(jia)(jia)(jia)(jia)(jia)(jia)熱(re)元件為同(tong)參數同(tong)結構。

1)采(cai)用中冷連續式滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)爐(lu)進(jin)(jin)(jin)行(xing)滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)、緩冷和(he)再(zai)加(jia)(jia)熱淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)，可(ke)以(yi)細化材(cai)(cai)料(liao)的(de)(de)(de)晶(jing)(jing)(jing)粒(li)(li)度(du)(du)和(he)顯微組織(zhi)，并提高(gao)(gao)材(cai)(cai)料(liao)的(de)(de)(de)彎曲疲(pi)勞強度(du)(du)、抗沖擊性(xing)能(neng)、接(jie)觸疲(pi)勞性(xing)能(neng)及耐磨性(xing)能(neng)。 2)采(cai)用中冷滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)爐(lu)進(jin)(jin)(jin)行(xing)滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)、緩冷和(he)再(zai)加(jia)(jia)熱淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)，不僅可(ke)以(yi)使20MnVB、20MnTi2B、18CrMnB及20CrMnMo、20Cr等(deng)粗晶(jing)(jing)(jing)粒(li)(li)鋼工(gong)(gong)(gong)件(jian)(jian)進(jin)(jin)(jin)行(xing)大批量滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)，簡(jian)化熱處理工(gong)(gong)(gong)藝，提高(gao)(gao)熱處理生(sheng)產(chan)(chan)效率，降低成本，而(er)且還可(ke)以(yi)使工(gong)(gong)(gong)件(jian)(jian)獲得合格的(de)(de)(de)與比較(jiao)(jiao)細小的(de)(de)(de)晶(jing)(jing)(jing)粒(li)(li)度(du)(du)和(he)顯微組織(zhi)。 3)對于(yu)Cr-Ni、Cr-Ni-Mo等(deng)含(han)(han)Ni材(cai)(cai)料(liao)，尤其是含(han)(han)Ni量較(jiao)(jiao)高(gao)(gao)的(de)(de)(de)材(cai)(cai)料(liao)，通過中冷滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)爐(lu)進(jin)(jin)(jin)行(xing)滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)、緩冷和(he)再(zai)加(jia)(jia)熱淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)，并采(cai)用較(jiao)(jiao)低碳(tan)(tan)(tan)勢(shi)、適當溫(wen)度(du)(du)和(he)較(jiao)(jiao)長周(zhou)期(qi)的(de)(de)(de)滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)工(gong)(gong)(gong)藝，降低了殘留奧(ao)氏(shi)體(ti)量，使工(gong)(gong)(gong)件(jian)(jian)的(de)(de)(de)金相組織(zhi)達到了產(chan)(chan)品的(de)(de)(de)技術要求，因此可(ke)以(yi)實(shi)現部分含(han)(han)Ni較(jiao)(jiao)高(gao)(gao)工(gong)(gong)(gong)件(jian)(jian)的(de)(de)(de)大批量滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)直接(jie)淬(cui)(cui)(cui)火(huo)(huo)(huo)(huo)(huo)

所(suo)加工(gong)(gong)(gong)的(de)(de)低(di)(di)碳(tan)(tan)合(he)金鋼18Cr2Ni4WA 含有較多的(de)(de) Cr、Ni 等合(he) 金元素(su)，使用滲(shen)碳(tan)(tan)爐以后具(ju)有良好的(de)(de)力(li)學和(he)工(gong)(gong)(gong)藝性能，是(shi)生產高(gao)速重(zhong)(zhong)載(zai) 零部件的(de)(de)重(zhong)(zhong)要材料。高(gao)速重(zhong)(zhong)載(zai)零部件的(de)(de)工(gong)(gong)(gong)作環(huan)境往往 較為(wei)惡劣，受(shou)力(li)狀(zhuang)態復(fu)雜，復(fu)雜的(de)(de)工(gong)(gong)(gong)況不(bu)僅要求工(gong)(gong)(gong)件表 面(mian)具(ju)有高(gao)的(de)(de)硬度(du)和(he)耐磨性，而且要求心(xin)部有足夠的(de)(de)強 度(du)和(he)良好的(de)(de)韌性，那么滲(shen)碳(tan)(tan)爐處(chu)理的(de)(de)工(gong)(gong)(gong)藝是(shi)怎(zen)么樣(yang)的(de)(de)呢？1) 18Cr2Ni4WA 鋼滲(shen)碳(tan)(tan)后，經高(gao)溫回(hui)火(huo)(huo)(huo)(huo)、淬火(huo)(huo)(huo)(huo)、深(shen)(shen) 冷和(he)低(di)(di)溫回(hui)火(huo)(huo)(huo)(huo)處(chu)理后，滲(shen)碳(tan)(tan)層(ceng)深(shen)(shen)度(du)幾乎(hu)不(bu)受(shou)影響，表面(mian) 殘(can)留奧(ao)氏體含量(liang)顯(xian)著(zhu)降低(di)(di)，低(di)(di)于14． 62%。2) 對比兩種 18Cr2Ni4WA 鋼滲(shen)碳(tan)(tan)后的(de)(de)熱處(chu)理工(gong)(gong)(gong) 藝，經 680 ℃ × 5 h 兩次高(gao)溫回(hui)火(huo)(huo)(huo)(huo) + 860 ℃ 淬火(huo)(huo)(huo)(huo) + －115． 3 ℃深(shen)(shen)冷 + 160 ℃低(di)(di)溫回(hui)火(huo)(huo)(huo)(huo)工(gong)(gong)(gong)藝處(chu)理后，試(shi) 樣(yang)表面(mian)硬度(du)為(wei)64． 2 HＲC，滲(shen)碳(tan)(tan)層(ceng)深(shen)(shen)度(du)為(wei) 0． 86 mm，符(fu) 合(he)工(gong)(gong)(gong)藝目標(biao)。并得到(dao)由針狀(zhuang)回(hui)火(huo)(huo)(huo)(huo)馬氏體、少量(liang)殘(can)留奧(ao) 氏體和(he)彌散分布的(de)(de)顆粒狀(zhuang)碳(tan)(tan)化物組成(cheng)的(de)(de)滲(shen)碳(tan)(tan)層(ceng)組織(zhi)和(he) 由低(di)(di)碳(tan)(tan)板條狀(zhuang)回(hui)火(huo)(huo)(huo)(huo)馬氏體組成(cheng)的(de)(de)心(xin)部組織(zhi)，兼顧了滲(shen) 碳(tan)(tan)層(ceng)表面(mian)的(de)(de)高(gao)硬度(du)和(he)心(xin)部的(de)(de)強韌性。