前處理工藝：金屬件前處理脫脂技術說明
脫脂是(shi)(shi)金屬(shu)件加(jia)工(gong)(gong)的(de)前(qian)處理工(gong)(gong)藝，基本上金屬(shu)件加(jia)工(gong)(gong)前(qian)都有這么一(yi)(yi)道(dao)工(gong)(gong)序(xu)。主要(yao)就是(shi)(shi)增加(jia)鍍層(ceng)(ceng)附著力。另外(wai)五(wu)金件一(yi)(yi)般要(yao)經(jing)過電(dian)鍍設備處理的(de)，都是(shi)(shi)冷(leng)軋鋼板材，在(zai)自然環境中48小(xiao)時(shi)內就會生(sheng)銹，所(suo)以表(biao)面上一(yi)(yi)般都會涂上一(yi)(yi)層(ceng)(ceng)防(fang)銹油。這跟鋼材的(de)生(sheng)產工(gong)(gong)序(xu)有關系。
對形狀(zhuang)復(fu)雜(za)(za)(za)(接縫、盲(mang)孔(kong)狀(zhuang))的小零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)、有(you)(you)色金屬件(jian)(jian)(jian)(jian)(jian)、油污嚴重的零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)及易被堿溶(rong)液腐蝕的零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)初步脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)可采(cai)(cai)用(yong)(yong)有(you)(you)機(ji)溶(rong)劑脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)，此(ci)(ci)方(fang)法(fa)皂化(hua)(hua)油脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)和非油脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)均能溶(rong)解(jie)，一(yi)般不腐蝕零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)。脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)快(kuai)，但不徹(che)底，需用(yong)(yong)化(hua)(hua)學(xue)或(huo)電化(hua)(hua)學(xue)方(fang)法(fa)補充脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)。有(you)(you)機(ji)溶(rong)劑易燃(ran);有(you)(you)毒(du)、成本較高。一(yi)般零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)采(cai)(cai)用(yong)(yong)化(hua)(hua)學(xue)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)，此(ci)(ci)方(fang)法(fa)簡便，設備(bei)簡單，成本低(di)，但脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)時間長。一(yi)般零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)的脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)或(huo)陽極去(qu)除浸(jin)濕殘渣可采(cai)(cai)用(yong)(yong)電化(hua)(hua)學(xue)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)，此(ci)(ci)方(fang)法(fa)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)效(xiao)率高，能除去(qu)零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)表面(mian)的浮灰，浸(jin)濕殘渣等(deng)機(ji)械雜(za)(za)(za)質，但陰極電解(jie)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)易滲氫，深孔(kong)內油污去(qu)除較慢，且(qie)需有(you)(you)直流電源。大(da)、中(zhong)型零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)或(huo)不宜用(yong)(yong)其(qi)他(ta)方(fang)法(fa)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)的零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)可采(cai)(cai)用(yong)(yong)擦(ca)拭脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)，此(ci)(ci)方(fang)法(fa)操作(zuo)靈(ling)活方(fang)便，不受零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)限制(zhi)，但勞動(dong)強度大(da)工(gong)效(xiao)低(di)。精度不太(tai)高的小型零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)可采(cai)(cai)用(yong)(yong)滾筒(tong)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)，此(ci)(ci)方(fang)法(fa)功(gong)效(xiao)高，質量(liang)好，但不適應于(yu)大(da)零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)和易變形的零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)。形狀(zhuang)復(fu)雜(za)(za)(za)特殊(shu)零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)可采(cai)(cai)用(yong)(yong)超(chao)聲波脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)，此(ci)(ci)方(fang)法(fa)對基體(ti)腐蝕小、脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)效(xiao)率高、凈化(hua)(hua)效(xiao)果好。復(fu)雜(za)(za)(za)零(ling)(ling)(ling)(ling)件(jian)(jian)(jian)(jian)(jian)邊角、細孔(kong)、盲(mang)孔(kong)以及空腔內壁等(deng)都能徹(che)底脫(tuo)(tuo)(tuo)(tuo)脂(zhi)(zhi)(zhi)(zhi)(zhi)(zhi)。
一(yi)(yi)般(ban)的(de)，溫(wen)度越(yue)(yue)高，脫(tuo)(tuo)脂(zhi)(zhi)越(yue)(yue)徹底(di)。但并不(bu)所有(you)(you)場合都為溫(wen)度越(yue)(yue)高越(yue)(yue)好，各(ge)種脫(tuo)(tuo)脂(zhi)(zhi)劑(ji)(ji)有(you)(you)其適合溫(wen)度范圍(wei)，采某(mou)一(yi)(yi)種類表面活性劑(ji)(ji)脫(tuo)(tuo)脂(zhi)(zhi)液中，過高溫(wen)度使表面活性劑(ji)(ji)析出聚(ju)集如(ru)同(tong)油珠(zhu)附著于表面上，造(zao)成(cheng)磷(lin)化(hua)膜發花(hua)不(bu)均勻(yun)。保證(zheng)有(you)(you)足夠脫(tuo)(tuo)脂(zhi)(zhi)時(shi)間，壓(ya)力(li)噴(pen)射脫(tuo)(tuo)脂(zhi)(zhi)時(shi)間一(yi)(yi)般(ban)一(yi)(yi)點(dian)五到(dao)三(san)分(fen)(fen)鐘(zhong)，浸漬脫(tuo)(tuo)脂(zhi)(zhi)三(san)到(dao)五分(fen)(fen)鐘(zhong)。借助(zhu)壓(ya)力(li)噴(pen)射，攪拌等機械作用非(fei)常有(you)(you)效，噴(pen)射時(shi)迫(po)使新(xin)鮮脫(tuo)(tuo)脂(zhi)(zhi)溶液，零件表面具良(liang)好接觸，且整脫(tuo)(tuo)脂(zhi)(zhi)液含(han)量(liang)(liang)均勻(yun)，利于提(ti)高脫(tuo)(tuo)脂(zhi)(zhi)效果。脫(tuo)(tuo)脂(zhi)(zhi)劑(ji)(ji)的(de)組成(cheng)和使用方(fang)法對(dui)脫(tuo)(tuo)脂(zhi)(zhi)效果有(you)(you)很大(da)的(de)影響(xiang)，為提(ti)高油污(wu)乳化(hua)，分(fen)(fen)散能力(li)，適當提(ti)高脫(tuo)(tuo)脂(zhi)(zhi)劑(ji)(ji)表面活性劑(ji)(ji)含(han)量(liang)(liang)為有(you)(you)效，不(bu)同(tong)表面活性劑(ji)(ji)品種，不(bu)同(tong)堿性物都使脫(tuo)(tuo)脂(zhi)(zhi)效果產(chan)生一(yi)(yi)定差異，良(liang)好脫(tuo)(tuo)脂(zhi)(zhi)劑(ji)(ji)都經(jing)大(da)量(liang)(liang)試驗，對(dui)其組分(fen)(fen)相互搭配比例進行反復篩選而確定的(de)。
掃一掃