NGUYEN TAC ANHGIiO TRINHCONG KIM LOA IHi(eu dinh: PGS.TS. Hoang Trong BaDAI HOC SP PHAM KY THUAT TP. HO CHI MINHNAM 2004(LV HANH NO BO) Dé o i‹zo thea iizcing cfing ngie, phét buy tin rich cizc cfi‹z ngizfii fioc v‹i tho diéu kien thuén lot cho gif a vién giéng day bang céc ph :cmg tien dqy he.c ... Gigo trinh C©NG NGHE KIM LOAI dupc bién soan la i cc ban d(a trén giéo trinh CHP TAO PHO‘II cfi‹z Dat Hoc Ba ch Khoa Hésung mot so néi dung mii cho ph h hpp vat céng nghé thu:c Ie hién nay. NGHIEP, khoa Co khi may, Try:g Dat Hoc Su: Pha in Kj Theft. Thenhphc ‘Ho Chi Minh. PHAN ICONG NGHE DUCChifdng 1KH NIEM VE QUA TRINH SAN XUAT DUC1.1Phfin loai c:ie phifdng ph:ip diicDfic la mot phu’dng phap ché ta o phfii cho quit trinh gia cling cat got tiép sau. Nganh cfing nghiép ché tao may phat trién, lu’dng phfii diic ngay cang doi hoi nhiéu hfin.1.1.1DJnb nghia:Thu’c chfit ciia duc la qu:i trinh dién dfiy kim loai fi thé long vao long khufin duc co hinh dang, kich thu’fic dinh san . Sau khi kim loai dong dac, ta thu du’dc sfin pham tu’dng ring vfii long khuon. Skin pham do goi la vat dfic. N¼u dem vat duc gia cfing tiép theo nhu’ gia cfing c:i I got thi no du’fic goi la phfii diic.1.1.2Da)c diém:Co nhiéu phu’6ng ph:ip ta o phoi duc khac nhau. Moi phu’dng phap tao ra s:i n pham co dac tinh kh:ic nhau, nhuYig can cut vao th c chat chung, san xuat diic co cac dac tinh sau:Mot loai vat lieu nhu’ gang, thép, hdp kim mau, vat lieu phi kim khi nau ch:iy long du’dc deu duc du’dc.Tao ra vat dfic co két cau phtic tap, nhtrng vat duc co khoi 1u’dng 1dn ma chic phu’dng phap gia cfing phfii kh:ic khfing thu’c hién du’dc.Mfit so phu’fing ph:ip duc tién tién co the tao ra san pham co chat 1u’dng cao, kich thu’fic chinh xac, do bong bé mat cao va co khii nang cd khi hoa, hoac IQ dong hoa cao.Gi:i thanh cua san xuat diic noi chung ha h6n so vfii c:ic dang san xuat kh:ic.Tuy vay, qu:i trinh san xuat diic con can phai khac phuc mot so cac rri:i t han che sau: Do qua trinh két tinh tif the long nén trong vat diic de ton tai chic dang ro co, ro khi, niit, Ian tap chat.v.v...Khi duc trong khufi n cat dfi chinh xac vé kich thu’fic va do bfi ng thap.Tiéu hao mot phan khfing nho kim loai cho he thong rot, dau ngot va cho cac dai 1u’cIng khac (1u’fing du’, do xién v.v.. .)Phu’fing ph:ip duc dii sao van la mot trong cac phu’dng phii p du’dc diing rong rat de ché tao ra mot khoi 1u’cIng san pham kim loai rat 1dn. Chat 1u’fing cu a san pham ngay cang du’dc nang cao ciing vfii nhiing két qua nghién ciiu va su’ hién dai ho:i qua trinh san xuat dtic. Nhii’ng san pham dtic rat da dang nhu’ thfin may cfing cu, c:ic vfi hop giiim toc, vfi dfing cd dien, vfi m:iy phat dien, cac loai gia dd va nhiéu loai chi tiét m:iy quan trong khac bang kim loai den va hdp kim m:iu.1.1.3 Pharr loai cac phififng ph:i p due:Phu’dng phap s:in xuat dfic du’dc phfin loai tiiy thuoc vao loai khufin, mau, phu’fing phap lam khufin v. v...Theo loai khufin dtic ngu’iii ta phan ra:a.Due trong khufin clit: do la dang duc pho bién. Khufin cat la loai khufin dfic mfit lfin (chi rot mot Ian rot ph:i khufin). Vat duc tao hinh trong khufin clit co do chinh xac thap, dfi bong bé mat kém, 1u’dng du’ gia cling 1cin . Nhtfng khufin c:i t tao ra vii t dfic co ké I cfiu phii’c tap, khfii 1u’dng ldn.b.Dfic da)c bi9t: Ngoai khufin cat, c:ic dang duc trong khufin duc (kim loai, vfimong...) du’ijc gop chung la dtic dac bi t.Dfic d:ic bié I cho san phfim chat lu’dng cao hdn, dfi chinh xac, dfi bfing cao hdn vfit dtic trong khufin c:it. Ngoai ra phfin lean c:ic phu’dng phap duc d:ic biét co n:ing su:It cao hdn. Tuy nhién dfic d:ic biét thu’iIng chi tao du’dc vfit dii c nhfi va trung binh.Trong bang du’tii dfiy trinh bay tom ta I c:ic dang s:in xufit duc, phu’dng phap taokhufin va tinh v½c si’i’ dung cua chung.