Izigaba Zokukhiqiza Insimbi Engagqwali
Insimbi engagqwali iwumndeni wezinto ezisekelwe ensimbini ezaziwa ngokumelana kwayo nokugqwala, amandla amahle okusebenza, kanye nokulula kokugcinwa. Izakhiwo zayo "ezimelana nokugqwala" zivela ngokuyinhloko kokuqukethwe kwayo kwe-chromium (Cr), okwakha ungqimba oluncane olungenamsebenzi lwe-chromium oxide ebusweni bensimbi. Lolu ungqimba luvikela insimbi ekungcolisweni okuqhubekayo, luyivimbele ekugqwaleni ngisho nasezindaweni ezinomswakama noma ezinolaka. Ngemuva kokusebenza kwayo, insimbi engagqwali idlula enkambisweni yokukhiqiza ende neqinile ukuqinisekisa ukuthi ukwakheka kwayo kwamakhemikhali, ubumsulwa bensimbi, kanye nesakhiwo sayo esincane kuhlangabezana nezimfuneko. Okulandelayo kuchaza izigaba zokukhiqizwa kwensimbi engagqwali, kusukela ezintweni zokusetshenziswa kuya kumkhiqizo oqediwe.
1. Ukukhethwa Kwezinto Zokusetshenziswa Nokuhlela Ukwakheka
Isigaba sokuqala siqala ngokunquma uhlobo lwensimbi engagqwali okufanele yenziwe, isibonelo i-austenitic (njengochungechunge lwe-304/316), i-ferritic (uchungechunge lwe-430), i-martensitic (uchungechunge lwe-410), kuya ku-duplex (inhlanganisela ye-austenitic-ferritic). Ukukhethwa kwalolu hlobo kunquma ukwakheka kwe-alloy okudingekayo: i-chromium njengesici esiyinhloko (ngokuvamile okungenani i-10,5% ukwakha ungqimba olungasebenzi), i-nickel yokuqinisa isigaba se-austenite nokwandisa i-ductility, i-molybdenum yokumelana nokugqwala kwemigodi (ikakhulukazi ku-316), nezinye izinto ezifana ne-manganese, i-silicon, i-nitrogen, i-titanium, noma i-niobium ngezinjongo ezithile.
Izinto zokusetshenziswa zingabandakanya insimbi eqoshiwe (izicucu zensimbi engagqwali), izicucu zensimbi yekhabhoni, i-ferrochrome (i-Fe-Cr alloy), i-ferronickel noma i-nickel emsulwa, i-ferromolybdenum, kanye nama-carbon binders nama-deoxidizer. Izimboni eziningi zensimbi engagqwali zanamuhla zithembele kakhulu ezicucuni ngoba zisebenza kahle kakhulu futhi zisekela umnotho ojikelezayo. Kodwa-ke, ikhwalithi yezicucu kumele ilawulwe ukuze kugwenywe "ukungcoliswa" kokwakheka (isb., ithusi eliningi noma ezinye izinto ezingcolisayo).
2. Ukuncibilika ku-Electric Arc Furnace (EAF)
Iningi lensimbi engagqwali likhiqizwa kusetshenziswa i-Electric Arc Furnace (EAF). Ku-EAF, ingxube yezingcezu kanye ne-alloy ifakwa esithandweni bese incibilikiswa ukushisa kwe-arc kagesi enamandla aphezulu. Lesi sigaba sincibilikisa insimbi bese siqala ukusetha ukwakheka kwayo kwamakhemikhali. Ngesikhathi sokuncibilika, opharetha unezela i-flux (isb., i-lime/dolomite) ukusiza ekwakheni i-slag ebamba ukungcola okuthile.
Ukulawulwa kwenqubo ku-EAF kufaka phakathi izinga lokushisa, isikhathi sokuncibilika, kanye nokuhlaziywa kwamakhemikhali kokuqala. Imikhiqizo ye-EAF ngokuvamile ayihlangabezani nemigomo yokugcina ngoba idinga ukuhlungwa okwengeziwe—ikakhulukazi ukulawula amazinga e-carbon, i-sulfur, ne-phosphorus, kanye nokuthuthukisa okuqukethwe kwe-chromium kanye ne-nickel.
3. Ukuhlanzwa: i-AOD noma i-VOD
Uma insimbi ewuketshezi evela ku-EAF isilungile, ithuthelwa esigabeni sesibili sokucwenga, ngokuvamile kusetshenziswa i-AOD (Argon Oxygen Decarburization) noma i-VOD (Vacuum Oxygen Decarburization).
I-AOD (i-Argon Oxygen Decarburization)
Ku-AOD, ingxube ye-oxygen ne-argon ishaywa ibe yinsimbi encibilikisiwe. I-oxygen isiza eku-oxidizeni i-carbon (decarburization), inciphise okuqukethwe yi-carbon. I-Argon inciphisa igesi futhi ikhuthaze ukusabela okukhethayo, ivimbele uku-oxidation ngokweqile kwe-chromium. Isigaba se-AOD sibalulekile ngoba insimbi engagqwali idinga okuqukethwe okuphansi kwe-carbon ukuvimbela ukuna kwe-chromium carbides, okunganciphisa ukumelana nokugqwala (ukuzwela), ikakhulukazi kwezinye izinhlelo zokusebenza.
I-VOD (Ukususwa Kwe-Oxygen Ye-Vacuum)
I-VOD inenjongo efanayo, kodwa yenziwa ngaphansi kwe-vacuum. I-vacuum isiza ukwehlisa ingcindezi engaphelele yegesi ye-carbon monoxide, okuvumela ukusabela kokunciphisa ikhabhoni ukuthi kuqhubeke ngempumelelo ekushiseni okuthile. I-VOD ivame ukukhethwa ngenxa yamazinga adinga ikhabhoni ephansi kakhulu noma ukulawulwa kwegesi encibilikisiwe okuqinile.
Kulesi sigaba sokucwenga, kwenziwa nokulungiswa kokwakheka kokugcina: ukwengeza i-nickel, i-molybdenum, i-nitrogen, noma izinto eziqinisayo njenge-titanium/niobium ngokwezinga eliqondiwe.
4. Ukwelashwa Ngendebe: Ukususa i-oxidation, Ukususa i-sulfurization, kanye ne-Homogenization
Ngaphambi kokuphotha, insimbi encibilikisiwe ingase iphathwe ngendebe. Izinhloso zifaka:
– Ukususa i-oxidation, ukunciphisa i-oxygen encibilikisiwe ukuze kuvinjelwe ukufakwa kwe-oxide.
– Ukususa i-sulfurization, kunciphisa isibabule okungabangela ukushoda kokushisa futhi kunciphise ukuqina.
– Ukuxuba i-Argon ukuze kuhlanganiswe ukwakheka kanye nokushisa, kanye nokusiza ukuntanta okufakiwe ku-slag.
Ukuhlanzeka kuyisici esibalulekile ensimbi engagqwali, ikakhulukazi ekusetshenzisweni okudinga ukumelana nokugqwala okuphezulu, ukuqeda kahle ubuso, noma izinqubo zokwakheka ezisindayo.
5. Ukuphonsa: Ukuphonsa Okuqhubekayo noma Ukuphonsa Okungenayo
Insimbi encibilikisiwe efinyelele ukwakheka okufunwayo ithululwa ibe yisimo esiqinile ngenqubo yokubumba. Indlela evame kakhulu namuhla ukubumba okuqhubekayo, lapho insimbi encibilikisiwe igeleza khona ngesikhunta esipholile ngamanzi bese iqina kancane kancane ukuze yakhe i-slab (yensimbi yeshidi), i-bloom, noma i-billet (yenduku nentambo). Ukubumba okuqhubekayo kusebenza kahle kakhulu, kuyahambisana, futhi kunciphisa amaphutha kunobumba bendabuko be-ingot.
Kodwa-ke, ngezidingo ezithile ezikhethekile, ama-ingot okuphonsa asasetshenziswa, bese ama-ingot eqhubeka nokucutshungulwa ngokushisa kanye nokuqala/ukugaya.
6. Ukuvuselela Nokusebenza Okushisayo
Imikhiqizo yokukhipha, njenge-slabs, bese ifudunyezwa kabusha esithandweni sokushisa kabusha ukuze ifinyelele izinga lokushisa elifanele ngaphambi kokugoqa okushisayo. Enqubweni yokugoqa okushisayo, i-slab icindezelwa ngokusebenzisa ama-roll stand, kunciphisa ukujiya kwayo futhi kwandise ubude bayo. Ukugoqa okushisayo kwakha isakhiwo sokuqala, kulungisa ezinye izimbobo, futhi kukhiqize umkhiqizo oqediwe kancane njenge-hot-rolled coil noma ipuleti.
Ngenxa yokuthi insimbi engagqwali inokuziphatha okuhlukile kokuguquguquka kanye nokuqhuba ukushisa kunensimbi yekhabhoni, ukulawula izinga lokushisa kanye nesivinini sokugingqika kubalulekile ukuze kugwenywe imifantu eshisayo, amagagasi, noma ukukhubazeka kwendawo.
7. Ukuhlanganisa: Kubuyisela Ukuguquguquka Futhi Kulungisa Isakhiwo Esincane
Ngemva kokugoqa okushisayo, izinto ngokuvamile zibhekana nokuqina kokucindezeleka kanye nokusatshalaliswa kwesakhiwo esingaphansi kwesimo esifanele. Ngakho-ke, ukunamathisela (ukwelashwa kokushisa okuthambisayo) kwenziwa ukuze:
- Kuqeda ukucindezeleka okusele,
- Buyisela ukuqina,
– Izigaba zokuzinzisa (isb. ku-austenitic),
- Kusiza ekuncibilikiseni ama-precipitate angafuneki.
Kwi-austenitic stainless, i-annealing ivame ukuhilela i-solution annealing emazingeni okushisa aphezulu, kulandelwe ukupholisa okusheshayo ukuze kulondolozwe isakhiwo esifunwayo futhi kuncishiswe ingozi yokuzwela.
8. Ukususa Isilinganiso Se-Oxide: Ukususa Isilinganiso Se-Oxide
Izinqubo zokushisa (ukugoqa okushisayo kanye nokunamathisela) zakha isikali se-oxide ebusweni. Lesi sikali kumele sisuswe ukuze kutholakale indawo ehlanzekile elungele ukucutshungulwa okuqhubekayo. Izindlela ezivamile zifaka:
– I-Pickling isebenzisa isisombululo se-asidi (isib. ingxube ye-nitric acid ne-hydrofluoric acid, noma ezinye izinhlelo zesimanje zokugaya) ukuze kuncibilikiswe ama-oxide,
– Ukususa amabala ngomshini njengokuqhumisa ngesibhamu noma ukuxubha ukuze kusize ekukhipheni amabala.
Isigaba sokwehlisa izinga sibaluleke kakhulu ngekhwalithi yendawo yokugcina, ikakhulukazi uma izinto zizosetshenziselwa imishini yokudla, ukwakheka kwezakhiwo, noma imboni yemithi.
9. Ukugoqa Okubandayo: Ukufinyelela Ubukhulu Obuqondile kanye Nezindawo Ezibushelelezi
Ukuze kudalwe amashidi amancane anezimo eziqinile nezindawo ezibushelelezi, insimbi engagqwali iyagoqwa ibanda. Ngenxa yokuthi yenziwa emazingeni okushisa aphansi, ukugoqwa okubandayo kwandisa amandla ngokuqinisa umsebenzi kodwa kunciphisa ukuguguleka. Ngakho-ke, ukugoqwa okubandayo kuvame ukulandelwa ukugoqwa okwengeziwe (ukugoqwa okuphakathi) kuye ngokunciphisa ukujiya okudingekayo.
Umphumela wokugoqa okubandayo ngokuvamile kuba yi-coil enobukhulu obuqondile kanye nekhwalithi engcono yobuso, okuba yisisekelo sokuqeda okuhlukahlukene njenge-2B, i-BA (ekhanyayo efakwe annealed), noma amaphethini okuhlobisa.
10. Ukuqeda Kokugcina, Ukuhlolwa, kanye Nokupakisha
Isigaba sokugcina sihlanganisa izinqubo ezahlukahlukene ngokuya ngomkhiqizo wokugcina:
– Ukudlula kwesikhumba ukuthuthukisa ukuthamba nokubukeka kobuso,
– Ukupholisha ukuze kukhiqizwe ubuso obukhazimulayo (isibuko) noma obucwebezelayo,
– Ukusika nokusika ukuze kuhlukaniswe ama-coil abe ububanzi obuthile noma amapuleti asikiwe,
– Ukwakha (ongakukhetha) njengokugoba, ukudweba okujulile, noma ukwenza amapayipi (ipayipi elihlanganisiwe) ngokushisela kanye nokwelashwa okwengeziwe kokushisa.
Ngemva kwalokho, kwenziwa ukulawulwa kwekhwalithi: ukuhlolwa kokwakheka kwamakhemikhali, ukuhlolwa komshini (ukuthamba, ubulukhuni), ukuhlolwa kokugqwala (uma kudingeka), ukuhlolwa kokukhubazeka kobuso, kanye nokuqinisekiswa kobukhulu. Imikhiqizo ephumelelayo ibe isinikezwa inombolo yokushisa/ukuhlonza indawo, imbozwe ngesembozo sobuso esivikelayo (isb. ifilimu), bese ipakishwa ukuze ithunyelwe.
I-Penutup
Inqubo yokwenza insimbi engagqwali ihilela inhlanganisela elawulwa kakhulu yezinqubo zensimbi nezokukhiqiza: kusukela ekukhethweni kwezinto zokusetshenziswa kanye nokwakhiwa kokwakheka, ngokusebenzisa ukuncibilikisa i-EAF, ukucwenga i-AOD/VOD, ukuphotha, ukugoqa okushisayo, ukunamathisela, ukususa i-scaling, ukugoqa okubandayo, kuya ekuqedeni nasekuhlolweni. Isigaba ngasinye sidlala indima ebalulekile ekuqinisekiseni ukuthi insimbi engagqwali ihlangabezana nokumelana nokugqwala, amandla, kanye namazinga ekhwalithi ephezulu. Ngakho-ke, naphezu kwegama layo elibonakala lilula, "insimbi engagqwali," empeleni ingumphumela wezinqubo zobunjiniyela eziyinkimbinkimbi ezenzelwe ukukhiqiza izinto ezinokwethenjelwa zokusetshenziswa ezimbonini eziningi—kusukela ezintweni zasekhishini kuya ekufakweni kwamakhemikhali nasolwandle.
