Matanho Ekugadzira Simbi Isina Kushanda
Simbi isina ngura imhuri yezvinhu zvakagadzirwa nesimbi inozivikanwa nekudzivirira ngura, simba rayo remakanika, uye nyore kugadzirisa. Hunhu hwayo "hunodzivirira ngura" hunobva zvakanyanya muhuwandu hwayo hwe chromium (Cr), iyo inoumba chidimbu chakatetepa che chromium oxide pamusoro pesimbi. Chidimbu ichi chinodzivirira simbi kubva pakuoxidation, ichiidzivirira kuti isaite ngura kunyangwe munzvimbo dzine hunyoro kana hune simba. Mushure mekushanda kwayo, simbi isina ngura inofamba kwenguva refu uye yakaoma yekugadzira kuitira kuti ive nechokwadi chekuti makemikari ayo, kuchena kwesimbi, uye microstructure zvinosangana nezvinodiwa. Izvi zvinotevera zvinotsanangura matanho ekugadzirwa kwesimbi isina ngura, kubva pazvinhu zvakagadzirwa kusvika kune zvakagadzirwa.
1. Kusarudzwa kweZvishandiso Zvisina Kugadzirwa uye Kuronga Kuumbwa
Danho rekutanga rinotanga nekusarudza rudzi rwesimbi isingatsvedzeri inofanira kugadzirwa, semuenzaniso austenitic (yakadai se304/316 series), ferritic (430 series), martensitic (410 series), kuita duplex (musanganiswa we austenitic-ferritic). Kusarudzwa kwerudzi urwu kunosarudza kuumbwa kwealloy kunodiwa: chromium sechinhu chikuru (kazhinji kacho inenge 10,5% kuti igadzire passive layer), nickel yekudzikamisa austenite phase uye kuwedzera ductility, molybdenum yekudzivisa ngura (kunyanya mu316), nezvimwe zvinhu zvakaita semanganese, silicon, nitrogen, titanium, kana niobium kune zvinangwa zvakananga.
Zvinhu zvakagadzirwa zvinogona kusanganisira simbi dzakasara (simbi isina tsvina), simbi yakasara yekabhoni, ferrochrome (Fe-Cr alloy), ferronickel kana pure nickel, ferromolybdenum, pamwe chete necarbon binders uye deoxidizers. Mazhinji emazuva ano esimbi dzisina tsvina anovimba zvakanyanya nesimbi dzakasara nekuti dzinoshandisa simba rakawanda uye dzinotsigira hupfumi hwakatenderera. Zvisinei, mhando yesimbi dzakasara inofanira kudzorwa kudzivirira "kusvibiswa" kwemusanganiswa (semuenzaniso, mhangura yakawandisa kana zvimwe zvinosvibisa).
2. Kunyunguduka muFirnace yeMagetsi (EAF)
Simbi zhinji dzinogadzirwa uchishandisa Electric Arc Furnace (EAF). MuEAF, musanganiswa wezvimedu ne alloy unoiswa muchoto wonyungudutswa nekupisa kwe arc yemagetsi ine simba guru. Danho iri rinonyungudutsa simbi uye rinotanga kugadzira makemikari ayo. Panguva yekunyunguduka, mushandisi anowedzera flux (semuenzaniso, lime/dolomite) kuti ibatsire kugadzira tsvina inobata tsvina.
Kudzora maitiro muEAF kunosanganisira tembiricha, nguva yekunyunguduka, uye kuongorora kwekutanga kwemakemikari. Zvigadzirwa zveEAF hazviwanzo sangana nezvinodiwa zvekupedzisira nekuti zvinoda kunatswa zvakanyanya—kunyanya kudzora huwandu hwekabhoni, sarufa, uye phosphorus, uye kugadzirisa huwandu hwechromium nenickel.
3. Kucheneswa: AOD kana VOD
Kana simbi yemvura inobva kuEAF yagadzirwa, inoendeswa kune imwe nzvimbo yekunatsa, kazhinji uchishandisa AOD (Argon Oxygen Decarburization) kana VOD (Vacuum Oxygen Decarburization).
AOD (Argon Oxygen Decarburization)
MuAOD, musanganiswa weokisijeni neargon unopfurwa musimbi yakanyungudutswa. Okisijeni inobatsira kuoxidation yekabhoni (decarburization), ichideredza huwandu hwekabhoni iri mairi. Argon inonyungudutsa gasi uye inokurudzira sarudzo yakasarudzika, ichidzivirira chromium oxidation yakawandisa. Danho reAOD rakakosha nekuti simbi isingatsvedzi inoda kabhoni shoma kudzivirira kunaya kwechromium carbides, izvo zvinogona kuderedza kuramba ngura (sensitization), kunyanya mune mamwe mashandisirwo.
VOD (Kubvisa Okisijeni Mumhepo)
VOD ine basa rakafanana, asi inoitwa pasi pevacuum. Vacuum iyi inobatsira kuderedza kumanikidzwa kwegasi recarbon monoxide, zvichiita kuti maitiro ekuderedza kabhoni aenderere mberi zvakanaka patembiricha yakatarwa. VOD inowanzo sarudzwa kune magiredhi anoda kabhoni shoma kana kuti gasi rakanyungudutswa rakasimba.
Padanho iri rekunatswa, kugadziriswa kwemusanganiswa wekupedzisira kunoitwawo: kuwedzera nickel, molybdenum, nitrogen, kana zvinhu zvinosimbisa zvakaita setitanium/niobium zvichienderana negiredhi rakatarwa.
4. Kurapa nendiro: Kubvisa oxidation, Kubvisa sulfurization, uye Homogenization
Simbi yakanyungudutswa inogona kuiswa mune imwe ndiro isati yagadzirwa. Zvinangwa zvinosanganisira:
- Kubvisa okisijeni mumuviri, kuderedza okisijeni yakanyungudika kudzivirira kubatanidzwa kweokisijeni mumuviri.
– Kubvisa sarufa, kunoderedza sarufa iyo inogona kukonzera kupisa kushoma uye kuderedza kuomarara.
– Kukurunga argon kuti zvinhu zvive zvakafanana uye tembiricha iite zvakafanana, uye kubatsira kuyangarara zvinhu zvinosanganisirwa muslag.
Kuchena chinhu chakakosha musimbi isingatsvi, kunyanya pakushandiswa kusingadi ngura yakawanda, kupedzwa zvakanaka kwenzvimbo, kana maitiro ekuumba akakora.
5. Kukanda: Kukanda Kunoramba Kuchiitwa kana Kukanda Ingot
Simbi yakanyungudutswa yasvika padanho raunoda inodururwa muchimiro chakasimba kuburikidza nemaitiro ekukanda. Nzira yakajairika nhasi ndeyekukanda nguva nenguva, umo simbi yakanyungudutswa inoyerera nemuforoma inotonhodzwa nemvura uye inosimba zvishoma nezvishoma kuita slab (yesimbi yesheet), maruva, kana billet (yetsvimbo newaya). Kukanda nguva nenguva kunoshanda zviri nani, kunoenderana, uye kunoderedza zvikanganiso pane kukanda ingot kwechinyakare.
Zvisinei, kune zvimwe zvinodiwa zvakakosha, ma ingot ekukanda achiri kushandiswa, ipapo ma ingot anogadziriswazve kuburikidza nekupisa uye kutanga kugadzira/kukuya.
6. Kudziisazve uye Kupisa
Zvigadzirwa zvekukanda, zvakaita sema slabs, zvinozodziiswazve muchoto chekudziisa kuti zvisvike pakupisa kwakakodzera zvisati zvaitwa. Mukuita kwekukanda zvinopisa, slab inodzvanywa kuburikidza nema roll stands, zvichideredza ukobvu hwayo uye zvichiwedzera kureba kwayo. Kukanda zvinopisa kunogadzira chimiro chekutanga, kunogadzirisa mamwe maburi, uye kunogadzira chigadzirwa chakapedzwa zvishoma senge hot-rolled coil kana plate.
Nekuti simbi isingasvibi ine maitiro akasiyana ekuchinja uye kufambisa kwekupisa pane simbi yekabhoni, kudzora tembiricha uye kumhanya kwekutenderera kwakakosha kudzivirira kuputika kwekupisa, mafungu, kana zvikanganiso pamusoro.
7. Kunyungudutsa: Kunodzoreredza Ductility uye Kugadzirisa Microstructure
Mushure mekuputirwa nekupisa, chinhu chacho chinowanzo sangana nekuomarara uye kupararira kusina kunaka kwechinhu chacho. Saka, annealing (kurapa kupisa kunopfavisa) kunoitwa kuti:
- Inobvisa kushushikana kwakasara,
- Dzorera kusimba,
– Madanho ekudzikamisa (semuenzaniso mu austenitic),
- Inobatsira kunyungudutsa mvura isingadiwe.
Kune austenitic stainless, annealing inowanzosanganisira annealing yemvura pakupisa kwakakwirira, zvichiteverwa nekutonhora nekukurumidza kuchengetedza chimiro chaunoda uye kuderedza njodzi yekunzwa.
8. Kubvisa Oxide Scale: Kubvisa Oxide Scale
Maitiro ekupisa (kupisa kunopfungaira uye kunyorovesa) zvinoumba chiyero che oxide pamusoro. Chiyero ichi chinofanira kubviswa kuti pave nepamusoro pakachena pakagadzirirwa kugadziriswa zvakare. Nzira dzakajairika dzinosanganisira:
– Pickling inoshandisa mvura ine acid solution (semuenzaniso musanganiswa we nitric acid ne hydrofluoric acid, kana mamwe masisitimu emazuva ano e pickling) kunyungudutsa ma oxides,
– Kubvisa maganda nekushandisa michina yakaita sekupfura kana kukwesha kuti zvibatsire pakubvisa maganda.
Danho rekubvisa ganda rakakosha zvikuru pamhando yepamusoro pevhu rekupedzisira, kunyanya kana zvinhu zvacho zvichizoshandiswa pakugadzira michina yechikafu, kuvaka, kana indasitiri yemishonga.
9. Kutenderera Kwechando: Kuwana Zviyero Zvakarurama uye Nzvimbo Dzakatsetseka
Kuti pave nemachira matete ane tsiye dzakasimba uye nzvimbo dzakatsetseka, simbi isingatsvedzeri inomonerwa nechando. Nekuti inoitirwa patembiricha yakaderera, kumonerwa nechando kunowedzera simba kuburikidza nekuoma kwebasa asi kunoderedza ductility. Nokudaro, kumonerwa nechando kunowanzo teverwa nekumwe kumonerwa (intermediate annealing) zvichienderana nekuderedzwa kweukobvu kunodiwa.
Mhedzisiro yekumonera nechando inowanzova coil ine ukobvu hwakakodzera uye yepamusoro pechiso chiri nani, ichiva hwaro hwemagadzirirwo akasiyana-siyana akadai se2B, BA (yakajeka annealed), kana mapatani ekushongedza.
10. Kupedzisa Kwekupedzisira, Kuongorora, uye Kurongedza
Danho rekupedzisira rinosanganisira maitiro akasiyana-siyana zvichienderana nekugadzirwa kwekupedzisira:
- Kupfuura kweganda kuti rive rakati sandara uye chitarisiko chepamusoro,
– Kupolisha kuti pave negirazi rinopenya kana kuti satin pamusoro,
- Kucheka nekucheka kuti upatsanure ma coil kuita mamwe mapatya akafara kana kuti mapurati akachekwa,
– Kugadzira (sarudzo) zvakaita sekukombama, kudhirowa zvakadzama, kana kugadzira mapaipi (chubhu yakasungirirwa) nekusanganisa uye kuwedzera kupisa.
Mushure meizvozvo, kudzorwa kwemhando kunoitwa: kuyedzwa kwemakemikari, kuyedzwa kwemakanika (kusimba, kuoma), kuyedzwa kwekuora (kana zvichidikanwa), kuongororwa kwehurema hwepamusoro, uye kusimbiswa kwehukuru. Zvigadzirwa zvinobudirira zvinopihwa nhamba yekupisa/kuzivikanwa kwenzvimbo, zvakafukidzwa nependi yekudzivirira pamusoro (semuenzaniso, firimu), uye zvakarongedzwa kuti zvitumirwe.
Penutup
Maitiro ekugadzira simbi isina ngura anosanganisira musanganiswa wakanyatsorongeka wemaitiro esimbi uye ekugadzira: kubva pakusarudzwa kwezvinhu zvisina kugadzirwa uye dhizaini yekuumbwa, kuburikidza neEAF smelting, AOD/VOD refining, casting, hot rolling, annealing, descaling, cold rolling, kusvika pakupedzisa nekuongorora. Danho rega rega rinoita basa rakakosha mukuona kuti simbi isina ngura inosangana nekurasika kwengura, simba, uye mwero wemhando yepamusoro. Saka, pasinei nezita rayo rinoratidzika kunge riri nyore, "stainless steel," chaizvoizvo imhedzisiro yemaitiro akaomarara einjiniya akagadzirirwa kugadzira chinhu chakavimbika chekushandisa mumaindasitiri akasiyana-siyana - kubva kumidziyo yekicheni kusvika kumidziyo yemakemikari neyemugungwa.
