Iyini imiphumela ye-magnesium eyinsalela ephezulu nephansi kububanzi be-graphite ngokweqile kanye nokukhubazeka okuqhakaza kwe-graphite ku-iron ductile

Okuqukethwe kwe-magnesium okuyinsalela ekukhiqizweni kwe-iron ductile kudinga ukulawulwa ngokunembile ngaphakathi "kobubanzi bewindi obufanele" (imvamisa cishe bungu-0.04% -0.055%, kuye ngokwakheka nenqubo). Ukuchezuka kulobu bubanzi, kungakhathaliseki ukuthi kuphezulu kakhulu noma kuphansi kakhulu, kungabangela ukuwohloka kwe-graphite morphology, kodwa ukubonakaliswa kanye nendlela eyisisekelo kuhluke ngokuphelele.

1, Umthelela wokuqukethwe kwe-magnesium eyinsalela ephansi ukuthi okuqukethwe kwe-magnesium eyinsalela kungaphansi kwenani elibalulekile eliyisisekelo elidingekayo ukuze i-spheroidization (ngokuvamile engaba ngu-0.03% -0.035%), okuyisizathu esiqondile nesiyisisekelo sokukhubazeka kokuqhakaza kwe-graphite, futhi umthelela kububanzi be-graphite ungowesibili. Indlela eyisisekelo yethonya eliwujuqu ekuqhakazeni kwe-graphite ukuthi indima eyinhloko yesici se-magnesium ukukhangisa endaweni eyikristalu yokukhula kwegraphite, ukucindezela imvelo yayo yokukhula, ukuphoqelela ukukhula kwayo kwe-isotropic, futhi ngaleyo ndlela yakhe isimo esiyindilinga. Uma okuqukethwe kwe-magnesium eyinsalela kunganele, lo mphumela wokukhangiswa nokuvimbela uyehluleka esigabeni sakamuva sokukhula kwe-graphite, ikakhulukazi esigabeni sakamuva sokuqiniswa kwe-eutectic. Ukwakheka kwesici: I-graphite engavinjelwe izobuyisela imodi yayo yokukhula ngokushesha futhi engazinzile, okubangela ukuthi i-graphite eyindilinga eseyakhiwe kakade iqhume futhi igxumeke, okuholela ekungeneni ngaphakathi nokuqhuma noma amakhorali njengamaphethelo, okuyi-graphite evamile "eqhakaza". Lokhu kubonisa ukuthi i-spheroidization yehlulekile. Umthelela ongaqondile kububanzi be-graphite: Ezindaweni zasendaweni lapho i-magnesium eyinsalela isenqenqemeni yokunganeli kodwa ingazange ihluleke ngokuphelele, ukuncishiswa kwama-nucleation cores asebenzayo kungase kuphumele enanini elincane lama-graphite spheres asele akhule abe mkhulu. Kodwa-ke, isici esigqame kakhulu kuleli cala ukubukeka kwenani elikhulu le-graphite engelona i-spherical (njenge-worm, njengembali), futhi ubuqhwaga obulula be-graphite akuwona ukubonakaliswa kwawo okuyinhloko. ·Imbangela evamile yokuncipha kwe-magnesium eyinsalela wukugcwala kwesibabule ensimbi yokuqala encibilikisiwe, edla i-magnesium eningi kakhulu. Ukubala okunganele kwenani le-ejenti ye-spheroidizing engeziwe noma izinga lokumunca eliphansi lokusabela. Ngemuva kokwelashwa kwe-spheroidization, isikhathi sokuhlala sensimbi encibilikisiwe side kakhulu, futhi i-magnesium yonakaliswa kakhulu. Kunezinto ezinamandla eziphazamisayo ezinjengomthofu ne-bismuth kunsimbi encibilikisiwe, ezinciphisa umphumela we-spheroidization we-magnesium. Kafushane: I-magnesium eyinsalela ephansi iholela ekulahlekelweni ikhono le-spheroidization futhi ikhuthaza ngokuqondile ukuqhakaza kwe-graphite.

I-2, Umthelela wokuqukethwe kwe-magnesium eyinsalela ngokweqile uphakeme kakhulu kunobubanzi obufanele (njengokudlula u-0.06% -0.07%), ikakhulukazi awuholeli ekuqhakazeni, kodwa ngochungechunge lwemiphumela engaqondile, okuba yisici esibalulekile ekukhuthazeni ububanzi be-graphite obudlulele (obumahhadla), obuhambisana nezinye iziphambeko ezinkulu zokuphonsa. Indlela yokuphromotha engaqondile yobubanzi be-graphite obukhulu kakhulu (amaholoholo) iwukwenza buthaka umphumela wokufukamela futhi unciphise umgogodla we-nucleation. I-Magnesium iyisici esiqinile sokulwa ne-graphitization (emhlophe). I-magnesium eyinsalela eyeqile izokwandisa kakhulu ukuthambekela kokupholisa okukhulu kwensimbi encibilikisiwe. Lokhu kwenza kube nzima ukuthi i-heterogeneous core ehlinzekwa yizijovo ezivamile ze-ferrosilicon ukuthi zisebenze ngokuzinza, okuholela ekuwohlokeni "kokusabela kwe-incubation". Umphumela oqondile uwukuncipha kwenani le-graphite spherical nuclei. Ngaphansi kwesisekelo sengqikithi yekhabhoni engaguquki, ama-cores ambalwa akhona, iba nkulu ubukhulu ibhola ngalinye le-graphite elingakhula ngalo, ngaleyo ndlela lakhe amabhola amaholoholo kodwa okungenzeka ukuthi asale ayindilinga ngokuqhathaniswa. Indlela yesi-2: Ukubangela ukulungiswa kwenqubo okungalungile. Ukuze kuliwe nokuthambekela okumhlophe okubangelwa i-magnesium ephezulu, opharetha bangaphoqeleka ukuthi bakhulise okulingana nekhabhoni (ikakhulukazi okuqukethwe kwe-silicon) noma bafake incubation eyeqile. Ngaphansi kwezimo ezilingana nekhabhoni ephezulu, ikakhulukazi uma ukupholisa kwezingxenye eziwugqinsi nezinkulu kuhamba kancane, kunikeza izimo ezivumayo zokukhula okubhodlayo kwegraphite. I-Magnesium, enomthelela omkhulu ku-morphology ye-graphite, ingabangela ukuncipha kokujikeleza kwama-graphite sphere, okwenza kube lula ukukhiqiza i-clumpy noma i-graphite engavamile, kodwa ngokuvamile ayikwenzi ngokuqondile izimbali eziqhumayo. Ingozi yokufakwa kwe-slag iye yanda kakhulu ngenxa yezinye izinkinga ezinkulu zenqubo: i-magnesium eyengeziwe ijwayele ukusabela nge-oksijeni nesibabule ukuze ikhiqize i-slag efana ne-MgO ne-MgS, engagingqwa ibe yi-castings futhi ifake amaphutha okufakwa kwe-slag. Ukuqinisa ukuthambekela kokuncipha: I-magnesium ephezulu ikhulisa uhla lokuqiniswa kokunamathisela njengoketshezi lwensimbi, ivimbela ukuncipha kokufakwa, ikhuphule ngokuphawulekayo ukuthambekela kokushwabana okuncane, futhi kuthinte kakhulu ukuminyana kokubunjwa. Ukuncipha kwe-liquidity kanye nokunyuswa kokunyuswa.

Isifinyezo: I-magnesium eyinsalela eningi ngendlela engaqondile iholela ekubanjeni kwe-graphite "ngokuvimbela i-nucleation nokunciphisa inani lama-sphere", futhi iletha uchungechunge lwemiphumela emibi eyingozi njengokufakwa kwe-slag kanye nokuncipha.

3, Umthelela we-magnesium eyinsalela "efanele kodwa eyancipha" yisimo esivame kakhulu esihlangatshezwana naye ekukhiqizeni kwangempela, okuholela kububanzi begraphite ngokweqile. Iveza ukubaluleka kwezinguquko eziguqukayo "kokuqukethwe kwe-magnesium esebenzayo". Iphuzu lokuqala: Ekupheleni kokwelashwa kwe-spheroidization, i-magnesium eyinsalela isebangeni elifanele, inakekelwe ngokugcwele, futhi amabhola e-graphite mancane, ayindilinga, futhi maningi. Inqubo yokwenqaba: Kusukela ekuphothulweni kokwelashwa kuya ekuqinisweni kokubunjwa, insimbi encibilikisiwe igcina igcinwe, okuholela "ekunciphiseni kwe-spheroidization" (isici se-magnesium esivuthayo nokuntanta) kanye "nokwehla kwe-incubation" (ukuchithwa kwe-nucleation core noma ukwehluleka). ·Indlela yokwakheka kwesici: Okuqukethwe kwe-magnesium eyinsalela esebenzayo kancane kancane kuncipha, futhi umgoqo ekukhuleni kwegraphite uba buthaka. Inani lama-nucleation cores asebenzayo liyehla ngokuhamba kwesikhathi. Umphumela we-superposition walokhu okubili: Ngaphambi kokuba i-magnesium eyinsalela ifinyelele "eqophelweni elibucayi" elibangela ukuqhakaza, ama-graphite spheres asele azoqhubeka ekhula ngaphansi kwezimo zokuncishiswa kwezingqinamba kanye nemithombo ye-carbon eyanele, ekugcineni yakhe i-graphite enobukhulu obumahhadla kodwa i-morphology esamukelekayo (njengebanga lesi-6 noma ngisho nangaphezulu). Uma ukwehla kuqhubeka, kuzoshelela ku-spheroidization embi kanye nokuqhakaza.

Inhloso eyinhloko yesifinyezo sokugcina sesiqondiso esisebenzayo akukhona nje kuphela ukulawula i-magnesium eyinsalela enanini eliqondiwe, kodwa futhi ukuqinisekisa ukusebenza kahle kwayo nokuzinza kuyo yonke inqubo yokuthela. Ukuvimbela ukuqhakaza (okubalulekile ukuvimbela i-magnesium ephansi): Nciphisa ngokuqinile futhi uzinzise okuqukethwe kwesulfure yensimbi yokuqala encibilikisiwe. Qinisekisa ukungezwa okwanele nokunembile kwe-ejenti ye-spheroidizing. Nciphisa isikhathi sokuhlala ngemva kwe-spheroidization ukuze uzuze ukuthululwa ngokushesha. Ukuvimbela i-coarsening (isihluthulelo sokugcina ibhalansi phakathi kwe-nucleation ephumelelayo ne-magnesium): Ukusebenzisa amasu e-incubation esiteji sekwephuzile ephumelelayo futhi ephikisana nokuguga (njengokungena kwe-flow inoculation kanye ne-mold inoculation) ukuhlinzeka ngokuqhubekayo ama-nucleation cores amasha kuyindlela ephumelela kakhulu yokulwa nokubola nokucwenga i-graphite. Ukugwema ukwanda ngokungaboni okusele kwensalela ye-magnesium ngenxa "yomshwalense" kuyindlela ehlukene ebheke ekuncipheni, ekufakweni kwe-slag, kanye nama-graphite coarsening. Ezingxenyeni eziwugqinsi nezinkulu, kuyadingeka ukugcwalisa ngokugcwele ukwakheka okulinganayo kwekhabhoni nezimo zokupholisa. Ngamafuphi, "ukuzinzisa isulfure, ukulawula i-magnesium (okulinganiselayo), ukuthululwa ngokushesha, kanye nokujova okuqinile kwangemuva" kuyizinqubo eziyinhloko zenqubo yokuthola isakhiwo sensimbi ye-ductile ephezulu ngenkathi ugwema ukuqhakaza kwe-graphite nokugqugquzelwa.