Zithini iimpembelelo ze-magnesium ephezulu kunye nesezantsi eshiyekileyo kububanzi begraphite egqithileyo kunye neziphene eziqhakaza zegraphite kwi-iron ductile

Umxholo oseleyo we-magnesium kwimveliso yensimbi ye-ductile kufuneka ilawulwe ngokuchanekileyo ngaphakathi "kwefestile efanelekileyo yoluhlu" (ngokuqhelekileyo malunga ne-0.04% -0.055%, kuxhomekeke ekubunjweni kunye nenkqubo). Ukutenxa kolu luhlu, nokuba kuphezulu kakhulu okanye kuphantsi kakhulu, kunokubangela ukuwohloka kwe-graphite morphology, kodwa ukubonakaliswa kunye neendlela ezisisiseko zahluke ngokupheleleyo.

I-1, Impembelelo yomxholo we-magnesium yentsalela ephantsi kukuba umxholo we-magnesium oseleyo ungaphantsi kwexabiso elincinci elibalulekileyo elifunekayo kwi-spheroidization (ngokubanzi malunga ne-0.03% -0.035%), eyona sizathu esithe ngqo kunye nesisisiseko sokukhubazeka kweentyantyambo zegraphite, kwaye impembelelo kwi-graphite diameter yeyesibini. Indlela esisiseko yempembelelo eqinisekileyo ekudubuleni kweentyatyambo zegraphite yeyokuba eyona ndima yendima ye-magnesium kukubhengeza kumphezulu wekristale yokukhula kwegraphite, ukucinezela indalo yayo yokukhula, ukunyanzela ukukhula kwayo kwe-isotropic, kwaye ngaloo ndlela yenze imilo engqukuva. Xa umxholo we-magnesium oshiyekileyo ungonelanga, le mpembelelo ye-adsorption kunye ne-inhibition iyasilela kwisigaba samva sokukhula kwegraphite, ngakumbi kwinqanaba lokugqibela lokuqina kwe-eutectic. Ukwakhiwa kwesiphako: Igraphite enganyanzelwanga iya kubuyisela imo yokukhula ngokukhawuleza kunye nokungazinzi, okubangela ukuba igraphite esele yenziwe i-spherical graphite igqabhuke kwaye igqwese, kubangele ukuba kubekho umngxuma ngaphakathi kunye nokugqabhuka okanye i-coral efana nemiphetho, eyi "graphite yentyatyambo" eqhelekileyo. Oku kubonisa ukuba i-spheroidization ayiphumelelanga. Impembelelo engathanga ngqo kwi-diameter yegraphite: Kwiindawo zengingqi apho i-magnesium eseleyo ikwicala lokungonelanga kodwa ayiphumelelanga ngokupheleleyo, ukuncitshiswa kwee-nucleation cores ezisebenzayo kunokubangela ukuba inani elincinci le-graphite spheres likhule libe likhulu. Nangona kunjalo, olona phawu lubalaseleyo kule meko kukubonakala kwesixa esikhulu segraphite engekho spherical (efana nentshulube, njengentyatyambo), kwaye uburhabaxa begraphite asikokubonakaliswa kwayo okuphambili. ·Oyena nobangela wentsalela ye-magnesium ephantsi sisiqulatho esiphezulu sesulfure kwintsimbi yokuqala enyibilikisiweyo, etya i-magnesium eninzi kakhulu. Ubalo olungonelanga lobungakanani be-agent ye-spheroidizing eyongeziweyo okanye isantya sokufunxa esisezantsi. Emva konyango lwe-spheroidization, ixesha lokuhlala lentsimbi etyhidiweyo lide kakhulu, kwaye i-magnesium iyancipha kakhulu. Kukho izinto ezinamandla eziphazamisayo ezifana nelothe kunye ne-bismuth kwintsimbi etyhidiweyo, eyenza i-neutralize i-spheroidization effect ye-magnesium. Isishwankathelo: Intsalela ye-magnesium ephantsi ikhokelela ekulahlekeni kwesakhono se-spheroidization kwaye ikhuthaza ngokuthe ngqo ukudubula kwegraphite.

I-2, Impembelelo yomxholo we-magnesium eseleyo ngokugqithisileyo iphezulu kakhulu kunoluhlu olufanelekileyo (njengokudlula i-0.06% -0.07%), ngokukodwa engakhokelela kwiintyatyambo, kodwa ngoluhlu lwemiphumo engathanga ngqo, ibe yinto ebalulekileyo ekukhuthazeni i-graphite egqithisileyo (erhabaxa), ehamba kunye nezinye iziphene ezinzulu zokuphosa. Indlela yokukhuthaza ngokungathanga ngqo kwidayamitha yegraphite enkulu kakhulu (erhabaxa) kukwenza buthathaka isiphumo sokufukamela kunye nokunciphisa undoqo wenucleation. I-Magnesium yinto eyomeleleyo ye-anti graphitization (emhlophe). I-magnesium eshiyekileyo egqithisileyo iya kwandisa kakhulu ukuthambekela kokupholisa okuphezulu kwentsimbi etyhidiweyo. Oku kwenza kube nzima kumbindi we-heterogeneous obonelelwa zizitofu ze-ferrosilicon eziqhelekileyo ukuba zisebenze ngokuzinzileyo, okukhokelela ekuwohlokeni kwe "incubation response". Isiphumo esithe ngqo kukuncitshiswa kwenani leenuclei zegraphite spherical. Phantsi kwesiseko esihlala sisonke isiqulatho sekhabhoni, ii-cores ezimbalwa zikho, kokukhona ubukhulu besayizi nganye ibhola yegraphite inokukhulela kubo, ngaloo ndlela yenze ukuba rhabaxa kodwa kusenokwenzeka ukuba zingqukuva iibhola zegraphite. Inkqubo yesi-2: Ukudala uhlengahlengiso lwenkqubo engafanelekanga. Ukuze kuthintelwe ukuthambekela okumhlophe okubangelwa yi-magnesium ephezulu, abaqhubi banokunyanzelwa ukuba banyuse ukulingana kwekhabhoni (ingakumbi umxholo we-silicon) okanye bangene kwi-incubation egqithisileyo. Phantsi kweemeko ezilinganayo zekhabhoni, ngakumbi xa ukupholisa kwamacandelo ashinyeneyo namakhulu kucotha, kunika iimeko ezilungele ukukhula okurhabaxa kwegraphite. I-Magnesium, enempembelelo ephezulu enokubakho kwi-morphology yegraphite, inokubangela ukuhla kokujikeleza kwee-graphite spheres, okwenza kube lula ukuvelisa i-clumpy okanye i-graphite engaqhelekanga, kodwa ngokuqhelekileyo ayenzi ngokuthe ngqo iintyatyambo eziqhelekileyo eziqhumayo. Umngcipheko wokufakwa kwe-slag uye wanda kakhulu ngenxa yezinye iingxaki ezinzulu zenkqubo: i-magnesium engaphezulu ixhomekeke ekuphenduleni i-oksijini kunye ne-sulfure ukuvelisa i-slag efana ne-MgO kunye ne-MgS, enokuthi ifakwe kwi-castings kunye ne-slag inclusion defects. Ukuqinisa ukuthambekela kokucutheka: I-magnesium ephezulu ikhulisa uluhlu lokuqiniswa kwentlama njengolwelo lwe-iron, ithintela ukongezwa kokucutheka, yonyusa kakhulu i-micro shrinkage thrinkage, kwaye ichaphazela ngokunzulu ingxinano yokuphosa. Ukwehla kwamandla okuhlawula amatyala kunye nokunyuka kokuncipha.

Isishwankathelo: Intsalela ye-magnesium eninzi ngokungathanga ngqo ikhokelela kwi-graphite coarsening ngokusebenzisa "ukuthintela i-nucleation kunye nokunciphisa inani leengqungquthela", kwaye izisa uthotho lweziphumo ezibi ezinobungozi ezifana nokufakwa kwe-slag kunye nokuncipha.

I-3, Impembelelo ye-magnesium eseleyo "efanelekileyo kodwa iyancipha" yeyona meko ixhaphakileyo edibana nayo kwimveliso eyiyo, ekhokelela kubukhulu begraphite. Ibonisa ukubaluleka kweenguqu eziguqukayo "kwimixholo ye-magnesium esebenzayo". Indawo yokuqala: Ekupheleni konyango lwe-spheroidization, i-magnesium eseleyo ikuluhlu olufanelekileyo, lukhuliswe ngokupheleleyo, kwaye iibhola zegraphite zincinci, zijikeleze, kwaye zininzi. Inkqubo yokunciphisa: Ukususela ekugqityweni kwonyango ukuya ekuqinisweni kokuphosa, isinyithi esinyibilikisiweyo sigcina ukugcinwa, okubangelwa "i-spheroidization yehla" (i-magnesium element evuthayo kunye ne-floating) kunye "nokuncipha kwe-incubation" (i-nucleation core dissolution okanye ukungaphumeleli). ·Isixhobo sokwenza isiphene: Umthamo wentsalela yemagnesium uyehla ngokuthe ngcembe, kwaye umqobo ekukhuleni kwegraphite uba buthathaka. Inani lee-nucleation cores ezisebenzayo liyancipha ngokuhamba kwexesha. Impembelelo ye-superposition yezi zimbini: Phambi kokuba i-magnesium eyintsalela ifikelele "kwindawo ebaluleke kakhulu" ebangela ukuba iintyatyambo, i-graphite spheres eseleyo iya kuqhubeka ikhula phantsi kweemeko zokunciphisa imiqobo kunye nemithombo yekhabhoni eyaneleyo, ekugqibeleni yenze i-graphite enobungakanani oburhabaxa kodwa i-morphology esamkelekileyo (efana nebakala lesi-6 okanye i-coarser). Ukuba ukwehla kuyaqhubeka, kuya kutyibilika kwi-spheroidization embi kunye nokudumba kweentyatyambo.

Injongo ephambili yesishwankathelo sokugqibela sesikhokelo esisebenzayo asikona nje ukulawula i-magnesium eseleyo kwixabiso elijoliswe kuyo, kodwa nokuqinisekisa ukusebenza kwayo kunye nokuzinza kuyo yonke inkqubo yokugalela. Ukuthintela iintyatyambo (isitshixo kukuthintela i-magnesium ephantsi): Nciphisa ngokungqongqo kwaye uzinzise umxholo wesulfure wentsimbi yokuqala etyhidiweyo. Qinisekisa ukongezwa okwaneleyo kunye nokuchanekileyo kwe-arhente ye-spheroidizing. Ukunciphisa ixesha lokuhlala emva kwe-spheroidization ukufezekisa ukuthulula ngokukhawuleza. Ukuthintela i-coarsening (isitshixo sokugcina ibhalansi phakathi kwe-nucleation esebenzayo kunye ne-magnesium): Ukusebenzisa iindlela ezisebenzayo kunye nokuchasana nokuguga kwesigaba se-incubation sexesha elide (ezifana ne-flow inoculation kunye ne-mold inoculation) ukubonelela ngokuqhubekayo i-nucleation cores entsha yeyona ndlela isebenzayo yokuchasana nokubola kunye nokucoca igraphite. Ukunqanda ngokumfamekileyo ukwandiswa komxholo wentsalela ye-magnesium ngenxa ye "inshurensi" yindlela eyahlukileyo eya ekuncipheni, ekufakweni kwe-slag, kunye ne-graphite coarsening. Kumacandelwana ashinyeneyo namakhulu, kuyafuneka ukuba uphucule ngokupheleleyo uyilo olulinganayo nekhabhoni kunye neemeko zokupholisa. Ngamafutshane, "ukuzinzisa isulfure, ukulawula i-magnesium (imodareyitha), ukugalela ngokukhawuleza, kunye ne-post inoculation eyomeleleyo" ziinkqubo eziphambili zenkqubo yokufumana ubume bentsimbi ye-ductile ephezulu ngelixa uphepha ukuqhakaza kwegraphite kunye nokuqina.