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Effects of process parameters on surface quality, composition segregation, microstructure and properties of QSn6. 5-0. 1 alloy slabs fabricated by HCCM horizontal continuous casting
J our na lo fI r onandS t e e lRe s e a r ch, I n t e r na t i ona l２４ (２０１７) ２７３－２８１
E f f e c t so fp r o c e s sp a r ame t e r sons u r f a c equ a l i t ompo s i t i ons eg r ega t i on, y, c mi c r o s t ruc t ur eandpr ope r t i e so fQSn６ ５ Ｇ ０ １a l l oys l absf ab r i c a t edby HCCM ho r i z on t a lc on t i nuousc a s t i ng YangL i u, Xi n Ｇ huaL i u∗ , Hua Ｇ dongFu, Mi n ＧxuanLou, J i an Ｇx i nXi e
I ns t i t u t ef o rAdvanc ed Ma t e r i a l sandTe chno l ogy, Un i ve r s i t fSc i enc eandTe chno l ogyBe i i ng, Be i i ng１０００８３, Ch i na yo j j ARTICLEINFO
ABSTRACT
Keywo rds: QSn６ ５c oppe ra l l oy He a t i ng Ｇ c oo l i ng c omb i nedmo l d Ho r i z on t a lc on t i nuous c a s t i ng Mi c r o s t r uc t ur e Me chan i c a lp r ope r t y Compo s i t i ons eg r ega t i on
Co l umna r Ｇ r a i nedQSn６ ５ Ｇ ０ １a l l oys l abswi t hawi d t ho f７０mmandt h i ckne s so f１０mm we r ef abr i c a t ed g byhe a t i ng Ｇ c oo l i ngc omb i nedmo l d (HCCM) ho r i z on t a lc on t i nuousc a s t i ng．Thee f f e c t so fp r o c e s spa r ame Ｇ ompo s i t i ons eg r ega t i onand me chan i c a lp r ope r t i e s t e r sons o l i d i f i c a t i on mi c r o s t r uc t ur e, sur f a c equa l i t y, c e l l en tme chan i c a lp r ope r t i e s we r es t ud i ed．Ther e su l t sshowedt ha tt hes l abswi t hgoodsur f a c equa l i t y, exc andnoobv i ouss eg r ega t i onc ou l dbep r epa r eda tt heme l tc a s t i ngt empe r a t ur eo f１２５０° C,t hehe a t i ng Ｇmo l d t empe r a t ur eo f１１５０－１２００° C, t hec oo l i ngwa t e rf l owr a t eo f６００L/handt hec a s t i ngspe edo f２０－８０ mm/mi n．Thes l abshadt hey i e l ds t r eng t ho f１２４－１５５ MPa, t hee l onga t i onr a t eo f４６ ６％－５６ ３％ and t hesur f a c er oughne s so f０ ２２－０ ５５μm, wh i chenab l edt hemt obed i r e c t l r o c e s s edwi t hou tsubs equen t yp mi l l i ngsur f a c e．Ther a t i oo fSnc on t en ti nt hesur f a c et ot ha ti nt hec o r ewa s０ ８３－１ １０, wi t hanave r age va l uec l o s et o１ ０, andno tobv i ous l n f l uenc edbyp r o c e s spa r ame t e r s．Whent hec a s t i ngspe edi nc r e a s ed yi f r om２０t o８０ mm/mi n, t heg r a i ns i z echangedl i t t l ei ft heo t he rp r o c e s spa r ame t e r swe r et hes ame．When t hehe a t i ng Ｇmo l dt empe r a t ur ei nc r e a s edf r om１１５０t o１２００° C,t heg r a i ns i z ewa sobv i ous l e f i nedandbe Ｇ yr c amemo r eun i f o rmi ft hec a s t i ngspe edwa st hes ame．Wi t h i nt her angeo ft hec a s t i ngspe eda twh i cht he c o l umna rg r a i ns t r uc t ur ec ou l dbeob t a i ned, t hec o l umna rg r a i ns i z ewa sma i n l n f l uenc edbyt hehe a t i ng Ｇ yi mo l dt empe r a t ur e．
１． I n t r odu c t i on QSn６ ５ Ｇ ０ １a l l oyi soneo ft he mo s timpo r t an t coppe ra l l oys c ompo s ed o ft i n and pho spho rus, wh i chi sknowna st het i n pho spho rb r onz e．S i nc e [ , ] t hea l l oyno ton l sh i chan i c a lp r ope r t i e s１ ２ yha ghme [ ] bu ta l s oha sgoodwe a rr e s i s t anc e３ , goodc o r r os i on [４,５] r e s i s t anc e , nospa rksdu r i ngimpa c t i ngandnon Ｇ , magne t i sm i t ss t r i sbe enwi de l edi ni ndus Ｇ pha yus t r st hepr oduc t i ono fs ep t a, d i aphr agmand y, sucha spa c e ri nt hei ns t rumen ti ndus t r he manu f a c t ur Ｇ y, t [ ] i ngo fe l e c t r on i cc onne c t o r si ne l e c t r on i c ss e c t o r s６ ande l a s t i cc omponen t ssuch a ssp r i ngs, swi t che s [３,７ Ｇ ９] andbe a r i ngs ． Theex i s t i ngp r oduc t i on me t hodsf o rQSn６ ５ Ｇ ０ １ a l l oy ma i n l nc l ude sve r t i c a ls emi Ｇ c on t i nuousc a s Ｇ yi t i ng― ho tr o l l i ng― c o l dr o l l i ngp r o c e s s, a ndho r i z on Ｇ [ , ] t a lc on t i nuou sc a s t i ng ― c o l dr o l l i ngp r o c e s s１０ １１ , and t hel a t t e ri sr e a r d e da st h ema i non e．Howe v e r,f o rt he g r e l a t i v e l i d es o l i d Ｇ l i i dph a s ez on eo fQSn ６ ５ Ｇ ０ １a l Ｇ yw qu on t i nuou sc a s t i ngo fi t ss l a ba lwa sha st hr e ema Ｇ l o y,c y ∗ Co r r e spond i ngau t ho r．As s o c．Pr o f． EＧma i laddr e s s: Li uxi nhua１８＠１６３c ． om (XH ． Li u) ．
o rp r ob l ems: F i r s t, abno rma ls eg r ega t i on o ft he j s l ab ma c r os cop i ccompos i t i oni sobs e r ved, t ha ti s, t hecon t en to ft i n on s l ab sur f a c ei ss i i f i c an t l gn y h i rt hant ha ti nt heco r e; Se cond, t hesur f a c e ghe l i t spoo rduet ot hef o rma t i ono fCuandSn qua yi br i t t l epha s eons l absur f a c e; Th i rd, mi c r os t ruc t ur e o fs l abf abr i c a t ed by s emi Ｇ con t i nuousc a s t i ng and t r ad i t i ona lho r i z on t a lcon t i nuousc a s t i ngi sr e l a t i ve l y coa r s eco l umna rg r a i nspe rpend i cu l a rt ot her o l l i ng [ , ] d i r e c t i on１２ １３ ．Atp r e s en t, t hema i n me t hodst or e Ｇ so l veabovep r ob l emsa r ec a r r i edou tbyhomogen i Ｇ z a t i onanne a l i ngf o ral ongt ime, mi l l i ngsur f a c eand so f t en i nganne a l i ngr epe a t ed l f o r et heco l dr o l l Ｇ ybe [ ] i ng１１ , wh i ch maket hep r oduc t i onp r oc e s sanden Ｇ e r t i ono ft i n phospho rbr onz ep l a t ei n Ｇ gyconsump c r e a s e, y i e l dr e du c e, andt hep r odu c t i onc o s timp r ov e． The r e f o r e, how t ocon t r o lt he ma c r os eg r ega t i on and mi c r os t ruc t ur eo fcon t i nuousc a s t i ngs l ab, imＧ r ovet hes u r f a c equ a l i t fs l ab, c omp a c tt hep r o c e s s p yo f l ow, andr educ et hecos to fp r oduc t i ona r eexp l o r ed by manyr e s e a r che r s．Thee f f e c to fe l e c t r omagne t i c
Re c e i ved２Novembe r２０１６; Re c e i vedi nr ev i s edf o rm１８J anua r c ep t ed６Febr ua r y２０１７; Ac y２０１７ Ava i l ab l eon l i ne１５ Ma r ch２０１７ １００６ Ｇ ７０６X/Copy r i tⓒ２０１７, Th ee d i t o r i a lo f f i c eo fJ ou r n a lo fI r ona ndS t e e lRe s e a r c h, I n t e r n a t i on a l． Pub l i s h e dbyE l s e v i e rL imi t e d．Al lr i t sr e s e r v e d． gh gh
/Journa Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１ Y ．
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f i e l dapp l i edi nt hef r on to fs o l i d Ｇ l i i di n t e r f a c eon qu t he mi c r o s t ruc t u r e and me chan i c a lp r ope r t i e so f QSn６ ５a l l oys l abswa ss t ud i eddu r i ngt heho r i z on Ｇ [ ] I twa sf oundt ha texe r Ｇ t a lcon t i nuousc a s t i ng１４Ｇ１７ ． t i nge l e c t r omagne t i cf i e l di nt hes o l i d i f i c a t i onf r on t cou l dimpr ovet heun i f o rmi t ft h ec ompo s i t i on,f r a Ｇ yo g me n t a t et h ec o a r s ec o l umna rg r a i nspe r i cu l a rt o pend t hec a s t i ngd i r e c t i on, ob t a i nt hef i neequ i axedg r a i n mi c r o s t ruc t u r e, andr educ et hesu r f a c es eg r ega t i on o ft hec on t i nuousc a s t i ngs l abt os omeex t en t． [ ] a t i ng Ｇ c oo l i ng comＧ I na p r ev i ouss t udy１８ , a he b i ned mo l d ( HCCM) ho r i z on t a lc on t i nuousc a s t i ng me t hodwa sdeve l opedt os o l vet hep r ob l emsi nt he conven t i ona lho r i z on t a lc on t i nuousc a s t i ngo ft hecu Ｇ r on i cke la l l oyp i s, sucha spoo rsu r f a c equa l i t p pe y andcoa r s ec o l umna rc r t a lg r owi nga l ongr ad i a ld i Ｇ ys r e c t i on, wh i chshowedexc e l l en tc o l d wo rk i ngpe r Ｇ f o rmanc ea l ongt heax i a ld i r e c t i onandc ou l dbed i Ｇ r e c t l r o c e s s edt oal a r f o rma t i onamoun ta t yp gede [ ] r oomt empe r a t u r ewi t hou tmi l l i ngs u r f a c e１９Ｇ２３ ．HowＧ e v e r, be c aus eQSn６ ５a l l oyhad manyd i f f e r en tf e a Ｇ t ur e sc ompa r ed w i t hc up r on i c k e la l l o e t h e rt he y, wh r o c e s sc ou l dh e l os o l vet hesu r f a c equa l i t eg r e Ｇ p pt y, s t i onando t he rs e r i ousp r ob l emsi nt r ad i t i ona lcon Ｇ ga t i nuousc a s t i ngf o rQSn６ ５a l l oyne ededt obef ur Ｇ t he rs t ud i ed． The r e f o r e, QSn６ ５ Ｇ ０ １a l l oys l abswe r ef ab r i c a Ｇ , t edby HCCM ho r i z on t a lc on t i nuousc a s t i ng and t hee f f e c t so f pa r ame t e r s on t he mi c r o s t ruc t ur e, sur f a c equa l i t ompo s i t i ons eg r ega t i ono ft he y andc a l l oy we r ei nve s t i t edi nt h i ss t udy． ga
２．Exp e r imen t a lMe t hod
２ １． Expe r imen t a lma t e r i a l sande ipmen t qu QSn６ ５ Ｇ ０ １a l l oy wa sus eda st heexpe r imen t a l ma t e r i a l． I t schemi c a lc ompo s i t i on (GB/T５２３１) i s s howni nT a b l e１．As e l f Ｇ d e v e l op e d HCCM ho r i z on t a l c on t i nuou sc a s t i ngequ i twa sapp l i edt op r epa r e pmen s l abs, a ndt h es c h ema t i co ft h ee i n ti ss howni n qu pme , F i １ ． T h ed e v i c ec o n s i s t e do fa m e l t i n f u r n a c e a g g ho l d i ngf u r n a c e, a ni ndu c t i onh e a t i ngs s t emf o rhe a t Ｇ y , i ng Ｇmo l d ac o o l i ngs s t ema ndad r aw i nge i n t． y qu pme Tab l e１ Chemi c a lc ompo s i t i ono fQSn６ ５ Ｇ ０ １ (wt ％ ) Sn
Al
Zn
Ni
Fe
Pb
P
Cu
６ ０－７ ０ ０ ００２ ０ ３ ０ ２ ０ ０５ ０ ０２０ １０－０ ２５ Ba l anc e
２ ２． Expe r imen t a lpr o c e s s i ngparame t e r s Thema i np r o c e s s i ngpa r ame t e r so ft heho r i z on t a l con t i nuousc a s t i ngp r o c e s sc ons i s t edo fc a s t i ngt emＧ r a t u r e (t het empe r a t u r eme a s u r e dbyt h e rmo c oup l e pe No ５showni nF i １(a)), he a t i ng Ｇmo l dt empe r a Ｇ g t ur e (t het empe r a t ur eme a sur edbyt he rmocoup l e
１— Me l t i ngc r uc i b l e; ２, ５, ９—The rmo c oup l e; ３—S t oppe rr od; ４—Coppe rl i i d; ６— Ho l d i ngc r uc i b l e; ７—Duc t; qu ８—I nduc t i onhe a t i ngdev i c e; １０—Cr t a l l i z e r; １２—Dr awi ng ys equ i t; １３—Gr aph i t emo l d; １４—Se c onda r oo l i ngwa t e r． pmen yc I— He a t i ng Ｇmo l ds e c t i on; I I—Coo l i ng Ｇmo l ds e c t i on． (a) Schema t i co fdev i c ef o rHCCM ho r i z on t a lc on t i nuous t r uc t ur eo fHCCM． c a s t i ng; (b) S
F i １． S c h ema t i co fHCCMho r i z on t a lc on t i nuousc a s t i ngf o r g f ab r i c a t i ngc oppe ra l l oys l ab．
No ９showni nF i １(a)), coo l i ng wa t e rf l owr a t e, g c a s t i ngspe edando t he r s．S l abd r awi ngp r oc e s swa s con t r o l l edby d i f f e r en t “pu l l Ｇ s t op Ｇba ck” pe r i od i c a l d r awi ngs t em, andt hec a s t i ngspe edi st heave r Ｇ ys agespe edo fe a chc l e．Fo rexamp l e, i fones t ep yc l eng t handt imeo fpu l l i ng we r e０ ７ mmand０ ６s, r e spe c t i ve l r awi ngs t opt imewa s０ １s, ones t ep y, d l eng t handt imeo fba ckwe r e０ １mmand０ １s, r e Ｇ spe c t i ve l he spe ed wa s ４０ mm/mi n．The y, and t HCCM ho r i z on t a lcon t i nuousc a s t i ng p r oc e s s wa s us edt of abr i c a t e QSn６ ５ Ｇ ０ １ a l l oy s l ab wi t ht he c r os ss e c t i ons i z eo f７０ mm×１０ mm．Thep r oc e s s a r a m e t e r sa r es h o w n i nT a b l e２． p Tab l e２ Expe r imen t a lp r o c e s s i ngpa r ame t e r so fHCCM ho r i z on t a l c on t i nuousc a s t i ngf o rf ab r i c a t i ngQSn６ ５ Ｇ ０ １a l l oys l ab Coo l i ngwa t e rf l owo fc r t a l l i z e r/(Lh－１) ys Ca s t i ngt empe r a t ur e/° C
６００
Ca s t i ngspe ed/(mmmi n－１)
２０, ４０, ６０, ８０
He a t i ng Ｇmo l dt empe r a t ur e/° C
１２００－１２５０ １１００, １１５０, １２００
２ ３．Pe rfo rmanc et e s t i ng ands t ruc t ur echarac t e r Ｇ i za t i on (１) Sur f a c er oughne s sme a sur emen t Oneo ft het a r t so fs l abc a s t i ng wa st oob t a i n ge oduc t swi t hh i f a c equa l i t no rde rt oe l imi Ｇ pr ghsur yi
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
na t et hen e e df o rmi l l i ngs u r f a c ep r o c e s s．Th e r e f o r e,i n t h i spape r, t oeva l ua t et hesu r f a c equa l i t hesur Ｇ y, t f a c er oughne s so f QSn６ ５ Ｇ ０ １a l l oy s l ab p r epa r ed by HCCM ho r i z on t a lc on t i nuousc a s t i ng wa sana Ｇ l z edbyDek t ak１５０su r f a c ep r o f i l e r．Anave r agewa s y ob t a i neda f t e rt hr e et ime sme a s u r eme n tf o re a c hd a t a． (２) Me a s u r eme n to fme c h a n i c a lp r ope r t i e so fs l ab a tr oomt empe r a t u r e Thee l onga t i onandy i e l ds t r eng t ho ft hes l abwe r e / t e s t eda c c o r d i ngt oGB T２２８ １．Thet ens i l et e s twa s c a r r i edou tona mi c r o e l e c t r on i cun i v e r s a lt e s t i ng ma Ｇ c h i n e, a ndt h et e n s i l es e e d wa ss e tt o０ ５ mm/mi n． p Thet ens i l et e s ts amp l es i z ei si l l us t r a t edi nF i ２． g Ea ch da t um wa s me a su r ed t hr e et ime s, and t he , max imum t he mi n imum and t he ave r age va l ue s we r eg i venont hecu r ve． (３) Me t a l l og r aph i cobs e r va t i on Me t a l l og r aph i cs amp l e s we r ee t ched by f e r r i c ch l o r i dei nhyd r o ch l o r i ca c i ds o l u t i onf o r１０－１５s, wh i chwa sc ompo s edo fFeCl３(５g), HCl(１０ mL), andH２O (９０ mL) ．Thee t chedspe c imenswe r eob Ｇ s e r vedandpho t og r aphedunde raNi konEc l i eLV ps １５０ me t a l l og r aph i cmi c r o s c ope． (４) Cha r a c t e r i z a t i on o fs eg r ega t i on deg r e eo f QSn６ ５a l l oy．
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F i ２． Schema t i co ft ens i l es amp l e． g
Thecon t en to fSni nt hewho l et h i ckne s sd i r e c t i on wa sme a sur edbys e l e c t eda r e aSEMs c anana l s i s o y t cha r a c t e r i z et hes eg r ega t i ondeg r e eo fs l ab．Ea chda Ｇ t ame a sur edt hr e eva l ue sandt ookt heave r age．
３．Re s u l t sandDi s c u s s i on
３ １．Effe c tof c on t i nuou sca s t i ng parame t e r son mac r os hapeofs l ab ３ １ １．Effe c tofca s t i ngt empe ra t ur eonc on t i nu Ｇ ou sca s t i ngpr o c e s sofs l ab Ca s t i ngt empe r a t ur ewa sanimpo r t an tpa r ame t e r i n f l uenc i ngt hef o rmab i l i t ft hecon t i nuousc a s t i ng yo o fa l l oy．Thei n f l uenc eo fme l tc a s t i ngt empe r a t ur e oncon t i nuousc a s t i ngp r oc e s so fs l ab wa ss t ud i ed． F i ３showst hee f f e c to fme l tc a s t i ngt empe r a t ur e g on HCCM con t i nuousc a s t i ngp r oc e s so fs l abunde r t hes ameo t he rp r oc e s scond i t i ons．
(a) １２２０° C; (b) １２４０° C; (c) １２５０° C．
F i ３． Appe a r anc eo fQSn６ ５s l absf ab r i c a t edbyHCCM ho r i z on t a lc on t i nuousc a s t i nga tva r i ousme l tc a s t i ngt empe r a t u r e s． g
Asshowni nF i ３, a tt he me l tt empe r a t u r eo f g １２２０° C, t h eh e a t i ng Ｇmo l dt emp e r a t u r eo f１１５０° Cand t hec a s t i ngspe edo f２０mm/mi n, mi s runde f e c thap Ｇ nc on t i nuousc a s t i ngp r o c e s s, andt heedgeo f penedi r epa r ed QSn６ ５ Ｇ ０ １a l l oy s l ab wa sobv i ous l n Ｇ p yi comp l e t e．Th i swa s ma i n l aus edbytwor e a sons: yc , F i r s tb e c a u s et h epho s rb r on z ewa sat i c a lwi d e pho yp so l i d Ｇ l i i dpha s ez onea l l oy, whent heme l tc a s t i ng qu t empe r a t u r e wa sl ow, t he pa s t es o l i d Ｇ l i i d pha s e qu z onei ns o l i d i f i c a t i onf r on twa sw i d e r, a ndi t sf l u i d i t y wa spo o r, s of i l l i ng wa sno tc omp l e t e．Th es e c ondwa s r e l a t edt ot hec a s t i ng mo l ds t ruc t u r e．Mo l dc av i t f yo s l abi nt h i ss t udy wa sr e c t ang l e wi t h ar e l a t i ve l y l a r a t i oo fwi d t ht ot h i ckne s sandwi t ht het h i ckＧ ger ne s so fon l r i ngs o l i d i f i c a t i on p r o c e s s, y１０ mm．Du t hena r r ows i deo fs l abwa sc oo l edi ntwod i r e c t i ons f r omt heb r oads i deandna r r ows i deo fc r t a l l i z e r． ys Thus, t he me l tt empe r a t u r ene a rt hena r r ow s i de
wa se a s or educ ef i r s t l i ch madet hef l u i d i t yt y, wh y andf i l l i ngab i l i t o f a l l o w e a k e na n dc a u s e d t h ed e Ｇ y y f e c to fi ncomp l e t ef i l l i ng．Whent he me l tc a s t i ng t empe r a t ur ei nc r e a s ed wi t ht hes ameo t he rc a s t i ng cond i t i ons, t hec a s t i ngf o rmab i l i t ft hea l l oys l ab yo be c amebe t t e r．Asshowni nF i ３(b), whent he g me l tc a s t i ngt empe r a t ur er e a ched１２４０° C,f i l l i ngc a Ｇ c i t simp r oved, s l abf i l l i ngde f e c td i s appe a r ed pa y wa r adua l l l ab qua l i t ss i i f i c an t l g y, and s y wa gn y imＧ r oved．F i ３(c) wa st he ma c r os cop i c mo r l ogy p g pho o fcon t i nuousc a s t i ngs l aba tt he me l tc a s t i ngt emＧ r a t ur eo f１２５０° C, t het empe r a t ur eo ft hehe a t i ng Ｇ pe mo l ds e c t i ono f１１５０° Candt hec a s t i ngspe edo f２０ mm/mi n． I tcou l dbes e ent ha tt hesur f a c equa l i t f yo con t i nuousc a s t i ngs l ab wa sgood whent hec a s t i ng t empe r a t ur ewa sf ur t he ri nc r e a s edt o１２５０° C． Fr omd i s cus s edabove, unde rexpe r imen t a lcond i Ｇ t i onso fc a s t i ngt empe r a t ur eo f１２５０° C, QSn６ ５ Ｇ ０ １
２７６
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
r i oushe a t i ng Ｇmo l dt empe r a t ur e so f１１００, １１５０and １２００° C, r e spe c t i ve l t ht heme l tt empe r a t ur eo f y, wi １２５０° Candt hec a s t i ngspe edo f２０ mm/mi n．F i ４ g showst ha twhent hehe a t i ng Ｇmo l dt empe r a t ur ewa s ３ １ ２．Effe c t of hea t i ng Ｇmo ld t empe ra t ur e on １１００° C, t hes l ab hads imi l a rde f e c t st ot ha tob Ｇ , c on t i nuou sca s t i ngpr o c e s sofs l ab t a i nedi nl ow c a s t i ngt empe r a t ur econd i t i ons, i e． I no r de rt os t udyt hei n f l uenc eo ft hehe a t i ng Ｇmo l d i ncomp l e t ef i l l i ng, andt her e a sonwa sa l soba s i c a l l y s e c t i ont empe r a t u r eont hequa l i t ft hec on t i nuous s imi l a r．When t he he a t i ng Ｇmo l dt empe r a t ur ei n Ｇ yo c a s t i ngs l abo fQSn６ ５a l l oy, he a t i ng Ｇmo l ds e c t i on c r e a s edt o１１５０o r１２００° C, t hesur f a c equa l i t o y f , t empe r a t u r e wa schanged f r om １１００ t o １２００° C． c a s t i ngs l abbe c ameve r he r e we r eno ygood andt F i ４showst heQSn６ ５a l l oys l absp r epa r eda tva Ｇ obv i ousde f e c t si nt hesur f a c eo fc a s t i ngs l ab． g s l ab wi t h goodsu r f a c e qua l i t ou l d bef ab r i c a t ed yc suc c e s s f u l l r ope r l us t i ng he a t i ng Ｇmo l d y by p y ad j t empe r a t u r eandc a s t i ngspe ed．
(a) １１００° C; (b) １１５０° C; (c) １２００° C．
F i ４． Appe a r anc eo fQSn６ ５s l absf ab r i c a t edbyHCCM ho r i z on t a lc on t i nuousc a s t i nga tva r i oushe a t i ng Ｇmo l dt empe r a t u r e s． g
The r e f o r e, a tt he me l tc a s t i ng t empe r a t u r eo f １２５０° Candhe a t i ng Ｇmo l dt empe r a t u r ef r om１１５０t o １２００° C, s l abwi t hc omp l e t ef i r eandgoodsu r f a c e gu l i t ou l d bef ab r i c a t ed by HCCM c on t i nuous qua yc c a s t i ng．
３ ２．Effe c tof c on t i nuou sca s t i ng parame t e r son s ur ac er oughne s sofs l ab f
Ti n pho spho rusb r onz ea l l oy ha stwos i i f i c an t gn : f e a t ur e s onei st heex i s t enc eo fl ow me l t i ngpo i n t a l l oye l emen t s, andt heo t he ri si t sr e l a t i ve l de y wi so l i d Ｇ l i i dtwo Ｇ s ez one; f o ri ns t anc e, t het emＧ qu pha r a t u r ed i f f e r enc ebe twe ens o l i dusandl i i dusc an pe qu r e a ch１５０° C．The r e f o r e, unde rt hec ond i t i ono fd i e c a s t i ngo ro r d i na r on t i nuousc a s t i ng, t hea l l oyha s yc
s eve r edend r i t es e r e a t i onandan t i Ｇ s e r e a t i on．Thu s, g g g g t i n Ｇ r i chcoppe rpha s eo f t enappe a r sont hesur f a c eo f s l abf abr i c a t edbyt heconven t i ona lc a s t i ng, o fwh i ch t heappe a r anc el ooksl i ke g r ay po i n t s．The ma c r o f e a t ur e so ft he QSn６ ５a l l oy s l abs p r epa r edunde r d i f f e r en tp r oc e s spa r ame t e r sa r eshowni nF i ５． I t g cou l dbes e ent ha tt hesur f a c e so fs l absf abr i c a t edby HCCMcon t i nuousc a s t i ng we r esmoo t handsh i n i ng wi t hou tobv i ouss c a randa sh． I no rde rt of ur t he rcha r a c t e r i z esur f a c equa l i t f yo t heQSn６ ５a l l oys l abs, t hesur f a c er oughne s sva l Ｇ ue s (Ra) o ft hes l abspr epa r edbyd i f f e r en tcon t i nu Ｇ ousc a s t i ng p r oc e s s pa r ame t e r s we r e me a sur ed by Dek t ak１５０sur f a c ep r o f i l e r．TheRa va l uewa sanav Ｇ e r ageva l uec a l cu l a t edbyt heab s o l u t ev a l u eo fs u r f a c e
F i ５． Sur f a c emorpho l og i e so fs l abspr epa r eda the a t i ng Ｇmo l dt empe r a t ur eo f１１５０and１２００°Candc a s t i ngspe edo f g ２０ mm/mi n (a, e), ４０ mm/mi n (b, f), ６０ mm/mi n (c, g), and８０ mm/mi n (d, h) ．
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
imp l i ngsandp i t s, wh i chr e f l e c t edt heave r agef l uc Ｇ p t ua t i ono ft hesu r f a c ec on t ou rwi t h i nac e r t a i nl eng t h r ange．Thus, t hel a r rt heva l ueo fr oughne s s, t he ge r e a t e rt hedeg r e eo ff l uc t ua t i on, andt hust hesur Ｇ g f a c e wa s mo r er ough．Fr om t he p r i nc i l eo ft he p r oughne s s me a su r emen t me t hod, t he t e s tl eng t h wa sr equ i r ed, andusua l l s h o u l dn o tb el e s st h a n y twot ime so ft hena t u r a lc c l e w h i c h d e e n d e do n y p r t i cu l a rsu r f a c es t a t e．The r e f o r e, i nt h i spape r, ３ pa mm wa sus eda st hes c ant e s tl eng t handt her e su l t s a r eshowni nF i ６ wi t ht hehe a t i ng Ｇmo l dt empe r a Ｇ g
２７７
t ur eo f１２００° Candc a s t i ngspe edso f２０, ４０, ６０and ８０ mm/mi n, r e spe c t i ve l co rd i ngt ot he g r oup y．Ac con t ourcur ve s, as e to fr oughne s sva l ueda t a wa s ob t a i nedf o re a ch p r oc e s s i ngpa r ame t e r s, a sshown i nTab l e３． I twa sf oundt ha tt her oughne s so ft he uppe rsur f a c e wa ss l i t l a r rt hant ha to ft he gh yl ge l owe rsur f a c eunde rd i f f e r en tspe eds．Howeve r, sur Ｇ f a c er oughne s sva l ue swe r ea l lbe l ow０ ６μmi nt h i s s t udy, wh i chi nd i c a t edt ha tt hes l abcou l dbed i r e c t Ｇ l edf o rsubs equen tr o l l i ngde f o rma t i on wi t hou t y us mi l l i ngp r oc e s s．
F i ６． Lowe rsur f a c epr o f i l ecur ve so fs l abspr epa r eda the a t i ng Ｇmo l dt empe r a t ur eo f１２００°Candc a s t i ngspe edo f g ２０ mm/mi n (a), ４０ mm/mi n (b), ６０ mm/mi n (c), and８０ mm/mi n (d) ． Tab l e３ Roughne s so fs l absp r epa r eda tva r i ousc a s t i ngspe eds Ca s t i ngspe ed/ (mmmi n－１)
Roughne s so fuppe rsur f a c e/μm
２０
０ ３９６
６０
０ ６６３
４０ ８０
０ ４９７ ０ ３８４
Me a sur edva l ue ０ ６１３
０ ４６７
０ ３７３
０ ３８５
０ ３１４ ０ ６６３
０ ２８０ ０ ３３９
Ave r age
Roughne s so fl owe rsur f a c e/μm
０ ４９２
０ ３８７
０ ４７４
０ ３０９
０ ３６４ ０ ４６２
０ １６０ ０ ３５０
Me a sur edva l ue ０ ４１８
０ １８３
０ ２２６
０ ３５３
０ ２４７ ０ ４２３
０ ２５７ ０ ３４９
Ave r age ０ ３２９ ０ ２２１ ０ ２９６ ０ ３７４
I ti sshownf r om Tab l e３t ha t wi t ht hec a s t i ng sur f a c eo f mo l d wa suneven, t hep r o f i l eo fc a s t i ng spe edi nc r e a s i ngf r om２０t o８０mm/mi n, t hesu r f a c e mo l dsur f a c e wou l d bes t enc i l edont hesur f a c eo f r oughne s sva l ue o fs l absi nc r e a s edf r om ０ ３６４t o s l ab．Cons equen t l hei n t e rna lsur f a c eo fmo l do f Ｇ y, t ０ ４９２μm．Thesu r f a c er oughne s sva l uewa saphys i Ｇ t ende t e rmi nedt he ma c r os cop i cappe a r anc eo ft he c a lquan t i t t h a t r e f l e c t s t h ed e r e eo f s u r f a c e r o u h Ｇ c a s t i n s u r f a c e ． y g g g ne s so fs o l i d i f i ed me t a l, wh i ch wa s ma i n l n f l u Ｇ Se cond, i twa sa l sor e l a t edt ot hep r oc e s scond i Ｇ yi enc edbys eve r a lf a c t o r s． F i r s t,i twa sa f f e c t edbyt he t i onsando t he rf a c t o r sdur i ngt heso l i d i f i c a t i on．The sur f a c es t a t eo fc a s t i ngmo l d． Be c aus es l abwa sso l i d Ｇ g r e a t e rp r e s sur eandt heh i rt empe r a t ur eo ft he ghe i f i edi na mo l d, t he me t a lwa si nc l o s ec on t a c twi t h l i i d me t a l, t hebe t t e rt hef l u i d i t fl i i d me t a l qu yo qu t hemo l dsu r f a c ebe f o r es o l i d i f i c a t i on． I ft hei n t e rna l andt hef i l l i ngpe r f o rmanc e．Ononehand, be c aus eo f
２７８
/Journa Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１ Y ．
t hee f f e c to fg r av i t nho r i z on t a lc on t i nuousc a s t i ng y,i r oc e s s, t hel i i d me t a li ns o l i d Ｇ l i i di n t e r f a c e p qu qu f r on twa sa lwaysi nc l o s ec on t a c twi t ht hel owe rsur Ｇ f a c eo fmo l d wh i ch wa sa lwayspo l i shedt oal owe r r oughdeg r e e; t hus, t hel owe rsu r f a c ec ou l dhavea l owr oughne s s．Ont heo t he rhand, du r i ngs o l i d i f i c a Ｇ t i onp r o c e s s, t heuppe r me t a lg r adua l l s l i tf r o m y p t hemo l dbe c aus eo ft hes o l i d i f i c a t i onshr i nkageand be c ameaf r e esu r f a c e wh i ch a lways had a h i r ghe , r oughdeg r e e．The r e f o r e t heuppe rsu r f a c eo ft he s l abwa susua l l oughe rt hant hel owe rsu r f a c ei n yr s l abf ab r i c a t edbyho r i z on t a lc on t i nuousc a s t i ng, a s showni nTab l e３．
spe edsa r eshowni nF i ７．Fr om t hel ong i t ud i na l g s e c t i on mi c r os t ruc t ur eshowni nF i ７(a,c,e,g), g whent hec a s t i ngspe ed wa sl ow, t he wi d t ho fco Ｇ l umna rc r t a lwa sl a r l rtwog r a i ns ys ge, andon yoneo cou l dbes e eni nt hewho l es e c t i on．Wi t hi nc r e a s i ng t hec a s t i ngspe ed, g r a i n wi d t hbe c amesma l l e rand s t r a i t ne s so fc r t a lbounda r sgood．Whent he gh ys ywa c a s t i ngspe edi nc r e a s edt o８０mm/mi n, t hes t r a i h Ｇ gt ne s so fco l umna rg r a i n bounda r s i n i f i c a n t l b e y g y Ｇ c amewo r s e．Fr om t he mi c r os t ruc t ur eo fc r os ss e c Ｇ t i onshowni nF i ７ (b,d,f,h),i tcou l dbes e ent ha t g t he r ewe r eon l ewl a r r a i ns, wi t hsomesma l l yaf geg r a i nswhos es i z e swe r ed i f f e r en tf r omt hos eo fl a r g ge r a i ns, andt hei nhomogene i t fg r a i ns i z ewa sob Ｇ g yo ３ ３．Effe c tof c on t i nuou sca s t i ng parame t e r son v i ous．Ther e a sonf o rt hef o rma t i ono fsma l lg r a i ns mi c r o s t ruc t ur eofs l ab wa susua l l e l a t edt ocompe t i t i ve g r a i ng r owt hi n yr [ ] As men t i onedabove, whent he me l tt empe r a t ur e so l i d i f i c a t i on p r o c e s s２４ ．I nt he p r o c e s s o fg r a i n wa s１２５０° C, he a t i ng Ｇmo l dt empe r a t u r e wa sf r om g r owt h, t heysome t ime shadd i f f e r en tg r owt hr a t e s １１５０t o１２００° Candt hec a s t i ngspe ed wa sf r om ２０ andcompe t edwi t he a cho t he r． Fo rt hos eg r a i nswi t h t o８０ mm/mi n, QSn６ ５a l l oys l abswi t h goodsur Ｇ as l owe rg r owt hr a t e, wheni t me e t so t he rg r a i ns f a c equa l i t r eob t a i n e d．Th el ong i t ud i n a la ndc r o s s wi t hah i rg r owt hr a t e,i twou l dg r a du a l l ee l imi Ｇ y we ghe yb s e c t i onso fQSn６ ５a l l oys l abp r epa r eda tahe a t i ng Ｇ n a t e dands t opg r owi ng．The r e f o r e, pa r t i a lg r a i nwa s mo l dt empe r a t u r eo f１１５０° C and va r i ous c a s t i ng obv i ous l l l e ri ns i z eonc r os ss e c t i ons． ysma
F i ７． Mi c r os t ruc t ur e so fl ong i t ud i na landc r os ss e c t i ono fQSn６ ５a l l oys l abpr epa r eda the a t i ng Ｇmo l dt empe r a t ur eo f g １１５０° Candc a s t i ngspe edo f２０ mm/mi n (a, b), ４０ mm/mi n (c, d), ６０ mm/mi n (e, f), and８０ mm/mi n (g, h) ．
３ ４．Effe c tof c on t i nuou sca s t i ng parame t e r son s l abs egr ega t i on Seg r ega t i onc anbed i v i dedi n t o ma c r o s eg r ega t i on andmi c r o s eg r ega t i on．Thet empe r a t u r er angeo fso Ｇ ; l i d i f i c a t i ono ft i n Ｇ h o s h o rb r o n z e i s l a r e f o re x a m Ｇ p p g , l et het empe r a t u r ed i f f e r enc eo fs o l i dusandl i i Ｇ p qu [ ] duso fQSn６ ５ Ｇ ０ １c anr e a ch１５０° C２５ ．Be c aus et he t i ne l emen tha sas t r ongt e nd e n c fa n t i Ｇ s e r e a t i on, yo g g i tmake st i nc on t en ti nt hesu r f a c eo ft i nb r onz ei n Ｇ tmuch mo r et hant ha ti nt hec o r e．Ast i nc on t en t go i nt hesu r f a c ei nc r e a s e s, i ti se a s o gene r a t et i n Ｇ yt r i chha r db r i t t l epha s e, mak i ngt hes l abhaveobv i Ｇ ous l nhomogeneousc ompo s i t i onandt endt oc r a ck yi ont hesu r f a c ei nt her o l l i ngp r o c e s s．The r e f o r e, a l ongt imeun i f o rm anne a l i ngshou l dbeusua l l e Ｇ yne dedt o maket hec ompo s i t i ono fc on t i nuousc a s t i ng o fs l ab un i f o rm i nt he c onven t i ona lp r oduc t i on r oc e s so fQSn６ ５a l l oys t r i tf i r s t, andt henon Ｇ p pa l i nesu r f a c e mi l l i ngt r e a tmen tshou l dbec a r r i edou t t or emovet het i n Ｇ r i chl aye ront hesu r f a c e, andt hen
c o l d Ｇ r o l l i ngf o rmi ngc anb e ma d e, wh i c h ma r ke d l n Ｇ yi c r e a s e st hep r oc e s sf l owo fQSn６ ５a l l oys t r i p, and r e a t l educ e st hey i e l d． g yr I no rde rt oana l z et hecompos i t i ons eg r ega t i ono f y QSn６ ５a l l oy s l abf abr i c a t ed by HCCM ho r i z on t a l con t i nuousc a s t i ng, t het i ne l eme n tc on t e n to fQSn ６ ５ a l l oys l abwa sme a sur edbys e l e c t eda r e aSEM ene r Ｇ c t rumana l i si nt hea r e ao f５０μms r eon gyspe ys qua t hesur f a c eandi nt heco r eo ft hes l ab, a sshowni n F i ８and９, r e spe c t i ve l e ed i f f e r en ta r e a son gs y．Thr t hesur f a c eandi nt heco r e we r es e l e c t edandana Ｇ l z ed s epa r a t e l hen t he ave r age va l ue wa s y y and t t aken, andt heana l i sr e su l t sa r eshowni nTab l e４． ys Ass e enf r om Tab l e４, wi t ht hei nc r e a s ei nc a s t i ng spe ed, t het i ncon t en tont hesur f a c eo ft hes l abi n Ｇ c r e a s edf r om５ ５０ wt ％ t o６ ６３ wt ％ andt ha ti n t heco r echangedf r om５ ４５wt ％ t o６ ２５wt ％ a t t hehe a t i ng Ｇmo l dt empe r a t ur eo f１１５０° C．Whent he he a t i ng Ｇmo l dt empe r a t ur ewa s１２００° C, t het i ncon Ｇ t en tchangedi nt hea lmos ts imi l a rway wi t ht hei n Ｇ c r e a s ei nc a s t i ngspe ed．
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
２７９
F i ８． Schema t i co fpo s i t i ono fs e l e c t eda r e aana l s i s． y g
F i ９． Se l e c t eda r e aSEMs c animageo fsu r f a c e (a) andc o r e (b) ． g Tab l e４ Re su l t so ft i ne l emen tc on t en tbys e l e c t eda r e aSEMs c anana l s i s y He a t i ng Ｇmo l d t empe r a t ur e/° C １１５０
１２００
Ca s t i ngspe ed/ (mmmi n－１)
Ti nc on t en to fsur f a c ea r e a/ma s s％
２０
５ ５０
６０
５ ３１
４０ ８０ ２０ ４０ ６０ ８０
４ ８５ ６ ９６ ５ ０８ ４ ７４ ４ ７４ ４ ７０
Me a sur edva l ue ５ ５８
５ ４１
５ ７８
５ ８８
５ ９１ ６ ４５ ５ １８ ４ ５２ ５ ４５ ５ １７
６ １７ ６ ４９ ４ ８５ ４ ７７ ４ ３０ ５ ４１
Ti npho spho rusb r onz ewa sat i c a lan t i Ｇ s eg r ega Ｇ yp t i ona l l oy． I nt h i spape r, t os t udyt hean t i Ｇ s eg r ega Ｇ t i on phenomenon o ft hea l l oy p r epa r ed by HCCM ho r i z on t a lc on t i nuous c a s t i ng, an an t i Ｇ s eg r ega t i on coe f f i c i en twa sde f i ned, wh i ch wa sequa lt ot het i n con t en to fsu r f a c ea r e ad i v i dedbyt ha to fc o r ea r e a． Us i ngt heda t ai nTab l e４, t hean t i Ｇ s eg r ega t i onr a t i o wa sc a l cu l a t edunde rd i f f e r en tp r o c e s s pa r ame t e r s, andt her e su l t sa r el i s t edi nTab l e５． An t i Ｇ s eg r ega t i onc oe f f i c i en ti sac r i t e r i ono fan t i Ｇ s eg r ega t i on, t ha ti s, wheni twa sg r e a t e rt han１, i t c an be de t e rmi ned t ha t an t i Ｇ s eg r ega t i on happens, andt hesma l l e rt hec oe f f i c i en t, t he mo r es eve r et he an t i Ｇ s eg r ega t i on．Howe v e r, wh e na n t i Ｇ s e r e t i onco Ｇ g ga e f f i c i en ti sl e s st han１,i ti susua l l f i neda sano r Ｇ yde
Ave r age
Ti nc on t en to fc o r ea r e a/ma s s％
５ ５０
４ ９９
５ ６６
５ ４９
５ ６４ ６ ６３ ５ ０４ ４ ６８ ４ ８３ ５ ０９
６ ６７ ６ １４ ５ ４０ ５ ４８ ４ ７９ ４ ４９
Me a sur edva l ue ５ ６７
５ ６８
６ ０６
６ ５５
５ ７７ ５ ８４ ５ ２２ ５ ５１ ５ ０６ ５ ６２
６ ３０ ６ １０ ５ ２８ ５ ８３ ５ ３０ ５ １５
Ave r age ５ ４５ ６ ２５ ６ ０３ ６ ０３ ５ ３０ ５ ６１ ５ ０５ ５ ０９
Tab l e５ Ant i Ｇ segr ega t i oncoe f f i c i ento fphosphorbronz es l ab r epa r edbyHCCM ho r i z on t a lc on t i nuousc a s t i ngwi t h p d i f f e r en tpa r ame t e r s Ca s t i ng spe ed/ (mmmi n－１) ２０ ４０
６０ ８０
An t i Ｇ s eg r ega t i onc oe f f i c i en t
He a t i ng Ｇmo l d He a t i ng Ｇmo l d t empe r a t ur e１１５０° C t empe r a t ur e１２００° C １ ０１
０ ９５
０ ９４
０ ９６
０ ９０ １ １０
０ ８３ １ ００
ma ls eg r ega t i on． I tcou l dbes e enf r om Tab l e５t ha t t hes eg r ega t i oncoe f f i c i en to ft hes l absp r epa r edby HCCM ho r i z on t a lcon t i nuousc a s t i ngunde rd i f f e r en t
２８０
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
r oc e s spa r ame t e r schangedf r om０ ８t o１ １, wh i ch p i nd i c a t edt ha tt hes eg r ega t i on o fs l ab p r epa r ed by HCCM wa sno ts e r i ous, andt he r ewa snos eg r ega Ｇ t i ono rno rma ls eg r ega t i oni n mo s tc a s e． Fr omt h ei n f l u e n c eo fp r o c e s sp a r ame t e r s, t h ee f f e c t o fhe a t i ng Ｇmo l dt empe r a t u r eons eg r ega t i onwa sno t obv i ouswi t h i nt heexpe r imen t a lpa r ame t e r s．HowＧ eve r, whent hehe a t i ng Ｇmo l dt empe r a t u r e wa scon Ｇ s t an t, t hean t i Ｇ s eg r ega t i on c oe f f i c i en thad asma l l , changewi t ht hei nc r e a s eo ft hec a s t i ngspe ed and r e a cheda mi n imum and max imum a tt he c a s t i ng spe edo f４０and８０ mm/mi nr e spe c t i ve l y． Theabover e su l t sshowedt ha tt he r ewa snoobv i Ｇ ousma c r o s eg r ega t i oni nt hes l abf ab r i c a t edby HCＧ CM ho r i z on t a lc on t i nuousc a s t i ng; t hus,i tp r omi s ed t og r e a t l r t eno ravo i dhomogen i z i nganne a l i ng ysho t imei nt hesubs equen tp r o c e s s, and maket hes l ab d i r e c t l o l l edwi t hou tsu r f a c emi l l i ngt or emovet he yr s e r i ousnon Ｇ un i f o rms u r f a c el a e r, wh i c hc ou l dg r e a t l y y compa c tt hepr o c e s s e sandimp r ovet hey i e l d．
３ ５．Effe c t sof c on t i nuou sca s t i ng parame t e r son me chan i ca lpr ope r t i e sofs l ab
r e l a t edt oi t s mi c r os t ruc t ur e．As men t i onedabove, t hemi c r os t ruc t ur eo fQSn６ ５a l l oys l abp r epa r edby HCCM ho r i z on t a lcon t i nuousc a s t i ngwa saco l umna r c r t a la l ongt hecon t i nuousc a s t i ngd i r e c t i on．HowＧ ys eve r, f r om F i ７, owi ngt ot hea s t r i c a lcoo l Ｇ g ymme i ngi n t ens i t twe en uppe randl owe rsur f a c e so f y be s l abi nho r i z on t a lcon t i nuousc a s t i ngp r oc e s s, t hed i Ｇ r e c t i ono fco l umna rc r t a lo fs l abwa sno tcomp l e t e Ｇ ys , l a r a l l e l t ot h a to f c a s t i n b u th a dac e r t a i na n l e yp g g be twe ent hem．Whent hec a s t i ng spe edi nc r e a s ed, t hee f f e c to fa s t r i c a lhe a td i s s i t i onbe twe en ymme pa t heuppe randl owe rsur f a c e sde c r e a s ed, andt hust he ang l ebe twe eng r owt hd i r e c t i ono fco l umna rc r t a l ys andt hec a s t i ng d i r e c t i onbe come ssma l l e r, t heco Ｇ l umna rc r t a lwa ss t r a i t e r, andt hede f o rma t i on ys gh coo rd i na t i on wa sbe t t e rdur i ngt ens i l ede f o rma t i on, wh i chr e su l t edi nl a r rp l a s t i c i t hec a s t i ng ge y．Ast spe edi nc r e a s ed, t he g r a i ns i z e be c ame mo r e un i Ｇ f o rm, wh i chmadede f o rma t i onmo r econs i s t en tdur Ｇ i ng t het ens i l ede f o rma t i on, andt husi t wa sa l so bene f i c i a lt ot hep l a s t i c i t emen t． yenhanc
４．Conc l u s i on s
(１) QSn ６ ５ Ｇ ０ １s l abwi t hgoods u r f a c equ a l i t yand mi c r os t ruc t ur eo r i en t eda l ong t hec a s t i ng d i r e c t i on cou l dbep r epa r edby HCCM ho r i z on t a lcon t i nuous c a s t i nga tt he me l tc a s t i ngt empe r a t ur eo f１２５０° C, he a t i ng Ｇmo l dt emp e r a t u r eo f１１５０－１２００° Candc a s t i ng spe edo f２０－８０ mm/mi n．Thes l abshadgoodcomＧ b i nedp r ope r t i e s wi t hsur f a c er oughne s so f０ ２２－ ０ ５５μm, t het ens i l es t r eng t ho f２７５－３２５ MPa, t he i e l ds t r eng t ho f１２４－１５５ MPa, andt hee l onga t i on y r a t eo f４６ ６％ －５６ ３％ , wh i chimp l i edt ha tt hey cou l dbed i r e c t l r oc e s s edwi t hou tsubs equen tmi l l Ｇ yp i ngsur f a c e． (２) Thes e r i ouss eg r ega t i ono ft i ne l emen ti nt he con t i nuousc a s t i ng o fQSn６ ５a l l oycou l dbee f f e c Ｇ t i ve l l vedby HCCM ho r i z on t a lcon t i nuousc a s t Ｇ yso i ng．Ther a t i oo fSncon t en ti nt hesur f a c et ot ha ti n t heco r ewa s０ ８３－１ １０, whos eave r ageva l uewa s c l os et o１ ０, andno tobv i ous l n f l uenc edbyp r oc e s s yi r ame t e r s． pa (３) Whent hec a s t i ngspe edi nc r e a s edf r om２０t o /mi ,t ８ ０mm n h e r a i ns i z e c h a n e d l i t t l e i f t h eo t h e r g g F i １０． Me chan i c a lp r ope r t i e so fQSn６ ５a l l oys l abp r epa r ed g r oc e s spa r ame t e r swe r et hes ame．Whent hehe a t Ｇ p byHCCM ho r i z on t a lc on t i nuousc a s t i ngwi t hd i f f e r en tc a s t i ng i ng Ｇmo l dt empe r a t ur ei nc r e a s edf r om １１５０t o１２００ r ame t e r s． pa ° C, t heg r a i ns i z ewa sobv i ous l educ edandbe c ame yr I tc ou l db es e e nt h a tt h et e n s i l es t r e ng t ho fs l a bwa s mo r eun i f o rm i ft hec a s t i ng spe ed wa st hes ame． ２７５－３２５ MPa, t h ey i e l ds t r e ng t h wa s１２４－１５５ MPa Wi t h i nt her angeo ft hec a s t i ngspe eda twh i cht he andt h ee l ong a t i onwa s４６ ６％ －５６ ３％ a tt h eh e a t i ng Ｇ co l umna rg r a i ns t ruc t ur ecou l dbeob t a i ned, t heco Ｇ mo l dt empe r a t u r eo f１１５０and１２００° C．Thee l onga Ｇ l umna rg r a i ns i z ewa sma i n l n f l uenc edbyt hehe a t Ｇ yi t i oni nc r e a s eds l i t l t ht hei nc r e a s ei nt hec a s t Ｇ i ng Ｇmo l dt empe r a t ur e． gh y wi i ngspe ed, bu ta tt hes amec a s t i ngspe ed, t hee l on Ｇ Acknowl e dgmen t t i ona lmo s thadl i t t l ed i f f e r enc ewi t hhe a t i ng Ｇmo l d ga t empe r a t u r ei nc r e a s i ngf r om １１５０t o１２００° C．The Theau t ho r sa r eg r a t e f u lt ot hef i nanc i a lsuppo r t me chan i c a lpr ope r t i e so ft he ma t e r i a l we r ec l os e l r omt heNa t i ona lKeyTe chno l ogySuppo r tPr og r am y f Tens i l espe c imens we r ep r epa r edi na c c o r danc e wi t ht heCh i ne s ena t i ona ls t anda r d (GB/T ２２８ １) ． Thr e es amp l e swe r et akenf o re a chs l abunde rapa Ｇ r ame t e rby wi r e Ｇ e l e c t r odecu t t i ng．F i １ ０s h o w st h e g t ens i l eme chan i c a lp r ope r t i e so fs l absp r epa r ed wi t h d i f f e r en tc a s t i ngpa r ame t e r s．
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
o fCh i n a (No．２０１１BAE２３B０３), t h e Na t i on a lNa t u r a l S c i e n c eFound a t i ono fCh i n a (５１５０４０２３) a ndt h eCh i n a S c ho l a r s h i c i lP r o e c t(No． ２０１５０６４６５０５５)． pCoun j
Re f e r enc e s
[１] HF．Yu a n, L．Xu, Hun a n Non f e r r ou s Me t a l s３０ (２０１４) No ３, ４６ Ｇ ４９ (i nCh i ne s e) ． [２] D H． L i u, P．Ma, WY． Cu i, Non f e r r ousMe t a l sPr o c e s s i ng４０ (２０１１) No ５, ８ Ｇ １２ (i nCh i ne s e) ． [３] H．Ka t o, M．Takama, Y． Iwa i, We a r２５４ (２００３) ５７３ Ｇ ５７８． [４] D．Ša t ov i c, L．V．Žu l sn i c a, Co r r o s．Sc i．５１ (２００９) j, V．De １５９６ Ｇ １６０３． [５] X．L i ao, F．Cao, A．Chen, Tr ans．Non f e r r ousMe t． So c．Ch i na ２２ (２０１２) １２３９ Ｇ １２４９． [６] X． L i, J H．Yang, Coppe rEng i ne e r i ng (２０１３) No ４, １１ Ｇ １５ (i n Ch i ne s e) ． [７] F．Koh l e r, T．Camp a n e l l a, S．Nak a n i s h i, Ac t a Ma t e r． ５６ (２００８) １５１９ Ｇ １５２８． [８] X．L i u, J．Luo, X．Wang, Tr ans．Non f e r r ous Me t．So c．Ch i na ２５ (２０１５) １９０１ Ｇ １９１０． [９] R , Y．Xu, J C．Mu t h i ah, J A． P f a e nd t n e r, C J．McMahonJ r． L． Ba s s a n i, Ma t e r． Sc i．Eng．A２３４ Ｇ ２３６ (１９９７) １０３３ Ｇ １０３６． [１０] R t Ｇ T． Zhou, J our na lo fAnhu iUn i ve r s i t fTe chno l ogy (Na yo ur a lSc i enc e) ２４ (２００７) No １, ２９ Ｇ ３２ (i nCh i ne s e) ． [１１] J C． Zou, Ch i naNon f e r r ousMe t a l s (２０１３) No １６, ３０ Ｇ ３２ (i n Ch i ne s e) ． [１２] J M． Xu, Phy s Ｇ Lou, C M．Hu a ng, L P． Lu, F W． Dong, HF．
[１３] [１４] [１５] [１６] [１７] [１８]
[１９] [２０] [２１] [２２] [２３] [２４] [２５]
２８１
i c a lTe s t i ngandChemi c a lAna l i sPa r tA: Phys i c a lTe s t i ng ys (２００３) No ８, ３９８ Ｇ ４００ (i nCh i ne s e) ． J P．Lu, S H．Zhang, YX．Xi n, Spe c i a lCa s t i ng & Non f e r Ｇ r ousAl l oys (２００３) No ３, ５７ Ｇ ５９ (i nCh i ne s e) ． C H．Hu i, T J．L i, WZ． J i n, J．Guo, Ra r e Me t a lMa t e r i a l s andEng i ne e r i ng３７ (２００８) ７２１ Ｇ ７２４ (i nCh i ne s e) ． T J．L i, K． J i n, X G．Zhang, Non f e r r ous Me t a l sPr o c e s s i ng (２００６) No １, １５ Ｇ １６ (i nCh i ne s e) ． X．L i, A．Ga u t r e l l e, Z M．Re n, R．Mo r e a u, Y D． gnoud, Y．Fa Zh a ng, C．Es l i ng, Ac t a Ma t e r． ６０ (２０１２) ３３２１ Ｇ ３３３２． AE．Ar e s, S F．Gue i E． Schve z ov, J． Cr t．Gr owt h jman, C ys ３１２ (２０１０) ２１５４ Ｇ ２１７０． J X．X i e, J．Me i, X H．L i u, X F．L i u, A He a t i ng Ｇ c o o l i ngComＧ b i n e dMo l d Ho r i z on t a lCon t i nuousCa s t i ng Me t hodandEqu i Ｇ p men tf o r Pr oduc t i on o f Cup r on i cke l Al l oy P i i na, pe, Ch ２０１０１０５０１４０７ ４, ２０１０． J．Me i, X H．L i u, J X．Xi e, I n t． J．Mi ne r．Me t a l l．Ma t e r． １９ (２０１２) ３３９ Ｇ ３４７． J．Me i, X H．L i u, J X．X i e, T r a n s．Non f e r r ou sMe t． So c．Ch i n a ２２ (２０１２) １４３０ Ｇ １４３９． X．Xi e, Tr ans．Non f e r r ous J．Me i, X H．L i u, YB． J i ang, J Me t． So c．Ch i na２２ (２０１２) ２５２９ Ｇ ２５３８． H．L i u, J X．Xi e, I n t． J．Mi ne r．Me t Ｇ J．Me i, YB． J i ang, X a l l．Ma t e r． １９ (２０１２) ７４８ Ｇ ７５８． i, S．Chen, J X．Xi e,i n: The１２ t hIUMRS YB． J i ang, J．Me I n t e r na t i ona lCon f e r enc ei nAs i a, Bus s an, Ko r e a, ２０１２, pp．． D．Tour r e t, A．Ka rma, Ac t a Ma t e r． ８２ (２０１５) ６４ Ｇ ８３． GP．Zhou, Z Y．L i u, S C．Yu, J．Chen, YQ．Qi u, GD． I r onS t e e lRe s． I n t． １８ (２０１１) No ２, １８ Ｇ ２３． Wang, J．
E f f e c t so fp r o c e s sp a r ame t e r sons u r f a c equ a l i t ompo s i t i ons eg r ega t i on, y, c mi c r o s t ruc t ur eandpr ope r t i e so fQSn６ ５ Ｇ ０ １a l l oys l absf ab r i c a t edby HCCM ho r i z on t a lc on t i nuousc a s t i ng YangL i u, Xi n Ｇ huaL i u∗ , Hua Ｇ dongFu, Mi n ＧxuanLou, J i an Ｇx i nXi e
I ns t i t u t ef o rAdvanc ed Ma t e r i a l sandTe chno l ogy, Un i ve r s i t fSc i enc eandTe chno l ogyBe i i ng, Be i i ng１０００８３, Ch i na yo j j ARTICLEINFO
ABSTRACT
Keywo rds: QSn６ ５c oppe ra l l oy He a t i ng Ｇ c oo l i ng c omb i nedmo l d Ho r i z on t a lc on t i nuous c a s t i ng Mi c r o s t r uc t ur e Me chan i c a lp r ope r t y Compo s i t i ons eg r ega t i on
Co l umna r Ｇ r a i nedQSn６ ５ Ｇ ０ １a l l oys l abswi t hawi d t ho f７０mmandt h i ckne s so f１０mm we r ef abr i c a t ed g byhe a t i ng Ｇ c oo l i ngc omb i nedmo l d (HCCM) ho r i z on t a lc on t i nuousc a s t i ng．Thee f f e c t so fp r o c e s spa r ame Ｇ ompo s i t i ons eg r ega t i onand me chan i c a lp r ope r t i e s t e r sons o l i d i f i c a t i on mi c r o s t r uc t ur e, sur f a c equa l i t y, c e l l en tme chan i c a lp r ope r t i e s we r es t ud i ed．Ther e su l t sshowedt ha tt hes l abswi t hgoodsur f a c equa l i t y, exc andnoobv i ouss eg r ega t i onc ou l dbep r epa r eda tt heme l tc a s t i ngt empe r a t ur eo f１２５０° C,t hehe a t i ng Ｇmo l d t empe r a t ur eo f１１５０－１２００° C, t hec oo l i ngwa t e rf l owr a t eo f６００L/handt hec a s t i ngspe edo f２０－８０ mm/mi n．Thes l abshadt hey i e l ds t r eng t ho f１２４－１５５ MPa, t hee l onga t i onr a t eo f４６ ６％－５６ ３％ and t hesur f a c er oughne s so f０ ２２－０ ５５μm, wh i chenab l edt hemt obed i r e c t l r o c e s s edwi t hou tsubs equen t yp mi l l i ngsur f a c e．Ther a t i oo fSnc on t en ti nt hesur f a c et ot ha ti nt hec o r ewa s０ ８３－１ １０, wi t hanave r age va l uec l o s et o１ ０, andno tobv i ous l n f l uenc edbyp r o c e s spa r ame t e r s．Whent hec a s t i ngspe edi nc r e a s ed yi f r om２０t o８０ mm/mi n, t heg r a i ns i z echangedl i t t l ei ft heo t he rp r o c e s spa r ame t e r swe r et hes ame．When t hehe a t i ng Ｇmo l dt empe r a t ur ei nc r e a s edf r om１１５０t o１２００° C,t heg r a i ns i z ewa sobv i ous l e f i nedandbe Ｇ yr c amemo r eun i f o rmi ft hec a s t i ngspe edwa st hes ame．Wi t h i nt her angeo ft hec a s t i ngspe eda twh i cht he c o l umna rg r a i ns t r uc t ur ec ou l dbeob t a i ned, t hec o l umna rg r a i ns i z ewa sma i n l n f l uenc edbyt hehe a t i ng Ｇ yi mo l dt empe r a t ur e．
１． I n t r odu c t i on QSn６ ５ Ｇ ０ １a l l oyi soneo ft he mo s timpo r t an t coppe ra l l oys c ompo s ed o ft i n and pho spho rus, wh i chi sknowna st het i n pho spho rb r onz e．S i nc e [ , ] t hea l l oyno ton l sh i chan i c a lp r ope r t i e s１ ２ yha ghme [ ] bu ta l s oha sgoodwe a rr e s i s t anc e３ , goodc o r r os i on [４,５] r e s i s t anc e , nospa rksdu r i ngimpa c t i ngandnon Ｇ , magne t i sm i t ss t r i sbe enwi de l edi ni ndus Ｇ pha yus t r st hepr oduc t i ono fs ep t a, d i aphr agmand y, sucha spa c e ri nt hei ns t rumen ti ndus t r he manu f a c t ur Ｇ y, t [ ] i ngo fe l e c t r on i cc onne c t o r si ne l e c t r on i c ss e c t o r s６ ande l a s t i cc omponen t ssuch a ssp r i ngs, swi t che s [３,７ Ｇ ９] andbe a r i ngs ． Theex i s t i ngp r oduc t i on me t hodsf o rQSn６ ５ Ｇ ０ １ a l l oy ma i n l nc l ude sve r t i c a ls emi Ｇ c on t i nuousc a s Ｇ yi t i ng― ho tr o l l i ng― c o l dr o l l i ngp r o c e s s, a ndho r i z on Ｇ [ , ] t a lc on t i nuou sc a s t i ng ― c o l dr o l l i ngp r o c e s s１０ １１ , and t hel a t t e ri sr e a r d e da st h ema i non e．Howe v e r,f o rt he g r e l a t i v e l i d es o l i d Ｇ l i i dph a s ez on eo fQSn ６ ５ Ｇ ０ １a l Ｇ yw qu on t i nuou sc a s t i ngo fi t ss l a ba lwa sha st hr e ema Ｇ l o y,c y ∗ Co r r e spond i ngau t ho r．As s o c．Pr o f． EＧma i laddr e s s: Li uxi nhua１８＠１６３c ． om (XH ． Li u) ．
o rp r ob l ems: F i r s t, abno rma ls eg r ega t i on o ft he j s l ab ma c r os cop i ccompos i t i oni sobs e r ved, t ha ti s, t hecon t en to ft i n on s l ab sur f a c ei ss i i f i c an t l gn y h i rt hant ha ti nt heco r e; Se cond, t hesur f a c e ghe l i t spoo rduet ot hef o rma t i ono fCuandSn qua yi br i t t l epha s eons l absur f a c e; Th i rd, mi c r os t ruc t ur e o fs l abf abr i c a t ed by s emi Ｇ con t i nuousc a s t i ng and t r ad i t i ona lho r i z on t a lcon t i nuousc a s t i ngi sr e l a t i ve l y coa r s eco l umna rg r a i nspe rpend i cu l a rt ot her o l l i ng [ , ] d i r e c t i on１２ １３ ．Atp r e s en t, t hema i n me t hodst or e Ｇ so l veabovep r ob l emsa r ec a r r i edou tbyhomogen i Ｇ z a t i onanne a l i ngf o ral ongt ime, mi l l i ngsur f a c eand so f t en i nganne a l i ngr epe a t ed l f o r et heco l dr o l l Ｇ ybe [ ] i ng１１ , wh i ch maket hep r oduc t i onp r oc e s sanden Ｇ e r t i ono ft i n phospho rbr onz ep l a t ei n Ｇ gyconsump c r e a s e, y i e l dr e du c e, andt hep r odu c t i onc o s timp r ov e． The r e f o r e, how t ocon t r o lt he ma c r os eg r ega t i on and mi c r os t ruc t ur eo fcon t i nuousc a s t i ngs l ab, imＧ r ovet hes u r f a c equ a l i t fs l ab, c omp a c tt hep r o c e s s p yo f l ow, andr educ et hecos to fp r oduc t i ona r eexp l o r ed by manyr e s e a r che r s．Thee f f e c to fe l e c t r omagne t i c
Re c e i ved２Novembe r２０１６; Re c e i vedi nr ev i s edf o rm１８J anua r c ep t ed６Febr ua r y２０１７; Ac y２０１７ Ava i l ab l eon l i ne１５ Ma r ch２０１７ １００６ Ｇ ７０６X/Copy r i tⓒ２０１７, Th ee d i t o r i a lo f f i c eo fJ ou r n a lo fI r ona ndS t e e lRe s e a r c h, I n t e r n a t i on a l． Pub l i s h e dbyE l s e v i e rL imi t e d．Al lr i t sr e s e r v e d． gh gh
/Journa Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１ Y ．
２７４
f i e l dapp l i edi nt hef r on to fs o l i d Ｇ l i i di n t e r f a c eon qu t he mi c r o s t ruc t u r e and me chan i c a lp r ope r t i e so f QSn６ ５a l l oys l abswa ss t ud i eddu r i ngt heho r i z on Ｇ [ ] I twa sf oundt ha texe r Ｇ t a lcon t i nuousc a s t i ng１４Ｇ１７ ． t i nge l e c t r omagne t i cf i e l di nt hes o l i d i f i c a t i onf r on t cou l dimpr ovet heun i f o rmi t ft h ec ompo s i t i on,f r a Ｇ yo g me n t a t et h ec o a r s ec o l umna rg r a i nspe r i cu l a rt o pend t hec a s t i ngd i r e c t i on, ob t a i nt hef i neequ i axedg r a i n mi c r o s t ruc t u r e, andr educ et hesu r f a c es eg r ega t i on o ft hec on t i nuousc a s t i ngs l abt os omeex t en t． [ ] a t i ng Ｇ c oo l i ng comＧ I na p r ev i ouss t udy１８ , a he b i ned mo l d ( HCCM) ho r i z on t a lc on t i nuousc a s t i ng me t hodwa sdeve l opedt os o l vet hep r ob l emsi nt he conven t i ona lho r i z on t a lc on t i nuousc a s t i ngo ft hecu Ｇ r on i cke la l l oyp i s, sucha spoo rsu r f a c equa l i t p pe y andcoa r s ec o l umna rc r t a lg r owi nga l ongr ad i a ld i Ｇ ys r e c t i on, wh i chshowedexc e l l en tc o l d wo rk i ngpe r Ｇ f o rmanc ea l ongt heax i a ld i r e c t i onandc ou l dbed i Ｇ r e c t l r o c e s s edt oal a r f o rma t i onamoun ta t yp gede [ ] r oomt empe r a t u r ewi t hou tmi l l i ngs u r f a c e１９Ｇ２３ ．HowＧ e v e r, be c aus eQSn６ ５a l l oyhad manyd i f f e r en tf e a Ｇ t ur e sc ompa r ed w i t hc up r on i c k e la l l o e t h e rt he y, wh r o c e s sc ou l dh e l os o l vet hesu r f a c equa l i t eg r e Ｇ p pt y, s t i onando t he rs e r i ousp r ob l emsi nt r ad i t i ona lcon Ｇ ga t i nuousc a s t i ngf o rQSn６ ５a l l oyne ededt obef ur Ｇ t he rs t ud i ed． The r e f o r e, QSn６ ５ Ｇ ０ １a l l oys l abswe r ef ab r i c a Ｇ , t edby HCCM ho r i z on t a lc on t i nuousc a s t i ng and t hee f f e c t so f pa r ame t e r s on t he mi c r o s t ruc t ur e, sur f a c equa l i t ompo s i t i ons eg r ega t i ono ft he y andc a l l oy we r ei nve s t i t edi nt h i ss t udy． ga
２．Exp e r imen t a lMe t hod
２ １． Expe r imen t a lma t e r i a l sande ipmen t qu QSn６ ５ Ｇ ０ １a l l oy wa sus eda st heexpe r imen t a l ma t e r i a l． I t schemi c a lc ompo s i t i on (GB/T５２３１) i s s howni nT a b l e１．As e l f Ｇ d e v e l op e d HCCM ho r i z on t a l c on t i nuou sc a s t i ngequ i twa sapp l i edt op r epa r e pmen s l abs, a ndt h es c h ema t i co ft h ee i n ti ss howni n qu pme , F i １ ． T h ed e v i c ec o n s i s t e do fa m e l t i n f u r n a c e a g g ho l d i ngf u r n a c e, a ni ndu c t i onh e a t i ngs s t emf o rhe a t Ｇ y , i ng Ｇmo l d ac o o l i ngs s t ema ndad r aw i nge i n t． y qu pme Tab l e１ Chemi c a lc ompo s i t i ono fQSn６ ５ Ｇ ０ １ (wt ％ ) Sn
Al
Zn
Ni
Fe
Pb
P
Cu
６ ０－７ ０ ０ ００２ ０ ３ ０ ２ ０ ０５ ０ ０２０ １０－０ ２５ Ba l anc e
２ ２． Expe r imen t a lpr o c e s s i ngparame t e r s Thema i np r o c e s s i ngpa r ame t e r so ft heho r i z on t a l con t i nuousc a s t i ngp r o c e s sc ons i s t edo fc a s t i ngt emＧ r a t u r e (t het empe r a t u r eme a s u r e dbyt h e rmo c oup l e pe No ５showni nF i １(a)), he a t i ng Ｇmo l dt empe r a Ｇ g t ur e (t het empe r a t ur eme a sur edbyt he rmocoup l e
１— Me l t i ngc r uc i b l e; ２, ５, ９—The rmo c oup l e; ３—S t oppe rr od; ４—Coppe rl i i d; ６— Ho l d i ngc r uc i b l e; ７—Duc t; qu ８—I nduc t i onhe a t i ngdev i c e; １０—Cr t a l l i z e r; １２—Dr awi ng ys equ i t; １３—Gr aph i t emo l d; １４—Se c onda r oo l i ngwa t e r． pmen yc I— He a t i ng Ｇmo l ds e c t i on; I I—Coo l i ng Ｇmo l ds e c t i on． (a) Schema t i co fdev i c ef o rHCCM ho r i z on t a lc on t i nuous t r uc t ur eo fHCCM． c a s t i ng; (b) S
F i １． S c h ema t i co fHCCMho r i z on t a lc on t i nuousc a s t i ngf o r g f ab r i c a t i ngc oppe ra l l oys l ab．
No ９showni nF i １(a)), coo l i ng wa t e rf l owr a t e, g c a s t i ngspe edando t he r s．S l abd r awi ngp r oc e s swa s con t r o l l edby d i f f e r en t “pu l l Ｇ s t op Ｇba ck” pe r i od i c a l d r awi ngs t em, andt hec a s t i ngspe edi st heave r Ｇ ys agespe edo fe a chc l e．Fo rexamp l e, i fones t ep yc l eng t handt imeo fpu l l i ng we r e０ ７ mmand０ ６s, r e spe c t i ve l r awi ngs t opt imewa s０ １s, ones t ep y, d l eng t handt imeo fba ckwe r e０ １mmand０ １s, r e Ｇ spe c t i ve l he spe ed wa s ４０ mm/mi n．The y, and t HCCM ho r i z on t a lcon t i nuousc a s t i ng p r oc e s s wa s us edt of abr i c a t e QSn６ ５ Ｇ ０ １ a l l oy s l ab wi t ht he c r os ss e c t i ons i z eo f７０ mm×１０ mm．Thep r oc e s s a r a m e t e r sa r es h o w n i nT a b l e２． p Tab l e２ Expe r imen t a lp r o c e s s i ngpa r ame t e r so fHCCM ho r i z on t a l c on t i nuousc a s t i ngf o rf ab r i c a t i ngQSn６ ５ Ｇ ０ １a l l oys l ab Coo l i ngwa t e rf l owo fc r t a l l i z e r/(Lh－１) ys Ca s t i ngt empe r a t ur e/° C
６００
Ca s t i ngspe ed/(mmmi n－１)
２０, ４０, ６０, ８０
He a t i ng Ｇmo l dt empe r a t ur e/° C
１２００－１２５０ １１００, １１５０, １２００
２ ３．Pe rfo rmanc et e s t i ng ands t ruc t ur echarac t e r Ｇ i za t i on (１) Sur f a c er oughne s sme a sur emen t Oneo ft het a r t so fs l abc a s t i ng wa st oob t a i n ge oduc t swi t hh i f a c equa l i t no rde rt oe l imi Ｇ pr ghsur yi
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
na t et hen e e df o rmi l l i ngs u r f a c ep r o c e s s．Th e r e f o r e,i n t h i spape r, t oeva l ua t et hesu r f a c equa l i t hesur Ｇ y, t f a c er oughne s so f QSn６ ５ Ｇ ０ １a l l oy s l ab p r epa r ed by HCCM ho r i z on t a lc on t i nuousc a s t i ng wa sana Ｇ l z edbyDek t ak１５０su r f a c ep r o f i l e r．Anave r agewa s y ob t a i neda f t e rt hr e et ime sme a s u r eme n tf o re a c hd a t a． (２) Me a s u r eme n to fme c h a n i c a lp r ope r t i e so fs l ab a tr oomt empe r a t u r e Thee l onga t i onandy i e l ds t r eng t ho ft hes l abwe r e / t e s t eda c c o r d i ngt oGB T２２８ １．Thet ens i l et e s twa s c a r r i edou tona mi c r o e l e c t r on i cun i v e r s a lt e s t i ng ma Ｇ c h i n e, a ndt h et e n s i l es e e d wa ss e tt o０ ５ mm/mi n． p Thet ens i l et e s ts amp l es i z ei si l l us t r a t edi nF i ２． g Ea ch da t um wa s me a su r ed t hr e et ime s, and t he , max imum t he mi n imum and t he ave r age va l ue s we r eg i venont hecu r ve． (３) Me t a l l og r aph i cobs e r va t i on Me t a l l og r aph i cs amp l e s we r ee t ched by f e r r i c ch l o r i dei nhyd r o ch l o r i ca c i ds o l u t i onf o r１０－１５s, wh i chwa sc ompo s edo fFeCl３(５g), HCl(１０ mL), andH２O (９０ mL) ．Thee t chedspe c imenswe r eob Ｇ s e r vedandpho t og r aphedunde raNi konEc l i eLV ps １５０ me t a l l og r aph i cmi c r o s c ope． (４) Cha r a c t e r i z a t i on o fs eg r ega t i on deg r e eo f QSn６ ５a l l oy．
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F i ２． Schema t i co ft ens i l es amp l e． g
Thecon t en to fSni nt hewho l et h i ckne s sd i r e c t i on wa sme a sur edbys e l e c t eda r e aSEMs c anana l s i s o y t cha r a c t e r i z et hes eg r ega t i ondeg r e eo fs l ab．Ea chda Ｇ t ame a sur edt hr e eva l ue sandt ookt heave r age．
３．Re s u l t sandDi s c u s s i on
３ １．Effe c tof c on t i nuou sca s t i ng parame t e r son mac r os hapeofs l ab ３ １ １．Effe c tofca s t i ngt empe ra t ur eonc on t i nu Ｇ ou sca s t i ngpr o c e s sofs l ab Ca s t i ngt empe r a t ur ewa sanimpo r t an tpa r ame t e r i n f l uenc i ngt hef o rmab i l i t ft hecon t i nuousc a s t i ng yo o fa l l oy．Thei n f l uenc eo fme l tc a s t i ngt empe r a t ur e oncon t i nuousc a s t i ngp r oc e s so fs l ab wa ss t ud i ed． F i ３showst hee f f e c to fme l tc a s t i ngt empe r a t ur e g on HCCM con t i nuousc a s t i ngp r oc e s so fs l abunde r t hes ameo t he rp r oc e s scond i t i ons．
(a) １２２０° C; (b) １２４０° C; (c) １２５０° C．
F i ３． Appe a r anc eo fQSn６ ５s l absf ab r i c a t edbyHCCM ho r i z on t a lc on t i nuousc a s t i nga tva r i ousme l tc a s t i ngt empe r a t u r e s． g
Asshowni nF i ３, a tt he me l tt empe r a t u r eo f g １２２０° C, t h eh e a t i ng Ｇmo l dt emp e r a t u r eo f１１５０° Cand t hec a s t i ngspe edo f２０mm/mi n, mi s runde f e c thap Ｇ nc on t i nuousc a s t i ngp r o c e s s, andt heedgeo f penedi r epa r ed QSn６ ５ Ｇ ０ １a l l oy s l ab wa sobv i ous l n Ｇ p yi comp l e t e．Th i swa s ma i n l aus edbytwor e a sons: yc , F i r s tb e c a u s et h epho s rb r on z ewa sat i c a lwi d e pho yp so l i d Ｇ l i i dpha s ez onea l l oy, whent heme l tc a s t i ng qu t empe r a t u r e wa sl ow, t he pa s t es o l i d Ｇ l i i d pha s e qu z onei ns o l i d i f i c a t i onf r on twa sw i d e r, a ndi t sf l u i d i t y wa spo o r, s of i l l i ng wa sno tc omp l e t e．Th es e c ondwa s r e l a t edt ot hec a s t i ng mo l ds t ruc t u r e．Mo l dc av i t f yo s l abi nt h i ss t udy wa sr e c t ang l e wi t h ar e l a t i ve l y l a r a t i oo fwi d t ht ot h i ckne s sandwi t ht het h i ckＧ ger ne s so fon l r i ngs o l i d i f i c a t i on p r o c e s s, y１０ mm．Du t hena r r ows i deo fs l abwa sc oo l edi ntwod i r e c t i ons f r omt heb r oads i deandna r r ows i deo fc r t a l l i z e r． ys Thus, t he me l tt empe r a t u r ene a rt hena r r ow s i de
wa se a s or educ ef i r s t l i ch madet hef l u i d i t yt y, wh y andf i l l i ngab i l i t o f a l l o w e a k e na n dc a u s e d t h ed e Ｇ y y f e c to fi ncomp l e t ef i l l i ng．Whent he me l tc a s t i ng t empe r a t ur ei nc r e a s ed wi t ht hes ameo t he rc a s t i ng cond i t i ons, t hec a s t i ngf o rmab i l i t ft hea l l oys l ab yo be c amebe t t e r．Asshowni nF i ３(b), whent he g me l tc a s t i ngt empe r a t ur er e a ched１２４０° C,f i l l i ngc a Ｇ c i t simp r oved, s l abf i l l i ngde f e c td i s appe a r ed pa y wa r adua l l l ab qua l i t ss i i f i c an t l g y, and s y wa gn y imＧ r oved．F i ３(c) wa st he ma c r os cop i c mo r l ogy p g pho o fcon t i nuousc a s t i ngs l aba tt he me l tc a s t i ngt emＧ r a t ur eo f１２５０° C, t het empe r a t ur eo ft hehe a t i ng Ｇ pe mo l ds e c t i ono f１１５０° Candt hec a s t i ngspe edo f２０ mm/mi n． I tcou l dbes e ent ha tt hesur f a c equa l i t f yo con t i nuousc a s t i ngs l ab wa sgood whent hec a s t i ng t empe r a t ur ewa sf ur t he ri nc r e a s edt o１２５０° C． Fr omd i s cus s edabove, unde rexpe r imen t a lcond i Ｇ t i onso fc a s t i ngt empe r a t ur eo f１２５０° C, QSn６ ５ Ｇ ０ １
２７６
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
r i oushe a t i ng Ｇmo l dt empe r a t ur e so f１１００, １１５０and １２００° C, r e spe c t i ve l t ht heme l tt empe r a t ur eo f y, wi １２５０° Candt hec a s t i ngspe edo f２０ mm/mi n．F i ４ g showst ha twhent hehe a t i ng Ｇmo l dt empe r a t ur ewa s ３ １ ２．Effe c t of hea t i ng Ｇmo ld t empe ra t ur e on １１００° C, t hes l ab hads imi l a rde f e c t st ot ha tob Ｇ , c on t i nuou sca s t i ngpr o c e s sofs l ab t a i nedi nl ow c a s t i ngt empe r a t ur econd i t i ons, i e． I no r de rt os t udyt hei n f l uenc eo ft hehe a t i ng Ｇmo l d i ncomp l e t ef i l l i ng, andt her e a sonwa sa l soba s i c a l l y s e c t i ont empe r a t u r eont hequa l i t ft hec on t i nuous s imi l a r．When t he he a t i ng Ｇmo l dt empe r a t ur ei n Ｇ yo c a s t i ngs l abo fQSn６ ５a l l oy, he a t i ng Ｇmo l ds e c t i on c r e a s edt o１１５０o r１２００° C, t hesur f a c equa l i t o y f , t empe r a t u r e wa schanged f r om １１００ t o １２００° C． c a s t i ngs l abbe c ameve r he r e we r eno ygood andt F i ４showst heQSn６ ５a l l oys l absp r epa r eda tva Ｇ obv i ousde f e c t si nt hesur f a c eo fc a s t i ngs l ab． g s l ab wi t h goodsu r f a c e qua l i t ou l d bef ab r i c a t ed yc suc c e s s f u l l r ope r l us t i ng he a t i ng Ｇmo l d y by p y ad j t empe r a t u r eandc a s t i ngspe ed．
(a) １１００° C; (b) １１５０° C; (c) １２００° C．
F i ４． Appe a r anc eo fQSn６ ５s l absf ab r i c a t edbyHCCM ho r i z on t a lc on t i nuousc a s t i nga tva r i oushe a t i ng Ｇmo l dt empe r a t u r e s． g
The r e f o r e, a tt he me l tc a s t i ng t empe r a t u r eo f １２５０° Candhe a t i ng Ｇmo l dt empe r a t u r ef r om１１５０t o １２００° C, s l abwi t hc omp l e t ef i r eandgoodsu r f a c e gu l i t ou l d bef ab r i c a t ed by HCCM c on t i nuous qua yc c a s t i ng．
３ ２．Effe c tof c on t i nuou sca s t i ng parame t e r son s ur ac er oughne s sofs l ab f
Ti n pho spho rusb r onz ea l l oy ha stwos i i f i c an t gn : f e a t ur e s onei st heex i s t enc eo fl ow me l t i ngpo i n t a l l oye l emen t s, andt heo t he ri si t sr e l a t i ve l de y wi so l i d Ｇ l i i dtwo Ｇ s ez one; f o ri ns t anc e, t het emＧ qu pha r a t u r ed i f f e r enc ebe twe ens o l i dusandl i i dusc an pe qu r e a ch１５０° C．The r e f o r e, unde rt hec ond i t i ono fd i e c a s t i ngo ro r d i na r on t i nuousc a s t i ng, t hea l l oyha s yc
s eve r edend r i t es e r e a t i onandan t i Ｇ s e r e a t i on．Thu s, g g g g t i n Ｇ r i chcoppe rpha s eo f t enappe a r sont hesur f a c eo f s l abf abr i c a t edbyt heconven t i ona lc a s t i ng, o fwh i ch t heappe a r anc el ooksl i ke g r ay po i n t s．The ma c r o f e a t ur e so ft he QSn６ ５a l l oy s l abs p r epa r edunde r d i f f e r en tp r oc e s spa r ame t e r sa r eshowni nF i ５． I t g cou l dbes e ent ha tt hesur f a c e so fs l absf abr i c a t edby HCCMcon t i nuousc a s t i ng we r esmoo t handsh i n i ng wi t hou tobv i ouss c a randa sh． I no rde rt of ur t he rcha r a c t e r i z esur f a c equa l i t f yo t heQSn６ ５a l l oys l abs, t hesur f a c er oughne s sva l Ｇ ue s (Ra) o ft hes l abspr epa r edbyd i f f e r en tcon t i nu Ｇ ousc a s t i ng p r oc e s s pa r ame t e r s we r e me a sur ed by Dek t ak１５０sur f a c ep r o f i l e r．TheRa va l uewa sanav Ｇ e r ageva l uec a l cu l a t edbyt heab s o l u t ev a l u eo fs u r f a c e
F i ５． Sur f a c emorpho l og i e so fs l abspr epa r eda the a t i ng Ｇmo l dt empe r a t ur eo f１１５０and１２００°Candc a s t i ngspe edo f g ２０ mm/mi n (a, e), ４０ mm/mi n (b, f), ６０ mm/mi n (c, g), and８０ mm/mi n (d, h) ．
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
imp l i ngsandp i t s, wh i chr e f l e c t edt heave r agef l uc Ｇ p t ua t i ono ft hesu r f a c ec on t ou rwi t h i nac e r t a i nl eng t h r ange．Thus, t hel a r rt heva l ueo fr oughne s s, t he ge r e a t e rt hedeg r e eo ff l uc t ua t i on, andt hust hesur Ｇ g f a c e wa s mo r er ough．Fr om t he p r i nc i l eo ft he p r oughne s s me a su r emen t me t hod, t he t e s tl eng t h wa sr equ i r ed, andusua l l s h o u l dn o tb el e s st h a n y twot ime so ft hena t u r a lc c l e w h i c h d e e n d e do n y p r t i cu l a rsu r f a c es t a t e．The r e f o r e, i nt h i spape r, ３ pa mm wa sus eda st hes c ant e s tl eng t handt her e su l t s a r eshowni nF i ６ wi t ht hehe a t i ng Ｇmo l dt empe r a Ｇ g
２７７
t ur eo f１２００° Candc a s t i ngspe edso f２０, ４０, ６０and ８０ mm/mi n, r e spe c t i ve l co rd i ngt ot he g r oup y．Ac con t ourcur ve s, as e to fr oughne s sva l ueda t a wa s ob t a i nedf o re a ch p r oc e s s i ngpa r ame t e r s, a sshown i nTab l e３． I twa sf oundt ha tt her oughne s so ft he uppe rsur f a c e wa ss l i t l a r rt hant ha to ft he gh yl ge l owe rsur f a c eunde rd i f f e r en tspe eds．Howeve r, sur Ｇ f a c er oughne s sva l ue swe r ea l lbe l ow０ ６μmi nt h i s s t udy, wh i chi nd i c a t edt ha tt hes l abcou l dbed i r e c t Ｇ l edf o rsubs equen tr o l l i ngde f o rma t i on wi t hou t y us mi l l i ngp r oc e s s．
F i ６． Lowe rsur f a c epr o f i l ecur ve so fs l abspr epa r eda the a t i ng Ｇmo l dt empe r a t ur eo f１２００°Candc a s t i ngspe edo f g ２０ mm/mi n (a), ４０ mm/mi n (b), ６０ mm/mi n (c), and８０ mm/mi n (d) ． Tab l e３ Roughne s so fs l absp r epa r eda tva r i ousc a s t i ngspe eds Ca s t i ngspe ed/ (mmmi n－１)
Roughne s so fuppe rsur f a c e/μm
２０
０ ３９６
６０
０ ６６３
４０ ８０
０ ４９７ ０ ３８４
Me a sur edva l ue ０ ６１３
０ ４６７
０ ３７３
０ ３８５
０ ３１４ ０ ６６３
０ ２８０ ０ ３３９
Ave r age
Roughne s so fl owe rsur f a c e/μm
０ ４９２
０ ３８７
０ ４７４
０ ３０９
０ ３６４ ０ ４６２
０ １６０ ０ ３５０
Me a sur edva l ue ０ ４１８
０ １８３
０ ２２６
０ ３５３
０ ２４７ ０ ４２３
０ ２５７ ０ ３４９
Ave r age ０ ３２９ ０ ２２１ ０ ２９６ ０ ３７４
I ti sshownf r om Tab l e３t ha t wi t ht hec a s t i ng sur f a c eo f mo l d wa suneven, t hep r o f i l eo fc a s t i ng spe edi nc r e a s i ngf r om２０t o８０mm/mi n, t hesu r f a c e mo l dsur f a c e wou l d bes t enc i l edont hesur f a c eo f r oughne s sva l ue o fs l absi nc r e a s edf r om ０ ３６４t o s l ab．Cons equen t l hei n t e rna lsur f a c eo fmo l do f Ｇ y, t ０ ４９２μm．Thesu r f a c er oughne s sva l uewa saphys i Ｇ t ende t e rmi nedt he ma c r os cop i cappe a r anc eo ft he c a lquan t i t t h a t r e f l e c t s t h ed e r e eo f s u r f a c e r o u h Ｇ c a s t i n s u r f a c e ． y g g g ne s so fs o l i d i f i ed me t a l, wh i ch wa s ma i n l n f l u Ｇ Se cond, i twa sa l sor e l a t edt ot hep r oc e s scond i Ｇ yi enc edbys eve r a lf a c t o r s． F i r s t,i twa sa f f e c t edbyt he t i onsando t he rf a c t o r sdur i ngt heso l i d i f i c a t i on．The sur f a c es t a t eo fc a s t i ngmo l d． Be c aus es l abwa sso l i d Ｇ g r e a t e rp r e s sur eandt heh i rt empe r a t ur eo ft he ghe i f i edi na mo l d, t he me t a lwa si nc l o s ec on t a c twi t h l i i d me t a l, t hebe t t e rt hef l u i d i t fl i i d me t a l qu yo qu t hemo l dsu r f a c ebe f o r es o l i d i f i c a t i on． I ft hei n t e rna l andt hef i l l i ngpe r f o rmanc e．Ononehand, be c aus eo f
２７８
/Journa Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１ Y ．
t hee f f e c to fg r av i t nho r i z on t a lc on t i nuousc a s t i ng y,i r oc e s s, t hel i i d me t a li ns o l i d Ｇ l i i di n t e r f a c e p qu qu f r on twa sa lwaysi nc l o s ec on t a c twi t ht hel owe rsur Ｇ f a c eo fmo l d wh i ch wa sa lwayspo l i shedt oal owe r r oughdeg r e e; t hus, t hel owe rsu r f a c ec ou l dhavea l owr oughne s s．Ont heo t he rhand, du r i ngs o l i d i f i c a Ｇ t i onp r o c e s s, t heuppe r me t a lg r adua l l s l i tf r o m y p t hemo l dbe c aus eo ft hes o l i d i f i c a t i onshr i nkageand be c ameaf r e esu r f a c e wh i ch a lways had a h i r ghe , r oughdeg r e e．The r e f o r e t heuppe rsu r f a c eo ft he s l abwa susua l l oughe rt hant hel owe rsu r f a c ei n yr s l abf ab r i c a t edbyho r i z on t a lc on t i nuousc a s t i ng, a s showni nTab l e３．
spe edsa r eshowni nF i ７．Fr om t hel ong i t ud i na l g s e c t i on mi c r os t ruc t ur eshowni nF i ７(a,c,e,g), g whent hec a s t i ngspe ed wa sl ow, t he wi d t ho fco Ｇ l umna rc r t a lwa sl a r l rtwog r a i ns ys ge, andon yoneo cou l dbes e eni nt hewho l es e c t i on．Wi t hi nc r e a s i ng t hec a s t i ngspe ed, g r a i n wi d t hbe c amesma l l e rand s t r a i t ne s so fc r t a lbounda r sgood．Whent he gh ys ywa c a s t i ngspe edi nc r e a s edt o８０mm/mi n, t hes t r a i h Ｇ gt ne s so fco l umna rg r a i n bounda r s i n i f i c a n t l b e y g y Ｇ c amewo r s e．Fr om t he mi c r os t ruc t ur eo fc r os ss e c Ｇ t i onshowni nF i ７ (b,d,f,h),i tcou l dbes e ent ha t g t he r ewe r eon l ewl a r r a i ns, wi t hsomesma l l yaf geg r a i nswhos es i z e swe r ed i f f e r en tf r omt hos eo fl a r g ge r a i ns, andt hei nhomogene i t fg r a i ns i z ewa sob Ｇ g yo ３ ３．Effe c tof c on t i nuou sca s t i ng parame t e r son v i ous．Ther e a sonf o rt hef o rma t i ono fsma l lg r a i ns mi c r o s t ruc t ur eofs l ab wa susua l l e l a t edt ocompe t i t i ve g r a i ng r owt hi n yr [ ] As men t i onedabove, whent he me l tt empe r a t ur e so l i d i f i c a t i on p r o c e s s２４ ．I nt he p r o c e s s o fg r a i n wa s１２５０° C, he a t i ng Ｇmo l dt empe r a t u r e wa sf r om g r owt h, t heysome t ime shadd i f f e r en tg r owt hr a t e s １１５０t o１２００° Candt hec a s t i ngspe ed wa sf r om ２０ andcompe t edwi t he a cho t he r． Fo rt hos eg r a i nswi t h t o８０ mm/mi n, QSn６ ５a l l oys l abswi t h goodsur Ｇ as l owe rg r owt hr a t e, wheni t me e t so t he rg r a i ns f a c equa l i t r eob t a i n e d．Th el ong i t ud i n a la ndc r o s s wi t hah i rg r owt hr a t e,i twou l dg r a du a l l ee l imi Ｇ y we ghe yb s e c t i onso fQSn６ ５a l l oys l abp r epa r eda tahe a t i ng Ｇ n a t e dands t opg r owi ng．The r e f o r e, pa r t i a lg r a i nwa s mo l dt empe r a t u r eo f１１５０° C and va r i ous c a s t i ng obv i ous l l l e ri ns i z eonc r os ss e c t i ons． ysma
F i ７． Mi c r os t ruc t ur e so fl ong i t ud i na landc r os ss e c t i ono fQSn６ ５a l l oys l abpr epa r eda the a t i ng Ｇmo l dt empe r a t ur eo f g １１５０° Candc a s t i ngspe edo f２０ mm/mi n (a, b), ４０ mm/mi n (c, d), ６０ mm/mi n (e, f), and８０ mm/mi n (g, h) ．
３ ４．Effe c tof c on t i nuou sca s t i ng parame t e r son s l abs egr ega t i on Seg r ega t i onc anbed i v i dedi n t o ma c r o s eg r ega t i on andmi c r o s eg r ega t i on．Thet empe r a t u r er angeo fso Ｇ ; l i d i f i c a t i ono ft i n Ｇ h o s h o rb r o n z e i s l a r e f o re x a m Ｇ p p g , l et het empe r a t u r ed i f f e r enc eo fs o l i dusandl i i Ｇ p qu [ ] duso fQSn６ ５ Ｇ ０ １c anr e a ch１５０° C２５ ．Be c aus et he t i ne l emen tha sas t r ongt e nd e n c fa n t i Ｇ s e r e a t i on, yo g g i tmake st i nc on t en ti nt hesu r f a c eo ft i nb r onz ei n Ｇ tmuch mo r et hant ha ti nt hec o r e．Ast i nc on t en t go i nt hesu r f a c ei nc r e a s e s, i ti se a s o gene r a t et i n Ｇ yt r i chha r db r i t t l epha s e, mak i ngt hes l abhaveobv i Ｇ ous l nhomogeneousc ompo s i t i onandt endt oc r a ck yi ont hesu r f a c ei nt her o l l i ngp r o c e s s．The r e f o r e, a l ongt imeun i f o rm anne a l i ngshou l dbeusua l l e Ｇ yne dedt o maket hec ompo s i t i ono fc on t i nuousc a s t i ng o fs l ab un i f o rm i nt he c onven t i ona lp r oduc t i on r oc e s so fQSn６ ５a l l oys t r i tf i r s t, andt henon Ｇ p pa l i nesu r f a c e mi l l i ngt r e a tmen tshou l dbec a r r i edou t t or emovet het i n Ｇ r i chl aye ront hesu r f a c e, andt hen
c o l d Ｇ r o l l i ngf o rmi ngc anb e ma d e, wh i c h ma r ke d l n Ｇ yi c r e a s e st hep r oc e s sf l owo fQSn６ ５a l l oys t r i p, and r e a t l educ e st hey i e l d． g yr I no rde rt oana l z et hecompos i t i ons eg r ega t i ono f y QSn６ ５a l l oy s l abf abr i c a t ed by HCCM ho r i z on t a l con t i nuousc a s t i ng, t het i ne l eme n tc on t e n to fQSn ６ ５ a l l oys l abwa sme a sur edbys e l e c t eda r e aSEM ene r Ｇ c t rumana l i si nt hea r e ao f５０μms r eon gyspe ys qua t hesur f a c eandi nt heco r eo ft hes l ab, a sshowni n F i ８and９, r e spe c t i ve l e ed i f f e r en ta r e a son gs y．Thr t hesur f a c eandi nt heco r e we r es e l e c t edandana Ｇ l z ed s epa r a t e l hen t he ave r age va l ue wa s y y and t t aken, andt heana l i sr e su l t sa r eshowni nTab l e４． ys Ass e enf r om Tab l e４, wi t ht hei nc r e a s ei nc a s t i ng spe ed, t het i ncon t en tont hesur f a c eo ft hes l abi n Ｇ c r e a s edf r om５ ５０ wt ％ t o６ ６３ wt ％ andt ha ti n t heco r echangedf r om５ ４５wt ％ t o６ ２５wt ％ a t t hehe a t i ng Ｇmo l dt empe r a t ur eo f１１５０° C．Whent he he a t i ng Ｇmo l dt empe r a t ur ewa s１２００° C, t het i ncon Ｇ t en tchangedi nt hea lmos ts imi l a rway wi t ht hei n Ｇ c r e a s ei nc a s t i ngspe ed．
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
２７９
F i ８． Schema t i co fpo s i t i ono fs e l e c t eda r e aana l s i s． y g
F i ９． Se l e c t eda r e aSEMs c animageo fsu r f a c e (a) andc o r e (b) ． g Tab l e４ Re su l t so ft i ne l emen tc on t en tbys e l e c t eda r e aSEMs c anana l s i s y He a t i ng Ｇmo l d t empe r a t ur e/° C １１５０
１２００
Ca s t i ngspe ed/ (mmmi n－１)
Ti nc on t en to fsur f a c ea r e a/ma s s％
２０
５ ５０
６０
５ ３１
４０ ８０ ２０ ４０ ６０ ８０
４ ８５ ６ ９６ ５ ０８ ４ ７４ ４ ７４ ４ ７０
Me a sur edva l ue ５ ５８
５ ４１
５ ７８
５ ８８
５ ９１ ６ ４５ ５ １８ ４ ５２ ５ ４５ ５ １７
６ １７ ６ ４９ ４ ８５ ４ ７７ ４ ３０ ５ ４１
Ti npho spho rusb r onz ewa sat i c a lan t i Ｇ s eg r ega Ｇ yp t i ona l l oy． I nt h i spape r, t os t udyt hean t i Ｇ s eg r ega Ｇ t i on phenomenon o ft hea l l oy p r epa r ed by HCCM ho r i z on t a lc on t i nuous c a s t i ng, an an t i Ｇ s eg r ega t i on coe f f i c i en twa sde f i ned, wh i ch wa sequa lt ot het i n con t en to fsu r f a c ea r e ad i v i dedbyt ha to fc o r ea r e a． Us i ngt heda t ai nTab l e４, t hean t i Ｇ s eg r ega t i onr a t i o wa sc a l cu l a t edunde rd i f f e r en tp r o c e s s pa r ame t e r s, andt her e su l t sa r el i s t edi nTab l e５． An t i Ｇ s eg r ega t i onc oe f f i c i en ti sac r i t e r i ono fan t i Ｇ s eg r ega t i on, t ha ti s, wheni twa sg r e a t e rt han１, i t c an be de t e rmi ned t ha t an t i Ｇ s eg r ega t i on happens, andt hesma l l e rt hec oe f f i c i en t, t he mo r es eve r et he an t i Ｇ s eg r ega t i on．Howe v e r, wh e na n t i Ｇ s e r e t i onco Ｇ g ga e f f i c i en ti sl e s st han１,i ti susua l l f i neda sano r Ｇ yde
Ave r age
Ti nc on t en to fc o r ea r e a/ma s s％
５ ５０
４ ９９
５ ６６
５ ４９
５ ６４ ６ ６３ ５ ０４ ４ ６８ ４ ８３ ５ ０９
６ ６７ ６ １４ ５ ４０ ５ ４８ ４ ７９ ４ ４９
Me a sur edva l ue ５ ６７
５ ６８
６ ０６
６ ５５
５ ７７ ５ ８４ ５ ２２ ５ ５１ ５ ０６ ５ ６２
６ ３０ ６ １０ ５ ２８ ５ ８３ ５ ３０ ５ １５
Ave r age ５ ４５ ６ ２５ ６ ０３ ６ ０３ ５ ３０ ５ ６１ ５ ０５ ５ ０９
Tab l e５ Ant i Ｇ segr ega t i oncoe f f i c i ento fphosphorbronz es l ab r epa r edbyHCCM ho r i z on t a lc on t i nuousc a s t i ngwi t h p d i f f e r en tpa r ame t e r s Ca s t i ng spe ed/ (mmmi n－１) ２０ ４０
６０ ８０
An t i Ｇ s eg r ega t i onc oe f f i c i en t
He a t i ng Ｇmo l d He a t i ng Ｇmo l d t empe r a t ur e１１５０° C t empe r a t ur e１２００° C １ ０１
０ ９５
０ ９４
０ ９６
０ ９０ １ １０
０ ８３ １ ００
ma ls eg r ega t i on． I tcou l dbes e enf r om Tab l e５t ha t t hes eg r ega t i oncoe f f i c i en to ft hes l absp r epa r edby HCCM ho r i z on t a lcon t i nuousc a s t i ngunde rd i f f e r en t
２８０
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
r oc e s spa r ame t e r schangedf r om０ ８t o１ １, wh i ch p i nd i c a t edt ha tt hes eg r ega t i on o fs l ab p r epa r ed by HCCM wa sno ts e r i ous, andt he r ewa snos eg r ega Ｇ t i ono rno rma ls eg r ega t i oni n mo s tc a s e． Fr omt h ei n f l u e n c eo fp r o c e s sp a r ame t e r s, t h ee f f e c t o fhe a t i ng Ｇmo l dt empe r a t u r eons eg r ega t i onwa sno t obv i ouswi t h i nt heexpe r imen t a lpa r ame t e r s．HowＧ eve r, whent hehe a t i ng Ｇmo l dt empe r a t u r e wa scon Ｇ s t an t, t hean t i Ｇ s eg r ega t i on c oe f f i c i en thad asma l l , changewi t ht hei nc r e a s eo ft hec a s t i ngspe ed and r e a cheda mi n imum and max imum a tt he c a s t i ng spe edo f４０and８０ mm/mi nr e spe c t i ve l y． Theabover e su l t sshowedt ha tt he r ewa snoobv i Ｇ ousma c r o s eg r ega t i oni nt hes l abf ab r i c a t edby HCＧ CM ho r i z on t a lc on t i nuousc a s t i ng; t hus,i tp r omi s ed t og r e a t l r t eno ravo i dhomogen i z i nganne a l i ng ysho t imei nt hesubs equen tp r o c e s s, and maket hes l ab d i r e c t l o l l edwi t hou tsu r f a c emi l l i ngt or emovet he yr s e r i ousnon Ｇ un i f o rms u r f a c el a e r, wh i c hc ou l dg r e a t l y y compa c tt hepr o c e s s e sandimp r ovet hey i e l d．
３ ５．Effe c t sof c on t i nuou sca s t i ng parame t e r son me chan i ca lpr ope r t i e sofs l ab
r e l a t edt oi t s mi c r os t ruc t ur e．As men t i onedabove, t hemi c r os t ruc t ur eo fQSn６ ５a l l oys l abp r epa r edby HCCM ho r i z on t a lcon t i nuousc a s t i ngwa saco l umna r c r t a la l ongt hecon t i nuousc a s t i ngd i r e c t i on．HowＧ ys eve r, f r om F i ７, owi ngt ot hea s t r i c a lcoo l Ｇ g ymme i ngi n t ens i t twe en uppe randl owe rsur f a c e so f y be s l abi nho r i z on t a lcon t i nuousc a s t i ngp r oc e s s, t hed i Ｇ r e c t i ono fco l umna rc r t a lo fs l abwa sno tcomp l e t e Ｇ ys , l a r a l l e l t ot h a to f c a s t i n b u th a dac e r t a i na n l e yp g g be twe ent hem．Whent hec a s t i ng spe edi nc r e a s ed, t hee f f e c to fa s t r i c a lhe a td i s s i t i onbe twe en ymme pa t heuppe randl owe rsur f a c e sde c r e a s ed, andt hust he ang l ebe twe eng r owt hd i r e c t i ono fco l umna rc r t a l ys andt hec a s t i ng d i r e c t i onbe come ssma l l e r, t heco Ｇ l umna rc r t a lwa ss t r a i t e r, andt hede f o rma t i on ys gh coo rd i na t i on wa sbe t t e rdur i ngt ens i l ede f o rma t i on, wh i chr e su l t edi nl a r rp l a s t i c i t hec a s t i ng ge y．Ast spe edi nc r e a s ed, t he g r a i ns i z e be c ame mo r e un i Ｇ f o rm, wh i chmadede f o rma t i onmo r econs i s t en tdur Ｇ i ng t het ens i l ede f o rma t i on, andt husi t wa sa l so bene f i c i a lt ot hep l a s t i c i t emen t． yenhanc
４．Conc l u s i on s
(１) QSn ６ ５ Ｇ ０ １s l abwi t hgoods u r f a c equ a l i t yand mi c r os t ruc t ur eo r i en t eda l ong t hec a s t i ng d i r e c t i on cou l dbep r epa r edby HCCM ho r i z on t a lcon t i nuous c a s t i nga tt he me l tc a s t i ngt empe r a t ur eo f１２５０° C, he a t i ng Ｇmo l dt emp e r a t u r eo f１１５０－１２００° Candc a s t i ng spe edo f２０－８０ mm/mi n．Thes l abshadgoodcomＧ b i nedp r ope r t i e s wi t hsur f a c er oughne s so f０ ２２－ ０ ５５μm, t het ens i l es t r eng t ho f２７５－３２５ MPa, t he i e l ds t r eng t ho f１２４－１５５ MPa, andt hee l onga t i on y r a t eo f４６ ６％ －５６ ３％ , wh i chimp l i edt ha tt hey cou l dbed i r e c t l r oc e s s edwi t hou tsubs equen tmi l l Ｇ yp i ngsur f a c e． (２) Thes e r i ouss eg r ega t i ono ft i ne l emen ti nt he con t i nuousc a s t i ng o fQSn６ ５a l l oycou l dbee f f e c Ｇ t i ve l l vedby HCCM ho r i z on t a lcon t i nuousc a s t Ｇ yso i ng．Ther a t i oo fSncon t en ti nt hesur f a c et ot ha ti n t heco r ewa s０ ８３－１ １０, whos eave r ageva l uewa s c l os et o１ ０, andno tobv i ous l n f l uenc edbyp r oc e s s yi r ame t e r s． pa (３) Whent hec a s t i ngspe edi nc r e a s edf r om２０t o /mi ,t ８ ０mm n h e r a i ns i z e c h a n e d l i t t l e i f t h eo t h e r g g F i １０． Me chan i c a lp r ope r t i e so fQSn６ ５a l l oys l abp r epa r ed g r oc e s spa r ame t e r swe r et hes ame．Whent hehe a t Ｇ p byHCCM ho r i z on t a lc on t i nuousc a s t i ngwi t hd i f f e r en tc a s t i ng i ng Ｇmo l dt empe r a t ur ei nc r e a s edf r om １１５０t o１２００ r ame t e r s． pa ° C, t heg r a i ns i z ewa sobv i ous l educ edandbe c ame yr I tc ou l db es e e nt h a tt h et e n s i l es t r e ng t ho fs l a bwa s mo r eun i f o rm i ft hec a s t i ng spe ed wa st hes ame． ２７５－３２５ MPa, t h ey i e l ds t r e ng t h wa s１２４－１５５ MPa Wi t h i nt her angeo ft hec a s t i ngspe eda twh i cht he andt h ee l ong a t i onwa s４６ ６％ －５６ ３％ a tt h eh e a t i ng Ｇ co l umna rg r a i ns t ruc t ur ecou l dbeob t a i ned, t heco Ｇ mo l dt empe r a t u r eo f１１５０and１２００° C．Thee l onga Ｇ l umna rg r a i ns i z ewa sma i n l n f l uenc edbyt hehe a t Ｇ yi t i oni nc r e a s eds l i t l t ht hei nc r e a s ei nt hec a s t Ｇ i ng Ｇmo l dt empe r a t ur e． gh y wi i ngspe ed, bu ta tt hes amec a s t i ngspe ed, t hee l on Ｇ Acknowl e dgmen t t i ona lmo s thadl i t t l ed i f f e r enc ewi t hhe a t i ng Ｇmo l d ga t empe r a t u r ei nc r e a s i ngf r om １１５０t o１２００° C．The Theau t ho r sa r eg r a t e f u lt ot hef i nanc i a lsuppo r t me chan i c a lpr ope r t i e so ft he ma t e r i a l we r ec l os e l r omt heNa t i ona lKeyTe chno l ogySuppo r tPr og r am y f Tens i l espe c imens we r ep r epa r edi na c c o r danc e wi t ht heCh i ne s ena t i ona ls t anda r d (GB/T ２２８ １) ． Thr e es amp l e swe r et akenf o re a chs l abunde rapa Ｇ r ame t e rby wi r e Ｇ e l e c t r odecu t t i ng．F i １ ０s h o w st h e g t ens i l eme chan i c a lp r ope r t i e so fs l absp r epa r ed wi t h d i f f e r en tc a s t i ngpa r ame t e r s．
/Journa Y ． Li ue ta l． lofI r onandSt e e lRe s ear ch, In t e rna t i ona l２４ (２０１７) ２７３－２８１
o fCh i n a (No．２０１１BAE２３B０３), t h e Na t i on a lNa t u r a l S c i e n c eFound a t i ono fCh i n a (５１５０４０２３) a ndt h eCh i n a S c ho l a r s h i c i lP r o e c t(No． ２０１５０６４６５０５５)． pCoun j
Re f e r enc e s
[１] HF．Yu a n, L．Xu, Hun a n Non f e r r ou s Me t a l s３０ (２０１４) No ３, ４６ Ｇ ４９ (i nCh i ne s e) ． [２] D H． L i u, P．Ma, WY． Cu i, Non f e r r ousMe t a l sPr o c e s s i ng４０ (２０１１) No ５, ８ Ｇ １２ (i nCh i ne s e) ． [３] H．Ka t o, M．Takama, Y． Iwa i, We a r２５４ (２００３) ５７３ Ｇ ５７８． [４] D．Ša t ov i c, L．V．Žu l sn i c a, Co r r o s．Sc i．５１ (２００９) j, V．De １５９６ Ｇ １６０３． [５] X．L i ao, F．Cao, A．Chen, Tr ans．Non f e r r ousMe t． So c．Ch i na ２２ (２０１２) １２３９ Ｇ １２４９． [６] X． L i, J H．Yang, Coppe rEng i ne e r i ng (２０１３) No ４, １１ Ｇ １５ (i n Ch i ne s e) ． [７] F．Koh l e r, T．Camp a n e l l a, S．Nak a n i s h i, Ac t a Ma t e r． ５６ (２００８) １５１９ Ｇ １５２８． [８] X．L i u, J．Luo, X．Wang, Tr ans．Non f e r r ous Me t．So c．Ch i na ２５ (２０１５) １９０１ Ｇ １９１０． [９] R , Y．Xu, J C．Mu t h i ah, J A． P f a e nd t n e r, C J．McMahonJ r． L． Ba s s a n i, Ma t e r． Sc i．Eng．A２３４ Ｇ ２３６ (１９９７) １０３３ Ｇ １０３６． [１０] R t Ｇ T． Zhou, J our na lo fAnhu iUn i ve r s i t fTe chno l ogy (Na yo ur a lSc i enc e) ２４ (２００７) No １, ２９ Ｇ ３２ (i nCh i ne s e) ． [１１] J C． Zou, Ch i naNon f e r r ousMe t a l s (２０１３) No １６, ３０ Ｇ ３２ (i n Ch i ne s e) ． [１２] J M． Xu, Phy s Ｇ Lou, C M．Hu a ng, L P． Lu, F W． Dong, HF．
[１３] [１４] [１５] [１６] [１７] [１８]
[１９] [２０] [２１] [２２] [２３] [２４] [２５]
２８１
i c a lTe s t i ngandChemi c a lAna l i sPa r tA: Phys i c a lTe s t i ng ys (２００３) No ８, ３９８ Ｇ ４００ (i nCh i ne s e) ． J P．Lu, S H．Zhang, YX．Xi n, Spe c i a lCa s t i ng & Non f e r Ｇ r ousAl l oys (２００３) No ３, ５７ Ｇ ５９ (i nCh i ne s e) ． C H．Hu i, T J．L i, WZ． J i n, J．Guo, Ra r e Me t a lMa t e r i a l s andEng i ne e r i ng３７ (２００８) ７２１ Ｇ ７２４ (i nCh i ne s e) ． T J．L i, K． J i n, X G．Zhang, Non f e r r ous Me t a l sPr o c e s s i ng (２００６) No １, １５ Ｇ １６ (i nCh i ne s e) ． X．L i, A．Ga u t r e l l e, Z M．Re n, R．Mo r e a u, Y D． gnoud, Y．Fa Zh a ng, C．Es l i ng, Ac t a Ma t e r． ６０ (２０１２) ３３２１ Ｇ ３３３２． AE．Ar e s, S F．Gue i E． Schve z ov, J． Cr t．Gr owt h jman, C ys ３１２ (２０１０) ２１５４ Ｇ ２１７０． J X．X i e, J．Me i, X H．L i u, X F．L i u, A He a t i ng Ｇ c o o l i ngComＧ b i n e dMo l d Ho r i z on t a lCon t i nuousCa s t i ng Me t hodandEqu i Ｇ p men tf o r Pr oduc t i on o f Cup r on i cke l Al l oy P i i na, pe, Ch ２０１０１０５０１４０７ ４, ２０１０． J．Me i, X H．L i u, J X．Xi e, I n t． J．Mi ne r．Me t a l l．Ma t e r． １９ (２０１２) ３３９ Ｇ ３４７． J．Me i, X H．L i u, J X．X i e, T r a n s．Non f e r r ou sMe t． So c．Ch i n a ２２ (２０１２) １４３０ Ｇ １４３９． X．Xi e, Tr ans．Non f e r r ous J．Me i, X H．L i u, YB． J i ang, J Me t． So c．Ch i na２２ (２０１２) ２５２９ Ｇ ２５３８． H．L i u, J X．Xi e, I n t． J．Mi ne r．Me t Ｇ J．Me i, YB． J i ang, X a l l．Ma t e r． １９ (２０１２) ７４８ Ｇ ７５８． i, S．Chen, J X．Xi e,i n: The１２ t hIUMRS YB． J i ang, J．Me I n t e r na t i ona lCon f e r enc ei nAs i a, Bus s an, Ko r e a, ２０１２, pp．． D．Tour r e t, A．Ka rma, Ac t a Ma t e r． ８２ (２０１５) ６４ Ｇ ８３． GP．Zhou, Z Y．L i u, S C．Yu, J．Chen, YQ．Qi u, GD． I r onS t e e lRe s． I n t． １８ (２０１１) No ２, １８ Ｇ ２３． Wang, J．