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Surface Carbon Chemical States of Ion Implanted AISI 440C Martensitic Stainless Steel
JOURNALOFIRON ANDSTEELRESEARCH,INTERNATIONAL２ ０ １ ５,２ ２( ６):５ １ ３ Ｇ ５ １ ８
Su r f a c eCa r bonChemi c a lS t a t e so fI onImp l an t e dAI S I４４０C Ma r t e n s i t i cS t a i n l e s sS t e e l J i eJ IN１ ２ , Feng Ｇ b i nLIU３ , Yun ＧboCHEN２ , Ke Ｇwe iGAO１ ,
( １． Schoo lo fMa t e r i a l sSc i enc eandEng i ne e r i ng,Un i ve r s i t fSc i enc eandTe chno l ogyBe i i ng,Be i i ng１０００８３, yo j j Ch i na; ２．Ch i naAc ademyo fMa ch i ne r i enc eandTe chno l ogy,Be i i ng１００１２０,Ch i na; ３．Co l l egeo f ySc j Me chan i c a landEl e c t r i cEng i ne e r i ng,No r t hCh i naUn i ve r s i t fTe chno l ogy,Be i i ng１００１４４,Ch i na) yo j Ab s t r a c t:Ca r bona t omss eg r ega t ei nt hesu r f a c er eg i onf o rpo l i shed AI S I４４０Cs t a i n l e s ss t e e l．Af t e ri onimp l an t a Ｇ t i on,t hesu r f a c ec a r bona t omsex i s ti nd i f f e r en tf o rms．Toe l uc i da t et he i rex i s t enc e,su r f a c es t r uc t u r e sandc a r bon chemi c a ls t a t e so fun imp l an t ed,N＋ imp l an t ed,Ti＋ imp l an t edandN＋/Ti＋ c o Ｇ imp l an t eds amp l e swe r eana l z edby y XＧ r ayd i f f r a c t i on ( XRD),t r ansmi s s i one l e c t r on mi c r o s c opy ( TEM)andXＧ r aypho t oe l e c t r onspe c t r o s c opy ( XPS)． Ther e su l t si nd i c a t edt ha tva r i ouspha s e sf o rmi nt hesu r f a c eo rsubsu r f a c er eg i ona f t e ri onimp l an t a t i on,wh i l et he su r f a c et opog r aphyo ft hes amp l e sr ema i nsi n t a c t． Fo rpo l i shedun imp l an t eds amp l e,be s i de ss omeFe３Cpha s eandC Ｇ Cpha s e,CrxCy pha s edomi na t e si t ssu r f a c er eg i on．L i t t l echangeo fc a r bonchemi c a ls t a t e so c cu r sa f t e rN＋ i onimＧ l an t a t i on．Fo rTi＋ imp l an t eds amp l e,be s i de ss omeme t a loxy c a r b i depha s e s,mo s tc a r bonamo r s e sf o rm p phouspha i nsu r f a c er eg i on．Conc e r n i ngN＋/Ti＋ c o Ｇ imp l an t a t i on,CrxCy c ompounda swe l la sFe３Cpha s edomi na t e st hesu r Ｇ f a c er eg i onwh i l enoC ＧCpha s ei sf ound． I nadd i t i on,c ompa r edwi t hs i ng l e Ｇ i onimp l an t a t i on,N＋/Ti＋ c o Ｇ imp l an t a Ｇ t i onwou l di nc r e a s et hei onimp l an t a t i ondep t hs i i f i c an t l o rmedpha s e so ft hec a r bona t omsp l ayanimpo r Ｇ gn y．Thef t an tr o l ei na f f e c t i ngt hesu r f a c ep r ope r t i e so fAI S I４４０Cs t a i n l e s ss t e e l． Ke r d s:AI S I４４０Cs t e e l;c a r bons eg r ega t i on;i onimp l an t a t i on;chemi c a ls t a t e;pha s e ywo
TheAIS I４４０Cbe a r i ngs t e e li swi de l l i edi n yapp va r i ousi ndus t r i a lf i e l dsf o ri t sexc e l l en tphys i c a land chemi c a lpr ope r t i e s．Howeve r,su r f a c eandsubsu r Ｇ f a c ef a i l ur ea lwayst ake sp l a c eove ral ongt e rms e r v Ｇ [] i c e１ ．To enhanc ei t ssu r f a c e pe r f o rmanc e, many a tt r e a t Ｇ s t r eng t hen i ng me t hods,sucha ssu r f a c ehe men t s,c a rbu r i z i ngo rn i t r i d i ng,c oa t i ng,e t c ,a r e [ ] app l i ed２Ｇ５ ．Amongt h em,i onimp l a n t a t i onh a s ma ny [ ] un i ea dv an t a e sanda t t r a c t swi dea t t en t i ons６Ｇ８ ． qu g Wi t hv a r i ou si onimp l a n t a t i on s,s u r f a c eme c h a n i c a l r op e r t t i Ｇ c o r r o s i onpe r f o rmanc eo fs t a i n l e s s p yandan [ ] s t e e l swou l db eimp r o v e dt ov a r i ngd e r e e s８Ｇ１０ ．Amo ng y g t hed i ve r s eimp l an t a t i oni ons,n i t r ogeni oni sex t en Ｇ s i ve l t ud i ed． I twa sf oundt ha ta f t e rn i t r ogeni on ys imp l an t a t i on,t hef o rma t i ono fNsupe r s a t u r a t eds o l Ｇ [ [ ６] １１] i ds o l u t i ons andme t a ln i t r i de s p l ayama o rr o l e j i nimpr ov i ngt hesu r f a c ep r ope r t i e so ft hes t a i n l e s s
s t e e l s．Conc e rn i ngt he me t a li onimp l an t a t i ons,t he s t r eng t hen i ng me chan i sm c an bea t t r i bu t edt ot he so l i d so l u t i on,i n t e rme t a l l i c compounds o r amo r Ｇ [ １２, １３] , s e s ． I nadd i t i ont onewpha s e si twa s phouspha f oundi nmanyl i t e r a t ur e st ha ta t omsl i keoxygenand c a rboni nt hes amp l e swou l da c cumu l a t ei nt hesur Ｇ [ , ] f a c er eg i ona f t e ri onimp l an t a t i on１４ １５ ．Sur f a c eoxy Ｇ t oms,wh i cha r i s e ma i n l r om adso rba t e so f gena yf [ １４] , t hes amp l e s ex i s ta sme t a lox i de so roxyn i t r i de s ． I nsur f a c ec a rbona c cumu l a t i on,t houghi t sex i s t enc e wa sr eve a l edi n manyl i t e r a t ur ea f t e ri onimp l an t a Ｇ t i on,c l e a ri n t e r r e t a t i on on i t ss eg r ega t i on and p [ , , ] chemi c a ls t a t e sr ema i nsunc l e a r１２ １４ １５ ． I nt h i s wo rk,sur f a c es t ruc t ur e sand c a rbon chemi c a ls t a t e sf o r po l i shed un imp l an t ed,N＋ imＧ l an t ed,Ti＋ imp l an t edand N＋/Ti＋ co Ｇ imp l an t ed p AIS I４４０Cs amp l e swe r es t ud i edbyXＧ r ayd i f f r a c t i on
Founda t i onI t em: I t em Spons o r edbyNa t i ona lNa t ur a lSc i enc eFounda t i ono fCh i n a( ５１０７５００４);Fund i ngPr o e c tf o rAc ademi cHumanRe s our c e s j Deve l opmen ti nI ns t i t u t i onso fHi h e rL e a r n i n n d e r t h eJ u r i s d i c t i ono fBe i i ng Mun i c i a l i t PHR２０１１０７１０９);Impo r t a t i ona nd g gu j p y( Deve l opmen to fHi Ｇ c a l i be rTa l en t sPr o e c to fBe i i ng Mun i c i lI ns t i t u t i ons ( CIT&TCD２０１３０４００５) gh j j pa B i o r aphy: k i ng２００３４６＠１６３ c om; Re c e i v e dDa t e:Febr ua r J i eJ IN,Ma s t e r,Sen i o rEng i ne e r; E Ｇma i l: j j y８,２０１４ g Co r r e s i ngAu t ho r:Feng Ｇ b i nLIU,Do c t o r,As s o c i a t ePr o f e s s o r; E Ｇma i l:f b l i u＠ncu t edu cn pond
J ou r na lo fI r onandS t e e lRe s e a r ch,I n t e r na t i ona l Vo l ２２
５１４
( XRD),t r an smi s s i one l e c t r on mi c r o s c opy ( TEM)a nd XＧ r aypho t oe l e c t r onspe c t r o s c opy (XPS)．Toru l e , ou tt het empe r a t u r ee f f e c t st hes amp l e swe r ekep t a tabou t２５ ℃ du r i nga l lt heimp l an t a t i onp r o c e s s e s．
１ Exp e r imen t a l
Thechemi c a lc ompo s i t i onso fun imp l an t edAI S I ４４０Cbe a r i ngs t e e l sa r el i s t edi n Tab l e１．Fo rc on Ｇ ven i enc e,t hey we r ecu ti n t os amp l e so fϕ２０ mmi n d i ame t e rand３ mmi nt h i ckne s s．Be f o r ei onimp l an Ｇ t a t i on,a l lt hes amp l e swe r epo l i shedandc l e anedu l Ｇ t r a s on i c a l l na c e t onef o r１５ mi n． yi
C
Tab l e１ Ch emi c a lc ompo s i t i on so fun imp l an t e d AI S I４４０Cb e a r i ngs t e e l s ma s s％
０ ９６
Cr
１８
S i
０ ８
Mn
Ni
S
P
０ ７ ０ ５８ ０ ０３ ０ ０３５
Fe
Ba l anc e
Fo rcompa r i s on,f ou rs amp l e swe r ep r epa r eda s ＋ un imp l an t e d,N imp l a n t e d,T i＋ imp l a n t e da nd N＋/ T i＋ c o Ｇ imp l an t e dAI S I４４０Cs t a i n l e s ss t e e ls amp l e s． Th e s amp l e swe r eimp l a n t e du s i ngt h e me t a lv a rv a c uum po a r c (MEVVA )s ou r c eimp l an t e r．Thede t a i l edimＧ l an t a t i onpa r ame t e r sa r el i s t edi nTab l e２． p , Af t e ri onimp l an t a t i on t hesu r f a c et opog r aphy o fAIS I４４０Cs t e e lwa si nve s t i t edus i nga wh i t e Ｇ ga l i h t i n t e r f e r i n r o f i l o m e t e r ． I o nd e t hd i s t r i b u t i o n g gp p o fi onimp l an t ed AI S I４４０Cs amp l e swa si nve s t i Ｇ ga t edbyXPS． I nadd i t i on,su r f a c es t ruc t u r e sandc a r Ｇ
Tab l e２ Imp l an t a t i onpa r ame t e r sf o r imp l an t e ds amp l e s Imp l an t a t i onpa r ame t e r /Pa Ba s ep r e s sur e
/℃ Imp l an t a t i ont empe r a t ur e / Ac c e l e r a t i ngvo l t age kV /cm－２ Imp l an t edi onnumbe r / Cur r en tdens i t y mA
Va l ue
３ ０×１０－４ ２５ ８０
２×１０１７
/h Imp l an t a t i ont ime
１０ ２
bonchemi c a ls t a t e so fi onimp l an t eds amp l es u r f a c e s , we r es t ud i e di nd e t a i lbyXRD TEMandXPS．
２ Re s u l t sandDi s c u s s i on
Thesur f a c ep r o f i l e sf o rt heun imp l an t edand d i f f e r en ti onimp l an t edAIS I４４０Cs t e e ls amp l e sa r e i veni nF i １． I ti sshownt ha tt hesur f a c e so ft he g g imp l an t eds amp l ea r ekep tsmoo t hcompa r ed wi t h t ha to ft heun imp l an t edone．Thesur f a c er oughne s s o fun imp l an t eds amp l ei s７ ６８nm,wh i l et hesur f a c e r oughne s s e so ft he N＋ imp l an t ed,Ti＋ imp l an t ed ＋ ＋ and N /Ti co Ｇ imp l an t eds amp l e sa r e８ ２５,８ ３６ and８ ４４ nm,r e spe c t i ve l i ch a r es imi l a rt o y, wh , e a cho t he r bu ts l i t l a r rt hant ha to ft heun Ｇ gh yl ge imp l an t eds amp l e．Ther e su l ti scons i s t en twi t ht he [ ] r ev i ouss t udy１４ ．Howeve r,t heb l i s t e r i nggene r a Ｇ p ＋ t i ona f t e rN imp l an t a t i onduet oN ga sbubb l e sr e Ｇ [] r t edi nl i t e r a t ur e６ i sno tf oundhe r e． I tmi tbe po gh a t t r i bu t edt ot hed i f f e r en timp l an t a t i onene r i e sand g imp l an t a t i ondos e．
( a)Un imp l an t eds amp l e; ( b)N＋ imp l an t eds amp l e; ( c)Ti＋ imp l an t eds amp l e; ( d)N＋/Ti＋ c o Ｇ imp l an t eds amp l e．
F i １ Su r f a c ep r o f i l e sf o rt h eun imp l an t e dandd i f f e r en ti onimp l an t e dAI S I４４０Cs t e e ls amp l e s g
I s sue６ Su r f a c eCa r bonChemi c a lS t a t e so fI onImp l an t edAI S I４４０C Ma r t ens i t i cS t a i n l e s sS t e e l
５１５
XRDr e s u l t so ft h eun imp l a n t e d,N＋ imp l a n t e d, ＋ ＋ ＋ T i imp l an t e da nd N /T i c o Ｇ imp l a n t e d AI S I４４０C s amp l e sa r es howni nF i ２． I ti sc l e a rt ha tt he r ea r e g obv i ous ma r t ens i t e ( α ′)pe aks a ta r ound ４４ ５ °, ６３ １ °and８２ ２ °,wh i cha r ei na c c o r dwi t ht hepowＧ ( ) de rd i f f r a c t i onf i l e PDF da t aba s e．Ev i den tchange
o c cu r sa tt hepe ako fa r ound４４ ５ °a f t e rd i f f e r en ti on imp l an t a t i ons．Fo rN＋ imp l an t a t i on,t hepe aka tt he s i t i ono fa r ound４４ ５ °be c ome sev i den t l de． I t po y wi mi tbea t t r i bu t edt ot hel a t t i c ed i s t o r t i ono ft he gh ma r t ens i t epha s ei nduc edbyN＋ imp l an t a t i on． I nad Ｇ , d i t i on ano t he rpe akc l o s et ot he４４ ５ °pe akeme r Ｇ [, ] s．Ac co rd i ng t o pr ev i ous s t ud i e s６ １１ ,i ta r i s e s ge f r omt hef o rma t i ono ft hesupe r s a t u r a t eds o l i ds o l u Ｇ ＋ t i ono rcomp l ex me t a ln i t r i de s．I nc on t r a s tt oN imp l an t a t i on,no pe aksappe a ra f t e r Ti＋ imp l an t a Ｇ , t i on．Howeve rt hema r t ens i t epe aka ta r ound４４ ５ ° a l s obe come sb r oade r,wh i chc anbea s c r i bedt ot he s o l i dso l u t i onf o rmed a f t e rt i t an i um a t oms pa r t l y ＋ ＋ / t ak i ngt hep l a c eo fme t a la t oms． Fo rN Ti c o Ｇ imＧ l an t eds amp l e s,t her e su l t sa r es imi l a rt ot ho s eo f p N＋ imp l an t ed s amp l e．Ev i den t l r s a t u r a t ed y supe ma r t ens i cpha s eo r mi xed me t a ln i t r i de sappe a ra t t hesur f a c eo ft hes amp l e． F i ３s howst hecu r ve so fe l emen tc onc en t r a t i on g
F i ２ XRDpa t t e rn so fun imp l an t e d,N＋ imp l an t e d,T i＋ g ＋ ＋ imp l an t e dandN /T i c o Ｇ imp l an t e dAI S I４４０Cs t e e l s
v s． dep t hf o rt heun imp l an t edandi onimp l an t edAI Ｇ S I４４０Cs amp l e s． I ti nd i c a t e st ha tf o ra l lt hes amＧ l e s,t he r ea r el o t so foxygena t omsandc a rbona t Ｇ p omsa c cumu l a t edi nt her angeo fabou t２０ nm i n t h i ckne s s．The r e f o r e,i ti sno ti onimp l an t a t i ont ha t i nduc e st hesur f a c es eg r ega t i ono foxygenandc a rbon
( a)Un imp l an t eds amp l e; ( b)N＋ imp l an t eds amp l e; ( c)Ti＋ imp l an t eds amp l e; ( d)N＋/Ti＋ c o Ｇ imp l an t eds amp l e．
F i ３ Cu r v e so fe l emen tc onc en t r a t i onv s． d ep t hf o run imp l an t e d,N＋ ,T i＋ imp l an t e dandN＋/T i＋ c o Ｇ imp l an t e ds amp l e s g
５１６
J ou r na lo fI r onandS t e e lRe s e a r ch,I n t e r na t i ona l Vo l ２２
a t oms．Asama t t e ro ff a c t,su r f a c ea t oms eg r ega t i on a r i s e sf r omt hepo l i sh i ngp r o c e s sbe f o r ei onimp l an Ｇ , t a t i on． I nt hea t om s eg r ega t i onr eg i on t hec onc en Ｇ t r a t i onso ft heFeandCra t omsa r el owe rt hant ho s e i nt hema t r i x．F i ３( b)showst hecu r veo fe l emen t g ＋ c onc en t r a t i onv s． dep t hf o rN imp l an t eds amp l e． I t r eve a l st ha tunde rt heabove Ｇmen t i oned N＋ imp l an Ｇ t a t i oncond i t i ons,n i t r ogena t omc and i f f us ei n t ot he , s amp l ewi t ht het h i ckne s so fa r ound２８０nm wh i l e i t sh i s ta t om c onc en t r a t i onl o c a t e sa tt het h i ck Ｇ ghe ne s so fa r ound７２nm bene a t ht hesu r f a c e．Fo rTi＋ imp l an t eds amp l e,t hepo s i t i ono ft heh i s tc on Ｇ ghe c e n t r a t i ono fT ia t omi sa tt h et h i c kn e s so f２６nm,and i t simp l an t a t i ondep t hi sa r ound１００nm,bo t hmuch ＋ sha l l owe rt hant ho s eo fN a t om f o r N imp l an t ed s amp l e． I tc anbea t t r i bu t edt ot hel a r rTia t omi c ge , s i z et hant ha to fNa t om wh i chs eve r e l e t a r dsi t s yr d i f f us i oni nt hes amp l e．Fo r N＋/Ti＋ c o Ｇ imp l an t ed s amp l e s( F i ３( d)),t heh i s tc onc en t r a t i onso f g ghe Na t omandTia t om a r ea tt het h i ckne s so fa r ound ５０nm．Thet h i ckne s si ssha l l owe rt hant ha tc o r r e Ｇ spond i ngt ot heh i s tc onc en t r a t i ono fn i t r ogena t Ｇ ghe omf o rN＋ imp l an t eds amp l e,bu tde epe rt hant ha t c o r r e spond i ngt ot h eh i e s tc on c en t r a t i ono ft i t an i Ｇ gh um a t om f o r Ti＋ imp l an t ed s amp l e．No t i ng t he ＋ ＋ / , dep t ho fN Ti c o Ｇ imp l an t a t i on Ni onsex t endt o t hedep t ho fa r ound４００nm,wh i l eTii onsd i f f us et o
t hedep t ho f２００nm．Bo t ho ft hem a r ef a rbeyond t hos eo fs i ng l e Ｇ i onimp l an t a t i on． I ti nd i c a t e st ha tco Ｇ imp l an t a t i on wou l dp r obab l r omo t et hed i f f us i on yp r oc e s ss i i f i c an t l t may bea t t r i bu t edt ot he p gn y．I s t r ongi n t e r a c t i onso ft heimp l an t edi ons．Theabove r e su l t sshowedt ha tt hed i s t r i bu t i onso ft heNandTi a t omscon f o rmt ot heGaus s i and i s t r i bu t i on,wh i ch [, ] i si ncons i s t enc ewi t ht hep r ev i ousr epo r t s９ １６ ．The r e su l t so fa t omconc en t r a t i onv s． dep t hshowedt ha t c a rbon wou l da c cumu l a t ei nt he sur f a c er eg i on． Howeve r,t he r ea r enoco r r e spond i ngpha s e sonc a r Ｇ boni n XRD pa t t e rns． I t mi tbea t t r i bu t edt oi t s gh nonc r t a l l i nes t a t e so rl ow con t en t．To e l uc i da t e ys t heex i s t i ng s t a t e so fabundan tc a rbon,C １sco r e fi onimp l an t eds amp l e s we r ei nve s t i t ed spe c t r ao ga byXPS． F i ４showsC１ sco r espe c t r ao ft heun imp l an t Ｇ g ed,N＋ imp l an t ed,Ti＋ imp l an t edand N＋/Ti＋ co Ｇ imp l an t eds amp l e s．I ti sr eve a l edi nF i ４( a)t ha t g CrxCy compoundco r r e spond i ngt ot heb i nd i ngene r Ｇ f２８２ １eV domi na t e st hesur f a c er eg i ono ft he gyo l i shedun imp l an t eds amp l e．Be s i de s,some Fe３C po s ea tt heb i nd i ng ene r f２８３ ２eV and CＧC pha gy o i nd i ngene r f２８５ ８eV a l so compoundsa tt heb gyo coex i s t．Sur f a c ec a rbon s eg r ega t i on o ft he un imＧ l an t eds amp l ea r i s e sf r om t he po l i sh i ng p r oc e s s． p Thecon t i nuousshe a r i ngi nduc edf r om po l i s h i ngf r e e s
( a)Un imp l an t eds amp l e; ( b)N＋ imp l an t eds amp l e; ( c)Ti＋ imp l an t eds amp l e; ( d)N＋/Ti＋ c o Ｇ imp l an t eds amp l e．
F i ４ Su r f a c eC１ sc o r es e c t r ao fun imp l an t e d,N＋ imp l an t e d,T i＋ imp l an t e dandN＋/T i＋ c o Ｇ imp l an t e ds amp l e s g p
I s sue６ Su r f a c eCa r bonChemi c a lS t a t e so fI onImp l an t edAI S I４４０C Ma r t ens i t i cS t a i n l e s sS t e e l
t hec a rbona t omsl o c a t eda tt hei n t e r s t i t i a ll a t t i c e s i t e．The s ec a rbona t omsmoveupwa r dst ot hesu r Ｇ f a c eandi n t e r a c twi t ho t he ra t omsl i kechr omi umo r [ ] c a rbont of o rmnewpha s e s１７ ．Howeve r,un l i ket ha t o fh i a rbons t e e l s,C ＧCc ompoundsa r eno tt he ghc ma i npha s e si nt hesu r f a c er eg i ono ft hepo l i shedun Ｇ imp l an t eds amp l e．Af t e rN＋ i onimp l an t a t i on,l i t t l e changeo fc a rbonchemi c a ls t a t e so c cu r s． I ti si nd i c a Ｇ ( ) t edi nF i ４ b t ha tt hesu r f a c ec a rbona t omsma i n Ｇ g l i s ta sCrxCy c ompound,a swe l la ss omeFe３C yex s eandCＧCc ompounds．Ther e su l t sob t a i nedi n pha t h i ss t udy a r e d i f f e r en tf r om t ho s ei nl i t e r a Ｇ [ , ] t u r e s１５ １７ ．Thef o rme rp r opo s edt ha tt hes i l i c onc a r Ｇ bon i t r i de sf o rm a f t e rN＋ i onimp l an t a t i on．Howev Ｇ , e rt hel a t t e ri nd i c a t edt ha tα ＧC pha s e sf o rm a f t e r N＋ i onimp l an t a t i on．Tof u r t he rve r i f heex i s t enc e yt o ft hec a rbona t oms,su r f a c eCr２p c o r espe c t rumo f ＋ N imp l an t eds amp l e wa sa l s oi nve s t i t ed,wh i ch ga s e sa r e i sshowni nF i ５． I ti sshownt ha tCrxCy pha g t hema i nex i s t enc es t a t eo fsu r f a c echr omi uma t oms． Ther e su l t sob t a i nedf r om Cr２p c o r espe c t rumve r i Ｇ f hef i nd i ngsf r om C１ sco r espe c t rum．The r e f o r e, yt
F i ５ Su r f a c eCr２p c o r es e c t r umo fN＋ imp l an t e ds amp l e g p
５１７
i tc an be deduc ed t ha timp l an t ed n i t r ogen a t oms r e f e r en t i a l l n t e r a c twi t hi r ona t omst of o rmso l i d p yi , so l u t i ono ri r onn i t r i de r a t he rt hanbondwi t hchr o Ｇ mi um a t omsi nt hep l a c eo fc a rbona t oms．Ther e Ｇ su l t sa r econs i s t en twi t ho t he rr epo r t s,wh i chi nd i Ｇ c a t et hef o rma t i ono fNi n t e r s t i t i a lso l i dso l u t i ono r i r onn i t r i de s,bu tno tchr omi um n i t r i de sa tl ow N＋ [ ] i onimp l an t a t i ont empe r a t ur e s１８ ．I nF i ４( c),i t g , r eve a l st ha tbe s i de ssome me t a loxyc a rb i de wh i ch ha sab i nd i ngene r fa r ound２８６ ４eV,c a rbona t Ｇ gyo omsa r e ma i n l i nt h ef o r m o f C Ｇ C s t r u c t u r e sa t y ＋ b i nd i ngene r f２８５ ４eVf o rTi imp l an t eds amＧ gyo l e．Theh i e so l u t i on TEM mo r l ogyands e Ｇ p ghr pho l e c t edd i f f r a c t i onr e su l t so ft heun imp l an t edandTi＋ imp l an t eds amp l e sa r eshowni nF i ６( a)and６ gs ( b),r e spe c t i ve l I ti sshowni nF i ６( a)t ha tt he y． g sur f a c ea t omsi nt heun imp l an t eds amp l ea r equ i t ei n o rde r．TheTEM mo r l og i e so fN＋ imp l an t edand pho N＋/Ti＋ co Ｇ imp l an t eds amp l e sa r es imi l a rt ot ha to f ＋ , un imp l an t eds amp l e．Howeve r a f t e rTi imp l an t a Ｇ t i on,anamo r aye rwi t ht het h i ckne s so fs ev Ｇ phousl e r a lnanome t e r sappe a r s,a sr eve a l edi nF i ６( b)． g Ther e su l t sa r equ i t econs i s t en twi t ht ha ti nl i t e r a Ｇ [ ] t ur e１５ ,i nwh i chanamo r s ewa sa l soob Ｇ phouspha s e r vedby TEM a f t e rTi＋ imp l an t a t i on．TheCＧCa Ｇ mo r t ruc t ur e smayi n t e r r e tt heTEMr e su l t s phouss p [ ] i nt h i s wo rkandl i t e r a t ur e１３ ．I t sf o rma t i on mi t gh bea t t r i bu t edt ot hes t r ongi n t e r a c t i onsbe twe enimＧ l an t edt i t an i uma t omsandi r ono rchr omi uma t oms p i n AIS I４４０Cs amp l e s．I n t e rme t a l l i ccompoundso f ＋ Tii n Feo rCrf o rm p r e f e r en t i a l l d u r i n T i i m Ｇ y g l an t a t i on,wh i chl i be r a t ec a rbona t omst oex i s ti n p t hef o rmo famo r s e s．Conc e rn i ng N＋/Ti＋ phouspha co Ｇ imp l an t a t i on,i ti sev i den tt ha tCrxCy and Fe３C s e sdomi na t et hesur f a c er eg i on． F i ７showst he pha g Ti２p co r espe c t r ao fN＋/T i＋ c o Ｇ imp l an t e ds amp l e． I t
F i ６ Hi e s o l u t i onTEM g r aphands e l e c t e da r e ad i f f r a c t i onr e s u l t so fun imp l an t e d( a)andT i＋ imp l an t e d( b)s amp l e s g ghr
J ou r na lo fI r onandS t e e lRe s e a r ch,I n t e r na t i ona l Vo l ２２
５１８
Re f e r enc e s:
F i ７ Su r f a c eT i２p c o r es e c t r ao f g p N＋/T i＋ c o Ｇ imp l an t e ds amp l e
i suncove r edt ha tt i t an i uma t omsp r e f e rt obondwi t h , n i t r ogent of o rm t i t an i um n i t r i de s r a t he rt hani n Ｇ t e r a c t i ng wi t h me t a la t omsl i kei r ono rchr omi um． Thus,d i f f e r en tf r om Ti＋ imp l an t a t i on,noc a rbon ＋ ＋ / amo r s e sappe a rf o rN Ti c o Ｇ imp l an t ed phouspha s amp l e． I nadd i t i on,t hec onc en t r a t i onr a t i oo fFe３C ompoundi nc r e a s e sc ompa r ed wi t h s et oCrxCy c pha ＋ N imp l an t eds amp l e． I tne edst obes t ud i edf u r t he r．
３ Conc l u s i on s
( １)Compa r ed wi t hs i ng l e Ｇ i onimp l an t a t i on, ＋ ＋ N /Ti co Ｇ imp l an t a t i onf o rAI S I４４０Cs t e e lwou l d i nc r e a s et hei onimp l an t a t i ondep t h． ( ２)Ca rbons eg r ega t i ona r i s e sf r om po l i sh i ng r o c e s s,bu tno ti onimp l an t a t i on． Fo rN＋ imp l an t a Ｇ p t i on and N＋/Ti＋ c o Ｇ imp l an t a t i on,c a rbon a t oms ma i n l i s ta s CrxCy pha s e s and Fe３C pha s e s． y ex Howeve r,c a rbonamo r s e sdomi na t et he phous pha su r f a c er eg i onf o rTi＋ imp l an t edAI S I４４０Cs t e e l．
[ １] T A．Ha r r i s,MN．Ko t z a l a s,Ro l l i ngBe a r i ng Ana l i s,５ t h ys ed ,Tay l o r& Fr anc i s,New Yo rk,２００６． [ ２] L．Roga l,J．Du t k i ewi c z,Z．Szk l a r z,H．Kr awi e c,M．Ko t,S． Z imowsk i,Ma t e r．Cha r a c t． ８８ ( ２０１４)１００ Ｇ １１０． [ ３] S A．Ba r aba s,C． Se r ban,Me t a l． I n t． １６ ( ２０１１)５ Ｇ ８． [ ４] R．Kuma r,J．Al a,R． Pr aka sh,KS． Boob,J．Ghanshy Ｇ phons am,P A．Ray ada,P M．Rao l e,S．Mukhe r e e,Bu l l．Ma t e r． j j Sc i． ３４ ( ２０１１)１５３ Ｇ １５９． [ ５] A．Cz zn i ewsk i,We a r２９６ ( ２０１２)５４７ Ｇ ５５７． y [ ６] C B．Me l l o,M．Ueda,C M．Lep i ensk i,H．Reu t he r,App l． Sur f． Sc i． ２５６ ( ２００９)１４６１ Ｇ １４６５． [ ７] M．Ueda,MM． S i l va,C．Ot an i,H．Reu t he r,M．Ya t suzuka, C M．Lep i ensk i,L A．Be r n i,Sur f．Coa t．Te chno l．１６９ Ｇ １７０ ( ２００３)４０８ Ｇ ４１０． [ ngshen,B K．Pan i r ah i,UK．Muda l i,Co r Ｇ ８] N．Padhy,S．Ni g r o s． Sc i． ５２ ( ２０１０)１０４ Ｇ １１２． [ ９] F B．L i u,J D．Wang,D R．Chen,YJ．Xu,M． Zhao,Tr i bo． Tr ans． ５３ ( ２０１０)２３９ Ｇ ２４３． [ １０] B D． Sa r twe l l,P N．Na t i shan,E P．Donovan,S N． Bunke r, AJ．Armi n i,Sur f．Coa t．Te chno l． ８３ ( １９９６)１８３ Ｇ １８８． [ １１] F B．L i u,GH． Fu,Y． Cu i,QG． Sun,M．Qu,Y． Sun,Nu Ｇ c l． I ns t r um．Me t hodsPhys．Re s．B３０７ ( ２０１３)４１２ Ｇ ４１８． [ １２] E V． Lego s t a eva,YP． Sha rke ev,Tr i bo l． I n t． ３９ ( ２００６)４１７ Ｇ
４２５． [ １３] A D． Po r e bn ak,A P．Kob z e v,B P．Gr i t s e nko,S． Soko l o v,E． g j Ba z l,N V． Sv i r i d e nko,A N．Va l a e v,Y F． I vanov,J．App l． y y Phys． ８７ ( ２０００)２１４２ Ｇ ２１４８． [ １４] A．Ol o f i n a n a,T．T e s f ami c h a e l,J M． Be l l,J．Ma t e r．Pr o c e s s． j Te chno l． １６４ Ｇ １６５ ( ２００５)９０５ Ｇ ９１０． [ １５] K． Feng,X． Ca i,Z G． L i,P K． Chu,Ma t e r． Le t t． ６８ ( ２０１２) ４５０ Ｇ ４５２． [ １６] R S．Chen,HW．Ni,HS．Zhang,G．Yue,WT．Zhan, cuum８９ ( ２０１３)２４９ Ｇ ２５３． P Y．Xi ong,Va [ １７] N．Kuma r,S．Ka t a r i a,S．Da sh,S K． Sr i va s t ava,C R．Da s, a r P．Chand r amohan,AK．Tyag i,KGM．Na i r,B．Ra j,We ２７４ Ｇ ２７５ ( ２０１２)６０ Ｇ ６７． [ １８] C E． Foe r s t e r,F C． Se r bena,S L R． daS i l va,C M． Lep i en Ｇ sk i,C J． deM．S i i r a,M．Ueda,Nuc l． I ns t r um．Me t hods que Phys．Re s．B２５７ ( ２００７)７３２ Ｇ ７３６．
JOURNALOFIRON ANDSTEELRESEARCH,INTERNATIONAL２ ０ １ ５,２ ２( ６):５ １ ３ Ｇ ５ １ ８
Su r f a c eCa r bonChemi c a lS t a t e so fI onImp l an t e dAI S I４４０C Ma r t e n s i t i cS t a i n l e s sS t e e l J i eJ IN１ ２ , Feng Ｇ b i nLIU３ , Yun ＧboCHEN２ , Ke Ｇwe iGAO１ ,
( １． Schoo lo fMa t e r i a l sSc i enc eandEng i ne e r i ng,Un i ve r s i t fSc i enc eandTe chno l ogyBe i i ng,Be i i ng１０００８３, yo j j Ch i na; ２．Ch i naAc ademyo fMa ch i ne r i enc eandTe chno l ogy,Be i i ng１００１２０,Ch i na; ３．Co l l egeo f ySc j Me chan i c a landEl e c t r i cEng i ne e r i ng,No r t hCh i naUn i ve r s i t fTe chno l ogy,Be i i ng１００１４４,Ch i na) yo j Ab s t r a c t:Ca r bona t omss eg r ega t ei nt hesu r f a c er eg i onf o rpo l i shed AI S I４４０Cs t a i n l e s ss t e e l．Af t e ri onimp l an t a Ｇ t i on,t hesu r f a c ec a r bona t omsex i s ti nd i f f e r en tf o rms．Toe l uc i da t et he i rex i s t enc e,su r f a c es t r uc t u r e sandc a r bon chemi c a ls t a t e so fun imp l an t ed,N＋ imp l an t ed,Ti＋ imp l an t edandN＋/Ti＋ c o Ｇ imp l an t eds amp l e swe r eana l z edby y XＧ r ayd i f f r a c t i on ( XRD),t r ansmi s s i one l e c t r on mi c r o s c opy ( TEM)andXＧ r aypho t oe l e c t r onspe c t r o s c opy ( XPS)． Ther e su l t si nd i c a t edt ha tva r i ouspha s e sf o rmi nt hesu r f a c eo rsubsu r f a c er eg i ona f t e ri onimp l an t a t i on,wh i l et he su r f a c et opog r aphyo ft hes amp l e sr ema i nsi n t a c t． Fo rpo l i shedun imp l an t eds amp l e,be s i de ss omeFe３Cpha s eandC Ｇ Cpha s e,CrxCy pha s edomi na t e si t ssu r f a c er eg i on．L i t t l echangeo fc a r bonchemi c a ls t a t e so c cu r sa f t e rN＋ i onimＧ l an t a t i on．Fo rTi＋ imp l an t eds amp l e,be s i de ss omeme t a loxy c a r b i depha s e s,mo s tc a r bonamo r s e sf o rm p phouspha i nsu r f a c er eg i on．Conc e r n i ngN＋/Ti＋ c o Ｇ imp l an t a t i on,CrxCy c ompounda swe l la sFe３Cpha s edomi na t e st hesu r Ｇ f a c er eg i onwh i l enoC ＧCpha s ei sf ound． I nadd i t i on,c ompa r edwi t hs i ng l e Ｇ i onimp l an t a t i on,N＋/Ti＋ c o Ｇ imp l an t a Ｇ t i onwou l di nc r e a s et hei onimp l an t a t i ondep t hs i i f i c an t l o rmedpha s e so ft hec a r bona t omsp l ayanimpo r Ｇ gn y．Thef t an tr o l ei na f f e c t i ngt hesu r f a c ep r ope r t i e so fAI S I４４０Cs t a i n l e s ss t e e l． Ke r d s:AI S I４４０Cs t e e l;c a r bons eg r ega t i on;i onimp l an t a t i on;chemi c a ls t a t e;pha s e ywo
TheAIS I４４０Cbe a r i ngs t e e li swi de l l i edi n yapp va r i ousi ndus t r i a lf i e l dsf o ri t sexc e l l en tphys i c a land chemi c a lpr ope r t i e s．Howeve r,su r f a c eandsubsu r Ｇ f a c ef a i l ur ea lwayst ake sp l a c eove ral ongt e rms e r v Ｇ [] i c e１ ．To enhanc ei t ssu r f a c e pe r f o rmanc e, many a tt r e a t Ｇ s t r eng t hen i ng me t hods,sucha ssu r f a c ehe men t s,c a rbu r i z i ngo rn i t r i d i ng,c oa t i ng,e t c ,a r e [ ] app l i ed２Ｇ５ ．Amongt h em,i onimp l a n t a t i onh a s ma ny [ ] un i ea dv an t a e sanda t t r a c t swi dea t t en t i ons６Ｇ８ ． qu g Wi t hv a r i ou si onimp l a n t a t i on s,s u r f a c eme c h a n i c a l r op e r t t i Ｇ c o r r o s i onpe r f o rmanc eo fs t a i n l e s s p yandan [ ] s t e e l swou l db eimp r o v e dt ov a r i ngd e r e e s８Ｇ１０ ．Amo ng y g t hed i ve r s eimp l an t a t i oni ons,n i t r ogeni oni sex t en Ｇ s i ve l t ud i ed． I twa sf oundt ha ta f t e rn i t r ogeni on ys imp l an t a t i on,t hef o rma t i ono fNsupe r s a t u r a t eds o l Ｇ [ [ ６] １１] i ds o l u t i ons andme t a ln i t r i de s p l ayama o rr o l e j i nimpr ov i ngt hesu r f a c ep r ope r t i e so ft hes t a i n l e s s
s t e e l s．Conc e rn i ngt he me t a li onimp l an t a t i ons,t he s t r eng t hen i ng me chan i sm c an bea t t r i bu t edt ot he so l i d so l u t i on,i n t e rme t a l l i c compounds o r amo r Ｇ [ １２, １３] , s e s ． I nadd i t i ont onewpha s e si twa s phouspha f oundi nmanyl i t e r a t ur e st ha ta t omsl i keoxygenand c a rboni nt hes amp l e swou l da c cumu l a t ei nt hesur Ｇ [ , ] f a c er eg i ona f t e ri onimp l an t a t i on１４ １５ ．Sur f a c eoxy Ｇ t oms,wh i cha r i s e ma i n l r om adso rba t e so f gena yf [ １４] , t hes amp l e s ex i s ta sme t a lox i de so roxyn i t r i de s ． I nsur f a c ec a rbona c cumu l a t i on,t houghi t sex i s t enc e wa sr eve a l edi n manyl i t e r a t ur ea f t e ri onimp l an t a Ｇ t i on,c l e a ri n t e r r e t a t i on on i t ss eg r ega t i on and p [ , , ] chemi c a ls t a t e sr ema i nsunc l e a r１２ １４ １５ ． I nt h i s wo rk,sur f a c es t ruc t ur e sand c a rbon chemi c a ls t a t e sf o r po l i shed un imp l an t ed,N＋ imＧ l an t ed,Ti＋ imp l an t edand N＋/Ti＋ co Ｇ imp l an t ed p AIS I４４０Cs amp l e swe r es t ud i edbyXＧ r ayd i f f r a c t i on
Founda t i onI t em: I t em Spons o r edbyNa t i ona lNa t ur a lSc i enc eFounda t i ono fCh i n a( ５１０７５００４);Fund i ngPr o e c tf o rAc ademi cHumanRe s our c e s j Deve l opmen ti nI ns t i t u t i onso fHi h e rL e a r n i n n d e r t h eJ u r i s d i c t i ono fBe i i ng Mun i c i a l i t PHR２０１１０７１０９);Impo r t a t i ona nd g gu j p y( Deve l opmen to fHi Ｇ c a l i be rTa l en t sPr o e c to fBe i i ng Mun i c i lI ns t i t u t i ons ( CIT&TCD２０１３０４００５) gh j j pa B i o r aphy: k i ng２００３４６＠１６３ c om; Re c e i v e dDa t e:Febr ua r J i eJ IN,Ma s t e r,Sen i o rEng i ne e r; E Ｇma i l: j j y８,２０１４ g Co r r e s i ngAu t ho r:Feng Ｇ b i nLIU,Do c t o r,As s o c i a t ePr o f e s s o r; E Ｇma i l:f b l i u＠ncu t edu cn pond
J ou r na lo fI r onandS t e e lRe s e a r ch,I n t e r na t i ona l Vo l ２２
５１４
( XRD),t r an smi s s i one l e c t r on mi c r o s c opy ( TEM)a nd XＧ r aypho t oe l e c t r onspe c t r o s c opy (XPS)．Toru l e , ou tt het empe r a t u r ee f f e c t st hes amp l e swe r ekep t a tabou t２５ ℃ du r i nga l lt heimp l an t a t i onp r o c e s s e s．
１ Exp e r imen t a l
Thechemi c a lc ompo s i t i onso fun imp l an t edAI S I ４４０Cbe a r i ngs t e e l sa r el i s t edi n Tab l e１．Fo rc on Ｇ ven i enc e,t hey we r ecu ti n t os amp l e so fϕ２０ mmi n d i ame t e rand３ mmi nt h i ckne s s．Be f o r ei onimp l an Ｇ t a t i on,a l lt hes amp l e swe r epo l i shedandc l e anedu l Ｇ t r a s on i c a l l na c e t onef o r１５ mi n． yi
C
Tab l e１ Ch emi c a lc ompo s i t i on so fun imp l an t e d AI S I４４０Cb e a r i ngs t e e l s ma s s％
０ ９６
Cr
１８
S i
０ ８
Mn
Ni
S
P
０ ７ ０ ５８ ０ ０３ ０ ０３５
Fe
Ba l anc e
Fo rcompa r i s on,f ou rs amp l e swe r ep r epa r eda s ＋ un imp l an t e d,N imp l a n t e d,T i＋ imp l a n t e da nd N＋/ T i＋ c o Ｇ imp l an t e dAI S I４４０Cs t a i n l e s ss t e e ls amp l e s． Th e s amp l e swe r eimp l a n t e du s i ngt h e me t a lv a rv a c uum po a r c (MEVVA )s ou r c eimp l an t e r．Thede t a i l edimＧ l an t a t i onpa r ame t e r sa r el i s t edi nTab l e２． p , Af t e ri onimp l an t a t i on t hesu r f a c et opog r aphy o fAIS I４４０Cs t e e lwa si nve s t i t edus i nga wh i t e Ｇ ga l i h t i n t e r f e r i n r o f i l o m e t e r ． I o nd e t hd i s t r i b u t i o n g gp p o fi onimp l an t ed AI S I４４０Cs amp l e swa si nve s t i Ｇ ga t edbyXPS． I nadd i t i on,su r f a c es t ruc t u r e sandc a r Ｇ
Tab l e２ Imp l an t a t i onpa r ame t e r sf o r imp l an t e ds amp l e s Imp l an t a t i onpa r ame t e r /Pa Ba s ep r e s sur e
/℃ Imp l an t a t i ont empe r a t ur e / Ac c e l e r a t i ngvo l t age kV /cm－２ Imp l an t edi onnumbe r / Cur r en tdens i t y mA
Va l ue
３ ０×１０－４ ２５ ８０
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/h Imp l an t a t i ont ime
１０ ２
bonchemi c a ls t a t e so fi onimp l an t eds amp l es u r f a c e s , we r es t ud i e di nd e t a i lbyXRD TEMandXPS．
２ Re s u l t sandDi s c u s s i on
Thesur f a c ep r o f i l e sf o rt heun imp l an t edand d i f f e r en ti onimp l an t edAIS I４４０Cs t e e ls amp l e sa r e i veni nF i １． I ti sshownt ha tt hesur f a c e so ft he g g imp l an t eds amp l ea r ekep tsmoo t hcompa r ed wi t h t ha to ft heun imp l an t edone．Thesur f a c er oughne s s o fun imp l an t eds amp l ei s７ ６８nm,wh i l et hesur f a c e r oughne s s e so ft he N＋ imp l an t ed,Ti＋ imp l an t ed ＋ ＋ and N /Ti co Ｇ imp l an t eds amp l e sa r e８ ２５,８ ３６ and８ ４４ nm,r e spe c t i ve l i ch a r es imi l a rt o y, wh , e a cho t he r bu ts l i t l a r rt hant ha to ft heun Ｇ gh yl ge imp l an t eds amp l e．Ther e su l ti scons i s t en twi t ht he [ ] r ev i ouss t udy１４ ．Howeve r,t heb l i s t e r i nggene r a Ｇ p ＋ t i ona f t e rN imp l an t a t i onduet oN ga sbubb l e sr e Ｇ [] r t edi nl i t e r a t ur e６ i sno tf oundhe r e． I tmi tbe po gh a t t r i bu t edt ot hed i f f e r en timp l an t a t i onene r i e sand g imp l an t a t i ondos e．
( a)Un imp l an t eds amp l e; ( b)N＋ imp l an t eds amp l e; ( c)Ti＋ imp l an t eds amp l e; ( d)N＋/Ti＋ c o Ｇ imp l an t eds amp l e．
F i １ Su r f a c ep r o f i l e sf o rt h eun imp l an t e dandd i f f e r en ti onimp l an t e dAI S I４４０Cs t e e ls amp l e s g
I s sue６ Su r f a c eCa r bonChemi c a lS t a t e so fI onImp l an t edAI S I４４０C Ma r t ens i t i cS t a i n l e s sS t e e l
５１５
XRDr e s u l t so ft h eun imp l a n t e d,N＋ imp l a n t e d, ＋ ＋ ＋ T i imp l an t e da nd N /T i c o Ｇ imp l a n t e d AI S I４４０C s amp l e sa r es howni nF i ２． I ti sc l e a rt ha tt he r ea r e g obv i ous ma r t ens i t e ( α ′)pe aks a ta r ound ４４ ５ °, ６３ １ °and８２ ２ °,wh i cha r ei na c c o r dwi t ht hepowＧ ( ) de rd i f f r a c t i onf i l e PDF da t aba s e．Ev i den tchange
o c cu r sa tt hepe ako fa r ound４４ ５ °a f t e rd i f f e r en ti on imp l an t a t i ons．Fo rN＋ imp l an t a t i on,t hepe aka tt he s i t i ono fa r ound４４ ５ °be c ome sev i den t l de． I t po y wi mi tbea t t r i bu t edt ot hel a t t i c ed i s t o r t i ono ft he gh ma r t ens i t epha s ei nduc edbyN＋ imp l an t a t i on． I nad Ｇ , d i t i on ano t he rpe akc l o s et ot he４４ ５ °pe akeme r Ｇ [, ] s．Ac co rd i ng t o pr ev i ous s t ud i e s６ １１ ,i ta r i s e s ge f r omt hef o rma t i ono ft hesupe r s a t u r a t eds o l i ds o l u Ｇ ＋ t i ono rcomp l ex me t a ln i t r i de s．I nc on t r a s tt oN imp l an t a t i on,no pe aksappe a ra f t e r Ti＋ imp l an t a Ｇ , t i on．Howeve rt hema r t ens i t epe aka ta r ound４４ ５ ° a l s obe come sb r oade r,wh i chc anbea s c r i bedt ot he s o l i dso l u t i onf o rmed a f t e rt i t an i um a t oms pa r t l y ＋ ＋ / t ak i ngt hep l a c eo fme t a la t oms． Fo rN Ti c o Ｇ imＧ l an t eds amp l e s,t her e su l t sa r es imi l a rt ot ho s eo f p N＋ imp l an t ed s amp l e．Ev i den t l r s a t u r a t ed y supe ma r t ens i cpha s eo r mi xed me t a ln i t r i de sappe a ra t t hesur f a c eo ft hes amp l e． F i ３s howst hecu r ve so fe l emen tc onc en t r a t i on g
F i ２ XRDpa t t e rn so fun imp l an t e d,N＋ imp l an t e d,T i＋ g ＋ ＋ imp l an t e dandN /T i c o Ｇ imp l an t e dAI S I４４０Cs t e e l s
v s． dep t hf o rt heun imp l an t edandi onimp l an t edAI Ｇ S I４４０Cs amp l e s． I ti nd i c a t e st ha tf o ra l lt hes amＧ l e s,t he r ea r el o t so foxygena t omsandc a rbona t Ｇ p omsa c cumu l a t edi nt her angeo fabou t２０ nm i n t h i ckne s s．The r e f o r e,i ti sno ti onimp l an t a t i ont ha t i nduc e st hesur f a c es eg r ega t i ono foxygenandc a rbon
( a)Un imp l an t eds amp l e; ( b)N＋ imp l an t eds amp l e; ( c)Ti＋ imp l an t eds amp l e; ( d)N＋/Ti＋ c o Ｇ imp l an t eds amp l e．
F i ３ Cu r v e so fe l emen tc onc en t r a t i onv s． d ep t hf o run imp l an t e d,N＋ ,T i＋ imp l an t e dandN＋/T i＋ c o Ｇ imp l an t e ds amp l e s g
５１６
J ou r na lo fI r onandS t e e lRe s e a r ch,I n t e r na t i ona l Vo l ２２
a t oms．Asama t t e ro ff a c t,su r f a c ea t oms eg r ega t i on a r i s e sf r omt hepo l i sh i ngp r o c e s sbe f o r ei onimp l an Ｇ , t a t i on． I nt hea t om s eg r ega t i onr eg i on t hec onc en Ｇ t r a t i onso ft heFeandCra t omsa r el owe rt hant ho s e i nt hema t r i x．F i ３( b)showst hecu r veo fe l emen t g ＋ c onc en t r a t i onv s． dep t hf o rN imp l an t eds amp l e． I t r eve a l st ha tunde rt heabove Ｇmen t i oned N＋ imp l an Ｇ t a t i oncond i t i ons,n i t r ogena t omc and i f f us ei n t ot he , s amp l ewi t ht het h i ckne s so fa r ound２８０nm wh i l e i t sh i s ta t om c onc en t r a t i onl o c a t e sa tt het h i ck Ｇ ghe ne s so fa r ound７２nm bene a t ht hesu r f a c e．Fo rTi＋ imp l an t eds amp l e,t hepo s i t i ono ft heh i s tc on Ｇ ghe c e n t r a t i ono fT ia t omi sa tt h et h i c kn e s so f２６nm,and i t simp l an t a t i ondep t hi sa r ound１００nm,bo t hmuch ＋ sha l l owe rt hant ho s eo fN a t om f o r N imp l an t ed s amp l e． I tc anbea t t r i bu t edt ot hel a r rTia t omi c ge , s i z et hant ha to fNa t om wh i chs eve r e l e t a r dsi t s yr d i f f us i oni nt hes amp l e．Fo r N＋/Ti＋ c o Ｇ imp l an t ed s amp l e s( F i ３( d)),t heh i s tc onc en t r a t i onso f g ghe Na t omandTia t om a r ea tt het h i ckne s so fa r ound ５０nm．Thet h i ckne s si ssha l l owe rt hant ha tc o r r e Ｇ spond i ngt ot heh i s tc onc en t r a t i ono fn i t r ogena t Ｇ ghe omf o rN＋ imp l an t eds amp l e,bu tde epe rt hant ha t c o r r e spond i ngt ot h eh i e s tc on c en t r a t i ono ft i t an i Ｇ gh um a t om f o r Ti＋ imp l an t ed s amp l e．No t i ng t he ＋ ＋ / , dep t ho fN Ti c o Ｇ imp l an t a t i on Ni onsex t endt o t hedep t ho fa r ound４００nm,wh i l eTii onsd i f f us et o
t hedep t ho f２００nm．Bo t ho ft hem a r ef a rbeyond t hos eo fs i ng l e Ｇ i onimp l an t a t i on． I ti nd i c a t e st ha tco Ｇ imp l an t a t i on wou l dp r obab l r omo t et hed i f f us i on yp r oc e s ss i i f i c an t l t may bea t t r i bu t edt ot he p gn y．I s t r ongi n t e r a c t i onso ft heimp l an t edi ons．Theabove r e su l t sshowedt ha tt hed i s t r i bu t i onso ft heNandTi a t omscon f o rmt ot heGaus s i and i s t r i bu t i on,wh i ch [, ] i si ncons i s t enc ewi t ht hep r ev i ousr epo r t s９ １６ ．The r e su l t so fa t omconc en t r a t i onv s． dep t hshowedt ha t c a rbon wou l da c cumu l a t ei nt he sur f a c er eg i on． Howeve r,t he r ea r enoco r r e spond i ngpha s e sonc a r Ｇ boni n XRD pa t t e rns． I t mi tbea t t r i bu t edt oi t s gh nonc r t a l l i nes t a t e so rl ow con t en t．To e l uc i da t e ys t heex i s t i ng s t a t e so fabundan tc a rbon,C １sco r e fi onimp l an t eds amp l e s we r ei nve s t i t ed spe c t r ao ga byXPS． F i ４showsC１ sco r espe c t r ao ft heun imp l an t Ｇ g ed,N＋ imp l an t ed,Ti＋ imp l an t edand N＋/Ti＋ co Ｇ imp l an t eds amp l e s．I ti sr eve a l edi nF i ４( a)t ha t g CrxCy compoundco r r e spond i ngt ot heb i nd i ngene r Ｇ f２８２ １eV domi na t e st hesur f a c er eg i ono ft he gyo l i shedun imp l an t eds amp l e．Be s i de s,some Fe３C po s ea tt heb i nd i ng ene r f２８３ ２eV and CＧC pha gy o i nd i ngene r f２８５ ８eV a l so compoundsa tt heb gyo coex i s t．Sur f a c ec a rbon s eg r ega t i on o ft he un imＧ l an t eds amp l ea r i s e sf r om t he po l i sh i ng p r oc e s s． p Thecon t i nuousshe a r i ngi nduc edf r om po l i s h i ngf r e e s
( a)Un imp l an t eds amp l e; ( b)N＋ imp l an t eds amp l e; ( c)Ti＋ imp l an t eds amp l e; ( d)N＋/Ti＋ c o Ｇ imp l an t eds amp l e．
F i ４ Su r f a c eC１ sc o r es e c t r ao fun imp l an t e d,N＋ imp l an t e d,T i＋ imp l an t e dandN＋/T i＋ c o Ｇ imp l an t e ds amp l e s g p
I s sue６ Su r f a c eCa r bonChemi c a lS t a t e so fI onImp l an t edAI S I４４０C Ma r t ens i t i cS t a i n l e s sS t e e l
t hec a rbona t omsl o c a t eda tt hei n t e r s t i t i a ll a t t i c e s i t e．The s ec a rbona t omsmoveupwa r dst ot hesu r Ｇ f a c eandi n t e r a c twi t ho t he ra t omsl i kechr omi umo r [ ] c a rbont of o rmnewpha s e s１７ ．Howeve r,un l i ket ha t o fh i a rbons t e e l s,C ＧCc ompoundsa r eno tt he ghc ma i npha s e si nt hesu r f a c er eg i ono ft hepo l i shedun Ｇ imp l an t eds amp l e．Af t e rN＋ i onimp l an t a t i on,l i t t l e changeo fc a rbonchemi c a ls t a t e so c cu r s． I ti si nd i c a Ｇ ( ) t edi nF i ４ b t ha tt hesu r f a c ec a rbona t omsma i n Ｇ g l i s ta sCrxCy c ompound,a swe l la ss omeFe３C yex s eandCＧCc ompounds．Ther e su l t sob t a i nedi n pha t h i ss t udy a r e d i f f e r en tf r om t ho s ei nl i t e r a Ｇ [ , ] t u r e s１５ １７ ．Thef o rme rp r opo s edt ha tt hes i l i c onc a r Ｇ bon i t r i de sf o rm a f t e rN＋ i onimp l an t a t i on．Howev Ｇ , e rt hel a t t e ri nd i c a t edt ha tα ＧC pha s e sf o rm a f t e r N＋ i onimp l an t a t i on．Tof u r t he rve r i f heex i s t enc e yt o ft hec a rbona t oms,su r f a c eCr２p c o r espe c t rumo f ＋ N imp l an t eds amp l e wa sa l s oi nve s t i t ed,wh i ch ga s e sa r e i sshowni nF i ５． I ti sshownt ha tCrxCy pha g t hema i nex i s t enc es t a t eo fsu r f a c echr omi uma t oms． Ther e su l t sob t a i nedf r om Cr２p c o r espe c t rumve r i Ｇ f hef i nd i ngsf r om C１ sco r espe c t rum．The r e f o r e, yt
F i ５ Su r f a c eCr２p c o r es e c t r umo fN＋ imp l an t e ds amp l e g p
５１７
i tc an be deduc ed t ha timp l an t ed n i t r ogen a t oms r e f e r en t i a l l n t e r a c twi t hi r ona t omst of o rmso l i d p yi , so l u t i ono ri r onn i t r i de r a t he rt hanbondwi t hchr o Ｇ mi um a t omsi nt hep l a c eo fc a rbona t oms．Ther e Ｇ su l t sa r econs i s t en twi t ho t he rr epo r t s,wh i chi nd i Ｇ c a t et hef o rma t i ono fNi n t e r s t i t i a lso l i dso l u t i ono r i r onn i t r i de s,bu tno tchr omi um n i t r i de sa tl ow N＋ [ ] i onimp l an t a t i ont empe r a t ur e s１８ ．I nF i ４( c),i t g , r eve a l st ha tbe s i de ssome me t a loxyc a rb i de wh i ch ha sab i nd i ngene r fa r ound２８６ ４eV,c a rbona t Ｇ gyo omsa r e ma i n l i nt h ef o r m o f C Ｇ C s t r u c t u r e sa t y ＋ b i nd i ngene r f２８５ ４eVf o rTi imp l an t eds amＧ gyo l e．Theh i e so l u t i on TEM mo r l ogyands e Ｇ p ghr pho l e c t edd i f f r a c t i onr e su l t so ft heun imp l an t edandTi＋ imp l an t eds amp l e sa r eshowni nF i ６( a)and６ gs ( b),r e spe c t i ve l I ti sshowni nF i ６( a)t ha tt he y． g sur f a c ea t omsi nt heun imp l an t eds amp l ea r equ i t ei n o rde r．TheTEM mo r l og i e so fN＋ imp l an t edand pho N＋/Ti＋ co Ｇ imp l an t eds amp l e sa r es imi l a rt ot ha to f ＋ , un imp l an t eds amp l e．Howeve r a f t e rTi imp l an t a Ｇ t i on,anamo r aye rwi t ht het h i ckne s so fs ev Ｇ phousl e r a lnanome t e r sappe a r s,a sr eve a l edi nF i ６( b)． g Ther e su l t sa r equ i t econs i s t en twi t ht ha ti nl i t e r a Ｇ [ ] t ur e１５ ,i nwh i chanamo r s ewa sa l soob Ｇ phouspha s e r vedby TEM a f t e rTi＋ imp l an t a t i on．TheCＧCa Ｇ mo r t ruc t ur e smayi n t e r r e tt heTEMr e su l t s phouss p [ ] i nt h i s wo rkandl i t e r a t ur e１３ ．I t sf o rma t i on mi t gh bea t t r i bu t edt ot hes t r ongi n t e r a c t i onsbe twe enimＧ l an t edt i t an i uma t omsandi r ono rchr omi uma t oms p i n AIS I４４０Cs amp l e s．I n t e rme t a l l i ccompoundso f ＋ Tii n Feo rCrf o rm p r e f e r en t i a l l d u r i n T i i m Ｇ y g l an t a t i on,wh i chl i be r a t ec a rbona t omst oex i s ti n p t hef o rmo famo r s e s．Conc e rn i ng N＋/Ti＋ phouspha co Ｇ imp l an t a t i on,i ti sev i den tt ha tCrxCy and Fe３C s e sdomi na t et hesur f a c er eg i on． F i ７showst he pha g Ti２p co r espe c t r ao fN＋/T i＋ c o Ｇ imp l an t e ds amp l e． I t
F i ６ Hi e s o l u t i onTEM g r aphands e l e c t e da r e ad i f f r a c t i onr e s u l t so fun imp l an t e d( a)andT i＋ imp l an t e d( b)s amp l e s g ghr
J ou r na lo fI r onandS t e e lRe s e a r ch,I n t e r na t i ona l Vo l ２２
５１８
Re f e r enc e s:
F i ７ Su r f a c eT i２p c o r es e c t r ao f g p N＋/T i＋ c o Ｇ imp l an t e ds amp l e
i suncove r edt ha tt i t an i uma t omsp r e f e rt obondwi t h , n i t r ogent of o rm t i t an i um n i t r i de s r a t he rt hani n Ｇ t e r a c t i ng wi t h me t a la t omsl i kei r ono rchr omi um． Thus,d i f f e r en tf r om Ti＋ imp l an t a t i on,noc a rbon ＋ ＋ / amo r s e sappe a rf o rN Ti c o Ｇ imp l an t ed phouspha s amp l e． I nadd i t i on,t hec onc en t r a t i onr a t i oo fFe３C ompoundi nc r e a s e sc ompa r ed wi t h s et oCrxCy c pha ＋ N imp l an t eds amp l e． I tne edst obes t ud i edf u r t he r．
３ Conc l u s i on s
( １)Compa r ed wi t hs i ng l e Ｇ i onimp l an t a t i on, ＋ ＋ N /Ti co Ｇ imp l an t a t i onf o rAI S I４４０Cs t e e lwou l d i nc r e a s et hei onimp l an t a t i ondep t h． ( ２)Ca rbons eg r ega t i ona r i s e sf r om po l i sh i ng r o c e s s,bu tno ti onimp l an t a t i on． Fo rN＋ imp l an t a Ｇ p t i on and N＋/Ti＋ c o Ｇ imp l an t a t i on,c a rbon a t oms ma i n l i s ta s CrxCy pha s e s and Fe３C pha s e s． y ex Howeve r,c a rbonamo r s e sdomi na t et he phous pha su r f a c er eg i onf o rTi＋ imp l an t edAI S I４４０Cs t e e l．
[ １] T A．Ha r r i s,MN．Ko t z a l a s,Ro l l i ngBe a r i ng Ana l i s,５ t h ys ed ,Tay l o r& Fr anc i s,New Yo rk,２００６． [ ２] L．Roga l,J．Du t k i ewi c z,Z．Szk l a r z,H．Kr awi e c,M．Ko t,S． Z imowsk i,Ma t e r．Cha r a c t． ８８ ( ２０１４)１００ Ｇ １１０． [ ３] S A．Ba r aba s,C． Se r ban,Me t a l． I n t． １６ ( ２０１１)５ Ｇ ８． [ ４] R．Kuma r,J．Al a,R． Pr aka sh,KS． Boob,J．Ghanshy Ｇ phons am,P A．Ray ada,P M．Rao l e,S．Mukhe r e e,Bu l l．Ma t e r． j j Sc i． ３４ ( ２０１１)１５３ Ｇ １５９． [ ５] A．Cz zn i ewsk i,We a r２９６ ( ２０１２)５４７ Ｇ ５５７． y [ ６] C B．Me l l o,M．Ueda,C M．Lep i ensk i,H．Reu t he r,App l． Sur f． Sc i． ２５６ ( ２００９)１４６１ Ｇ １４６５． [ ７] M．Ueda,MM． S i l va,C．Ot an i,H．Reu t he r,M．Ya t suzuka, C M．Lep i ensk i,L A．Be r n i,Sur f．Coa t．Te chno l．１６９ Ｇ １７０ ( ２００３)４０８ Ｇ ４１０． [ ngshen,B K．Pan i r ah i,UK．Muda l i,Co r Ｇ ８] N．Padhy,S．Ni g r o s． Sc i． ５２ ( ２０１０)１０４ Ｇ １１２． [ ９] F B．L i u,J D．Wang,D R．Chen,YJ．Xu,M． Zhao,Tr i bo． Tr ans． ５３ ( ２０１０)２３９ Ｇ ２４３． [ １０] B D． Sa r twe l l,P N．Na t i shan,E P．Donovan,S N． Bunke r, AJ．Armi n i,Sur f．Coa t．Te chno l． ８３ ( １９９６)１８３ Ｇ １８８． [ １１] F B．L i u,GH． Fu,Y． Cu i,QG． Sun,M．Qu,Y． Sun,Nu Ｇ c l． I ns t r um．Me t hodsPhys．Re s．B３０７ ( ２０１３)４１２ Ｇ ４１８． [ １２] E V． Lego s t a eva,YP． Sha rke ev,Tr i bo l． I n t． ３９ ( ２００６)４１７ Ｇ
４２５． [ １３] A D． Po r e bn ak,A P．Kob z e v,B P．Gr i t s e nko,S． Soko l o v,E． g j Ba z l,N V． Sv i r i d e nko,A N．Va l a e v,Y F． I vanov,J．App l． y y Phys． ８７ ( ２０００)２１４２ Ｇ ２１４８． [ １４] A．Ol o f i n a n a,T．T e s f ami c h a e l,J M． Be l l,J．Ma t e r．Pr o c e s s． j Te chno l． １６４ Ｇ １６５ ( ２００５)９０５ Ｇ ９１０． [ １５] K． Feng,X． Ca i,Z G． L i,P K． Chu,Ma t e r． Le t t． ６８ ( ２０１２) ４５０ Ｇ ４５２． [ １６] R S．Chen,HW．Ni,HS．Zhang,G．Yue,WT．Zhan, cuum８９ ( ２０１３)２４９ Ｇ ２５３． P Y．Xi ong,Va [ １７] N．Kuma r,S．Ka t a r i a,S．Da sh,S K． Sr i va s t ava,C R．Da s, a r P．Chand r amohan,AK．Tyag i,KGM．Na i r,B．Ra j,We ２７４ Ｇ ２７５ ( ２０１２)６０ Ｇ ６７． [ １８] C E． Foe r s t e r,F C． Se r bena,S L R． daS i l va,C M． Lep i en Ｇ sk i,C J． deM．S i i r a,M．Ueda,Nuc l． I ns t r um．Me t hods que Phys．Re s．B２５７ ( ２００７)７３２ Ｇ ７３６．