搜索
~48:~6+Vol.48No.62012 6~641—648 ACTAMETALLURGICASINICAJun.2012pp.641–648 ℄ I‘;FQ–P–T(CV US[∗uvyojzkiqpswl(WJ %g~+gE~28G~;,WJ200240)bZ{ Fe–0.25C–1.48Mn–1.20Si–1.51Ni–0.05Nb(j ,%).&HhlQ–P–T9 VW℄ns0vQ3 R‘N ‘pv Ur . ’{ Q–P–T.DQ‘HHl20 t!KvXRD5 Rn r)wt!vTEMA5,Z eV * Ær(TRIP)b vaD.q-n HHlwt!R20 t!lv&d 5 RTEMvA8, ZeDl .l h Rv20 t!Jyd(DARA)hb D{ .l( aD,&Z QeDARAb dv# , e20 t!I303 .Ærvsh.)/ 03 .,Q–P–T9 ,&d ,20 t!,20 t!Jyd(DARA)b fK#&3+TG142NR ?8AN +0412−1961(2012)06−0641−08ANEWEFFECTOFRETAINEDAUSTENITEONDUCTIL-ITYENHANCEMENTOFLOWCARBONQ–P–TSTEELWANGYing,ZHANGKe,GUOZhenghong,CHENNailu,RONGYonghuaSchoolofMaterialsScienceandEngineering,ShanghaiJiaoTongUniversity,Shanghai200240Correspondent:RONGYonghua,professor,Tel:13817568426,E-mail:yhrong@sjtu.edu.cnSupportedbyNationalNaturalScienceFoundationofChina(Nos.51031001and51071101)Manuscriptreceived2012–01–19,inrevisedform2012–03–09ABSTRACTAlowcarbonFe–0.25C–1.48Mn–1.20Si–1.51Ni–0.05Nb(massfraction,%)steelex-hibitsthecombinationofhightensilestrengthandgoodelongationaftertreatedbyanovelquenching–partitioning–tempering(Q–P–T)process.ThevariationinvolumefractionofretainedausteniteinthissteelwithstrainismeasuredbyXRD,andthedeformedtwin–typemartensiteplatesarealsoobservedbyTEM,fromwhichthetransformationinducedplasticity(TRIP)effectinthissteelisconfirmed.BasedonthemeasurementofaveragedislocationdensitiesinbothmartensiteandretainedaustenitecombinedwithTEMobservation,theeffectofdislocationabsorptionbyretainedaustenite(DARA)isfoundinthelowcarbonsteel,similartothatinthemediumcarbonsteelproposedrecently,fromwhichthegenerationconditionsofDARAeffectisproposed,andthemechanismofretainedausteniteonductilityenhancementofhighstrengthsteelisclarified.KEYWORDShighstrengthsteel,quenching–partitioning–tempering(Q–P–T)process,averagedislocationdensity,retainedaustenite,effectofdislocationabsorptionbyretainedaustenite(DARA)9f 9S7,h,^ Z d^PS _h/,P&14/(AHSSs)-Yf W(DP)/[1] W+ s(TRIP)/[2] ‘m–! (Q&P)/[3,4]q‘m–! –jm(Q–P–T)/[5,6]w L,Sd14/ }q.*GWX: ot’)w5B ^,-*E DF qp Y 51031001RE DF q XY 51071101~vypO2L,:2012–01–19,ypu)2L,:2012–03–09 Q :2!, ,1982 d,%ndDOI:10.3724/SP.J.1037.2012.000423E’ 14 w)h J ?w s.me$ 2wP&14/w℄ s op, }4 w 1 s ℄OÆ.QT’I5B ^SGWX: w_}T& ) 114 /w spF / RxwC .2003 ,~FSpeery[3,4] Rfxu/GWXwi: :‘m–! (quenching&partitioning,Q&P): ,(: LSi/^kW u‘mexuWk (Ms)Sn (Mf)℄ w ‘m (Tq),E^E(Tq ( ) )p1.(Tq ( ) ) h ,jC^I Swxum! (PT)q um,^ j&Cw uE ^VB 642! } } ~48:qvwIIm JB ’ exuW.-Q&P: WX^/w5B ^9xurS&C31 uwbW%V ^. .Speery[3] Rw |’Z(constrainedcarbonparaequilibrium,CCE)Xt m,’y eFEQ&P/mIR,S3 SfIR4ew $.9[,r.Q&P: ,Xu(w )[5].2007 Rf‘m–! –jm(quenching–partitioning–tempering,Q–P–T)i: ,4 Z$Nb,VSTiy5V#e6 IR4eSM*4ewq s, ’I|FVqwjm j eFExur TIR.atbRwp,Q–P–T: m‘m (Tq)w|?7X 1KEr.Q&P: wCCEXt m, [,Q–P–T: m1.vw‘m (Tq)Gj14 /ot X*‘m–jm(Q–T): : w31 u[7],^ Qu 1f14 /w s.Q–P–T/w5B ^p’=emÆ$xur TIRw eFSWnLdw&C u E,QmR%aw4 sw V[6−9].31 up 114 / swt ^, . J4/w stiG{ q50 1.Zackayy[10].1967 E/m RfTRIP .’.31 u-Yf + xuW,’[ LfoIIm=ew4* ℄xm,j ℄C!(,.Kf ., 1f=? aq,^ ot7Ow s.Webster[11]E1968 Rf31 u jPL(BCP) ,zjPL^{E um&p,pRE^YxuÆ$m Po1&p,S3 1f j vw d,’[ 1f/wIsS s.^vwY?,TRIP ( eEBCP ℄1. TRIP d(E ℄BI + xuW vwk ah- e.1w ℄at T .oIIm=ewJ‘y. ‘Æ$.ETRIP e vwk ℄1,31 uEoIIm/TÆ$,Sp H ’{ _b wC . ’, H ’I Fe–0.42C–1.46Mn–1.58Si–0.028Nb(kd! ,%)Q–P–T/E’)o xuS31 umw’==e &pX℄U ℄6 , S umw=e w 1 L J ,mxumw=e EoPk (Q3% ) |.;Ra1,_q=?o(12% ) ^-BIo1xumw=e .So S℄p’ $TRIP SBCP T rw.9[, H Rf31 uKz=ew , 9DARA ,zEoIIm,xumw=e=IW &R um,^ u Kz [12]. .1- 2Em Q–P–T/m SfDARA , p 50 1 RwTRIP SBCP ^w, 5i ,( t[.p#7((qs.9[, H _}f o| Q–P–T/,’I: _}j.ot31 uLdh.10%w ;[13], [T DARA p#E| Q–P–T/m e,)hxTRIP ,9 m31 uJ414 /w s i rU.1=X 5.$i $/p66Xu(w )[5] Rw14/_} X iw,7we E!(kd! ,%)9:C0.256,Si1.20,Mn1.48,Ni1.51,Nb0.053,P0.017,S0.008,Fe1d..m |wCLdG [Q–P–T/ot w4 ,)h7( OwGMs;SiG$T i_s (Fe3C)woE;MnGÆ|Ms , 1 uwB s;Nb’%G(Me7k u*\, 6E ^wQ–P–T: jmIIm TIR eF otC 4e.i $/ES/| mji vw50kgm#TI, nmN_, ^ wEM990mm×110mm×600mmww ,CG E75mm\wÆ!.E^qi Gq1200 3h, ^-95r\GKoE12mm\wGKÆ,.^GKÆ,/ÆYU53 ?2mm\w Æx &p :SGWX..$N $Gleeble3500G x t6 f(/owkW uoEw | (Ac3) MsSMf ,!#9880,395S235 .66CCE mSKoistinen–Marburger(K–M)xuW ℄ I[14]C fVXwPk‘m , _}RW wQ–P–TGWX: .|F930 w ue p 6(V#wAc3 Æ0B,~N!0E ue3E!=?e,, f u*\wILeA.-i ,ot 31 uLdwQ–P–TGWX: 9x 930 ue300s,E300 5nm‘m15s,E^E400 5nmjm3C !30s, n ‘ev.5oRax w!8A SM !#915mmS5mm,x \ 91.4mm,Rai EZwickT1–FR020TNA50x tY&p,x Raw q910−3s−1.,℄ 0(TEM)B9EJEM–2100FSJEM–2100Y&p.31 uLdw6 ED/max–2550X℄U ℄ (XRD)Y&p,.$Cu ,U 935◦—105◦,U q95◦/min. otwXRD 6 &p} ,zP;txu(α)S u(γ)bL CαSCγ,E^’IOlot31 uwu! fγ:fγ=11+IαCγIγCα(1)lm,IαSIγ!#9xuS uwu!4 .9 [6 w,Cs,!#|?200α,211α,200γ,220γS311γ V ,E^;?’=a[15,16].~6+1x:1/ sH2z Q–P–T- quga 643 ’..$TEM*} 6 =e ot ?w*} 6,m .1 w; =eD ,C6 [17]. [,.$1- 2 j$wX℄UUo!I(XLPA) [18,19]6 ’)oOxuS31 umw’==e . (ε2α)1/29xu ’=5B ,(ε2γ)1/29 u ’=5B ,ρα9xu ’==e ,ργ9 u ’==e .}5Ra !#|?25 %&pXRD6d.6dh|? uw200γ ℄Sxuw211α ℄,6d !#948◦—54◦S80◦—85◦, 0.2◦/minw q&pyU ,