Vol,23 No.3 李龙飞等：低碳钢铁素体相区变形特性 ·229· wstresses of strain-stress curves gradually increases to a peak followed by a strain softening and then a steady state at high strain,indicating that dynamic recovery or dynamic recrystallization occurs in the steel.The slow- er the strain rate,and/or the higher the deformation temperature,the smaller the strain corresponding to the peak stress.The hot deformation activation energy (of the steel tested is calculated to be 300.4 kJ/mol from the values of Zener-Hollomon parameters and peak stresses. KEY WORDS Low carbon steel;Zener-Hollomon parameter;ferrite;hot deformation;activation energy 米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米米 Corrosion Fatigue Behavior of Duplex Stainless Steel in 3.5%Sodium Chlor- ide Solution Abubakir S H,WU Yinshun,DING Baofeng,LI Jiuqing,CAO Bei Material Science and Engineering School,University of Science and Technology Beijing,Beijing 100083,China Abstract:The corrosion fatigue behavior of duplex stainless steel (DSS)was studied at different cyclic stress levels in 3.5%NaCl (mass fraction,so as the follows)solution(pH=7)at 50C.The results showed that DSS was susceptible to pitting corrosion and corrosion fatigue.Both intergranluar corrosion cracking and transgranlular corrosion cracking initiated at the bottom of pitting ho- les.Furthermore,the corrosion fatigue properties of DSS in 3.5%NaCl solution may be relatived to complex electrochemical and mechanical coupling effects between the three phases(austenite,ferrite and martensite),where martensite and ferrite were anodic in the corrosion cell and could be prone to cracking under certain condition. Key words:corrosion fatigue;duplex stainless steel;sodium chloride solution [From Journal of University of Science and Technology Beijing,2001,8(2):133] Behavior of Non-metallic Inclusions in Centrifugal Induction Electroslag Castings CHEN Xichun,FU Jie,ZHOU Deguang,XU Weiguo Metallurgy School,University of Science and Technology Beijing,Beijing 100083,China Abstract:In order to know the behavior of non-metallic inclusions in centrifugal induction electroslag castings(CIESC),non- metallic inclusions in 5CrMnMo and 4Cr5MoSiVl were qualitatively and quantitatively analyzed.The largest size of inclusions in the casting and the thermodynamic possibility of TiN precipitation in steel were also calculated.The results show that sulfide inclusions are evenly distributed and the content is low.The amount of oxide inclusions in CIESC 4Cr5MoSiv1 steel is close to the ESR steel and lower than that in the EAF steel,and there are some differences along radial direction.Nitride inclusions are fine and the diameter of the largest one is 3-4um.With the increase of the centrifugal machine's rotational speed,the ratio ofround inclusions increases and the ratio of sharp inclusions decreases.According to the experiment and the calculation results,it is poin- ted out that the largest diameter of non-metallic inclusions in the CIESC 4Cr5MoSiV1 casting is only 6.6 um,and N%][i]in 4Cr5MoSiVI steel should be controlled less than 4.4x10in order to further reduce the amount and size of TiN inclusions. Key words:centrifugal induction electroslag casting;non-metallic inclusions;4Cr5MoSiVI steel;5CrMnMo steel;TiN precipi- tation [From Journal of University of Science and Technology Beijing,2001,8(2):91]V b l 一 2 3 N O J 李龙飞 等 : 低碳钢 铁素 体相 区变 形特性 一 22 9 . w srt e s s e s o f srt a让-l srt e s s c rvu e s g ra d us lyl nic re a s e s to a P e ak fo ll ow e d 妙 a s t a ni s o ft e ni n g na d th e n a ets a yd s公妓e at ih hg srt a ni , i n di c at 吨由a t dy n a m 1 c er c vo e yr or dy n am ic er c yr s alt 11乙眺 lon oc c u了s in het set el . Th e sl o 、 v . er ht e s tr a i n art e , an d/ o r het hi hg e r ht e de fo n n iat on t e m ep r a t 址 e , het sm al er het s扛a in c o n ℃ s加n d in g ot het p e ak setr s s . T七e h ot de fo n n iat on a c t i v at ion e n e珑守 ()Q o f 俪 set e z et set d 1 5 e a lcu l aet d ot b e 3 0 . 4 k J加0 1丘o m t h e v a lue s of Z冶n e r . 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K e y 邢 r d s : e o r o s ion fat i即e ; d u P lex s at i n l e s s s et e l : s od l切m c in ior de s o lut i o n 【F r o m oj u arn l of nU ~ 仰 of sc ien ce a dn eT C hon l侧到 eB ij i gn ` 2 0 1 , 8(2 ) : 13 3] B e h a v i o r o f N o n 一 m e t a m c I n e l u s i o n s i n C e n tr ifu g a l I n d u c iot n E l e e tr o s l a g C a s it n g s 口汪W iX e h un, F U iJ ,e Z HO U D终浏口叮g , 尤U 肠妙 口 M e回1训gy S e h o l , nU l v e rS iyt o f S e i enc e an d eT c hn o 1 o gy B e ij i咯 B e ij 吨 l 0() 0 83 , C 刊比a A b s t r a e t : nI o r d er ot kn o w het b e hva i o r o f n on 一 e at l li c i nc l us i o ns in c e n 幼加g a l in d u e it on e lec otr s l a g c as t in g s (C IE S C ) , no · m e at l li e in c lus i on s i n S C d 涯川随0 an d 4 C r 5M o s i V I We re 叨a liat t ive ly an d q u an t lat t ive ly an a ly z e d . hT e laJ 名e s t s公 o f icn lus i o ns in het c as tin g an d ht e ht e mr o dyn am ic po s ib il yt of 舫 N P r e c 珍汕tl on in st e l we er ia so c al c u 】at e d . 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A c e o r d ign t o het e xP e d m ent an d het e a l e u l at ion er s ul st , it 1 5 op i-n et d o u t ht a t het l a gr e st id am e t e r o f n on . m e at ll i c icn lus ion s in het CI E S C 4 Cr5 M o Si V l c aS t in g i s iOn y 6 . 6脚 , 即d 困% 」i[T % ] in 4 C r 5M o s iV I s te e l hs o u ld b e e o n tr o l l e d l e s s ht an 4 . 4 x l o 一 , in o dr er ot 丘团ht e r er d u Ce ht e a 幻。 。 u n t an d s iez o f 肠N in c l u s l o n s . K e y w o 川s : e e n itr fug ia idn uc it on e l e e otr s l昭 e as t in g ; n o -nt eat ll ic i n c in s in n s : 4 C r 5M o s i V l s et e l : S Cr M五 M o set e l : T创 P er e iP i - 怕ti o n 【F or m oj u r an l of nU 忍v e r , 仰 of cs 招 n c e a dn eT e h n 斑叫粼 刀` 犷才昭 , 2 0 1 , 8(2 ) : 91 〕