·490· 北京科技大学学报 1999年第5期 national Materials Reviews,1997,42(2):155 Appl Phys,1996,79(8):6286 4 Fujiwara H,Nishioka K,Metzger R.Temperature De- 5 MnMichael R D,Watanabe T,Egelhoff W F.Origins of pendence of the Pinning Field and Coercivity of NiFe Coercivity Increase in Annealed Symmetric Spin Valves. Layers Coupled with an Antiferromagnetic FeMn Layer.J IEEE Trans,1996,32:4636 Thermal Stability of Spin-valve Multilayers Chai Chunlin,Yu Guanghua",Lin Oingying,Lu Zhengqi,Lai Wuyan,Zhu Fengwu 1)Material Science and Engineering School,UST Beijing,Beijing 100083,China 2)Central Iron and Steel research Institute,Beijing 100081, China 3)Institute of Physics,Chinese Academy of Science,Beijing 100080,China ABSTRACT Thermal stability and interface diffusion of Si/Ta/NiFe/Cu/NiFe/FeMn/Ta spin-valve have been investigated.The columnar grains are observed by high resolution electron microscopy(HREM).The pinning field increases when annealing temperature is lower than 200 C;when the annealing temperature is higher than 200 C,the pinning field decreases and other properties deteriorates;at 300C the pinning field will be zero.From the results of Auger electron spectroscopy(AES),it can conclude that the diffusion among layers is mainly along grain boundary when the annealing temperature is lower than 200 C.The effect of bulk dif- fusion should be considered at300℃， KEYWORDS spin-valve;thermal stability;grain boundary diffusion 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米 Journal of University of Science and Technology Beijing(English Edition),1999,6(3),183] Development of a New Subermerged Entry Nozzle in Thin Slab Caster Yanping Bao,Jiangiang Zhu,Wei Jiang,Naiyuan Tian,Baomei Xu Abstract:The fluid flow in the mould of the thin slab continuous caster has a large influence on the quality of slabs and its productivity.The fluid flow pattern can be controlled by the SEN(Submerged Entry Nozzle) structure.Traditional SEN can not decrease the surface turbulence and penetration depth at the same time,es- pecially at high casting speed.In order to improve the fluid flow in the mould,a new structure SEN-Dissi- pation SEN have been invented.The water modeling experiments proved that the dissipation SEN could satisfy the needs of fluid flow condition in the mould at high casting speed. Key words:thin slab caster mould;dissipation submerged entry nozzle;water-model一 4 9 0 . 北 京 科 技 大 学 学 报 1 9 9 9 年 第 5 期 n at i o n a l M at e r i a l s Re v i e w s , 1 9 97 , 4 2 ( 2 ) : 1 5 5 4 F uj iw ar H , N i s h i o k a K , M e tZ g e r R . eT m P e art ur e D e - P e n d e n e e o f th e P in i n g F i e l d an d C o e cr i v iyt o f N IF e L a y e r s C o u P l e d w iht an A n t i fe r o m ag n e t i e F e M n L ay e L J A PP I Ph y s , 19 96 , 79 (8) : 6 2 86 5 M n M i e h a e l R D , W 台t a n ab e T, E g e lh o f W .F O r i g in s o f C o e r e i v i yt I n c r e as e in A n n e a l e d Sy m m e tr i e S Pi n 垅 I v e s . 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K E Y W O R D S s Pi n 一 v a l v e : ht emr a l s t a b iliyt : gr a i n b o un d a yr d i伪 s i o n O[J u nr a l of nU iv e sr 仰 of cs i e n c e a n d eT c h n o l o舒 B e扩ign (E n g lis h E id tio n ) , 19 9 9 , 6 ( 3 ) , 18 3」 D e v e l o P m e n t o f a N e w S u b e r m e r g e d E n t yr N o z z l e i n T h i n S l a b C a s et r aY 即加g B a o , iJ a n q ia 护Z g hZ u, 脸i ij a gn, aN iy u a 月 万 a ,n aB o m e i Xu A b s t r a e t : T h e fl u id fl o w i n t h e m o u ld o f t h e ht i n s l a b e o n t i n u o u s e a s et r ha s a l agr e in fl u e n e e o n ht e qu a liyt o f s l a b s an d it s P r o du e t i v iyt . T h e fl u i d fl o w P a t e m e an b e e o n tr o ll e d b y ht e S E N ( S ub m e gr e d E n ytr N o z z l e ) s utr c trU e . rT a d it i o n a l SE N e an n o t d e e r e a s e ht e s ur af e e trU b u l e n e e an d Pen e tr at ion de Pht at ht e s am e t im e , e s - Pe e i a ll y a t h i g h e a s t i n g s P e e d . I n o r d e r t o im P r o v e ht e fl u id fl o w i n ht e m o u ld , a n e w s trU e trU e S E N 一D i s s i - Pa t i o n S E N h a v e b e e n i n v e nt e d . T h e w a t e r m o d e li n g e x Pe r irn e nt s P r o v e d ht at ht e id s s iP at i o n S EN c o u ld s at i s fy ht e n e e d s o f fl u id fl o w e o n d it i o n i n th e m o u ld at h ig h e a s t i n g s Pe e d . K e y w o r d s : ht i n s l a b e a s t e r m o u ld : d i s s iPa t i o n s ub m e gr e d e n ytr n o z l e : w at e r 一 m o d e l