·556· 北京科技大学学报 1996年No.6 3 Zhang Xinxin,Yu Fan,Gao Guangning.Thermal Conductivity Measurement of Semitransparent Media at Temperatures from 300 to 800 K by Hot-wire Method.IN:4th ATPC Proceedings.Tokyo, 1995.433~436 Simultaneous Conduction and Radiation in Semitransparent Media in the Hot -wire Experiment Yu Fan Zhang Xinxin Gao Zhonglong Department of Energy Engineering.USTB,Beijing 100083,PRC ABSTRACT The full integro-differential equation governing the simultaneous conduction and radiation in semitransparent media in the hot-wire experiment is solved numerically. The radiative contribution to the heat flux is analyzed.The effects of medium's absorp-- tion coefficient and emissivity on the temperature rise are studied.The effective mean absorption coefficient of medium and the effective emissivity of hot-wire are introduced, and the simplified model is discussed. KEY WORDS heat radiation,thermal conductivity,hot-wire,semitransparent media ☆☆☆☆☆☆☆女☆☆☆女☆☆☆☆☆☆止☆☆☆☆☆☆☆☆☆☆止☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆☆止 (上接541页) Simulating Evolution of Microstructure during Metal Hot Forming Dou Xiaofeng Zhao Hui Lu Shouli Yang Juexian Zhao Junping Department of Metals Forming,USTB,Beijng 100083,PRC ABSTRACT During hot forming,there are a series of dynamic structure changes in form- ing metal.These changes have influence on not only the structure,phase transition and qual- ity of product after forming but also the flow stress and forming process.On the basis of taking account of evolution of microstructure effected by forming history and the influ- ence of these changes to forming process,the models to simulate the evoluition of microstructure changes is set up.The simulated results accord with the tested. KEY WORDS hot forming,simulation of microstructure,flow stress. 5 5 6 . 北 京 科 技 大 学 学 报 1 9 9 6年 N o . 6 3 Z h a n g X 以 i n , Y u F a n , G a o G u a n g n in g . T h e mr a l C o n d u e ti v i yt M e a s ur e m e n t o f S e m i tr a n s Par e n t M e d i a a t T e m P e ar tU r e s for m 3 0 0 t o 8 0 0 K by H o t 一 w ir e M e ht o d . NI : 4 ht A T P C P or e e e d i n g s . T o 勺。 , 1 9 9 5 . 4 3 3 一 4 3 6 S i r n u lt a n e o u s C o n du e ti o n a n d i n t h e H o t R a d iat i o n i n S e m i tr an s P ar e n t M e d i a 一 VV甘e uY aF n hZ a n g iX n x i n D e P a r tl n e n t o f E n e 唱y E n g in e e irn g , E x P e r im e n t G a o hZ o n g ot n g U S T B , B e ij in g 100 0 8 3 , PR C A B S T R A C T T h e fu ll in t e g r o 一 d i fe r e n t i a l e qu at i o n g o v e m i n g ht e s imu lt a n e o u s e o n d u e t i o n an d r a d i a t i o n i n s e m i tr a n s Par e n t m e d i a i n ht e h o t 一 w i er e x Pe ir m e n t 1 5 s o l v e d num e ir e a lly . T h e r a d i a t i v e e o n tr i b u t i o n t o th e h e a t n u x 1 5 an a l y z e d . T h e e fe e t s o f m e d i u m , 5 a b s o 甲一 t i o n e o e if e i e n t a n d e m i s s i v iyt o n ht e t e m P e r aut r e r i s e ar e s ut d i e d . T h e e fe e t i v e m e an a b s o rp t i o n e o e m e i e n t o f m e d i u m an d ht e e fe e t i v e e m i s s i v i yt o f h o t 一 w i r e ar e i n tr o du e e d , an d ht e s而 Pliif e d m o d e l 1 5 d i s c u s s e d . K E Y W O R D S h e a t r a d i a ti o n , ht e mr a l e o n d u e ti v iyt , h o t 一 w i r e , s e m i tr an s Par e n t m e d i a ☆ ☆☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ 资 ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ ☆ 去 ☆ ☆ ☆ ☆ ☆ ☆ ☆ (上 接 5 4 1 页 ) S im u l a t i n g E v o l u t i o n o f M i c r o s trU e ut r e d u r i n g M e t a l H o t F o mr i n g D o u iX a oj 砂n g D e P hZ a o H 加1 L u hS o u li aY n g uJ ex i a n hZ a o uJ nP in g a rt m e n t o f M e at l s F o mr i n g , B e ij n g 10 0 0 8 3 , P R C A B S T R A C T D u r i n g h o t of rm i n g , th e r e ar e a i n g m e t a l . T h e s e e h an g e s h a v e i n fl u e n e e o n n o t o f d y n a m i e s tur c ut r e e h a n g e s ht e s t ur e ut r e , Ph a s e tr an s i t i o n i yt o f P r o d u e t a ft e r fo mr i n g b u t a l s o ht e fl o w s tr e s s a n d fo mr i n g P r o e e s s . o f t a k i n g a e e o u n t o f e v o l u t i o n o f m i e r o s trU e ut r e e fe e te d b y fo mr i n g h i s t o yr i n fo r n l - a n d qu a l - th e b a s i s ht e i n fl u - e n e e o f ht e s e e h a n g e s t o fo mr i n g P r o e e s s , m i e r o s trU e ut r e e h a n g e s 1 5 s e t u P . T h e s im u l a t e d th e m o d e l s t o r e s u lt s a e e o r d s im u l a t e ht e e v o l u i t i o n o f w it h t h e t e s t e d . K E Y W O R D S h o t fo mr i n g , s im u l a t i o n o f m i e r o s t ur e ut r e , fl o w s t r e s s