A debate on the bainite reaction
- PDF / 3,432,579 Bytes
- 18 Pages / 612 x 792 pts (letter) Page_size
- 31 Downloads / 186 Views
O N the o c c a s i o n of h i s 80th b i r t h d a y , it m u s t be a s o u r c e of both p l e a s u r e and f r u s t r a t i o n to Dr. E d g a r C o l l i n s Bain to o b s e r v e that the p h a s e t r a n s f o r m a t i o n n a m e d in his honor c o n t i n u e s to be the s u b j e c t of so m u c h r e s e a r c h throughout the world, and yet r e m a i n s so c o n t r o v e r s i a l that, m o r e than 40 y e a r s a f t e r its d i s c o v e r y , a l m o s t the only a s p e c t of it upon which t h e r e i s g e n e r a l a g r e e m e n t i s that s t i l l m o r e r e s e a r c h is needed! In the hope of e n c o u r a g i n g a m o r e f o c u s s e d effort to r e s o l v e t h e s e c o n t r o v e r s i e s , the p r e s e n t a u t h o r s have s e l e c t e d the t h r e e i s s u e s which they cons i d e r to f o r m t h e i r c o r e and have engaged in a debate upon t h e m . In r e s p e c t of the f i r s t i s s u e , that of a n s w e r i n g the q u e s t i o n "what is b a i n i t e ? " , the two s i d e s (RFH on one; HIA and KRK on the other) exchanged s t a t e m e n t s of p o s i t i o n a n d then two f u r t h e r r o u n d s of r e b u t t a l . C o n s i d e r a t i o n s of length r e s t r i c t e d debate on the o t h e r two t o p i c s , " t h e growth m e c h a n i s m of the f e r r i t i c component of b a i n i t e " and " t h e s o u r c e s of b a i n i f i e c a r b i d e p r e c i p i t a t i o n " , to two exchanges on each. No s u b s t a n t i a l a l t e r a t i o n s w e r e s u b s e q u e n t l y m a d e in t h e s e e x c h a n g e s . Not s u r p r i s i n g l y , the l e v e l of a g r e e m e n t r e a c h e d was s u f f i c i e n t l y m o d e s t so that for the S u m m a r y s e c t i o n the v i e w s of the two s i d e s w e r e again s e p a r a t e l y p r e p a r e d . The b a s i c n a t u r e of the p r o b l e m s involved, however, a p p e a r s to have been c l a r i f i e d , and a s a r e s u l t the paths which f u t u r e e x p e r i m e n t a l and t h e o r e t i c a l s t u d i e s m i g h t m o s t p r o f i t a b l y follow now s e e m to be b e t t e r i l l u m i n a t e d . R. F. HEHEMANN is Professor of Physical Metallurgy, Division of Cleveland, Ohio. K. R. KINSMANis associated with the Metallurgy Department, Scientific Research Staff, Ford Motor Company, Dearborn, Michigan. H. I. AARONSON, formerly with Ford Motor Company, is now Professor, Department of MetallurgicalEngineering, MichiganTechnological University, Houghton, Mich. METALLURGICALTRANSACTIONS
TOPIC I: WHAT IS B A I N I T E ? R. F . H. (Round 1) The t e r m b a i n i t e r e f e r s to the a c i c u l a r d e c o m p o s i tion p r o d u c t s that f o r m when a u s t e n i t e is t r a n s f o r m e d at i n t e r m e d i a t e t e m p e r a t u r e s . The s i m i l a r i t i e s b e t w e e n b a i n i t e and m a r t e n s i t e on the one hand and between bainite and Widmanstatten ferrite on the other have been recognized since the pioneering work of
Data Loading...
