Effect of aluminum nitride formation on the recrystallization of Fe-0.06 pct Al single crystals
- PDF / 2,776,545 Bytes
- 10 Pages / 612 x 792 pts (letter) Page_size
- 5 Downloads / 232 Views
T H E s u p e r i o r d r a w a b i l i t y of a l u m i n u m - k i l l e d sheet s t e e l as compared with low-carbon r i m m e d s t e e l s can be attributed to the s t r o n g e r ~111} component of the texture in the a l u m i n u m - k i l l e d s t e e l s . Although t h e r e is no a g r e e m e n t as to the p r e c i s e m e c h a n i s m for the development of this stTong {111 } t e x t u r e , it has been established that the p r e c i p i t a t i o n of aluminum n i t r i d e during the box-annealing cycle is a n e c e s s a r y condition for the production of good d e e p - d r a w i n g p r o p e r t i e s in the annealed sheet. 1-4 Several i n v e s t i g a t o r s have postulated z'3'5-7 that the formation of aluminum n i t r i d e p r e c i p i t a t e p a r t i c l e s or p r e - p r e c i p i tation c l u s t e r s at the subgrain and a s - r o l l e d g r a i n boundaries during the box-annealing cycle controls the r e c r y s t a l l i z a t i o n texture by preventing the nucleation o r growth of u n d e s i r a b l e , mainly {100 }, t e x t u r a l components. It has been shown by qualitative electron diffraction techniques that the s t o r e d energy of c o l d - r o l l e d g r a i n s of iron depends on t h e i r orientation r e l a t i v e to the roiling plane. 6'7 Of the main t e x t u r a l c o m ponents in c o l d - r o i l e d bcc m e t a l s those g r a i n s with t h e i r {111} planes p a r a l l e l to the s u r f a c e , i . e . the {111} (110) components have the highest s t o r e d ene r g y and the {100} g r a i n s have the lowest. B e c a u s e of the higher energy of the { l l l } - o r i e n t e d g r a i n s , these a r e ~he f i r s t to r e c r y s t a l l i z e . 6'7 F u r t h e r m o r e , the orientation of the r e e r y s t a l l i z e d g r a i n s is also W. JOLLEY is Research Engineer, Homer Research Laboratories, Bethlehem Steel Corp., Bethlehem, Pa. Manuscript submitted February 3, 1971. METALLURGICALTRANSACTIONS
~111 } and they a r e nucleated within the a s - r o l l e d { I l l , o r i e n t e d g r a i n s , with the r e s u l t that the {111} a s - r o l l e d g r a i n s a r e r e p l a c e d by {111} r e c r y s t a l l i z e d g r a i n s . These o b s e r v a t i o n s c o n t r a s t somewhat with the o b s e r v a t i o n s for single c r y s t a l s where {111} (211 ) - o r i e n t e d a s - rolled c r y s t a l s r e c r y s t a l l i z e to give a {110} (001) texture. 8'9 At s o m e stage a f t e r the ~111 } g r a i n s have begun to r e c r y s t a l l i z e in p o l y c r y s t a l l i n e iron, the remaining o r i e n t a t i o n s , including the {100}, r e c r y s t a l l i z e by the nucleation of new g r a i n s , mainly at the a s - r o l l e d g r a i n boundaries .6,7 These b o u n d a r y - n u c l e a t e d grains a r e randomly orientated and grow by absorbing the remaining u n r e c r y s t a l l i z e d g r a i n s . Thus, the {111} component r e m a i n s a p p r o x i m a t e l y constant o r inc r e a s e s slightly in goin
Data Loading...
