Solubility of nitrogen in liquid Fe-Cr-Ni alloys containing manganese and molybdenum
- PDF / 570,420 Bytes
- 8 Pages / 603.28 x 783.28 pts Page_size
- 74 Downloads / 182 Views
I N I T R O G E N , as an e l e m e n t in alloy s t e e l s , can be b e n e f i c i a l or d e l e t e r i o u s to m e c h a n i c a l p r o p e r t i e s depending upon its c o n c e n t r a t i o n , t h e r m a l p r o c e s s i n g of the alloy, and the p r e s e n c e of other a l l o y i n g e l e m e n t s . P r o p e r c o n t r o l of n i t r o g e n is an i m p o r t a n t aspect in the p r o d u c t i o n of alloy s t e e l s . S e v e r a l q u e s t i o n s , such as the n i t r o g e n s o l u b i l i t y in m u l t i c o m p o n e n t alloy s t e e l s , the effect of t e m p e r a t u r e on n i t r o g e n solubility, the n i t r o g e n l e v e l at which v a r i o u s n i t r i d e s p r e c i p i t a t e in alloy s t e e l s , a r e s t i l l to be a n s w e r e d . C h i p m a n and C o r r i g a n ~ found that the heat of s o l u tion of n i t r o g e n in liquid b i n a r y i r o n a l l o y s was p r o p o r t i o n a l to the i n t e r a c t i o n p a r a m e t e r , and p r o p o s e d an e m p i r i c a l l i n e a r equation for p r e d i c t i n g n i t r o g e n s o l u b i l i t y in i r o n alloys in the r a n g e of s t e e l m a k i n g t e m p e r a t u r e s . The e x p e r i m e n t a l d a t a i n r e l a t i v e l y dilute i r o n alloys were in good a g r e e m e n t with a l i n e a r r e l a t i o n s h i p . However, the d e v i a t i o n of the l i n e a r equation f r o m the e x p e r i m e n t a l d a t a b e c a m e s i g n i f i c a n t in m o r e highly alloyed s t e e l s . T u r n o c k and Pehlke 2 m e a s u r e d the heat of s o l u t i o n of n i t r o g e n in liquid b i n a r y , t e r n a r y and m u l t i c o m p o n e n t i r o n alloys, and p r o p o s e d a s e c o n d o r d e r equation in t e r m s of the l o g a r i t h m of the activity c o e f f i c i e n t of n i t r o g e n . Kunze, Schilmann and P a r l e e 3 e v a l u a t e d all a v a i l a b l e e x p e r i m e n t a l data on n i t r o g e n s o l u b i l i t y in i r o n - b a s e alloys, and p r o p o s e d an equation p r e d i c t i n g n i t r o g e n s o l u b i l i t y at any t e m p e r a t u r e and c o m p o s i t i o n f r o m the value of heat of s o l u t i o n . A " c a r b o n " r e f e r e n c e c u r v e was i n t r o d u c e d by t h e m f r o m which the value of heat of s o l u t i o n of n i t r o g e n in alloys could be r e a d . Wada and P e h l k e 4 m e a s u r e d the n i t r o g e n s o l u b i l i t y in b i n a r y and t e r n a r y liquid F e - C r - N i alloys up to 40 pct Cr and 20 pct Ni over a wide r a n g e of t e m p e r a t u r e s . They d e t e r m i n e d the f i r s t and second o r d e r i n t e r a c t i o n s among Cr, Ni and n i t r o g e n as a function of t e m p e r a t u r e , and obtained a s e c o n d o r d e r e q u a t i o n p r e d i c t i n g n i t r o g e n s o l u b i l i t y in F e - C r - N i alloys at any t e m p e r a t u r e and c o m p o s i t i o n .
HARUE WADAis Research Associate, and ROBERT D. PEHLKE, is Professor and Cha
Data Loading...
