Identification of atomic boron in steel by auger electron spectroscopy
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A. P. COLDREN is Staff Metallurgist, Climax Molybdenum Company of Michigan, Ann Arbor, Michigan. A. JOSHI is Researcher, Physical Electronics Industries, Inc., Edina, Minnesota. D. F. STEIN is Professor and Head, Department of MetallurgicalEngineering, Michigan Technological University, Houghton, Michigan. Manuscript submitted April 9, 1975. 2304-VOLUME 6A, DECEMBER 1975
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ONSTEEL~BSTR~TE.....X20
A. P. COLDREN, A. JOSHI, AND D. F. STEIN In the c o u r s e of an i n v e s t i g a t i o n of v a r i a t i o n s in the toughness p r o p e r t i e s in b a i n i t i c 0.12 pct C-0.5 pct Mn0.5 pct Mo-0.005 pct B s t e e l s , an a t t e m p t was made to c o r r e l a t e the 50 pct s h e a r Charpy V - n o t c h i m p a c t t r a n s i t i o n t e m p e r a t u r e with the a m o u n t of a t o m i c b o r o n s e g r e g a t e d at the p r i o r a u s t e n i t e g r a i n b o u n d a r i e s . The d e t e c t i o n and m e a s u r e m e n t of the b o r o n was by Auger E l e c t r o n S p e c t r o s c o p y (AES) applied to p r e d o m i n a n t l y i n t e r g r a n u l a r f r a c t u r e s u r f a c e s of s p e c i m e n s f r a c t u r e d in the h i g h - v a c u u m (10 -9 T o r r ) c h a m b e r of the AES i n s t r u m e n t . The technique and i n s t r u m e n t a t i o n have b e e n d e s c r i b e d e a r l i e r . 1 The d e t e c t i o n of s e g r e gated a t o m i c b o r o n was s u c c e s s f u l , but the a t t e m p t to d e t e r m i n e the a m o u n t of b o r o n q u a n t i t a t i v e l y failed b e c a u s e of the p r e s e n c e of v a r i a b l e a m o u n t s of s u l f u r and n i t r o g e n and b e c a u s e the p e r c e n t a g e of i n t e r g r a n u l a r f r a c t u r e a r e a was not d e t e r m i n e d for the m i x e d t r a n s granular/inter granular fractures. The m a i n p u r p o s e of this c o m m u n i c a t i o n is to r e p o r t the o b s e r v a t i o n of two d i s t i n c t p o s i t i o n s of the p r i n c i pal b o r o n Auger peak that a p p a r e n t l y r e p r e s e n t d i f f e r ent c h e m i c a l s t a t e s of the b o r o n atom. One of the peak p o s i t i o n s was 181 eV, in r e a s o n a b l e a g r e e m e n t with the v a l u e s of 180 eV and 179 eV r e p o r t e d for e l e m e n t a l b o r o n by H a r r i s 2 and the Handbook of Auger E l e c t r o n Spectroscopy, 3 r e s p e c t i v e l y . The other p o s i t i o n of the b o r o n peak was at 170 eV. This c o r r e s p o n d s v e r y c l o s e l y to the 169 eV p o s i t i o n of the b o r o n peak o b s e r v e d by Bishop and R i v i e r e 4 after they heated s p u t t e r - c l e a n e d s p e c i m e n s of b o r o n - d o p e d i r o n (0.018 and 0.09 pct b o r o n by weight) in the r a n g e 500~ to 1050~ i n v a c u o . While Bishop and R i v i e r e a p p a r e n t l y a s s u m e d that they w e r e m e a s u r i n g s u r f a c e s e g r e g a t i o n of atomic boron, they n o t e d - - w i t h o u t f u r t h e r c o m m e n t - t h a t changes in
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