Strain-aging of vanadium, niobium or titanium-strengthened high-strength low-alloy steels
- PDF / 399,672 Bytes
- 4 Pages / 612 x 792 pts (letter) Page_size
- 81 Downloads / 158 Views
point C is now h i g h e r than the flow s t r e s s B at the end of p r e s t r a i n i n g . This i n c r e a s e in yield o r flow s t r e s s upon u n l o a d i n g and aging is the m o s t u n i v e r s a l i n d i c a t i o n of s t r a i n - a g i n g . G e n e r a l l y , t h e r e m a y also be an i n c r e a s e in the u l t i m a t e t e n s i l e s t r e n g t h (UTS) of the m e t a l . In this p a p e r the e f f e c t s of s t r a i n - a g i n g in c o m m e r c i a l l y a v a i l a b l e V, Nb o r T i - s t r e n g t h e n e d HSLA s t e e l s a r e c o m p a r e d with s i m i l a r effects in a h o t - r o l l e d l o w - c a r b o n (AISI-1008) s t e e l . The c o m p o s i t i o n s and t h i c k n e s s e s of the s t e e l s t e s t e d a r e l i s t e d in Table I.
M. S. RASHIDis Associate Senior Research Engineer,General Motors Research Laboratories, Warren, Mich. 48090. Manuscript submitted October 18, 1973.
Fig. l--Schematic representation of the effects of s t r a i n aging on the s t r e s s / s t r a i n curve of low-carbon or HSLA steels.
METALLURGICAL TRANSACTIONS A
AY = change in yield stress due to strain aging AU
=
change in UTS due to strain aging
Ae
=
change in total elongation due to strain aging strain aged
~ower
I
In)
X
/initial lower
!
yield
I
j
1
I
Strain
VOLUME 6A, JUNE 1975-1265
Table I. Chemical Composition and Thickness of Steels
Tested
ppm
Wt Pet
Steel
Thickness, mm
N
O
C
Ti
Ti-HSLA- 1 Ti-HSLA-2 Nb-HSLA V-HSLA Low C arbon (AISI- 1008)
1.88 1.92 1.98 2.18 3.05
81 44 70 t 61 64
26 25 15 9 307
0.087 0.093 0.108 0.125 0.045
0.16 0.23
Data Loading...
