Steels_ Metallurgy and Applications, Third Edition

40 Steels: Metallurgy and Applications

(a)

2.0

_= r

r 1.5

1.0

,,O

. 0

t Ann. 775 ~ 60s

• I , I I I
  -0.01 0 0.01 0.02 0.03
  Ti~ (=TI-(4C+3.43N))

0.04

(b) 2.4. .....

2.2

2.0

::3

1.8

~E

1.6q

1.41

1.2

O ~

o9 o'' o o o

0~o, ~ Uo~ 9 u

!

O 9 AI<0.004 WT PCT.

o A1=0.014 to 0.068 WT PCT. "

0.036 AVG.

0 .()2 .(~4 .(~ .0'8 .1'0 12 .14 .16 .18 .20

Nb a wt pct.

Figure 1.37 Variation of rm value with excess (a) titanium content and (b) niobium
content (After Takahashi et al. ~ and Tokunaga et al. 67)

50

44

42

2.0

1.8

i~. 1.6

1.4

1.2

720 *(3 (CT)! [Nb/C ..... = 1 ', '

N,,D, [ (at. ratloj

N:

soo oc (CT) I ~

' ~,. ,Ig'1~-,~.

. .... :.-. 9
! I 1

f i.

I _ = .... L -^9 -

0.01 0.02 0.03 0.04 0 0.01 0.02 0.03 0.04

Nb (wt%) Nb (wt%)

(a) Nb - IF (b) Nb- Ti-IF

Ti -IF

. ~2o oc (cr) I j..4p--w.
9 ~ ,~..o.

" 600 o C (CT),sF | / '

" "s"O'~'~ i TI/(C+N)=I

" d" ~

i i

| e ii |

0 0.01 0.02 0.03 0.04 0.05

Ti (wt%)

(c) Ti-IF

Figure 1.38 Effect of alloying element on the mechanical properties of Nb-, Nb-Ti- and
Ti-IF steels containing 20-30 ppm carbon and 26-35 ppm N. (After Tokunaga et al. 6s)