Steels_ Metallurgy and Applications, Third Edition

162 Steels: Metallurgy and Applications

10 (a)

8

6

cr

4

2 Cr

I Pi~sbuNh, P.A. Si

17 years

o t I 1 I I 1

lol

Kearny N.J.

15.51Yearn

, I

~(b)

~ U

.o_

C

el. ,.- 4

._o ICJ

8 2

~ 0 ,

~ 10

Ic)

8

Si Ni "~-

Cr

l l I I I

6

(^4) P Si Ni Cr
2 Kure Beach N.C. 800 foot lot
15.5 years
0 ,,1, I I I , I I I,
0.2 0.4 0.6 0.8 1.0 1.2 1.4
% Alloying element
Figure 2.14 Corrosion behaviour of weathering steels: (a) Bethlemen data on Mayari
R; (b) USS Cor-Ten A in industrial atmosphere; (c) USS Cor-Ten A in marine atmosphere
At the latter site, the order of effectiveness is as follows:
Most beneficial P
Si
Cu (up to 0.3%)
Cr
Ni
Cu (>3%)