Page 721 - Corrosion Engineering Principles and Practice

674 C h a p t e r 1 5 H i g h - Te m p e r a t u r e C o r r o s i o n 675

NiS 2 Ni S
3 4
0
NiS
Ni S
3 2
–10
NiSO 4
Log pS 2 (g) –20

Ni NiO

–30

–40
–50 –40 –30 –20 –10 0 10
Log pO 2

FIGURE 15.6 Stability diagram of the Ni-S-O system at 870°C.

0
Co S
3 4
CoSO 4
–10
Log pS 2 (g) –20

CoO
Co

–30
Co 3 O 4
–40
–50 –40 –30 –20 –10 0 10
Log pO 2

FIGURE 15.7 Stability diagram of the Co-S-O system at 870°C.