| Forms of Corrosion: There are several forms of corrosion, also referred to as modes
or mechanisms of corrosion. Sub-forms can also be identified for
several forms of corrosion. The different forms and sub-forms of corrosion are analogous
to different failure mechanisms in the mechanical world (fast fracture, fatigue, ductile
tearing, brittle cleavage, wear etc...).
A popular classification of forms of corrosion has been made by Fontana,
on the basis of the visual appearance of corrosion damage. More information on monitoring
different forms of corrosion is available from the list below:
Forms of corrosion should not be confused with causes of
corrosion.
Another useful classification scheme of forms and subforms has been
presented by Craig and Pohlman as follows (partial listing, with numerous general
corrosion subforms omitted):
| General (uniform) corrosion Localized
corrosion
filiform corrosion
crevice corrosion
pitting corrosion
localized biological corrosion
Metallurgically influenced corrosion
intergranular corrosion
dealloying corrosion
Mechanically assisted degradation
erosion corrosion
fretting corrosion
cavitation and water drop impingement
corrosion fatigue
Environmentally induced cracking
stress-corrosion cracking
hydrogen damage
liquid metal embrittlement
solid metal induced embrittlement |
References/Literature:
M.G. Fontana: Corrosion Engineering, McGraw-Hill, New York, 1986.
C.P. Dillon (Ed.): Forms of Corrosion - Recognition and Prevention: NACE
Handbook 1, Vol. 1, NACE International, Houston, 1982.
B. Craig and S.L. Pohlman: in ASM Handbook, Vol.13 "Corrosion",
ASM International, 1987.
Links:
Examples presented by Kennedy Space Center at:
http://corrosion.ksc.nasa.gov/html/forms.htm
Photoarchive of corrosion forms presented by Kennedy Space Center at:
http://corrosion.ksc.nasa.gov/html/paforms.htm
Various corrosion case studies at
Reliability Engineering Snapshot
www.resnapshot.com
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