Nace CP 1, Course Manual

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NACE GLOSSARY OF CORROSION-RELATED TERMS
©
2002, NACE International. This publication may not be reprinted without the written consent of NACE International.
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EPOXY
Type of resin formed by the
reaction of aliphatic or aromatic
polyols (like bisphenol) with
epichlorohydrin and
characterized by the presence of
reactive oxirane end groups.
EQUILIBRIUM
POTENTIAL
The potential of an electrode in
an electrolyte at which the
forward rate of a given reaction is
exactly equal to the reverse rate;
the electrode potential with
reference to a standard
equilibrium, as defined by the
Nernst equation.
EROSION
The progressive loss of material
from a solid surface due to
mechanical interaction between
that surface and a fluid, a
multicomponent fluid, or solid
particles carried with the fluid.
EROSION-CORROSION
A conjoint action involving
corrosion and erosion in the
presence of a moving corrosive
fluid or a material moving through
the fluid, leading to accelerated
loss of material.
EXCHANGE CURRENT
The rate at which either positive
or negative charges are entering
or leaving the surface when an
electrode reaches dynamic
equilibrium in an electrolyte.
EXFOLIATION
CORROSION
Localized subsurface corrosion in
zones parallel to the surface that
result in thin layers of uncorroded
metal resembling the pages of a
book.
EXTERNAL CIRCUIT
The wires, connectors,
measuring devices, current
sources, etc., that are used to
bring about or measure the
desired electrical conditions
within an electrochemical cell. It
is this portion of the cell through
which electrons travel.
F
FATIGUE
The phenomenon leading to
fracture of a material under
repeated or fluctuating stresses
having a maximum value less
than the tensile strength of the
material.
FATIGUE STRENGTH
The maximum stress that can be
sustained for a specified number
of cycles without failure.
FAULT CURRENT
A current that flows from one
conductor to ground or to another
conductor due to an abnormal
connection (including an arc)
between the two. A fault current
flowing to ground may be called
a ground fault current.
FERRITE
The body-centered cubic
crystalline phase of iron-based
alloys.
FERRITIC STEEL
A steel whose microstructure at
room temperature consists
predominantly of ferrite.
FILIFORM CORROSION
Corrosion that occurs under a
coating in the form of randomly
distributed thread-like filaments.
FILM
A thin, not necessarily visible
layer of material.
FINISH COAT
[See Topcoat .]
FORCED DRAINAGE
Drainage applied to underground
or submerged metallic structures
by means of an applied
electromotive force or sacrificial
anode.
FOREIGN STRUCTURE
Any metallic structure that is not
intended as a part of a system
under cathodic protection.
FOULING
An accumulation of deposits.
This includes accumulation and
growth of marine organisms on a
submerged metal surface and
the accumulation of deposits
(usually inorganic) on heat
exchanger tubing.
FRACTOGRAPHY
Descriptive treatment of fracture,
especially in metals, with specific
reference to photographs of the
fracture surface.
FRACTURE MECHANICS
A quantitative analysis for
evaluating structural reliability in
terms of applied stress, crack
length, and specimen geometry.
FREE MACHINING
The machining characteristics of
an alloy to which an ingredient
has been introduced to give
small broken chips, lower power
consumption, better surface
finish, and longer tool life.
FRETTING CORROSION
Deterioration at the interface of