Corrosion 6 Flashcards

1
Q

is also
known as general corrosion. A
type of corrosion where the
corroded areas occur in a
manner evenly distributed
across the material being
attacked.

A

Uniform corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

is a primary cause of
uniform corrosion in steels,
alloys, and other metals in
natural environments.

A

Oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

is
also known as
intergranular attack (IGA).
This is a specialized type of
attack that takes place at
the grain boundaries of a
metal.

A

Intergranular corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

This form of corrosion is
often caused by impurities
in the metal, leading to
chemical or
electrochemical attack on
the grain boundaries.

A

INTERGRANULAR CORROSION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

is also known
as dissimilar metal corrosion or
bimetallic corrosion. When two
different metallic
materials are electrically
connected and placed in a
conductive solution (electrolyte),
an electric potential exists.

A

Galvanic corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

is a
localized type of corrosion
occurring within or adjacent
to narrow gaps.

A

Crevice corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

is
characterized by a highly
localized loss of metal. The
initiation of a pit is associated
with the breakdown of the
protective film on the metal
surface

A

Pitting corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

is
usually caused by an
aqueous or gaseous
corrodent flowing over
the metal surface or
impinging upon it.

A

Erosion corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

is a phenomenon where cracks
form and propagate in a
material due to the combined
effects of sustained tensile
stress and exposure to a
corrosive environment.

A

Stress corrosion cracking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

refers to the
degradation of metals caused
by the activity of living
organisms. This is also referred
to as microbial-induced
corrosion (MIC).

A

Biologically influenced
corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

is the term to
describe the leaching of zinc
from brass.

A

Dezincification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

is the term
used to describe the selective
leaching of iron from gray cast
iron.

A

Graphite corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When intergranular corrosion
takes place in a metal with a
highly directional grain structure,
it propagates internally, parallel
to the surface of the metal.

A

EXFOLIATION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

is the cracking of a
metal or alloy under the combined
action of a corrosive environment and
repeated or fluctuating stress.

A

Corrosion fatigue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

is when metals and
alloys fail by cracking when subjected
to cyclic or repetitive stress

A

Fatigue failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The growth formation is explained by the
formation of a differential aeration cell

A

FILIFORM CORROSION

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

the process
of a metal returning to
the material’s
thermodynamic stat

A

Corrosion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

The measure of the potential
difference between two half
cells in an electrochemical cell

A

Cell Potential

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

may be formed when two
dissimilar metals are in
contact or due to the
heterogeneity of the
same metal surface

A

Dissimilar electrode cells

20
Q

are
formed when the
electrodes are identical
but are in contact with
solutions of differing
composition

A

Concentration cells

21
Q

Formed when electrodes
of the same metal, each of
which is at a different
temperature, are
immersed in an
electrolyte of the same
initial composition

A

DIFFERENTIAL TEMPERATURE CELL

22
Q

This situation arises when
a significant difference in
metal ion concentration
exists over ametal
surface

A

METAL ION CONCENTRATION CELLS

23
Q

Also knownas Pourbaix Diagram

A

Potential-Ph Diagrams

24
Q

Constructed from calculations
based on the Nernst equation and
the solubility data for various
metal compounds

A

Potential-Ph Diagrams

25
Q

Under these
condition of potential and pH, the
metal remains in metallic form
and is free from corrosion

A

Immunity Zone

26
Q

Under these
condition of potential and pH, the
metal corrodes

A

Corrosion Zone

27
Q

Under these
condition of potential and pH,
protective layer of the metal’s
hydroxide or oxide form on iron
and further corrosion of metal
doesn’t take place

A

Passive zone

28
Q

The potential change caused by net
current to or from an electrode,
measured in volts

A

POLARIZATION

29
Q

is a manifestation of
the relative changes in the activation
energies for dissolution and deposition,
when equilibrium is disturbed.

A

Activation polarization

30
Q

Polarization of an electrolytic cell resulting
from changes in the electrolyte
concentration due to the passage of current
through the electrode/solution interface

A

Concentration Polarization

31
Q

The change in voltage associated with
effects of the environment and the circuit
between the anode and cathode sites. It
includes the effects of the resistivity of the
media, surface films, corrosion products,
etc.

A

Resistance Polarization

32
Q

is a
complicated electrochemical
process taking place in
corrosion cells consisting of
base metal, metallic corrosion
products, surface electrolytes,
and the atmosphere

A

Atmospheric corrosion

33
Q

is negligible in climates where the air temperature
is below the freezing point of water because ice is a poor
conductor and does not function effectively as an
electrolyte

A

Rusting

34
Q

refers to the length of
time during which
the metal surface is
covered by a film of
water

A

Time of wetness

35
Q

The amount of water adsorbed
on a metal surface depends on
the relative humidity of the
atmosphere and on the chemical
and physical properties of the
corrosion products.

A

Adsorption Layers

36
Q

Occurs when the temperature of the metal
surface is below the dew point of the
atmosphere

A

Dew

37
Q

creates even thicker layers of electrolyte on
the surface than dew. It affects corrosion by adding a phase layer of
moisture and corrosion stimulators.

A

Rain

38
Q

high acidity and high concentrations of sulfates
and nitrate can be found in fog droplets in areas
of high air pollution

A

Fog

39
Q

can promote corrosion because of their
hygroscopic nature

A

Dust

40
Q

on the surface will contain
various species deposited from the atmosphere or
originating from the corroding metal.

A

electrolyte film

41
Q

The metal is covered with a spontaneously formed
oxide and aqueous layer

A

INDUCTION PERIOD

42
Q

The oxide layer transforms into a fully developed
layer of corrosion products

A

TRANSITION PERIOD

43
Q

The surface being fully covered by corrosion
product and reach constant corrosion rate

A

STATIONARY PERIOD

44
Q

defined as the ratio of deposition rate of
any gaseous compound and the concentration of
that compound in the atmosphere

A

dry deposition velocity

45
Q

When small amounts of copper,
chromium, nickel, etc. are
added to carbon steel, low-alloy
carbon steel results. These
steels are known as

A

weathering
steels