NACE 2 CBT Study Guide Questions
and Answers 100% Pass
Corrosion is established as a what kind of current? - ✔✔Direct Current
All corrosion of iron at normal ambient conditions is ________________ ____________ -
✔✔an electrochemical process
Define, E=IR - ✔✔E is driving voltage, I is current magnitude, R is circuit resistance.
The less noble part of a corrosion cell - negatively charged - dissolves metallic iron then
converts it to positively charged ions - generates electrons - where oxidation occurs. -
✔✔Anode
The more noble region on the electrode - where electrons are consumed - positively
charged - where reduction occurs - ✔✔Cathode
The difference in potentials between the anode and the cathode create what? -
✔✔Voltage difference, which is the driving force for corrosion.
Allows for electrons generated at the anode to transport to the cathode. - ✔✔Return
path (metallic pathway)
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,Conducts ionic current - water-based - contains ions - pathway to transport ions -
carries corrosion current - ✔✔Electrolyte
Negatively charged ions - ✔✔Anions
Positively charged ions - ✔✔Cations
Four parts to a corrosion cell - ✔✔Anode, Cathode, Return Path, Electrolyte
Oxygen ____________ the rate of corrosion - ✔✔Increases
Corrosion proceeds ____________ in warmer environments than in cooler ones -
✔✔Faster
Chemical Salts like Sodium Chloride, act as a hygroscopic material (draws moisture
from the air), which _____________ corrosivity in non immersed areas. - ✔✔Increases
The wetter the environment, the ____________ corrosion is likely to occur - ✔✔more
What are the two types of corrosion? - ✔✔Localized and General
Corrosion that occurs in discrete sites on the metal surface - often occurs in areas
difficult to inspect - ✔✔Localized
Corrosion that occurs relatively uniform over the entire surface - ✔✔General
What type of corrosion can initiate at an open, freely exposed surface or at
imperfections in the coating? - ✔✔Pitting Corrosion
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,The type of corrosion that occurs on a metal surface that is shielded from full exposure
to the environment because of the close proximity of another material: (ex. common on
support straps, or pipe flanges) - ✔✔Crevice Corrosion
The type of corrosion that occurs through the electrochemical action of two dissimilar
metals in contact in the presence of an electrolyte and an electron conductive path
(Return Path): - ✔✔Galvanic Corrosion
The less effectively the coating insulates the structure, the __________ electric current is
required to provide catholic protection. - ✔✔more
Two types of Cathothic Protection Systems - ✔✔Impressed; Galvanic
A device that uses power from electric utility lines to convert the alternating current to a
lower voltage direct current by means of a step down transformer - ✔✔Rectifier
What is the minimum requirement for a cathodic protection potential? - ✔✔-0.85V
What occurs when potential in a cathodic protection system increases (more negative) -
✔✔Hydroxyl formation; Cathodic disbondment
Note: if the potential continues to increase(more negative) disbondment occurs through
the hydrogen process.
Formation of a protective oxide film on the surface reducing its chemical activity and its
ability to corrode - ✔✔Passivation
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, Why perform Air Turnovers (Air Turn): - ✔✔To eliminate air stratification; One to two
air changes per hour is industry recommendation
Enclosures must fit all of the following characteristics: - ✔✔1.Large enough to contain
the whole work area
2.Not be larger than the performance capabilities of dehumidifier
3.All weather resistant
4.Minimal leakage to maintain proper environmental conditions
Two ways to reduce RH, are: - ✔✔1.Increase surface temperature 2.Dehumidification
Two methods to increase surface temperature, are: - ✔✔1.Induction Heating
2.Resistance Heating
What is a common and economical dehumidification method to remove moisture from
air? - ✔✔Refrigeration
Substances that naturally have a high affinity for water, are: - ✔✔Desiccants
Desiccants in solid form are called _____________ while liquid desiccants are called
_____________ - ✔✔Adsorbent; Absorbent
Benefits of dehumidification: - ✔✔1.Work may began earlier in the day
2.Coating is done in ideal conditions
Brittie Donald, All Rights Reserved © 2025 4
and Answers 100% Pass
Corrosion is established as a what kind of current? - ✔✔Direct Current
All corrosion of iron at normal ambient conditions is ________________ ____________ -
✔✔an electrochemical process
Define, E=IR - ✔✔E is driving voltage, I is current magnitude, R is circuit resistance.
The less noble part of a corrosion cell - negatively charged - dissolves metallic iron then
converts it to positively charged ions - generates electrons - where oxidation occurs. -
✔✔Anode
The more noble region on the electrode - where electrons are consumed - positively
charged - where reduction occurs - ✔✔Cathode
The difference in potentials between the anode and the cathode create what? -
✔✔Voltage difference, which is the driving force for corrosion.
Allows for electrons generated at the anode to transport to the cathode. - ✔✔Return
path (metallic pathway)
Brittie Donald, All Rights Reserved © 2025 1
,Conducts ionic current - water-based - contains ions - pathway to transport ions -
carries corrosion current - ✔✔Electrolyte
Negatively charged ions - ✔✔Anions
Positively charged ions - ✔✔Cations
Four parts to a corrosion cell - ✔✔Anode, Cathode, Return Path, Electrolyte
Oxygen ____________ the rate of corrosion - ✔✔Increases
Corrosion proceeds ____________ in warmer environments than in cooler ones -
✔✔Faster
Chemical Salts like Sodium Chloride, act as a hygroscopic material (draws moisture
from the air), which _____________ corrosivity in non immersed areas. - ✔✔Increases
The wetter the environment, the ____________ corrosion is likely to occur - ✔✔more
What are the two types of corrosion? - ✔✔Localized and General
Corrosion that occurs in discrete sites on the metal surface - often occurs in areas
difficult to inspect - ✔✔Localized
Corrosion that occurs relatively uniform over the entire surface - ✔✔General
What type of corrosion can initiate at an open, freely exposed surface or at
imperfections in the coating? - ✔✔Pitting Corrosion
Brittie Donald, All Rights Reserved © 2025 2
,The type of corrosion that occurs on a metal surface that is shielded from full exposure
to the environment because of the close proximity of another material: (ex. common on
support straps, or pipe flanges) - ✔✔Crevice Corrosion
The type of corrosion that occurs through the electrochemical action of two dissimilar
metals in contact in the presence of an electrolyte and an electron conductive path
(Return Path): - ✔✔Galvanic Corrosion
The less effectively the coating insulates the structure, the __________ electric current is
required to provide catholic protection. - ✔✔more
Two types of Cathothic Protection Systems - ✔✔Impressed; Galvanic
A device that uses power from electric utility lines to convert the alternating current to a
lower voltage direct current by means of a step down transformer - ✔✔Rectifier
What is the minimum requirement for a cathodic protection potential? - ✔✔-0.85V
What occurs when potential in a cathodic protection system increases (more negative) -
✔✔Hydroxyl formation; Cathodic disbondment
Note: if the potential continues to increase(more negative) disbondment occurs through
the hydrogen process.
Formation of a protective oxide film on the surface reducing its chemical activity and its
ability to corrode - ✔✔Passivation
Brittie Donald, All Rights Reserved © 2025 3
, Why perform Air Turnovers (Air Turn): - ✔✔To eliminate air stratification; One to two
air changes per hour is industry recommendation
Enclosures must fit all of the following characteristics: - ✔✔1.Large enough to contain
the whole work area
2.Not be larger than the performance capabilities of dehumidifier
3.All weather resistant
4.Minimal leakage to maintain proper environmental conditions
Two ways to reduce RH, are: - ✔✔1.Increase surface temperature 2.Dehumidification
Two methods to increase surface temperature, are: - ✔✔1.Induction Heating
2.Resistance Heating
What is a common and economical dehumidification method to remove moisture from
air? - ✔✔Refrigeration
Substances that naturally have a high affinity for water, are: - ✔✔Desiccants
Desiccants in solid form are called _____________ while liquid desiccants are called
_____________ - ✔✔Adsorbent; Absorbent
Benefits of dehumidification: - ✔✔1.Work may began earlier in the day
2.Coating is done in ideal conditions
Brittie Donald, All Rights Reserved © 2025 4
