RATIONALES
SECTION 1: CORROSION FUNDAMENTALS (Questions 1–40)
1. All corrosion of iron at normal ambient conditions is:
A) A chemical reaction caused by oxygen
B) A process that always requires high temperatures
C) An electrochemical process
D) Caused by stray electrical currents only
Answer C:
Rationale: Corrosion of iron requires an anode, cathode, electrolyte, and
return current path, fitting the definition of an electrochemical cell.
2. Based on the Galvanic Series presented in the NACE CIP Level 1 Manual,
which three materials can be used effectively as galvanic anodes for carbon
steel?
,A) Copper, Brass, Bronze
B) Lead, Tin, Monel
C) Zinc, Aluminum, Magnesium
D) Graphite, Platinum, Titanium
Answer C:
Rationale: Zinc, aluminum, and magnesium are anodic (less noble) relative to
steel, meaning they corrode preferentially, protecting the steel substrate.
3. Dew point is defined as the temperature at which:
A) Water freezes
B) Relative humidity reaches 0%
C) Condensation occurs
D) The air is completely dry
Answer C:
Rationale: The dew point is the saturation temperature. If the surface
temperature falls below the dew point, moisture will condense on the surface.
4. A decrease in ambient temperature will generally cause the corrosion rate
to:
A) Increase
B) Decrease
,C) Remain the same
D) Fluctuate randomly
Answer B:
Rationale: Corrosion is an electrochemical reaction. Lower temperatures slow
down the kinetic energy of the reactants and the rate of the chemical
reaction.
5. What is the function of the electrolyte in a corrosion cell?
A) Allows flow of electrons between anode and cathode
B) Provides the metallic connection between anode and cathode
C) Allows passage of ions to connect the corrosion cell
D) Prevents the flow of electrical current
Answer C:
Rationale: The electrolyte is a medium that conducts ionic current, allowing
the passage of ions to connect the corrosion cell.
6. What is the function of the metallic pathway in a corrosion cell?
A) Allows the passage of ions to connect the corrosion cell
B) Allows the flow of electrons to connect the corrosion cell
C) Prevents corrosion from occurring
D) Acts as the electrolyte
, Answer B:
Rationale: The metallic pathway is the conductor that allows electrons to flow
from the anode to the cathode.
7. What is the galvanic series?
A) A listing of metals in order of their melting points
B) A listing of metals in order of reactivity (more or less noble) in seawater at
25°C
C) A listing of metals in order of their density
D) A listing of metals in order of their hardness
Answer B:
Rationale: The galvanic series ranks metals from more noble (cathodic) to less
noble (anodic) based on electrochemical reactivity.
8. The general rule of galvanic corrosion is:
A) The more noble metal will corrode preferentially
B) The less noble metal when connected to a more noble metal will corrode
preferentially
C) Both metals will corrode equally
D) Neither metal will corrode
Answer B: