with Detailed Correct Answers| Latest Update
2026/2027
Coating help minimize corrosion by - ANSWER -forming a physical barrier that
prevents the electrolyte from encountering the substrate. Coatigs provide this
protection through three different mechanisms, which are barrier, sacrificial, and
inhibitive.
Barrier coatings provides chemical and physical barrier between the substrate and
environment (this barrier prevents water, oxygen, and other corrosive agents like
salt from coming in contact with the substrate) - ANSWER -it retards moisture
permeation but cannot eliminate moisture permeation and contaminants, such as
salts, even when they are applied correctly
Sacrificial coatings (contain a metal, usually zinc, that is anodic to steel, which
corrodes preferentially) - ANSWER -are coatings that are more active that the
metal surface they protect.
ex. inorganic zinc, hot dip galvanized, spray metallizing, including thermal spray
aluminum (TSA) or zinc (TSZ)
Inhibitive coatings act as a barricade, (epoxies, alkyds, and urethanes) -
ANSWER -actively slowing down the reaction at the anode, cathode, or both. To
achieve this, inhibitive coatings contain special pigments (i.e., chromates and
phosphates) that react with any moisture or oxygen entering into the coating itself.
the reaction of these pigments pacifies the steel by triggering the coating to form a
hard, non-reactive surface film that then interferes with the corrosion process.
Pigments - ANSWER -are the solid particles used to provide specific protective
mechanical, or decorative qualities to a coating
Binders/Resins - ANSWER -are materials that convert coatings from a liquid to a
solid state that forms a stable, protective film
Solvents - ANSWER -are the liquid component of a coating that is responsible for
dissolving the solid binder/resin
, Organic coatings (vegetable oils animal fats) - ANSWER -contain carbon and
hydrogen
Inorganic coatings (silicone or silicates - ANSWER -Do not contain carbon
Additives - ANSWER -are special-purpose ingredients that enhance the
performance of a coating
Which component of a coating can contain harmful Volatile Organic Compounds?
- ANSWER -solvent
Based on the galvanic series presented which three materials are commonly used
as galvanic anodes for carbon steel? - ANSWER -Zinc, aluminum, magnesium
A decrease in temperature will generally cause the corrosion rate to - ANSWER -
decrease
The electrolyte is a medium that carries - ANSWER -ionic current
A barrier coating interrupts the __________ of the electrochemical cell -
ANSWER -electrolyte
How do electrons that are produced in the oxidation reaction flow? - ANSWER -
From the anode to the cathode through the metallic path
Binder - ANSWER -Bonds pigments together and adhere to surface
Solvent - ANSWER -Liquid that dissolves solid resins
Pigment - ANSWER -Hides the substrate, provides decorative color, enhances
desired properties
Additives - ANSWER -Special purpose ingredients used to enhance the
performance
Vehicle - ANSWER -liquid portion of paint; pigment is dispersed in liquid
vehicle which is made of binder and solvent.
Corrosion - ANSWER -the deterioration of a substance, usually a metal from a
reaction with its environment