Binder
Bonds pigments together
Solvent
Liquid that dissolves solid resins
Pigment
Hides the substrate provides decorative color, enhances desired properties
Additives
Special purpose ingredients to enhance the performance
Vehicle
liquid portion of the coating
Passivation
A layer of oxides formed on the surface of a metal that provides corrosion protection. Stainless steel for example.
Corrosion
The deterioration of a material, usually a metal, that results from a reaction with its environment
Elements of Corrosion Cell
Anode, Cathode, Metallic Pathway, Electrolyte
Anode
Area of metal surface that corrodes
Function of Electrolyte
It allows the passage of ions to conect the corrosion cell
Function of Metallic Pathway
It allows the flow of electrons to connect the corrosion cell
Galvanic Series
A listing of metals in order of reactivity (more or less noble) in seawater at 77*C
Rules of Galvanic Corrosion
The less noble ( or more reacitive ) metal when connected to a more noble ( or less reactive metal ) will corrode preferentially
Localized Corrosion
Typically Pitting and Crevice Corrosion. It is typically of the most concern as damage is concentrated and loss of integrity or structural failure can result.
5 Important Factors that affect the rate of corrosion
Humidity, oxygen, chemical salts, temperature and pollutants
General Corrosion
Relative uniform metal loss, general thinning of the affected surface and rarely contributes to catastrophic failure
Two broad classifications of coatings are
Organic and Inorganic
Two primary components of liquid applied coatings
Pigment and vehicle
List three desirable properties of a coating
Water resistance, cohesion strength, chemical resistance
List some of the common tools/methods used for corrosion control
Design, Inhibitors, Material selection, Cathodic protection, Protective coatings, Alteration of the environment
