6.4 Corrosion Flashcards
Reaction between metal and environment occurs in what 2 ways
1- chemical ( oxidation )
2- Electrochemical ( Galvanic )
what is galvanic action
Two dissimilar metals in contact with an electrolyte, causing the less noble metal to corrode
What colour is copper corrosion
Green
What is another name for copper corrosion
Verdigris
What are the 3 requirement for corrosion
Anode ( weak metal )
Cathode ( Noble metal )
Electrolyte ( Conductive Materials )
What effect does damp areas have on corrosion
Damp areas will accelerate corrosion
In an acid spillage what mix is used to neutralise the acid
use 10% baking soda by weight of the spillage
How is metal protected from corrosion
By chemical or electrolytic methods
What is andoizing
Dipping metal in electrolyte solution and passing current through it
what is metal spraying
Metalic coating by spraying molten metal onto a surface
what are the two methods of electroplating
Bath / Vat & Barrel method
What is hot dipping
Dipping 1 metal into another molten metal to form a thin coating
