Corrosion Flashcards
What is corrosion
Corrosion is the deterioration of metals that result from an electro chemical reaction between a metal and its environment
What are the 3 conditions for corrosion to occur
A difference in electric potential between the anode and cathode
Metallic connection between the anode and cathode
A continuous liquid path ie and electrolyte
Way to measure corrosion
Depth gauge
NDT
Optical depth micrometer
Straight edge
What are 3 types of coatings to prevent corrosion
Metallic
Surface conversion
Organic
What are metallic coatings
Cladding
Electroplating
Spraying
What are surface conversion coatings
Anodising
Alodine
Chromating
Phosphating
What are the 4 steps to corrosion removal
Clean and strip paint from area
Remove corrosion products
Restore surface treatments and protective films
Restore surface finish
What are the 10 factors affecting corrosion
Type pf metal Heat treatment + grain direction Dissimilar metals Availability of oxygen Length of exposure Temperature Presence of electrolytes or salts Electrolyte concentration Anode/Cathode surface area Mechanical stress
what are the three types of CPC
Type A, B and C
Short term, medium term, and long term application
What is the definition of
If the cathode is larger than the anode what will happen
It will corrode faster. Big Cathode = Big suck
What are the 13 types of corrosion
Uniform surface Microbial Pitting galvanic/Dissimilar metal Crevice Filiform Intergranular Exfoliation Erosion Stress Corrosion fatigue Fretting Hot
