MMET 207 Corrosion

anode

anode tries to give its electrons to the cathode unsuccessfully, corrodes

cathode

negative side of battery that does not get the electrons from the anode, does not corrode

electrolyte

allows the movement of electrons across the battery

Corrosion

loss of mechanical properties due to the environment

Galvanic Series

high on series = anode (more corrosion)
low on series = cathode

Corrosion Factors

inclusions of conductive materials, grain boundaries, local cold work, local stress, precipitates

Corrosion Allowance

adding extra metal to account for corrosion metal loss

Basic Types of Corrosion

1. Uniform (corrosion over a large area that is uniform)

2. Pitting (small localized area of corrosion)

3. Crevice (crack that allows corrosion)

4. Galvanic (two metals of different potential together)

5. Stress Corrosion Cracking

6. Intergranular Attack (corroding inside grain boundaries)

7. Dealloying (decarbonization, depleting materials)

8. Erosion (sand)