Question

With respect to galvanic corrosion, state:

a) 3 conditions that must exist in order for it to occur.
b) 4 conditions that affect the rate at which it occurs.

Answer 1

Galvanic corrosion requires two dissimilar metals or materials with different electrode potentials, a conductive medium for ion transfer, and an electrical path for electrons. The rate of galvanic corrosion is affected by the potential difference between metals, the size of anodic/cathodic areas, the medium's conductivity, and the condition of any protective coatings.

Step-by-step explanation:

With respect to galvanic corrosion, state:

1. 3 conditions that must exist in order for it to occur:

• Presence of two dissimilar conductive materials (usually metals) that have different electrode potentials.
• A conductive medium, such as a salt solution or humid environment, that allows for the transfer of ions.
• An electrical path for electron transfer between the two dissimilar metals or sites.

4 conditions that affect the rate at which it occurs:

• The difference in electrode potentials between the two metals involved; the greater the potential difference, the more rapid the galvanic action.
• The relative size of the anodic and cathodic areas; with larger cathodic areas tending to accelerate the corrosion of the anodic areas.
• The conductivity of the connecting medium; higher conductivity mediums increase the corrosion rate.
• The presence of protective coatings and their integrity; scratches or damages to protective coatings can lead to increased galvanic activity.