What are methods for reducing Corrosion onboard?

Following methods used on ships to reduce corrosion

1. SACRIFICIAL ANODIC PROTECTION METHOD.
2. IMPRESSED CURRENT CATHODIC PROTECTION METHOD

1. SACRIFICIAL ANODIC PROTECTION METHOD.

In this method, the metallic structure to be protected is made cathode by connection it with more active metal (anodic metal).

Hence, all the corrosion will concentrate only on the active metal. The parent structure is thus protected. The more active metal so employed is called sacrificial anode.

The corroded sacrificial anode block is replaced by a fresh one. Metals commonly employed as sacrificial anodes are magnesium, zinc, aluminium and their alloys. Magnesium has the most negative potential and can provide highest current output and hence is widely used in high resistivity electrolytes like soil.