Explain the following methods to protect metals from corrosion:
(a) Galvanization (b) Passivation

Explanation

(a) Galvanization : Galvanization is the process of coating metal surface with zinc so that the surface do not corrode. The most common method in hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc. Galvanizing protects in a number of molten zinc. Glavanizing protect in a number of ways. It forms a barriers that prevents metal. The Zinc serves as a reaching the underlying metal. The zinc serves as a sacrifical anode so that even if the coating is scratched, the exposed metal will still be protected by the remaining zinc. The zinc protects its base metal by corroding before the metal. The zinc surface reacts with the atmosphere to form a compact adherent patina that is insoluble in rainwater.
(b) Passivation : Passivation in the treatment of the surface of stainless steels, often with acid solutions (or pastes) to remove contaminanuts and promote the formation of the passive film on a freshly created surface (e.g., through grinding maching or mechanical damage). Common passivation treatments include nitric acid `(HNO_(3))` solutions or pastes which will clean the steel surface of free iron contaminants. Care must be taken in selecting and using passivation treatments to ensure the selected treatmet will target the contaminant. passivation will also aid in the rapid development of the passive usually result in a marked change in appearance of the steel surface.
Advantages of passivation:
1. Improved Corrosion Resistance.
2. Uniform, Smooth appearance and Finish
3. Deburring (Polished surface)
Improved and extended life of product.