Question

preventions for corrosion

Answer 1

galvanization : giving thin coating of irons 
tinning: coating of tin
annodizing: metals are electrically coated with a thin strong film of their oxides

and some are coating,electrolytes etc.

Answer 2

u can paint it as it prevents from corrosion or u can grease it with oil so that the iron oxide that is formed due to the oxygen content in the air starts to remove ..