The process in which metal surface is made inactive is called:

Passivation involves creation of an outer layer of shield material that is applied as a microcoating, created by chemical reaction with the base material, or allowed to build from spontaneous oxidation in the air.

Galvanization is the process of applying a protective zinc coating to steel or iron, to prevent rusting

Corrosion is a natural process, which converts a refined metal to a more chemically-stable form, such as its oxide. 

Pickling is the process of preserving or expanding the lifespan of food by either anaerobic fermentation in brine or immersion in vinegar.