• Coatec India

Phosphating System

Phosphating System is the mostly used pre-treatment method called as phosphating. Phosphate coating is the layer formed on surface, which includes iron, zinc or manganese crystals. There are three types of phosphate coatings: iron, zinc and manganese. The coating is used to cover iron and steel surfaces. immersion and spraying are the most commonly used methods. Phosphate coating reaction is known as the reaction between phosphoric acid and metal (acid ? base reaction). Metallic phosphate becomes insoluble on the surface and forms a layer with metallic colour. Passivation is used at the last stage of phosphating process. The surface coming after phosphating is not in homogeneous form. Passivation prevents air accumulation under paint cover. Passivation neutralizes the anions and cations that come with water. Phosphating system parts should not be held in passivation bath.