Corrison of iron

Introduction…………………………6 Electrochemical Mechanism (rusting)……7 Methods of Prevention of Corrosion…….8 Aim of the project……………………9 Requirement…………………………10 Procedure……………………….….11 Observation…………………………12 Conclusion………………………….13 Introduction: Metals and alloys undergo rusting and corrosion. The process by which some metals when exposed to atmospheric condition i.e., moist air, carbon dioxide form undesirable compounds on the surface is known as corrosion, The compounds formed are usually oxides . Rusting is also a type of corrosion but the term is restricted to iron or products made from it .Iron is easily prone to rusting making its surface rough. Chemically, rust is a hydrated ferric oxide Titanic‘s bow exhibiting microbial corrosion damage in the form of ‘rusticles’ Rusting an Electrochemical Mechanism ; Rusting may be explained by an electrochemical mechanism. In the presence of moist air containing dissolved oxygen or carbon dioxide, the commercial iron behave as if composed of small electrical cells. At anode of cell, iron passes into solution as ferrous ions. The electron moves towards the cathode and form hydroxyl ions. Under the influence of dissolved oxygen the ferrous ions and hydroxyl ions interact to form rust, i.e., hydrated ferric oxide. Methods of Prevention of Corrosion and Rusting Some of the methods used to prevent corrosion and rusting are discussed here : 1) Barrier Protection ; In the method , a barrier film is introduced between iron surface and atmospheric air. The film is obtained by painting,varnishing etc. 2) Galvanization ; The metallic iron is covered by a layer of more reactive metal such as zinc. The active metal losses electrons in preference of iron. Thus, protecting from rusting and corrosion. Galvanized Metals Aim of the project; In this project the aim is to investigate effect of the metals coupling on the rusting of iron. Metal coupling affects the rusting of iron . If the nail is coupled with a more electro-positive metal like