Corrosion
Posted: Tue Jun 25, 2013 2:27 am
Corrosion as a natural process commonly known as 'rust' or 'rusting' on metal surfaces such as Iron or Steel is often a problem for the Painter. It is a major problem for the Protective Coatings Industry in terms of its financial cost and its removal by means of suitable Protective Coatings. The Domestic Painter will often encounter corrosion in preparing and repainting of such metallic surfaces such as galvanized iron and various ferrous metals such as iron and steel. These are all used in guttering, downpipes, fencing, balustrades and of course roofing. But what is Corrosion you may well ask?
Corrosion is defined as" the destruction or deterioration of a material because of its reaction with the environment". Hence, corrosion is usually chemical in nature and demonstrates the tendency of steel which is made from iron ore found in the natural world to revert back to its original state as iron ore. Such a natural process is visually observed by the presence of rust or rusting which is a term reserved for corrosion of iron and steel and may be known chemically as ferric hydroxide (Fe(OH)3).
From the foregoing we see that corrosion is a chemical process because of the reaction of a metal with its environment which forms other compounds, such a reaction is electrochemical or more commonly known as electrolytic. This reminds us of the simple function of a battery which by means of a chemical reactions causes an electric current to flow which is utilized for some work. This simple example illustrates the benefits of the corrosion process.
The corrosion process consists of four major components well illustrated by means of a simple dry cell or wet cell battery. These are the anode, the cathode, conductor which connects the anode and cathode and the electrolyte which is the chemical or solution in which the anode and cathode are immersed. Further explanation of these will be in a future article.
Neil Mc Fadzen
National Institute of Painting and Decorating
Cert 3 in Surface Preparation and Coating Application TAFE
NACE Coating Inspector Level 2-Certified
Corrosion is defined as" the destruction or deterioration of a material because of its reaction with the environment". Hence, corrosion is usually chemical in nature and demonstrates the tendency of steel which is made from iron ore found in the natural world to revert back to its original state as iron ore. Such a natural process is visually observed by the presence of rust or rusting which is a term reserved for corrosion of iron and steel and may be known chemically as ferric hydroxide (Fe(OH)3).
From the foregoing we see that corrosion is a chemical process because of the reaction of a metal with its environment which forms other compounds, such a reaction is electrochemical or more commonly known as electrolytic. This reminds us of the simple function of a battery which by means of a chemical reactions causes an electric current to flow which is utilized for some work. This simple example illustrates the benefits of the corrosion process.
The corrosion process consists of four major components well illustrated by means of a simple dry cell or wet cell battery. These are the anode, the cathode, conductor which connects the anode and cathode and the electrolyte which is the chemical or solution in which the anode and cathode are immersed. Further explanation of these will be in a future article.
Neil Mc Fadzen
National Institute of Painting and Decorating
Cert 3 in Surface Preparation and Coating Application TAFE
NACE Coating Inspector Level 2-Certified