The Story of Iron and the Fight against Rust

We talk a lot about rust in these articles; about rust treatments, rust removers and rust converters, but we haven’t said a great deal about its mother lode – the most common element by mass on this planet – iron.

Although iron is all around us, it is too reactive with other naturally occurring chemicals such as oxygen and water, to exist in its elemental form – at least in the earth’s crust. Almost all the iron in the crust is in the form of oxides bound into silicate or carbonate minerals commonly referred to as iron ores. The word itself is Anglo Saxon and probably derived from the Scandinavian for iron – “iarn”.

So how did our ancestors discover this remarkable metal that was to transform our material world? Some believe that the first iron was produced when wood fires were lit on top of ore-bearing rocks. After a while the heat would have caused the carbon in the wood to react with the oxygen in the ore, leaving behind pure iron.

Smelted iron first occurs about 4,000 years ago but it took another 1000 years before formal iron production began for the manufacture of tools and weapons – starting in Mesopotamia (now Iraq) and then spreading into Europe and Africa during the Iron Age.

Iron continued to be to be used for tools and for weapons right through to the Industrial Revolution where it became the fundamental material for the construction of machinery, bridges, ships and buildings. But it was the discovery of steel and efficient methods for its production that really accelerated the use of iron.

Steel is a combination of iron, carbon and other alloys – the composition determining the characteristics of the finished product. Basic steel, containing about 1% carbon, is the most common form, used for car bodies and ships hulls, in construction and in machinery. Alloys such as nickel and tungsten are added to provide strength in different applications – nickel where tensile strength is needed and tungsten where strength at high temperatures is important.

But in spite of its strength and versatility, iron had one fatal flaw, rust – its impact no better illustrated than in the US where the area once known as the industrial heartland of the USA was renamed the Rust Belt as the car and steel industries collapsed in the 1980s.

The Roman author and philosopher, Pliny the Elder, said of iron: “Nature, in conformity with her usual benevolence, has limited the power of iron, by inflicting upon it the punishment of rust; and has thus displayed her usual foresight in rendering nothing in existence more perishable, than the substance which brings the greatest dangers upon perishable mortality.”

Pliny didn’t count on man’s ingenuity and determination to find a cure. It was the discovery of an iron alloyed with chromium, nickel and other metals, which would finally, though at a price, put paid to iron’s old enemy. Stainless steel was born in the early days of the 20th century.

It would have surprised him too, no doubt, that by wiping his sword with a magic potion called rust remover, the scourge could be eliminated from his shiny blade or, using another magical ointment, called rust converter, his rusty old shield could be restored and protected for years to come.