Steel is used in so many items that we use today that it’s hard to wonder about a world without it. Discovered around 2000 BCE, iron was used to replace bronze. This is because iron is harder, has a sharper edge, and is more durable than bronze. Iron was finally replaced by steel in 1870.
In the mid 1800s steel was expensive and hard to manufacture. The invention of the Bessemer converter, named after Sir Henry Bessemer, changed all that. This process allowed for the mass-production of cheap steel. Sir Henry created a converter which blew compressed air through molten metal. This allowed for molten pig iron to be cheaply be transformed into steel.
British inventor Robert Mushet improved upon Bessemer’s design. He found that the air blast was removing too much carbon and leaving behind too much oxygen in the metal. He discovered that by adding a small amount of molten spiegel (a compound of iron, carbon, and manganese) would fix the problem.
So next time you think of steel, you’ll have to thank Sir Henry Bessemer and Robert Mushet for pioneering the way steel is manufactured.