The Bessemer Processby Will Simons

-The Bessemer Process is a method of steel production created by Englishman Henry Bessemer.

-It involves forcing air through molten pig iron (iron with a high carbon content) to remove impurities like manganese, silicon, and carbon. -The process takes place in a steel container called a Bessemer converter.  Molten pig iron is poured into the converter as air is blown through multiple holes perforating the bottom.   -The air does not cool the iron, instead, it oxidizes the molten mass and raises the temperature even further.  This removes the impurities and rapidly reduces the carbon content to its desired level.

 

An Iron Carbon phase diagram explaining the various heat treatments of iron.

Before the Bessemer process, steel was too costly to make in great quantities.   Before the Bessemer process, steel could only be made through Benjamin Huntsman's crucible method.

The primary metal of the industrial revolution until then was iron.

Wrought iron has a low carbon content, which makes it softer and more malleable, while pig and cast iron have a high carbon content and are brittle. Steel has the ideal amount of carbon in it (.2% to 2.1%, depending on the grade).

Bessemer got the motivation for inventing the process when French army officer Claude-Etienne Minie expressed his reluctance to fire a 30 pound shot out of a 12 pound iron cannon.

Before the process, steel was made for around 50 pounds to 60 pounds (monetary) per ton. After, steel could be produced for around 7 pounds per ton. This made steel cost effective enough to mass produce and revolutionized weaponry, building, and many aspects of life. Steel rails replaced iron in the American railway system, making them safer. The mass production of steel led to the rise of the skyscraper in cities, allowing more people to move into them. Rich men were made from steel, with the most famous being Andrew Carnegie.   Jobs were created for unskilled laborers.Some argue that the mass production of steel greatly widened the gap between social classes in America and fed a long struggle between labor unions and large corporation. 

Without the mass production of steel, shipping would be miles behind what it is today.

Bessemer's process made steel comparably priced to wrought iron.  Steel allowed great strides in transportation, shipping, building and weaponry.  Higher strength steel components produced more powerful engines, guns, tanks, and naval ships.  The mass production of steel led to turbines and generators that made harnessing water and steam power plausible.  The effects of Bessemer's process extended across the world and have changed the way we live today.

                                Henry Bessemer                                                                           Andrew Carnegie