By: Austin Van Bruggen and Matthew Stein

What is Steel?  An alloy of iron and carbon.  One of the most commonly used materials today. It revolutionized:  Construction  Tool and machine making  Architecture

Steel is also…  Extremely strong.  Very durable.  Long lasting. Too good to be true? What’s the catch?

Pre-Bessemer Steel  Took too long to make.  Made in small quantities.  But mostly, it was very EXPENSIVE to make!!!!!  Cost about 40 pounds per long ton (2240 lbs).  Many thought it wasn’t worth the trouble of making. Until…..

Henry Bessemer  Developed the Bessemer process for steelmaking. Bessemer had many motives for inventing the Bessemer process, including:  Crimean War caused high demand for Steel and Iron.  Wanted to make stronger artillery.  Existing cannons weren’t strong enough.

Bessemer Process  Used a large container called a converter. Made of steel. Has a clay or silica lining. Has a carrying capacity of about 8 to 30 tons of molten iron.  Molten pig iron is poured into the Bessemer converter.

 Air is blown through the bottom of the converter and up through the molten iron.  This process is known as Oxidization or the Pneumatic Process.  This process only took around 20 minutes. Apposed to 3 plus hours.  Greatly increased annual steel production.  Reduced the cost substantially. Only about 7 pounds per long ton.

Crucible Steel Crucible steel was the most commonly used steel before the Bessemer process was introduced in  Any of the methods of making steel in a Crucible.  Has been used for well over 1000 years.

 The most common process was packing wrought iron into crucibles or an open hearth with charcoal.  It was heated to diffuse carbon into the iron to produce steel.  Was improved much later by Benjamin Huntsman.  Used coke fired furnace in which many clay crucibles are placed into.

Bessemer Steel vs. Crucible Steel Bessemer Steel was better than Crucible Steel in almost every way.  Was made faster.  Could more easily be adapted to fit individual needs.  Was much cheaper.  More could be made per load.  Was of better quality.

Variability of Steel The Bessemer process of steel allows for steel to be easily alloyed with other metals. Alloying is combining one metal with one or more other metals during the smelting process. When in combination with other metals, steel can have many different functions.

Steel Alloys Some steel alloys that are commonly used today are:  Chromium and Steel Hardness, strength, elasticity. Difficulty of acquiring rust and other discolorations.  Nickel and Steel Most commonly used steel alloy. Non-magnetic. Possesses a shock resistant quality.  Aluminum and Steel Smooth with high tensile strength.

Carbon Content Steel is an alloy of iron and carbon. Some of the qualities of steel rely on its carbon content. The higher the carbon content…  The strength and harness can increase with heat treating. This can make the steel less ductile.  The weldability of the steel decreases.  The melting point of the steel decreases.

Uses of Steel Today Steel is one of if not the most commonly used material used today. Because of its strength, durability, and adaptability, it is used in many different fields.  Construction  Weaponry  Transportation

Steel is used to make:  Gardening tools  Construction tools  Hygiene and health tools  Office supplies  Kitchenware  Sculptures

 Safety devises  Cars  Planes  Sports gear  Weaponry  Machinery made of metal/that contains metal parts

Steel Usage in Buildings Steel’s strength and durability make it a prime candidate for use in the construction industry.  Iron doesn’t last long enough and isn’t strong enough to support skyscrapers and other large buildings.  Builders wanted to eliminate the need for replacing buildings.  They want to build things that will be around longer than them.

Lasting Effects  In 1850, the production of steel in Britain was around 50,000 tons.  By 1880, the production of steel was about 1,300,000 tons.  Over 1,000,000 tons of this was Bessemer steel.  Henry Bessemer became a millionaire because of this and other inventions that he patented.  The Bessemer process was the most favored process for the development of steel until the middle of the 20 th century.

Open Hearth Process  The Bessemer converter was replaced by the open hearth furnace.  Made by Carl Wilhelm Siemens in the 1850’s.  Started being used for making steel in  It was slower, easier to control, allowed for the melting down and refining of scrap steel.  The Siemens-Martin process complimented the Bessemer process rather than superseding it.

Basic Oxygen Steelmaking  The open hearth process was superseded by basic oxygen steelmaking.  Similar to the Bessemer process.  Blows oxygen instead of air through the molten pig iron.  Reduced costs of production.  Reduced time of smelting from hours to under 40 mins.  Increased labor productivity.

Importance of the Bessemer Process The Bessemer process changed the world as we know it. It revolutionized construction and without it the Industrial Revolution wouldn’t have been possible. The processes that replaced it are, like many other scientific processes and inventions, just improvements upon previous works. The Bessemer process still has lasting effects to this day, and the world would be a very different place without.

EL FINAL