Iron was used to make the first railroad tracks.
Pure iron is a soft metal and rarely found in nature. The only pure iron known to exist comes from fallen meteorites. Iron is found in other elements, iron oxides being the most common. The minerals closest to the earth's surface have the highest iron content and are called iron ores. Iron ore is processed into different types of iron. Pig iron is limited in what it can be used for so it is converted into steel alloys. Cast iron and wrought iron are two common forms of iron in production today.
The Iron Age
The Iron Age began about 1000 B.C. During that time, progress was dependent on tools made of iron. This was largely the case until the Industrial Revolution which began around the middle of the eighteenth century. The Industrial Revolution brought about large mechanical production systems that produced machine tools and other equipment made from iron and steel.
Mid 1800's
The mid-1800's brought about many changes in the metal industry. The Bessemer process was invented which converted iron to steel. Pig iron was placed in a converter and blasted with extremely hot air. The Bessemer converter produced a high quantity of steel used for ships, railroads, bridges and buildings. A problem still existed with this new steel until Robert F. Mushet, an English metallurgist discovered fix it. The steel was brittle due to containing oxygen, phosphorus and sulfur. Mushet discovered that adding an iron alloy that contained manganese would remove the oxygen and that adding limestone would remove the phosphorus and most of the sulfur.
Mid to Late 1800's
From 1864 to 1877 improvements were made by adding scrap steel to molten iron, which created a hardened steel alloy that quickly became popular for commercial use. In 1877 Mushet made a high carbon steel that gave tools a longer life and in 1888 a chromium steel alloy was also produced. In 1882 a hardened manganese tool steel was invented but not put into production until a few years later.
Early to Mid 1900's
The electric furnace was invented in 1879 but was not used much until around 1910 due to the high cost of electricity. From 1910 to 1954 the electric furnace was used for nearly all steel production. 1954 brought about the first oxygen furnace. According to Science magazine, most of today's steel is made via an oxygen or electric furnace.
Modern Day
Modern tools are made from hardened steel alloys. Iron tools have not been produced since the mid 1800's. Branding irons are still made of cast iron as well as cast iron cookware. Iron is too soft and brittle for use as tools although iron ore is used along with other metals to form modern day steel. Wrought iron is currently used in the production of ornamental products.
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