Henry Bessemer
Inventor of Bessemer Steelmaking Process
Bessemer was born on January 19, 1813, in Charlton, England, to an engineer father who recognized and encouraged the boy’s mechanical tendencies. His first major invention, completed in 1833, was a typesetting machine for the prevention of government document forgeries. He also devised an improved graphite pencil, a process for making imitation lace, and a machine to make cheaper “gold powder,” a brass based substance mixed into paints to create a glittery effect.
During the Crimean War (185356), demand arose for a new metal to use in making guns. The two available types of iron were flawed: cast iron contained impurities and was brittle, while wrought iron, which was relatively pure, was difficult and time consuming to manufacture. Steel, defined as iron with less than 2% carbon, was non pliable and costly to make. In 1855, while attempting to fabricate stronger cast iron, Bessemer developed a quick, inexpensive technique that produced a more valuable steel, an alloy that could withstand considerable stresses.
The Bessemer process, as it came to be known, involves forcing air through a drum of molten crude iron, musing impurities to burn off without the consumption of fuel. Some of the carbon remains in the iron, producing a strong, light, and versatile metal. However, Bessemer had unknowingly used phosphorus free iron, and other metallurgists, using iron that contained phosphorus, failed to reproduce his results. Phosphorus, which lowers the melting point of iron, allowed more impurities to remain. Such impurities were not removed by the original Bessemer process, whereas they were effectively removed by traditional methods of manufacturing cast and wrought iron. To overcome this obstacle to success, Bessemer moved to northwestern England, where phosphorus free iron ore was plentiful, and opened a steel foundry.
In his last years, Bessemer engineered a solar furnace, a telescope, and equipment for polishing diamonds. He was knighted in 1879; he died in London on March 15, 1898.
Henry Bessemer’s Legacy
Although other innovations outproduced the Bessemer process by the end of the century; Bessemer was responsible for initiating the wide use of steel that continues today.
Sidney Gilchrist Thomas and Percy Gilchrist solved the phosphorus problem of the Bessemer process around 1878. They realized that the weakness lay not in the process itself, but in the ingredients that lined Bessemer’s drums. They added limestone to the drum material, which created the necessary environment for the removal of phosphorus from molten iron.
The Bessemer process enormously increased world steel output and transformed many metal industries. Steal became a readily available and highly prized product for numerous construction purposes, including railway lines. Steal replaced wrought iron in ship plate, girders, sheet, rods, wires, rivets, and various other metal components.
Bessemer’s success established metallurgy as a distinct discipline on the border between science and technology. Researchers experimented with steel by varying the carbon content and adding ingredients (such as manganese, tungsten, chromium, and vanadium): different types and qualities of steel resulted. The ancient craft of metallurgy thus acquired a scientific framework.
In 1861 Friedrich and Wilhelm Siemens invented the regenerative blast furnace, in which waste heat is efficiently recirculated to preheat the furl and air entering the furnace. This method achieved higher temperatures with better fuel economy than previous blast furnaces, and it allowed the use of lowgrade coal as fuel. Pierre and Emile Martin were the first to modify the regenerative furnace for making steel, yielding larger quantities and allowing tighter quality regulation than the Bessemer process. Later in the nineteenth century, the Bessemer process was overtaken by the Siemens Martin process. United States industrialist Andrew Carnegie contributed to the demise of the Bessemer process by adopting the Siemens Martin system for his steal mills.
Henry Bessemer – 1813-1898