Henry Bessemer - The Steel Man

Henry Bessemer and the Production of Steel

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Sir Henry Bessemer, an Englishman, invented the first process for mass-producing steel inexpensively in the 19th century. It was an essential contribution to the development of modern day skyscrapers.

The First System for Manufacturing Steel

An American, William Kelly, initially held a patent for "a system of air blowing the carbon out of pig iron," a method of steel production known as the pneumatic process.

Air was blown through molten pig iron to oxidize and remove unwanted impurities.

This was Bessemer’s starting point. When Kelly went bankrupt, Bessemer – who had been working on a similar process for making steel – bought his patent. Bessemer patented "a decarbonization process utilizing a blast of air" in 1855.

Modern Steel

Modern steel is made using technology based on Bessemer's process. On the making of the first steel ingot, Bessemer said:

"I well remember how anxiously I awaited the blowing of the first 7-cwt. charge of pig iron. I had engaged an ironfounder's furnace attendant to manage the cupola and the melting of the charge. When his metal was nearly all melted, he came to me and said hurriedly, "Where be going to put the metal, maister?" I said, "I want you to run it by a gutter into that little furnace," pointing to the converter, "from which you have just raked out all the fuel, and then I shall blow cold air through it to make it hot."

The man looked at me in a way in which surprise and pity for my ignorance seemed curiously blended, and he said, "It will soon be all of a lump." Notwithstanding this prediction, the metal was run in, and I awaited with much impatience the result. The first element attacked by the atmospheric oxygen is the silicon, generally present in pig iron to the extent of 1 1/2 to 2 percent; it is the white metallic substance of which flint is the acid silicate. Its combustion furnishes a great deal of heat, but it is very undemonstrative, a few sparks and hot gases only indicating the fact that something is going quietly on.

But after an interval of 10 or 12 minutes, when the carbon contained in grey pig iron to the extent of about 3 percent is seized on by the oxygen, a voluminous white flame is produced which rushes out of the openings provided for its escape from the upper chamber, and it brilliantly illuminates the whole space around. This chamber proved a perfect cure for the rush of slags and metal from the upper central opening of the first converter. I watched with some anxiety for the expected cessation of the flame as the carbon gradually burnt out. It took place almost suddenly, and thus indicated the entire decarburisation of the metal.

The furnace was then tapped, when out rushed a limpid stream of incandescent malleable iron, almost too brilliant for the eye to rest upon. It was allowed to flow vertically into the parallel undivided ingot mould. Then came the question, would the ingot shrink enough, and the cold iron mould expand enough, to allow the ingot to be pushed out? An interval of eight or 10 minutes was allowed, and then, on the application of hydraulic force to the ram, the ingot rose entirely out of the mould and stood there ready for removal."

Bessemer was knighted in 1879 for his contributions to science. The "Bessemer Process" for mass-producing steel was named after him.

Robert Mushet is credited with inventing tungsten steel in 1868, and Henry Brearly invented stainless steel in 1916.