A Brief History of Steel Production
Steel is something we come into contact with every single day, but not many of us think about how we got this far to be able to use a material to create so much of the infrastructure we rely on. Here at Mundy Structural Steel, we are experts in steel fabrication in London, so we have used this experience to talk about the brief history of steel production.
The Bessemer Process
After the specialist production methods to create blister steel and cast steel, in the 17th century and 18th century respectively, the Bessemer Process essentially saw the start of the steel industry.
By 1856, the iron industry was under too much pressure from railroad growth, but steel was expensive and unproven, so Sir Henry Bessemer created a process using a ‘pear-shaped’ converter that could heat iron while blowing in oxygen. This removed the carbon for purer iron but was so efficient that too much carbon was being removed, which meant it could not be used for steel production and Bessemer had to repay his investors until a solution was found.
The solution was found by British metallurgist Rober Mushet when he created spiegeleisen using iron and manganese. The manganese, in the right quantity, removed oxygen and added carbon to iron in the right amount to create steel.
Phosphorous still remained, however, which meant only phosphorous-free iron from Wales and Sweden could be used. That was until Welshman Sidney Gilchrist Thomas added limestone to pig iron, which removed the phosphorous into the slag – birthing an effective version of the Bessemer Process.
This development increased steel production and reduced costs, leading to the steel price falling by 80% between 1867 and 1884 – essentially creating the steel industry.
The next development was from German engineer Wilhelm Siemens and produced steel from pig iron in shallow furnaces. It uses high temperature to burn off carbon and other contaminants, with heated-brick chambers below the hearth providing the heat. This changed later to use the exhaust gas from the furnace to maintain the high temperatures in the brick chambers.
This process was slower but could produce steel in larger quantities and periodic testing to ensure specific requirements are met. Scrap metal can also be used as a raw material.
By 1900, the open-hearth process primarily replaced the Bessemer Process.
Capitalists invested heavily in steel production in the late 19th century. This led to huge developments in industry and allowed Andrew Carnegie’s US Steel Company, launched in 1901, to become the first ever corporation to be valued at $1bn.
Electric Arc Furnace
After almost a century of the Bessemer Process and open-hearth production, Paul Heroult’s electric arc furnace (EAF) improved steel production further by passing an electric current through charged material, creating an exothermic reaction and temperatures up to 1800 degrees Celcius.
By WWI, this was used for the mass production of steel alloys and the low-cost investment in mills meant it competed strongly with the traditional open-hearth producers like Steel Corp. and Bethlehem Steel.
Being able to use 100% scrap or cold ferrous feed, requiring less energy and less money, as well as being able to stop and start the process at a low cost, meant EAF steel production grew quickly and now accounts for 33% of global steel production.
Currently, 66% of steel is produced in basic oxygen facilities, which utilise a process that separates oxygen from nitrogen and became feasible at an industrial scale in the 1960s. The process blows oxygen in large quantities into a furnace of molten iron or scrap steel, which is much quicker than open-hearth methods.
350 metric tons can be converted to steel in under an hour, which is why open-hearth is now extinct, with the last facility closing in 2001 in China.
Steel Has Come Along Way
In essence, the history of steel production has been tumultuous and has come along way since even before the Bessemer Process. Without the progression of the steel industry, it’s hard to say what might still be made of the previously popular iron or perhaps another element that came along to replace it.
Mundy Structural Steel
If you have a construction project in London and are looking for a steel fabrication company, contact Mundy Structural Steel today by calling 020 8818 6930 or filling out our simple contact form.