Wrought iron: 0% carbon
Steel: .1-1.5% carbon
Cast iron: 2.5%+ carbon
Iron was made by heating up the ore hot enough to basically soften then
the resulting bloom was beaten to compact it and get rid of impurities.
If it got too hot, unlikely before blast furnaces, you got cast iron
which was not useful for most purposes. As mentioned earlier the first
methods of steel making were introducing carbon into wrought iron by
baking it for several days at about 1000 degrees F. Ther first real
innovation on this process came in about 1740 with the introduction of
crucible steel, a technique that takes the steel from the first process
and refines it further. This is still not a very productive process,
mass steel production then starts with the widespread introduction of
the Bessemer process, which was partially use in minor ways in the 17th
century but really takes off in the mid-1850's, steel starts out at 2%
of wrought iron production and skyrockets. Every once in a while a
factory in Europe will make some wrought iron for the few people who
still use it, but now steel is king!
~???? BC - iron in use
~1200 BC - steel in use
~600 BC - China uses cast iron for tools, 1400 AD for Europe!
~1400 AD - Europe begins the use of blast furnaces, more productive
~1700 AD - Coal in use as fuel, up till now everyone uses charcoal,
which limits how fast iron can be made since you have burn forests to
supply a foundry
1784 AD - Puddling furnace introduced, more productive
- AD - What can I say? how many TONS! of steel do you own
Sorry for boring everyone...