1856

Henry Bessemer developed a process for bulk steel production. He blew air in an
acid lined pear shaped vessel. The process is termed Acid Bessemer Process. No heat was supplied from outside. It did not become possible for him to remove S and P. Moreover oxygen content of steel was high. Hot shortness was a problem during rolling.

1878

S.G.Thomas and Gilchrist developed basic Bessemer process. They lined the vessel with basic refractory. High nitrogen content of steel, no usage of scrap and plugging of bottom blown tuyeres were the problems.

1868

Siemens’s and Martins developed Open Hearth Process. In this process thermal energy was supplied through combustion of gaseous and liquid fuels thus enabling them to use steel scrap in addition to other charge materials. Open Hearth Process for steelmaking has dominated the steel production for over approximately a century.

1900

Paul Heroult showed use of electricity for steel production. The quality of steel was better than open hearth process. The process was mainly used to produce alloy and special steels from scrap.

1950

Oxygen was used to produce steel at Linz and Donawitz and process was termed LD Converter steelmaking. Oxygen was supplied through a consumable single hole lance from top of a pear shaped vessel.

1960

Continuous casting was developed. Today most of the steel plants use continuous casting to produce billet/bloom/slab

1970 and till date