2014 Volume 100 Issue 4 Pages 456-471
As steel industry of our country developed, upsizing of steel materials and the mass production of various steel grades such as the high alloyed steel and the high quality steel have been requested. Crude steel was mass-produced from the late 1950 s by the primary refining process of the BOF and the electric arc furnace. After the initial period, the secondary refining technology replaced a part of the primary refining process function, improved the efficiency of the primary refining process by adding the new function and supplied the molten steel to the casting process stably. Furthermore, the secondary refining process enabled the production of the high quality steel materials and progressed rapidly in the after 70 s.
In our country, nearly 100% of the BOF steel and the electric arc furnace steel are treated by the secondary refining process now. Vacuum degassing is performed for approximately 80% of BOF steel. A variety of secondary refining processings are carried out in the electric furnace for the production of special steels, and the LF processing ratio reaches 95% in the electric arc furnace for common steel production. Secondary refining process comes to take charge of a reduction refining function.
In this paper, the development of the secondary refining process and technology, and its history are looked back, and the future prospects are reviewed.