Spheroidal graphite iron production of furnace roof hangers

The wire rod mill of the Ajaokuta Steel Company Limited produces coils, wire rods and re-bars of different sizes. Without the furnace hangers, it will be difficult for the mill to continue to operate. This paper describes the production of furnace roof hangers that are required for re-heating furnace using the spheroidal graphite iron (SGI), highlighting the sand-casting process, charge calculation, and the chemical compositions. The facilities within the foundry shop of the steel company are used to produce furnace roof hangers. The available materials used for the casting of the hangers are the pig iron, scrap ends, foundry returns and magnesium. The process of production was performed through the reheating furnace for the heating of 120 m x 120 m x 120 m billets. One ton induction furnace of low frequency was used as the melting vessel. Also, 6 kg of magnesium was introduced in the ladle before the liquid metal was teemed into it. A Spectro analytical instrument was used to determine the chemical compositions of the materials before and after the casting processes. The analysis of the chemical compositions of produced sample of SGI are presented and discussed.

Research on Temperature Distribution and Stress Distribution Model of Prefabricate Block Electric Furnace Roof

Electric furnace roof is an important device for electric steel making, whose heat preservation performance and life-span have a direct impact on the economic benefits of iron and steel enterprise. Considered contact behavior between prefabricate block, this paper establishes the complete CAD/CAE model of the electric furnace roof with finite element software based on the theory of transferring heating subject, and respectively calculates the stable temperature and stress field of the firebrick roof and the prefabricate block roof in last melting stage, as is advantageous to analyze the level and the distribution of temperature and stress of electric furnace roof.