Electric furnace steelmaking is a iron and steel smelting method with electricity as the heat source. There are two forms: one is electric arc furnace and the other is induction furnace.
As early as 1878, Siemens in Germany has used electric arc furnace to melt scrap steel. But at that time, the electricity bill was expensive and the supply was insufficient, so the law could not be made.
1898, an Italian named Stowe obtained a patent for steelmaking directly with iron ore in an electric arc furnace. 1900 French metallurgist Herut improved Stosa's invention and established the first industrial arc steelmaking furnace. An arc is generated between the huge carbon electrode on the top of the furnace and the scrap steel with known composition put into the furnace, and the resulting high temperature melts the scrap steel. The steel produced by this method is relatively pure. Other components can be added as needed to change the composition of steel; Limestone or fluorite can also be added to absorb impurities.
Since then, in some countries such as Germany, the combination of electric furnace and converter has been used to make steel. First, pig iron is blown in an alkaline converter to remove silicon, manganese and most of carbon, and then transferred to an alkaline electric arc furnace to further remove phosphorus and carbon until the required content is reached, so that the composition of each furnace of steel is basically the same.
Ferranti, an Italian, obtained the patent of induction furnace in 1887. He first used high-frequency induction furnace to melt metal. Using high frequency alternating current, with the help of eddy current, the material in the coil can be induced to generate heat and even melt. Swede Kling established the world's first induction furnace for industrial production in 1899. 1907 An experimental induction furnace was established in Sheffield, England, which can produce 2 tons of steel castings. 1925 The motor generator set invented can obtain a suitable current frequency (500-3000 cycles per second), thus accelerating the development of induction furnaces and gradually replacing glycoside crucible furnaces to produce high-quality tool steel. Induction only melts without melting, so that the composition of steel is uniform.
Electric furnace can smelt alloy steel with various properties.