Electric arc furnace steelmaking is based on electrodes to generate arcs, so that electric energy can be changed into heat energy in the arc, melting furnace burden and removing impurities such as sulfur and phosphorus, adding necessary elements (such as carbon, nickel, manganese, etc.) to smelt steel or alloy with various properties. Electric energy heating can accurately control the temperature of the furnace and produce low temperature waste gas. The heat efficiency of the arc steelmaking furnace is higher than that of the converter.
Technology development has a history of about 100 years in EAF steelmaking, although other methods always face the steelmaking challenges and competition, especially the high efficiency oxygen steelmaking impact, but the proportion of steel production of EAF steelmaking in the world steel output is still rising year by year. In the early 1990s, steel produced by EAF in the world accounted for 1 / 3 of the total steel output. In some countries, EAF was the main steelmaking technology in some countries, and the proportion of steel produced by EAF smelting was 70% higher than that in Italy.
In 1980s, widespread in the EAF steel production in continuous casting, and gradually formed a "energy-saving production process of a scrap preheating electric arc furnace smelting a refining continuous casting a continuous rolling, arc furnace is mainly used for rapid equipment scrap as raw material of steel-making. In order to fundamentally overcome the ultra high power AC arc furnace arc instability, three-phase power supply and current unbalance and severe impact on the power grid and the research of DC arc furnace, and put into industrial application on first Century 8O in the mid-1990s, DC arc furnace using only 1 root of the graphite electrode has been widely used in the world in 90s (2 with some graphite electrode DC arc furnace).
Greatly reduce the consumption of graphite electrodes is the greatest advantage of the DC arc furnace, before the end of 1970s, AC arc furnace per ton of steel consumption of graphite electrode in 5 ~ 8kg, graphite electrode costs accounted for 10% of the total cost of steel to 15%, although taken a number of measures, so that the graphite electrode consumption decreased to 4 6kg, or production costs accounted for 7% 10%, the use of high power and ultra high power steelmaking method, electrode yak is reduced to 2 ~ 3k.g / T steel, DC arc furnace which uses only 1 graphite electrode, graphite electrode consumption can be decreased to 1.5k.g / T steel under.
Both theory and practice show that the single consumption of graphite electrode can be reduced by 40% to 60% compared with the AC arc furnace.