Since the world's first industrial electric arc furnace was introduced in 1906, the history of electric arc furnace steelmaking has been 70 years. However, before the second world fade, due to the high cost of electricity and the lack of material restrictions, the level of electric arc furnace equipment and technology were still in the stage of continuous improvement. After World War II, the large-scale electric equipment and the improvement of steelmaking equipment and technology made the development of frozen steel in electric arc furnaces very fast. Especially in the past 20 years, with the rapid development of the oxygen top-blowing converter 44 method, the original open-hearth steelmaking method that consumed scrap steel has been increasingly replaced by the converter method that mainly uses molten iron charge, thus causing new changes in the supply and demand relationship of raw materials in the entire iron and steel industry. This requires the development of "scrap-eating" electric arc furnaces to balance. It can be said that electric arc furnace parts and top-blowing oxygen converters complement each other and become the two main steelmaking in the world in this century.

At present, the general trend of electric arc furnace development in the world is:

Furnace capacity At is becoming larger and larger, high-power, ultra-high-power power supply and off-furnace refining technology are developing rapidly, and the use of sponge iron steelmaking and automated continuous production have received widespread attention. Large pan electric arc furnace is conducive to improving the productivity of the electric furnace, reducing power consumption, reducing investment, simplifying the production process and the fork in the factory and workshop v_. (I effectively exert the effect of mechanization and automation, and realize automatic and continuous production explosion.) Because of this, at present, some major steel-producing countries in the world are moving towards furnaces, 11N-I large-scale development, and 600-ton large-scale electric arc furnaces have appeared. The large-scale capacity of the furnace is compatible with the large-scale capacity of the transformer, and the effective matching of the two can fully exert its effect. The so-called ultra-high power electric arc furnace means that the transformer capacity per ton of steel is more than twice the ordinary power rate. It is similar to an ordinary power furnace, in addition to moving, tilting, some can also rotate a certain angle to change the relative position of the electrode and the furnace lining K} t11. The "cold point" area of the molten pool is inserted into the oxygen gun (or urban spray gun) from the furnace wall or roof, and the energy altar is centrally supplied, so that the melting time of 100 tons of steel is shortened to 1~1.5 hours. As a kind of scrap steel or sponge iron melting equipment, with furnace refining, can greatly improve the productivity and equipment utilization rate of steel, improve the quality of steel, reduce various consumption, and greatly reduce the cost of steelmaking. In foreign countries, such as the United States, since the adoption of ultra-high power technology, the electric arc furnace, which originally mainly produced special steel, has gradually changed to the production of ordinary +1.7 9 with refining technology outside Shanghai, so that the quality of steel has been improved, and steel output has gradually approached the oxygen converter).

The so-called annealing furnace smelting is to put the general steelmaking: the refining tasks that should be completed in the furnace such as detachment. K. Desulfurization, de-de-urbanization, degassing, de-inclusion, and adjustment of molten steel composition and temperature are moved to ladle or other special containers to obtain the comprehensive technical and economic effect of improving the quality bearing of 1}'9. In this way, steelmaking is divided into two steps, so it is also called the secondary steelmaking method. The general steelmaking furnace in which the first step is carried out for primary refining is called the primary furnace, and the container that is dedicated to refining in the second step is called the refining furnace. Looking at the refining and finding technique outside the furnace, it can be roughly divided into two categories: one is the device (well furnace) that publishes the use of the light oxygen reaction under the real space for desalination and degassing. Such as VOD public (true air oxygen blowing decarburization), DH method (vacuum sodium package degassing), RH method (vacuum cycle degassing) and so on. One is to use the dilution effect of neutral gas rest, such as ammonia, grasping, and water vapor, to reduce the partial pressure of CO, thereby accelerating the carbon-oxygen reaction and promoting the refining of degassing. Such as AOD decarburization (cylinder oxygen decarburization refining), SOD method (water vapor decarburization refining) and so on. Sponge iron steelmaking, some people call direct reduction method. It is to pre-sinter the selected iron ore to make it into a sponge iron pellet with an iron content of more than 90%, and then directly use this pellet to make steel in the electric arc furnace, hence the name. The law began experimentation in 1961 and has developed rapidly over the years. At present, the total production capacity of sintered iron ore plants in the world has reached nearly 10 million tons. It not only adds the new Nil raw material for electric arc furnace steelmaking, but also lays the foundation for fully continuous steelmaking. Regarding the continuity of production operations, at present, it is mainly the joint use of melting equipment, so that the function of Huaben melting equipment is specialized, such as ultra-high power high-power electric furnace can be specially used to continuously melt charge. This makes it possible to carry out continuous loading operations.

Steelmaking automation is mainly the application of electronic computers to the steelmaking process. To realize automatic control of procedures such as melting, refining, and making A, automatic adjustment of power pleasure is realized to realize automatic control of heat supply, automatic control of various steelmaking operations, and automatic control of chemical analysis, product quality, counting, reporting, data processing, etc.

At present, many electric arc furnace steelmaking equipment with initial automation and operational continuity has appeared. The application of electronic computers in electric arc furnaces is also becoming more and more extensive, and the emergence of fully automated and continuous electric arc furnace steelmaking will not be too long.