Method for ensuring the quality of induction melting furnace steelmaking

Induction melting furnace steelmaking methods There are many methods for steel making, mainly induction melting furnace steelmaking, open hearth steelmaking, electric arc furnace steelmaking, and the like. Electric arc furnaces and induction melting furnaces commonly used in cast steel workshops . They have looser requirements on raw materials, higher quality of molten steel, and the steelmaking cycle is suitable for the characteristics of cast steel production. It is convenient to open and stop the furnace, and it is easy to coordinate with the progress of the process of molding and boxing. Organize production. In addition, the equipment for electric steelmaking is relatively simple, with less investment, and the infrastructure construction speed and capital recovery are fast. In recent years, induction melting furnace steelmaking has gradually developed. Induction melting furnace steelmaking process is relatively simple, and the quality of molten steel can be guaranteed. Many factories use induction melting furnace steelmaking to cast small castings, especially in investment casting foundries, where induction melting furnaces are widely used to melt molten steel. In heavy machinery plants, open hearth steelmaking is still used today. The capacity of open hearth furnaces is generally larger than that of electric furnaces. The steelmaking of open hearth furnaces can produce a large amount of molten steel at one time, which is suitable for pouring large and complex heavy castings. However, the period of the open hearth steelmaking is long, and the time for refining a furnace steel generally takes more than six hours. The open hearth structure is large and complex, the output is low, and the quality of the molten steel is not as good as that of the electric furnace, so its development is greatly limited. In some countries, new open hearths are no longer built. In recent decades, pure steel top-blown converters have been widely used in the steelmaking industry for steelmaking. This steelmaking method is fast, high in productivity, and the quality of molten steel is also guaranteed. This furnace is more suitable for steel ingot production. With the development of production and science and technology, new steelmaking methods for DC arc furnaces, vacuum induction melting furnaces and refining equipment outside the furnace have emerged, the quality of molten steel has been greatly improved, and the quality of castings has been greatly improved.

The main raw materials for induction melting furnace smelting are scrap steel and a part of pig iron. The purchased scrap has more rust, muddy sand and other dirt, and the content of sulfur and phosphorus in the steel is also high. The task of steelmaking is to smelt the raw materials of the above conditions into high-quality molten steel with low gas content, high inclusion content, qualified composition and temperature. Specifically, the basic tasks of steelmaking are: 　　

(1) melting solid charge (cast iron, scrap, etc.); 　　

(2) Bringing elements such as silicon, manganese and carbon in the molten steel to the specification components; 　　

(3) Remove harmful elements such as sulfur and phosphorus, and reduce their content below the specified limit; (4) Remove gas and non-metallic inclusions in the molten steel to make the molten steel pure; 　　

(5) adding alloying elements (melting alloy steel) to meet the requirements; 　　

(6) The molten steel is superheated to a certain temperature to ensure the need for pouring; 　　

(7) In order to increase production and reduce costs, it is necessary to rapidly steel-making; 　　

(8) Casting into a good casting.