The main raw materials for smelting are scrap steel and part of pig iron. The purchased scrap steel is rusty, mixed with mud, 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 with the above conditions into high-quality liquid steel with low gas and inclusion content, qualified composition and qualified temperature. Specifically speaking, the basic tasks of steelmaking are as follows:

(1) Melting solid charge (pig iron, scrap, etc.);

(2) Make silicon, manganese, carbon and other elements in molten steel reach the specification composition;

(3) Remove the harmful elements sulfur and phosphorus, and reduce their content below the specified limit;

(4) Remove the gas and nonmetal inclusion in the molten steel to make the molten steel pure;

(5) Adding alloy elements (smelting alloy steel) to make it meet the requirements;

(6) Overheat the molten steel to a certain temperature to ensure the need of pouring;

(7) In order to increase the output and reduce the cost, it is necessary to make steel rapidly;

(8) The casting is good.

2、 Methods of steelmaking

There are many methods of steelmaking, including induction furnace steelmaking, open hearth steelmaking, electric arc furnace steelmaking and so on.

Arc furnace and induction furnace are widely used in steel casting workshop. They have loose requirements for raw materials, high quality molten steel, and the steel-making cycle is suitable for the characteristics of cast steel production. It is convenient to start and stop the furnace, and it is easy to coordinate with the progress of molding, box closing and other processes, so as to organize production. In addition, EAF steelmaking equipment is relatively simple, investment is less, infrastructure construction speed and capital recovery is fast.

In recent years, induction furnace steelmaking has been developed gradually. The steelmaking process of induction furnace is relatively simple and the quality of molten steel can be guaranteed. Many factories use induction furnace steelmaking to cast small castings, especially in investment casting workshop, which widely uses induction furnace to melt molten steel.

In heavy machinery plants, open hearth furnace is still used for steelmaking. The capacity of open hearth furnace is generally larger than that of electric furnace. It can produce a large amount of molten steel at one time and is suitable for pouring large and complex heavy castings. However, the period of open hearth steelmaking is long, and it usually takes more than six hours to produce a furnace of steel. The structure of open hearth furnace is huge and complex, the output is low, and the quality of molten steel is inferior to that of electric furnace, so its development is greatly limited. In some countries, new open hearth furnaces are no longer built.

In recent decades, pure oxygen top blown converter has been widely used in steelmaking industry. This steelmaking method has the advantages of high speed, high productivity and guaranteed quality of molten steel. This kind of furnace is more suitable for ingot production.

With the development of production and science and technology, new steelmaking methods of DC electric arc furnace, vacuum induction furnace and refining equipment outside the furnace appear constantly. The quality of molten steel is greatly improved, and the quality of castings is greatly improved.

Yiphee Electric Furnace Co.,Ltd specializes in producing induction furnace.Tel(WhatsApp):+86-13450756789, yiphee@yiphee.cn