Not all of us have the opportunity to visit a steel mill and learn how steel is smelted. However, the algorithm of the production process of smelting has become familiar in general terms to many of us since school.
Instructions
Step 1
Usually, steel is smelted in open-hearth furnaces, electric steel-making (induction, electric arc) furnaces, as well as in converters. The starting material for steel is solid pig iron, steel scrap and wastes from forges or foundries. There are times when cast iron is used only in liquid form (in converter processes).
Step 2
The main tasks of steel production are as follows:
- melting of materials;
- alignment of the chemical composition of the metal;
- oxidation and removal of impurities (phosphorus, sulfur, gases, as well as non-metallic inclusions);
- subsequent deoxidation;
- bringing the chemical composition of the metal to the required parameters (in this case, add various chemical components);
- heating to the temperature required for pouring steel into molds and molds.
Step 3
After the materials are melted, the metal is refined (i.e. purified), freeing it from impurities, as a result of which it achieves uniformity in chemical composition.
Step 4
The oxidation process is as follows: carbon, previously dissolved in the liquid metal, is oxidized by oxygen from the air introduced into the furnace, ore oxygen or oxygen from the compressor air. It also helps to remove impurities from the metal.
Step 5
The deoxidation process is necessary for the final removal of impurities (especially sulfur) from the metal. To do this, the temperatures of the slag and metal are raised in the working space of the furnace, or components are introduced directly into the metal that reduce oxygen, silicon, carbon and manganese dissolved in it.
Step 6
After enough time has passed for the deoxidation process, the chemical composition of the steel is brought to the required level and alloyed with appropriate additives (for example, chromium).
Step 7
After that, the steel, heated to a certain temperature, is poured into a ladle. With the help of a ladle, the metal is released into molds or into a mold. In order not to start the oxidation process, the formation of the composition of the steel is carried out by deoxidizing it in a ladle, for example, using aluminum.