Steel is used for making many day-to-day products but have you every wondered, how it is made? Products made up of steel are durable and long lasting and therefore used in many forms. Steel making is a complex process comprising of many stages, each of these stages play an important role in creating high quality steel. Here, steel making industry introduction becomes necessary as it is responsible for providing us with the best quality steel.
A steel making industry is a business of converting iron ore into steel. Let’s go through steel making process flowchart to understand the process well. Read further for a detailed overview of each stage necessary in the steel manufacturing process.
Steel Manufacturing Step by Step Process
All of these steps lead to the making of steel, an alloy of iron and carbon with high crack resistance and strength.
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Raw Material Preparation
The raw material is extracted and collected under this step. The primary raw materials used in the steel making process are iron ore, and limestone. Iron ore is extracted through mining in the form of hematite or magnetite. Coal is turned into coke which is a high-carbon fuel needed for the blast furnace. Limestone is used to remove any impurities during the smelting stage.
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Iron Making
In this step the pig iron is produced from iron ore using the blast furnace. The raw materials are loaded from the top of the furnace and hot air usually enriched with oxygen is blasted from the bottom. When coke burns in the hot air, carbon monoxide and heat are produced. This carbon monoxide reduces the iron ore into carbon dioxide and molten iron. The limestone converts into lime and reacts with impurities comprising silica leading to the formation of slag. Slag which is light weight, comes at the top of molten iron and can be easily removed. The pig iron is drained from the bottom of the furnace.
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Steel Making
Pig iron is converted into steel through a basic oxygen furnace or BOF. This furnace is charged up with scrap steel & molten pig iron. After this, oxygen is blown in it to oxidize impurities such as silicon, sulphur, phosphorus, and carbon. This step leads to intense heat generation which converts pig iron into steel. The slag of impurities is carefully removed from the surface.
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Alloying
Once the steel is ready, different elements such as nickel, chromium, and manganese are added to gain desired properties. The electric arc furnace is used in this process where scrap is loaded and melted by the electric arcs generated by the graphite electrodes. Further, oxygen is blown to get rid of impurities leading to impurities turning into slag. Now, the desired elements are added to the molten steel to achieve required properties.
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Secondary Refining
Once the steel with required properties is ready, secondary refining step begins which occurs in a ladle, this is known as ladle metallurgy. Following this, desulfurization happens in which materials such as calcium carbide and magnesium are added to remove sulphur. Once it is done, hydrogen, nitrogen, and other gases are removed using vacuum degassing to improve the quality of steel. After this, the sulphur is remelted using the electroslag remelting process to purify and refine it further.
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Continuous Casting
The molten steel is now converted into semi-finished form known as slabs, blooms and billets through solidification. In this process, first the molten steel is poured into a tundish and then in water-cooled moulds. The steel begins to take solid form, it is continuously withdrawn until it is fully solidified by water sprays.
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Hot Rolling
The solid steel is reheated and given desired shapes by making them pass through the rolling mills. In this, the steel reduces its thickness and is changed into different shapes, sheets, coils, and bars.
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Finishing
The properties are further enhanced when steel is put at room temperature which improves its surface quality. Various coatings are done including galvanizing and tin plating to protect it from corrosion.
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Quality Control and Inspection
In every step, quality check is done to maintain high-quality and to ensure that the steel meets its required specification. The chemical composition is analysed to maintain right alloying elements. Tests are conducted to check its strength and mechanical properties. Surface inspection is done to see if there are any cracks or scales.
Steel manufacturing process industrial revolution has made the steel making process more efficient. The manufacturing steps include preparing raw materials, ironmaking, steelmaking, refining, casting, rolling and finishing. Testing and quality checks are done with every step to maintain high quality of the final product. Steel is used in the making of buildings, bridges, infrastructure, tools, machines, furniture and a lot more. Rigidind is one of the best steel furniture manufacturers in Dubai that offers supreme quality furniture. If you need a steel cupboard for your home or office, connect with us right away!