Difference between converter steelmaking and electric arc furnace steelmaking

Converter steelmaking is the process of converting molten iron from the blast furnace into oxygen. The furnace body can rotate. The steel plate is used as the shell, and the refractory material is used as the lining. During converter steelmaking, there is no need to heat the molten iron, because the molten iron itself is high temperature, and the oxidation reaction of heating continues inside. This reaction comes from silicon, carbon in the molten iron and oxygen blowing. Because it does not need to be heated with fuel, the energy and consumption are reduced, Therefore, it is widely used in steelmaking. After the oxygen blown into the furnace reacts with the carbon in molten iron, the carbon content in molten iron will be reduced and become steel. This reaction itself will generate heat. Therefore, molten iron will not only continue to melt, but may become hotter and hotter. Therefore, in order to adjust the suitable temperature of molten iron, people will add some scrap steel and a small amount of cold pig iron and ore, At the same time, some lime, quartz, fluorite, etc. should be added. These substances can form slag with the waste generated when molten iron turns into molten steel. Therefore, they are called slag making materials.

Converter steelmaking is a common steelmaking method in China. Molten iron in the furnace accounts for 90% and consumes oxygen. No steel can be left inside during tapping.

Converter steelmaking process

Blast furnace hot metal --- hot metal pretreatment --- combined blowing converter steelmaking --- outside furnace refining --- continuous casting --- hot rolling

Compared with the composition of molten steel, the converter steelmaking is quite different, while the composition of electric furnace steelmaking is stable.

Electric arc furnace steelmaking

However, electric arc furnace steelmaking does not have high requirements for raw materials. All scrap steel is OK. Electric furnace consumes electric energy and oxygen, and steel is usually reserved for operation.

The heat source of electric arc furnace steelmaking is electric energy, that is, there is an electrode made of graphite in the electric arc furnace. A strong arc can be generated between the end of the electrode and the furnace charge, which is similar to the lightning we see. It has very high heat energy. We know that during steelmaking, the carbon in molten iron is mainly oxidized to reduce the carbon content. However, when some steel varieties need to contain other elements that are easy to oxidize, if too much oxygen is blown, Those elements will also be oxidized. At this time, it is much more advantageous to use electric arc furnace to make steel. Therefore, electric arc furnace is often used to smelt alloy steel and carbon steel. Electric arc furnace mainly uses waste steel as raw material. After charging, the furnace cover will be covered, and then the electrode will drop close to the surface of the furnace charge. At this time, when the power is turned on, the electrode will send an electric arc to melt the charge near the electrode, and then increase the voltage to speed up the melting speed, With the melting process of the charge, the position of the charge (molten steel) will change. At this time, the electrode will automatically adjust its height without being submerged in the molten steel. When steelmaking with the electric arc furnace, it is also necessary to carry out an oxygen blowing to speed up the melting speed. The oxygen blowing time must be accurate, otherwise an explosion will occur. When the charge is about to melt, a layer of slag will float on the surface of the molten steel, At this time, the workers will take out some molten steel and slag to analyze their composition and see how the steel is refined. If there are elements harmful to the steel quality, they will continue to refine and remove them.