Today, the editor of Great Electric summed up some quality control problems in the smelting process when the electric furnace is working, to share with you.
Heat preservation of liquid iron: Heat preservation of liquid iron at high temperature will cause temperature change, elemental burning loss, dissolved gas and the state change of liquid iron itself.
Therefore, if long time insulation is needed, the temperature of insulation should be reduced as far as possible. For example, you can add a small amount of clean and dry return charge to cool down, and cover the surface of liquid iron with glass and other materials.
Liquid iron composition selection: The same furnace liquid iron to cast several castings, as far as possible according to the largest batch of castings.
Or the most important castings for batching, in the process of pouring molten steel, the carbon content in the furnace will continue to reduce, can consider adding inoculant to adjust first, and then consider the use of carburizing agent.
Liquid iron quality change: if there is residual ductile iron liquid iron in the furnace, if you want to melt gray iron liquid iron, if the remaining liquid iron is more, it is better to heat up to 1550℃, and hold heat for a period of time. Otherwise, there will be a lot of disorderly graphite blocks in the casting structure, which will affect the casting performance.
Metal charge: The induction furnace is used for melting. Although there is no frit, if the charge is filled from the beginning of the power supply, the load of the equipment will become larger and the frequency change will be prevented.
In addition, the parallel frequency conversion medium frequency induction furnace produces frequency variation disorder when it is under high load, so it is better to add the metal charge successively.
Heating points for attention: when the electric furnace is heating up, in order to avoid the change of the properties of liquid iron during this period of time, the furnace cover should be closed as far as possible to prevent the surface heat dissipation of liquid iron and achieve rapid heating.
From the point of view of safety, do not add the charge in the late melting period, because in the large amount of liquid iron that has been heated, add the pig iron with corrosion and water, when it is immersed in the depth of liquid iron, it will explode, causing the splash of liquid iron.
The oxidation problem of liquid iron: because the charge is not clean or the smelting process is not well controlled, it will lead to the serious oxidation of liquid iron and affect the casting quality problems.
Therefore, we should try to choose clean and clean charge, and then we can consider the use of silicon carbide, silicon calcium alloy to deoxidize, and then appropriate heating and insulation.
This is our knowledge sharing about intermediate frequency furnace today. I hope it can be helpful to you. Welcome to Luoyang Giant Electric to learn more about intermediate frequency furnace.
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Heating temperature is between 200-1400 degrees.
Induction billet furnaces can heat billets to temperatures ranging from room temperature to over 1200°C.
After the Slab is pulled out from the continuous casting machine,Surface temperature is 750 ~ 850℃.