Today, I will share with you some knowledge about the continuous casting machine on the rolling production line.
Refining period: During the steelmaking process, some elements and compounds that are harmful to the quality of the steel are selected by chemical reaction through slag making and other methods, or they are discharged or floated into the slag, so that they are excluded from the molten steel. .
Reduction period: In ordinary power electric arc furnace steelmaking operations, the period from the completion of slag removal at the end of oxidation to tapping is usually called reduction period. Its main task is to make reduced slag for diffusion, deoxidation, desulfurization, chemical composition control and temperature adjustment. The reduction period has been eliminated for the current high-power and ultra-power EAF steelmaking operations.
Out-of-furnace refining: The steel-making process in which the initially smelted molten steel in the steel-making furnace (converter, electric furnace, etc.) is moved to another container for refining, also called secondary metallurgy.
The steelmaking process is therefore divided into two steps: primary smelting and refining. Primary smelting: The charge is melted, dephosphorized, decarburized and mainly alloyed in an oxidizing atmosphere furnace.
Refining: Degassing, deoxidizing, desulfurizing, removing inclusions and fine-tuning components, etc.
The benefits of splitting steelmaking into two steps are: it improves the quality of the steel, reduces the smelting time, simplifies the process and reduces production costs. There are many types of out-of-furnace refining, which can be roughly divided into two categories: out-of-furnace refining under atmospheric pressure and out-of-furnace refining under vacuum. According to the different treatment methods, it can be divided into ladle processing type out-of-furnace refining and ladle refining type out-of-furnace refining.
Stirring of molten steel: the stirring of molten steel during the refining process outside the furnace. It homogenizes the composition and temperature of molten steel and can promote metallurgical reactions.
Most metallurgical reaction processes are phase interface reactions, and the diffusion rate of reactants and natural organisms is the limiting link of these reactions.
The metallurgical reaction speed of molten steel in static state is very slow. For example, it takes 30 to 60 minutes to desulfurize molten molten steel in an electric furnace, while it only takes 3 to 5 minutes for desulfurization by stirring molten steel in the refining outside the furnace. When the molten steel is in a static state, the inclusions are removed by floating up, and the removal speed is slow; when the molten steel is stirred, the removal speed of the inclusions increases exponentially, and is related to the stirring intensity, type, and the characteristics and concentration of the inclusions.
Ladle Treatment: Abbreviation for Ladle Treatment Out-of-furnace Refining. It is characterized by short refining time (about 10 to 30 minutes), single refining task, no heating device to compensate for the drop in molten steel temperature, simple process operation and low equipment investment.
Ladle Refining: Abbreviation for Ladle Refining Outside Furnace Refining. It is characterized by a longer refining time (about 60-180 minutes) than ladle treatment, with various properties, and a heating device to compensate for the drop in molten steel temperature, suitable for all kinds of high-alloy steel and special-performance steel grades (such as ultra-pure steel grades). ) refinement.
This is what we share today, I hope it can help you.
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