Study on Mathematical Modeling of Combined Top and Bottom Blowing VOD Refining Process of Stainless Steel

Wei, Ji-He; Yi, Li

doi:10.1002/srin.201400042

Cited by 8 publications

(5 citation statements)

References 13 publications

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“…The stirring intensity of the argon blowing during the VOD reduction stage was 800-1000 L/min, which was far stronger than the argon blowing intensity of 200-400 L/min during the LF stage [20,21]; therefore, the velocity at the interface between the steel and slag was greater than 2 m/s. The reaction between the slag and steel was very intense during the VOD refining process and the droplets were strongly mixed and changed into very small particles; as a result, the minimum size of the droplets during VOD refining was 5 µm.…”

Section: Generating the Mechanism Of Cao-sio2-al2o3-mgo-mno Inclusionsmentioning

confidence: 91%

Characteristics and Formation Mechanism of Inclusions in 304L Stainless Steel during the VOD Refining Process

Chen

Cheng

et al. 2018

Metals

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The formation and characteristics of non-metallic inclusions in 304L stainless steel during the vacuum oxygen decarburization (VOD) refining process were investigated using industrial experiments and thermodynamic calculations. The compositional characteristics indicated that two types of inclusions with different sizes (from 1 μm to 30 μm) existed in 304L stainless steel during the VOD refining process, i.e., CaO-SiO2-Al2O3-MgO external inclusions, and CaO-SiO2-Al2O3-MgO-MnO endogenous inclusions. The calculation results obtained using the FactSage 7.1 software confirmed that the inclusions that were larger than 5 μm were mostly CaO-SiO2-Al2O3-MgO; the similarity in composition to the slag indicated that these inclusions originated from the slag entrapment. The CaO-SiO2-Al2O3-MgO-MnO inclusions that were smaller than 5 μm originated mainly from the oxidation reaction with Ca, Al, Mg, Si, and Mn. The changes in the inclusion composition resulting from changes in the Ca, Al, and O contents, and the temperature during the VOD refining process was larger for the smaller inclusions. Generating mechanisms for the CaO-SiO2-Al2O3-MgO-MnO inclusions in the 304L stainless steel were proposed.

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Section: Generating the Mechanism Of Cao-sio2-al2o3-mgo-mno Inclusionsmentioning

confidence: 91%

Characteristics and Formation Mechanism of Inclusions in 304L Stainless Steel during the VOD Refining Process

Chen

Cheng

et al. 2018

Metals

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“…The proportion of oxygen partitioned during the oxidation reaction of element C, Equation (11), is then brought into Equation (12) to solve for the decarbonization rate.…”

Section: Carbon Content and Oxygen Supply Rate Transfer Functionmentioning

confidence: 99%

“…The most important parameters of the process include the carbon content at the end of smelting, as well as the converter temperature during the smelting process. The main objective of the study is to increase the smelting speed and accuracy and to control the converter temperature [11].…”

Section: Introductionmentioning

confidence: 99%

Study on Adaptive Parameter Internal Mode Control Method for Argon–Oxygen Refining Ferrochrome Alloy

Han

Wen

et al. 2023

Processes

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In order to determine a way to be able to shorten the smelting time of low-carbon ferrochrome alloys and to strengthen the temperature control capability of the AOD converter during the smelting process, this article establishes a mechanism model of the rate of oxygen supply and carbon content change in the smelting process as well as the temperature of the reaction fluid in the converter. The physical and chemical reactions of the smelting process and the actual smelting data are used as the basis. The temperature and carbon content in the smelting converter are considered as the output quantity and the rate of oxygen supply is considered as the input quantity. An expert internal model control framework is built. In addition, an adaptive parameter adjustment mechanism is added to the control framework, taking into account data such as the maximum gas supply rate and the maximum limiting temperature of the actual production process. This method improves the smelting speed and smelting accuracy compared to the general internal mode control method. Finally, according to this method, with the use of the built low-carbon ferrochrome alloy centralized control system for smelting, the system shortens the smelting time by 12.79% compared with the general method and controls the converter temperature below 1950 K, which achieves the expected goal according to the simulation and actual smelting results.

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“…Wei [ 21 ] suggested that the Gibbs free energy of the oxidation reaction for each element at the reaction interface is directly proportional to its oxygen distribution ratio. However, since ultrapure ferritic stainless steel contains high levels of [Cr], the Gibbs free energy variation of [Cr] is optimized through the significant plant data validation, as shown in the following equation.

$$\left(\phi\right)_{\left[\right.

…”

Section: Description Of Decarburization Modelmentioning

confidence: 99%

A Dynamic Decarburization Model in Vacuum Oxygen Decarburization Process for Ultrapure Ferritic Stainless Steel

Wang

Cheng

Zhang

et al. 2023

steel research int.

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A mathematical model incorporating dynamic parameters is proposed to investigate the overall decarburization process during the vacuum oxygen refining (VOD) process for ultrapure ferritic stainless steel. This paper also conducted a precise theoretical calculation of the C‐Cr equilibrium. Moreover, the top‐blowing oxygen distribution is categorized into six directions: [C] oxidation, alloy component oxidation, CO bubble oxidation above the bath surface, bath surface oxidation (FeO), dissolution in the molten steel ([O]), and escape into the exhausted gas. The FeO and Cr2O3 oxide are intermediate product of oxygen to oxidize [C] remaining in the molten steel during the VCD stage. The modified approach of Gibbs free energies determines the critical carbon concentration by the distribution ratio of carbon to the top‐blowing oxygen. The top‐blowing oxygen primarily consumed by CO‐CO2 bubble (49–55%) and Cr2O3 (26–33%). Additionally, the model considered operational aspects, the system's heat balance, and changes in overall metal‐slag conditions during the refining process. The exhausted gas composition and end‐point carbon concentration align well with industrial data. Within a certain range (approximately up to 0.50%), increasing initial carbon concentration can enhance overall decarburization efficiency.

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Study on Mathematical Modeling of Combined Top and Bottom Blowing VOD Refining Process of Stainless Steel

Cited by 8 publications

References 13 publications

Characteristics and Formation Mechanism of Inclusions in 304L Stainless Steel during the VOD Refining Process

Characteristics and Formation Mechanism of Inclusions in 304L Stainless Steel during the VOD Refining Process

Study on Adaptive Parameter Internal Mode Control Method for Argon–Oxygen Refining Ferrochrome Alloy

A Dynamic Decarburization Model in Vacuum Oxygen Decarburization Process for Ultrapure Ferritic Stainless Steel

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