Experimental and numerical study of calcium treatment of steel
| Autor: | Harsh Priyadarshi, Benjamin Boissiere, Pascal Gardin, Jean Lehmann, Luisa Silva |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Mass transfer coefficient
020203 distributed computing Materials science Bubble technology industry and agriculture 0211 other engineering and technologies Metals and Alloys Computational Mechanics chemistry.chemical_element Induction furnace 02 engineering and technology Calcium Superheating Boiling point chemistry Mechanics of Materials 0202 electrical engineering electronic engineering information engineering Materials Chemistry Composite material Superheated water Dissolution 021102 mining & metallurgy |
| Zdroj: | Metallurgical Research & Technology. 116:514 |
| ISSN: | 2271-3654 2271-3646 |
| DOI: | 10.1051/metal/2019007 |
| Popis: | In order to diminish the harmful effects of aluminate inclusions and improve the castability of molten steel, calcium treatment is widely used in Aluminum killed steels. However, calcium treatment gives irregular results. Even with many efforts done to understand the behavior of calcium in liquid steel, it is not yet accurately predicted. Therefore, the mechanism by which the calcium dissolves into the liquid steel and transforms the solid inclusions must be understood to optimize the process conditions such as injection speed, injection depth, injection wire diameter, stirring time, etc. In order to understand the mechanism by which the calcium dissolves into the liquid steel, laboratory scale experiments have been performed in a small induction furnace of 2.5 kg metal capacity. The calcium injections are performed at the temperature below and above the boiling point of calcium. Then, the corresponding yields (calcium recovery) are compared. Rise of calcium droplet or bubble in liquid steel is a three-phase problem (calcium droplet or calcium bubble/liquid steel/air at the top). Therefore, an in-house scientific computational platform (ICI-tech) based on finite element methods is adapted to allow the modeling of such three-phase flows, which is validated using the classical benchmark issued from the literature. The dissolution model has been implemented in our software, and their validation has been performed. Thereafter, the rise of Calcium droplets and bubbles are studied in the liquid steel, and their respective average mass transfer coefficient in the liquid steel is reported. In order to study the calcium liquid/gas phase change, the nucleation model has been implemented in the code (ICI-tech). A typical test is performed where the growth of a bubble (water vapor) in uniformly superheated water and growth of a calcium bubble in uniformly superheated Ca liquid is computed. |
| Databáze: | OpenAIRE |
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