What is The Deoxidation of Steel in The Ladle Furnace?

Deoxidation of molten steel in the ladle furnace refers to the process of adding deoxidizers (such as silicon, manganese, and aluminum) to the molten steel during the ladle refining furnaces process. These deoxidizers react chemically with oxygen in the steel to form oxides (such as SiO₂, MnO, and Al₂O₃), thereby reducing the oxygen content in the steel.

Deoxidation is a crucial step in steelmaking, improving steel purity and enhancing properties such as strength and toughness. The deoxidation process also helps control the form and quantity of inclusions, further improving steel quality.

What is Deoxidation in The Ladle Furnace?

Deoxidation in the LF furnace is a key operation during the secondary refining process to reduce the dissolved oxygen content in the molten steel through specific processes. The following is a detailed description of this process:

1. Core Purpose

• Improve steel quality: Eliminate or reduce oxide inclusions in the steel, preventing casting defects (such as porosity and looseness) and reduced mechanical properties caused by excessive oxygen content.

• Ensure subsequent processes: Provide pure molten steel for the continuous casting process, avoiding problems such as nozzle blockage.

2. Commonly Used Deoxidizers & Processes

• Aluminum-based deoxidizers: The mainstream choice, they rapidly reduce oxygen content through reaction, but are prone to forming high-melting-point chain-like Al₂O₃ inclusions and require calcium treatment for modification.

• Silicon-based deoxidizers: Lower cost, but are prone to forming silicate inclusions, which can exacerbate hot cracking.

• Calcium-based deoxidizers: Improve steel purity by modifying inclusion morphology.

• Carbon powder pre-deoxidation: Utilizes the release of CO gas generated by the carbon-oxygen reaction, eliminating the introduction of new inclusions and reducing aluminum usage and costs.

3. Synergistic Refining Processes

• LF ladle refining furnaces: Arc heating and bottom-blown argon agitation accelerate inclusion flotation, combined with white slag refining technology to adsorb inclusions.

• Vacuum treatment: RH or VD methods further reduce oxygen content and are particularly suitable for ultra-low carbon steel grades.

4. Key Control Parameters for LF Furnace

• Slag Composition: High-basicity, low-oxidizing refined slag facilitates desulfurization, deoxidation, and inclusion adsorption.

• Temperature Control: Ensures a sufficient deoxidation reaction and prevents secondary contamination from refractory erosion.

• Stirring Intensity: Promotes aggregation and flotation of deoxidized products, reducing microscopic inclusions.

In summary, deoxidation of molten steel in the ladle furnace is an essential and critical step in steelmaking and plays a crucial role in improving steel quality and performance.

If you have any questions or needs regarding ladle refining furnaces and other melting furnaces, please contact us. Sanrui Electric Furnace offers one-stop service!