Secondary refining is an important metallurgy operation to obtain high quality steel products.
This process normally takes place in ladle furnaces by blowing inert gas, mainly argon gas, through an argon stirring lance into molten steel to remove unwanted elements and get homogenization steel that meet strict requirements and specifications of mechanical performance.As this operation is at a severe condition of high temperature and strong corrosion, the quality of argon stirring lance is crucial for prolonging its lifetime and performance in the ladle metallurgy operations.
What is an Argon Stirring Lance ?
An Argon Stirring Lance is a special device in cylinder shape used to inject argon into molten steel during the refining process in a ladle furnace for removing impurities and promoting homogeneous melt. The lance is submerged in the ladle from the top so it is also called argon top lance.
Structure of an Argon Stirring Lance
- Refractory coating: rich alumina content refractory coating goes through a proper drying process to withstand high temperature, stress, thermal shock, and wear resistance from the slag.
- Core steel pipe: a calorized lance pipe produced by Daiwa Lance International is used as the core pipe to enhance the ability of heat resistance and anti-corrosion.
- Straight lance tip: a design to blow powders such as lime, calcium silicide, magnesium, aluminum oxide with inert gas as a carrier for desulfurization and decarburization.
- T-shaped lance tip: a design with two nozzles to disperse argon better without clogging.
- Porous plug lance tip: a design to produce bubbles of argon to provide more reaction interfaces for dehydrogenation reaction and thereby reducing the hydrogen solubility and promoting hydrogen removal from molten steel.
Typical sizes of Argon Stirring Lance
The length of argon lance is ranging from 3 meter to 5.5 meter with the diameter of core calorized lance pipe from 42.0mm (1-¼”) to 88.9mm (3.5”). The outer diameter of argon lance including refractory coating is up to 290mm.
Daiwa Lance can customize Argon Stirring Lance as requested by the customers. Please send us your inquiry or drawing then we can offer the most suitable Argon Stirring Lance meeting your requirements.
Why is The Argon Lance Required For Ladle Furnace Operations ?
As argon stirring lances are crucial in ladle furnaces operations, the roles of argon rinsing lances are extremely important in ensuring uniform temperature and composition, and for improving steel quality through degassing, deoxidation, desulfurization, and precise alloying.
Below are some key reasons for using an argon lance
Homogenization of Temperature and Composition
Argon lances disperse bubble argon gas through the molten steel promotes effective stirring and mixing, which eliminates temperature and chemical composition segregation and inconsistencies throughout the ladle, resulting in a more uniform and high-quality product.
Improvement of Purity and Alloying
Argon lance inject argon gas into the melt to facilitate the removal of dissolved gases like hydrogen and nitrogen, which can cause defects. Argon bubbles help carry impurities like metal oxides and inclusions to the surface, where they can be absorbed into the slag and removed. Additionally, the introduction of argon helps control the precise addition of alloying elements, enhancing the properties of steel that meet specific customer requirements.
Deoxidation and Desulfurization
The stirring action with argon lances accelerates the removal of non-metallic inclusions and promotes reactions that lead to lower sulfur and oxygen content in the molten steel. This is especially important in the production of stainless steels and other high-grade alloys where elements like chromium can be highly reactive.
Optimized Process Efficiency
By promoting efficient mixing and refining, the use of argon lances can contribute to the reduction of working time required for secondary refining processes in ladle furnaces. This application helps improve overall operational efficiency, leading to faster turnaround times and improved productivity.
Conclusion
The use of argon stirring lance in ladle furnace operations offers precision and control that are essential for refining of high quality steel. By enhancing steel homogeneity, improving purity, and optimizing process efficiency, argon lances play a crucial role in modern steel production. At Daiwa Lance International, we are dedicated to developing and providing superior argon stirring lances that are not only long lasting but also economical competitiveness.
Our Daiwa Argon Lance satisfies the rigorous demands of the steelmaking industry, ensuring you achieve the highest standards of quality and efficiency after the completion of your refining process.
If you are looking for a lighter and shorter argon lance for AOD/VOD process in stainless steel manufacturing plants, please refer to our previous post about Daiwa Heavy Lance here.
