AB/AQ70 Steel Plate

 

 

Basic Concept of Lance Position
During the converter steel - making process, the oxygen lance is a crucial device. The lance position refers to the distance between the lance nozzle and the liquid surface of the molten pool. It directly affects the impact depth of the oxygen jet on the molten pool, the stirring intensity, slag - forming and many other key aspects. An appropriate lance position can effectively facilitate the chemical reactions in the steel - making process and improve the quality of steel.

 

Adjust the Lance Position According to the Smelting Stage

 

Initial Blowing Stage
This stage is mainly the oxidation period of silicon and manganese. As the temperature inside the furnace is relatively low and the content of silicon and manganese in the hot metal is high, a relatively high lance position is required. For example, the lance position can be controlled between 1.2 - 1.5 meters (the specific value may vary depending on factors such as the capacity of the converter).
The function of the relatively high lance position is to make the impact depth of the oxygen jet on the molten pool shallower, so that the oxygen mainly reacts with silicon and manganese on the surface of the hot metal. The heat generated can quickly increase the temperature of the molten pool. At the same time, this kind of shallow impact is beneficial to the formation of the initial slag. Because the shallow impact can make part of the iron oxide and other slag - forming materials stay in the slag layer, laying the foundation for the subsequent slag - forming process.

 

Middle Blowing Stage
As the blowing process progresses, the temperature of the molten pool rises and carbon begins to oxidize in large quantities. At this time, it is necessary to appropriately reduce the lance position, generally around 0.8 - 1.2 meters.
Reducing the lance position can increase the impact depth of the oxygen jet and enhance the stirring intensity of the molten pool. This is because the carbon - oxidation reaction requires good kinetic conditions. Intense stirring can promote the contact between carbon and oxygen and accelerate the carbon - oxygen reaction. At the same time, appropriate adjustment of the lance position can control the content of iron oxide in the slag, avoiding the slag from being too oxidized or reduced and ensuring the performance of the slag.

 

Final Blowing Stage
When approaching the end of blowing, the lance position needs to be further reduced. For example, the lance position is controlled between 0.6 - 0.8 meters.
At this time, the temperature of the molten pool is already very high and the carbon content is low. The lower lance position is helpful for precisely controlling the oxygen content in the molten steel and preventing the molten steel from over - oxidation. Moreover, it can make the stirring of the molten pool more intense, promote the homogenization of the composition and temperature of the molten steel, and is also conducive to the further progress of dephosphorization, desulfurization and other reactions, so that the quality of steel meets the requirements.

 

 

 

 

Specification we supply：

Thickness	3-200mm
Width	1500-4000mm
Length	5000-15000mm

 

 

 

Adjust the Lance Position According to the Composition of Hot Metal

 

High - silicon Hot Metal
For hot metal with a high silicon content, a higher lance position should be adopted in the initial blowing stage. Because the silicon oxidation is a strongly exothermic reaction, a high lance position can enable silicon to be fully oxidized on the surface of the molten pool and utilize the heat released to increase the temperature of the molten pool. The lance position can be 0.2 - 0.3 meters higher than that of the hot metal with a normal silicon content in the initial blowing stage.

 

High - phosphorus Hot Metal
When the phosphorus content of hot metal is high, it is necessary to strengthen slag - forming to dephosphorize during the blowing process. In the early stage of blowing, the lance position can be appropriately raised to promote the melting of lime and the formation of slag, creating good conditions for dephosphorization. The lance position is generally 0.1 - 0.2 meters higher than normal. And during the blowing process, attention should be paid to maintaining the alkalinity and oxidizability of the slag. Through appropriate control of the lance position, the slag can have a good dephosphorization ability.

 

 

 

 

 

Why Choose Us?
We take pride in our ability to provide custom solutions for our customers' unique needs.
We analyze and compare the previous products and the current technical situation of our AB/AQ70 Steel Plate, and develop new technical specifications and processes.
Our customers trust us to deliver high-quality Cold-rolled Steel products on time and on budget.
We strictly implement the warm and thoughtful after-sales service, adhere to the development of good professional ethics.
We offer a wide range of Cold-rolled Steel products to meet diverse customer needs.
We adhere to the customer-centric and brand-oriented business philosophy, and continue to provide customers with reliable and excellent products and services.
Our factory is committed to upholding the highest standards of safety and quality.
All staff of our company and all departments work together to combine business management, professional technology, quantitative statistical methods and ideological education.
Our Cold-rolled Steel products are known for their durability and reliability.
Relying on the superior conditions and strong advantages of mass production, we are able to meet the different needs of our customers.

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