How to reduce the phosphorus and sulfur content in pipe fittings

In the production of high-quality steel products, controlling the levels of sulfur and phosphorus is crucial, as these elements can negatively impact the material properties, such as ductility, toughness, and overall strength. Sulfur, being a harmful impurity, can cause hot cracking during welding and reduce the material’s ability to withstand high temperatures. Phosphorus, on the other hand, can embrittle steel, especially at low temperatures, making the material prone to cracking.In the recent order from an Iranian customer, the customer required that the sulfur content of the product be less than or equal to 0.01 and the phosphorus content be less than or equal to 0.025. Haihao Group successfully met the customer’s requirements. Below we will introduce in detail the methods to reduce the phosphorus and sulfur content of the product.

HAIHAO GROUP

The primary methods used to control and reduce sulfur and phosphorus levels in steel are as follows:

Selection of Raw Materials: The quality of the raw materials used in steelmaking plays a significant role in determining the final chemical composition of the product. By sourcing high-quality iron ore with low sulfur and phosphorus content, the overall levels of these impurities can be minimized from the very beginning.

De-Sulfurization and De-Phosphorization Processes: During the steelmaking process, various techniques are employed to remove sulfur and phosphorus:

De-Sulfurization: One of the most common methods is to add calcium-based agents (such as calcium carbide or calcium oxide) to bind with sulfur to form calcium sulfide, which can then be removed from the molten steel.

De-Phosphorization: This process often involves adding fluxing agents like lime and adjusting the temperature to promote the chemical removal of phosphorus, turning it into a compound that can be separated from the steel.

Electric Arc Furnace (EAF) and Ladle Refining:

Electric Arc Furnace (EAF): In the EAF process, a higher degree of control over sulfur and phosphorus content can be achieved by adding fluxing agents that bind with these impurities and remove them efficiently.

Ladle Refining: Further refining in the ladle allows for precise control of the steel’s chemical composition, including reducing sulfur and phosphorus to meet specific customer requirements. The steel is heated and treated in the ladle to remove unwanted impurities.

Vacuum Treatment: In some cases, vacuum treatment can be used to further reduce sulfur and phosphorus content. This method involves creating a vacuum in the steelmaking furnace, which helps to drive off sulfur and phosphorus as gases.

Continuous Casting: Continuous casting also plays a role in ensuring that the steel solidifies evenly and avoids any localized accumulation of sulfur or phosphorus impurities, ensuring a consistent product with low impurity levels.

Haihao Group’s commitment to quality and customer satisfaction ensures that we can meet even the most demanding specifications, including low sulfur and phosphorus content. For our Iranian customer’s order, we have taken all necessary measures to ensure that the products meet their high standards for chemical composition, including sulfur ≤ 0.01% and phosphorus ≤ 0.025%. With our advanced production processes, stringent quality control, and attention to detail, Haihao Group is fully equipped to provide the high-quality products our customers need for critical applications. We look forward to continuing to serve our customers with top-quality materials and reliable solutions for their projects.