Key Factors Determining the Quality of Spiral Steel Pipes

How to Control the Quality of Spiral Steel Pipes

The quality of spiral steel pipes is primarily determined by several crucial factors, including the piercing temperature of the steel billet, which varies depending on the raw material used. For most hot-expanded welded pipes, the piercing temperature is around 1200°C. When the carbon content and other alloy elements are higher, this temperature tends to be slightly lower.

A critical aspect of heating is to minimize the formation of oxide layers. This is especially important in the hot extrusion process of bent pipes, where the surface quality of the hot-expanded welded pipes is becoming increasingly stringent.

In the production of spiral steel pipes, the initial processing occurs under hot conditions, making the heating operation a pivotal step in determining the final product quality.

The Role of Heating Furnaces

Heating furnaces play a crucial role in bringing the steel billets from room temperature to the necessary processing temperature. Proper heating is essential to prevent defects such as cracks, folds, and surface imperfections.

Among various types of heating furnaces, the annular heating furnace is the most commonly used. This furnace features a circular hearth that can rotate slowly, allowing steel billets to be loaded from the inlet along the diameter of the base. The billets are uniformly heated to the required temperature as they progress to the outlet.

Key Considerations in Heating Operations

Uniform Heating: It is vital to ensure the steel billets are heated evenly to the appropriate temperature for subsequent processing. Uneven heating can lead to significant defects in the final product.

Minimizing Oxidation: Reducing the formation of oxide films is essential, particularly during hot extrusion. Excessive oxidation can compromise the surface quality of the pipes.

Temperature Control: The temperature of the billets during the piercing process significantly affects the quality of the final product. Maintaining the correct temperature is crucial to achieving high-quality piercing results.

By focusing on these key areas—uniform heating, minimizing oxidation, and strict temperature control—Centerway can ensure the production of high-quality spiral steel pipes that meet stringent industry standards.