Hot-rolling Seamless Steel Pipe Production Process

The production process of hot-rolled seamless steel pipes involves a series of steps:

1. Raw Material Preparation:

   The first step in the production process is to prepare the raw materials. We select high-quality steel billets or ingots as the starting material for the production of seamless steel pipes.

2. Heating:

   We heat the selected steel billets or ingots in a furnace at a specific temperature range. This makes the steel malleable and suitable for further processing.

3. Piercing:

   Next, we pierce the heated billets with a piercing machine to create a hollow shell. The piercing process uses a mandrel to push through the center of the billet, forming the initial shape of the pipe.

4. Seamless Rolling:

   We subject the pierced billet to seamless rolling in a piercing mill or a rotary piercing mill. This process reduces the wall thickness and increases the outer diameter of the shell, while maintaining its length.
5. Sizing:

   The rolled pipe then passes through a series of sizing mills to achieve the desired outer diameter and wall thickness. This process improves dimensional accuracy and surface finish.

6. Cutting:

   After sizing, we cut the seamless pipe into desired lengths using a cutting machine. This ensures that the final product has uniform lengths as per customer requirements.

7. Straightening and Inspection:

   The cut pipes go through a straightening process to remove any deformations. Additionally, we conduct inspection to check the quality and integrity of the pipes, including dimensional accuracy, surface defects, and mechanical properties.

8. Heat Treatment:

   Certain grades of seamless steel pipes require heat treatment to enhance their mechanical properties. We perform processes like annealing, normalizing, or quenching and tempering, depending on the specific requirements of the pipe.

9. Surface Treatment:

   To improve corrosion resistance and aesthetics, the pipes may undergo surface treatment processes like pickling, passivation, or coating. This protects the pipes from rusting or other forms of degradation.
10. Final Inspection and Packaging:

    The finished seamless steel pipes undergo a final inspection to ensure they meet the required standards and specifications. We then appropriately package the pipes for storage and transportation, ready for delivery to customers.

This is a general overview of the production process of hot-rolled seamless steel pipes.