Piercing Process

Piercing is a crucial step in the manufacturing process of carbon seamless steel pipes and tubes. It involves creating a hollow center through a solid cylindrical billet. Here’s an overview of the piercing process:

  1. Billet Selection: High-quality carbon steel billets are selected based on the desired specifications of the final product.
  2. Heating: The billet is heated to a high temperature, typically above its recrystallization temperature, to make it more malleable for the piercing process. This temperature varies based on the material and size of the billet.
  3. Centring: The heated billet is centered to ensure uniform piercing and to minimize wall thickness variation in the final product.
  4. Piercing: The centered billet is then pierced with a piercing mill or a piercing press. This equipment consists of a piercing plug or mandrel that is forced through the center of the billet, creating a hollow tube. The mandrel is typically tapered to facilitate smooth piercing and reduce friction.
  5. Sizing: After piercing, the hollow tube is passed through a series of sizing rolls or stretch-reducing mills to achieve the desired outer diameter and wall thickness.
  6. Cooling: The newly formed seamless steel pipe or tube is rapidly cooled to room temperature to stabilize its microstructure and mechanical properties.
  7. Finishing: The pipe or tube may undergo additional finishing processes such as straightening, cutting, and surface treatment to meet specific customer requirements.
  8. Quality Control: Throughout the piercing process, quality control measures are implemented to ensure dimensional accuracy, surface finish, and material integrity of the final product.
  9. Testing: Finally, the finished pipes or tubes undergo various tests such as hydrostatic testing, non-destructive testing, and dimensional inspection to ensure they meet industry standards and customer specifications.

By following these steps with precision and care, manufacturers can produce high-quality carbon seamless steel pipes and tubes suitable for a wide range of applications in industries such as oil and gas, automotive, construction, and machinery.