1. Dimensional Inaccuracy

• Issue: Wall thickness and outer diameter may vary along the pipe length.

• Reason: Uneven piercing or rolling during hot forming.

• Impact: Can cause fit-up issues or affect pressure tolerance in precise systems.

2. Surface Defects

• Types: Scales, scratches, pitting, or surface cracks.

• Reason: Poor control of billet quality, oxidation during heating, or improper lubrication.

• Impact: Affects appearance and may weaken corrosion resistance.

3. Internal Defects

• Types: Inclusions, internal cracks, lamination, porosity.

• Reason: Defective billet, uneven piercing, or improper temperature control during rolling.

• Impact: Reduces mechanical strength and may lead to leakage under pressure.

4. Eccentricity (Uneven Wall Thickness)

• Issue: The pipe wall is thicker on one side and thinner on the other.

• Reason: Misalignment of piercing tools or mandrel.

• Impact: Poor pressure performance and uneven stress distribution.

5. Hardness and Mechanical Property Variations

• Issue: Uneven heat treatment or cooling can cause inconsistent hardness or brittleness.

• Impact: May lead to cracking or premature wear in service.

6. Handling and Storage Damage

• Issue: Bending, denting, or end deformation.

• Reason: Improper stacking, loading, or lack of protective caps.

• Impact: Reduces usability and may fail inspection.

7. Corrosion or Rusting

• Issue: Especially in carbon steel seamless pipes.

• Reason: Poor surface protection, moisture exposure during storage or transport.

• Impact: Shorter service life or failure under pressure.