Common Welding Defects of ERW Pipes

Here are some common welding defects of ERW pipes:

1. **Gap between the weld and the base material**: This defect occurs when the weld does not fully merge with the base material, leaving a gap or porosity.

2. **Sinking/Raising of the weld**: The weld may sink or raise excessively during welding, resulting in an uneven surface or distortion of the pipe.

3. **Undulation of the weld**: This occurs when the weld is not properly curved, resulting in an unsightly and weak spot in the pipe.

4. **Pile-up or Shot Bump**: This occurs when the electrode wire gets stuck and cannot be fed properly during welding, resulting in a bulge or bump on the weld.

5. **Non-uniform heat distribution**: If the heat distribution during welding is not uniform, it can result in poor fusion between the weld and base material, leading to porosity or gaps.

6. **Seizure or slag inclusion in the weld**: Seizure occurs when there is an improper movement of the electrode wire or arc during welding, resulting in improper fusion of materials. Slag inclusion occurs when slag enters the weld during welding, affecting its appearance and mechanical properties.

7. **Cratering**: This occurs when the molten metal droplets splatter outside the desired area during welding, resulting in a weak spot in the pipe.

8. **Non-uniform wall thickness**: If the wall thickness of the pipe is not uniform after welding, it may indicate improper control of the welding process or poor quality of the base material.

These are some common welding defects that can occur in ERW pipes during welding processes. Properly trained welders and quality control measures can help minimize these defects and ensure the quality of the final product.