Common Defects and Resolution Strategies in ERW Production

Systematic analysis and corrective actions address typical production issues.

Weld Line Defects

• Cold weld: Insufficient heat input
  Solution: Increase welding power, reduce speed

• Inclusions: Contaminated strip edges
  Solution: Enhance edge cleaning, improve mill sanitation

• Porosity: Moisture or contaminants
  Solution: Implement strip pre-heating, improve storage conditions

Dimensional Issues

• Ovality: Improper sizing roll adjustment
  Solution: Calibrate sizing stands, check roll wear

• Wall thickness variation: Forming roll misalignment
  Solution: Laser alignment verification, roll gap adjustment

• Length accuracy: Cutting system synchronization
  Solution: Encoder calibration, servo response adjustment

Surface Imperfections

• Scratches: Damaged forming rolls
  Solution: Roll polishing or replacement

• Roll marks: Improper roll pressure
  Solution: Tension control optimization

• Discoloration: Cooling rate issues
  Solution: Adjust cooling parameters, improve water quality

Preventive Measures

• Regular tooling inspection and maintenance

• Operator training programs

• Statistical process control implementation

• Comprehensive quality documentation systems