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The weld seam quality in ERW (Electric Resistance Welding) pipe production is critical for ensuring mechanical strength, pressure integrity, and longevity of the pipes. At Shijiazhuang Faith Machinery Co., Ltd, our approach integrates advanced technology, process control, and quality assurance measures to achieve consistent weld quality.
Key Factors Influencing Weld Quality
Strip Edge Preparation: Clean, parallel strip edges free from oxides and contaminants are essential. Our systems incorporate precision milling or cutting tools to ensure optimal edge conditions before forming.
High-Frequency Welding Parameters: The use of HF current (100–400 kHz) generates localized heat through skin and proximity effects. Proper control of power output, vee length, and squeeze pressure ensures complete fusion without defects.
Post-Weld Heat Treatment: Immediate normalizing or annealing of the weld zone refines grain structure and eliminates residual stresses, enhancing ductility and corrosion resistance.
Quality Assurance Measures
Non-Destructive Testing (NDT): In-line eddy current testing detects surface irregularities, while ultrasonic testing identifies subsurface flaws. Automated visual inspection systems monitor weld consistency.
Dimensional Checks: Laser profilometers continuously measure outer diameter and wall thickness, ensuring compliance with specified tolerances.
Process Monitoring: PLC systems track parameters like welding speed, temperature, and pressure, enabling real-time adjustments and data logging for traceability.
Common Challenges and Solutions
Weld Porosity: Caused by contaminants or moisture. Solutions include improved strip cleaning and controlled atmospheric conditions during welding.
Incomplete Penetration: Addressed by optimizing power input and alignment of squeeze rolls.
Our ERW mills at Shijiazhuang Faith Machinery incorporate these principles to deliver pipes with reliable weld seams suitable for demanding applications like oil and gas transmission or structural components.
