I. Prevention of Welding Quality Defects (Starting from the Source)
1. Preventing Porosity: Strictly Control Gas Purity
Use argon gas with a purity ≥ 99.99%, ensuring the gas cylinder is free of moisture and impurities.
Before welding, thoroughly clean the pipe opening and the area within 20mm on both sides to remove oil, rust, and paint. Anhydrous alcohol can be used for wiping.
Control ambient humidity and avoid outdoor work in strong winds or rain. Install windproof covers if necessary.
2. Avoid Incomplete Fusion/Penetration: Precisely Match Process Parameters
Set appropriate current and voltage according to wall thickness, for example:
Wall thickness 3~6mm: Current 120~180A, Voltage 16~20V
Wall thickness 8~10mm: Current 200~250A, Voltage 22~26V
Design standard V-groove (angle 30°~45°), control the blunt edge at 0.5~1.5mm, and the assembly gap at 2~4mm.
3. Reduce Undercut and Crater Cracks: Optimize Welding Torch Movement and Arc Termination Logic
Maintain a welding torch tilt angle of 10°~15°, move at a uniform speed, and avoid prolonged pausing or excessively rapid passage through corners.
Activate the equipment's "arc termination and crater filling" function, or use a back-welding finishing method to prevent rapid cooling and shrinkage cracking of the molten pool.
4. Prevent Weld Blackening: Ensure Integrity of Gas Protection
Check for oxidation and discoloration of the tungsten needle; replace it promptly. Ensure the argon flow rate is stable at 10-15 L/min.
When back protection is required inside the tube, seal it with high-temperature tape or a plug, leaving an exhaust port for pure argon protection.
II. Prevention of Mechanical System Failures (Focus on Daily Maintenance)
1. Prevent Welding Torch Deviation: Regularly Calibrate the Positioning System
Check the straightness of the guide rail and the clearance between the slider weekly; use a laser alignment instrument to calibrate the welding torch centerline.
Check the servo motor encoder feedback monthly to ensure it is normal and prevent track deviation due to step loss.
2. Avoid Poor Wire Feeding: Standardize Wire Feeding Mechanism Maintenance
The bending radius of the wire feeding hose must not be less than 150 mm to prevent damage to the internal cable.
Regularly clean the wire feeding wheel groove; replace worn contact nozzles and pressure rollers to ensure smooth and unobstructed wire feeding.
III. Prevention of Electrical and Control System Faults (Strengthening the Safety Bottom Line)
1. Preventing "No High Voltage" Faults: Inspecting Insulation and Connection Points
Before each startup, check the insulation condition of the secondary side of the high-frequency welding machine's output transformer, observing for signs of carbonization or arcing.
Ensure all wiring terminals are secure and free of oxidation, focusing on checking for potential discharge risks between the primary and secondary coils.
2. Preventing Control Malfunctions: Strengthening Anti-interference and Power Management
Install a voltage regulator and filter to prevent voltage fluctuations from affecting PLC operation.
Regularly back up welding program parameters to prevent accidental loss.
