Precautions for Using Automatic Welding Carriages in Steel Structure Welding

Date：2026-03-31

When using an automatic welding carriage for steel structure welding, strict control must be exercised over equipment commissioning, parameter settings, and operating specifications to ensure welding quality and production safety. Below are the key precautions:

1. Pre-Welding Preparation

1.1 Equipment Inspection

Verify smooth operation of mechanical components (travel mechanism, wire feeding system) with no jamming or looseness. Ensure guide rails are installed level for accurate carriage travel.
Check that the welding torch is securely fixed, the nozzle is unclogged, and the contact tip shows no excessive wear. Replace worn parts promptly to avoid affecting arc stability.
Confirm electrical components (cables, control wires) are intact with secure connections to prevent short circuits or poor contact.

1.2 Workpiece Preparation

Thoroughly clean oil, rust, moisture, and other contaminants from the steel surface using shot blasting or grinding to eliminate porosity, inclusions, and other defects.
Check assembly accuracy (gap, bevel angle) against process requirements. Use clamps if necessary to prevent deformation during welding.

1.3 Consumable Preparation

Select matching welding wire, electrodes, or flux based on the steel grade (e.g., Q235, Q345). Ensure specifications meet process standards and materials are free from moisture or rust.

2. Welding Process & Operation Tips

2.1 Parameter Setting & Commissioning

Welding Current & Voltage: Current too high causes burn-through or overheating; too low results in incomplete penetration. Voltage must match current: excessive voltage leads to wide, shallow beads; insufficient voltage causes poor metal flow and bad formation.
Travel Speed: Maintain a uniform travel speed (typically 150-300 mm/min, determined via test welds). Excessively fast speed causes narrow beads and insufficient penetration; slow speed leads to excessive heat input, deformation, or coarse grain structure.
Wire Feed Speed: Synchronize with welding current to ensure consistent melting and droplet transfer, avoiding feeding interruptions or wire breakage.

2.2 Trajectory & Position Control

Plan the weld path in advance. Use linear guides for straight welds; rely on guiding devices or programming (if equipped) for curved or complex welds to keep the torch centered on the joint.
Maintain a consistent torch-to-work angle (typically 70°-80°) to prevent arc deviation or undercutting.

2.3 Shielding Gas & Flux Management

For gas-shielded welding (e.g., CO₂, Ar), check stable gas flow (15-25 L/min) and sufficient cylinder pressure to avoid porosity from insufficient shielding.
For submerged arc welding, ensure uniform flux coverage (20-40 mm depth) and pre-dry the flux to prevent moisture-induced porosity.

3. Safety & Quality Control

3.1 Safe Operation

Operators must wear protective gear (face shields, gloves) to prevent arc radiation and spatter injury. Ensure proper equipment grounding to avoid electric shock.
Keep the work area free of flammable materials and have fire extinguishers on hand to prevent fires from sparks. Do not touch moving parts during carriage operation.

3.2 Real-Time Quality Monitoring

Inspect weld appearance for smoothness, cracks, undercutting, or porosity. Adjust parameters or check the equipment immediately if defects are found.
Measure weld dimensions (width, height) to ensure compliance with design requirements. Perform non-destructive testing (X-ray, ultrasonic) on critical components as needed.

3.3 Deformation Control

Control heat input to minimize distortion. Use anti-deformation methods, rigid fixation, or segment/balanced welding to reduce stress accumulation.
Avoid strong winds and vibration during outdoor welding. Use wind shields to maintain effective gas shielding.

4. Post-Welding Treatment & Maintenance

4.1 Post-Weld Cleaning

Remove slag and spatter from the weld surface. Recycle and screen unused flux in submerged arc welding.
Inspect weld appearance and perform repairs or touch-ups if necessary to meet surface quality standards.

4.2 Equipment Maintenance

Clean slag and spatter from all parts of the carriage, especially the wire feeder, guide rails, and moving components. Keep them well-lubricated.
Regularly inspect electrical components for aging and replace worn parts to ensure stable equipment performance.

5. Special Scenario Considerations

5.1 Thick Plate Welding

For thick steel plates, use multi-layer multi-pass welding with each layer controlled at 3-5 mm. Maintain interpass temperature at 100-250°C (adjust based on material) to prevent cold cracking.

5.2 High-Strength Steel & High-Hardness Materials

Preheat (typically 150-350°C) and post-heat (200-300°C, with insulation) to reduce hardening tendency and relieve residual stress. Refer to the material's specific characteristics for exact process parameters.

By strictly following these precautions, you can effectively improve welding quality and production efficiency with automatic welding carriages, ensuring the reliability and safety of steel structure products.