Welding Aluminum-Coated Steel Plates-Teda Metal

Welding Aluminum-Coated Steel Plates: Key Techniques and Conditions

Aluminum-coated steel plates, made from cold-rolled steel with an aluminum-silicon alloy coating, require specific welding conditions to ensure quality. Below are essential guidelines for welding these plates.

1. Characteristics of Aluminum-Coated Steel Plates

Weldability: Aluminum-coated steel plates are easy to weld, though their welding conditions differ from traditional plated steels.
Thermal Conductivity: Due to aluminum’s softness and high conductivity, the welded sections conduct heat more effectively than cold-rolled steel.
Melting Point and Smoke Reduction: The coating has a higher melting point than galvanized steel, reducing the need for high current and minimizing harmful smoke, which benefits the environment.

2. Welding Techniques

MIG Welding: Metal Inert Gas (MIG) welding, especially MIG “short arc” welding, is recommended. Using an argon-based gas shield stabilizes the welding arc, reduces spattering, and improves weld appearance.
Welding Voltage and Electrodes: MIG welding typically operates at a lower voltage (15-24V) and uses titanium electrodes for conventional welding.

3. High-Frequency and Low-Frequency Welding

For products like pipes, where high- or low-frequency welding is used, the steel plate edges should be cleaned before welding. This improves weld quality and prevents defects.

4. Spot Welding

Current and Monitoring: Spot welding aluminum-coated steel requires higher current and close process monitoring compared to cold-rolled steel. Regular electrode maintenance is crucial to prevent contact surface deformation.
Cooling System: Effective cooling with water (minimum 7 liters/min at temperatures below 25°C) extends electrode life. A hard copper alloy spherical electrode is recommended for optimal conductivity and thermal performance.

5. Seam Welding

Current Type: Intermittent current is preferred over continuous for seam welding aluminum-coated steel.
Knurled Wheels: Using copper alloy knurled wheels prevents coating adhesion and maintains a consistent surface width, reducing the need for frequent adjustments. Water cooling of the welding area further stabilizes the process.

Note: The provided welding parameters for aluminum-coated steel plates serve as a general guide. Adjustments may be necessary based on specific working conditions.