Pre-welding Workpiece Cleaning
Removal of oil and dust: Wipe the surfaces of the workpiece and filler wire with organic solvents such as gasoline or acetone; alternatively, use an alkaline degreasing solution, followed by drying.
Removal of oxide film:
Mechanical cleaning: Use tools such as abrasive belts, stainless steel wire brushes, or scrapers to grind the oxide film within a 30–50 mm range on both sides of the joint until the metallic luster is exposed; avoid sandblasting for soft metals.
Chemical cleaning: For non-ferrous metals like aluminum and magnesium, immersion in designated acidic or alkaline solutions followed by rinsing and drying offers higher cleaning efficiency.
Note: Welding must be completed within 24 hours after cleaning (or within 4 hours in humid environments); if this time limit is exceeded, the workpiece must be cleaned again.
Post-welding Weld Seam Cleaning
Mechanical cleaning: Use wire brushes, sandpaper, or polishing wheels to remove welding slag and surface oxide layers; blow away debris with compressed air after cleaning.
Chemical/Electrochemical cleaning: For stainless steel welds, use specialized pickling agents or passivation pastes, or employ electrolytic cleaning equipment to rapidly remove weld discoloration and enhance corrosion resistance.
Special treatment: For critical weldments, scrub with hot water (60–80°C), dip in a dilute chromic acid solution, and dry to ensure the cleanliness of the weld seam.
