Aluminum Welding Procedure – Aluminum Alloy Welding Preparation Before Welding

During the welding of aluminum alloy, it is required to strictly remove the oxide film and oil stains on the workpiece joints before welding.The cleaning quality will directly affect the welding quality of welding technology and joints, such as the tendency and mechanical properties of weld holes.

Aluminum Alloy Welding

Aluminum Alloy Welding

1.Chemical cleaning

Chemical cleaning is of high efficiency, stable quality, and suitable for cleaning welding wire and small size, batch production of the workpiece.Chemical cleaning is divided into two kinds: dipping and scrubbing.

2. Mechanical cleaning

Mechanical cleaning is often used when the workpiece is large size, long production cycle, and dirty after multi-layer welding or chemical cleaning.Wipe the surface with an organic solvent to remove oil.Then use the copper wire brush or stainless steel wire brush with about 0.15mm to brush to reveal the metallic luster.Sand wheel or sandpaper should not be used for grinding, because the sand is left on the metal surface, and it will produce the defects such as slag when welding.In addition, a scraper can be used to clean the welding surface.

Artifacts and wire can produce oxide film again during storage after cleaning, especially in the moist environment. So before the welding, the storage time should be shortened as far as possible, in the condition of damp climate, generally within 4 hours after clearing up, clean up after the storage time is too long, need to deal with.Recently developed successfully polished wire can be maintained for a long time in general air.The shelf life can reach more than half a year under plastic seal condition.

3. The plate

Strength of aluminum alloy at high temperature is low, liquid flow performance is good, metals tend to collapse when welding, in order to ensure that the weld penetration and does not collapse, plate welding are often used to hold  the molten metal and the metal near it. Plate can use graphite plate, stainless steel or carbon steel, etc.Open a circular arc wall plate surface to ensure the weld reverse side molding, also can not one-sided welding of plate shape, but it requires the skilled operation, or it can be applied to the arc welding power automatic feedback control and other advanced process strictly.

4. Preheating before welding

The thickness of the thin and small aluminum general need not preheating, more than 5 ~ 10 mm thick aluminum, in order to make the joint to achieve the required welding temperature, near to reduce defects such as deformation, reduce pores, it should be preheated before welding.The artifacts are slowly heated to a temperature of about 100 ~ 300 (depending on the different alloy).It can be heated by oxyacetylene flame or electric stove or torch.

Aluminum Alloy Welding

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