What needs attention in welding aluminium and aluminium alloy

What needs attention in welding aluminium and aluminium alloy

1. Welding characteristics: Aluminium and aluminium alloys have strong thermal conductivity and large heat capacity, large linear expansion coefficient, low melting point and small high temperature strength, etc. It is difficult to weld and certain measures should be taken to ensure the quality of welding. When aluminium and aluminium alloys are welded, there is no obvious colour change when they are transformed from solid to liquid state, so it poses a lot of difficulties to the operator during the welding process. Therefore, welders are required to master the heating temperature when welding, try to use flat welding and lead (close) the arc on the lead (close) arc plate.

2. pipe fittings and wire cleaning, welding wire and the surface within 50mm on both sides of the breach cleaned with acetone, using stainless steel wire brush to brush away the surface oxide film to reveal the metal luster, clean up the breach must be welded within 2 hours, clean up the wire into the unused cylinder, must be used up within 8 hours, otherwise reprocessing.

3. The tungsten rod is selected from cerium tungsten rod, the argon blunt quality is not less than 99.96%, and the water content should not be greater than 50mg/m3.

4. The ambient temperature should not be less than 5℃, otherwise it should be preheated to 100~200℃ before welding, and the relative humidity should be controlled.