MetFab - Air Products Welder's Handbook - Flipbook - Page 34
Lack of
fusion/penetration
Causes:
Prevention methods:
This occurs when the arc fails to melt the
base material. It can be caused by incorrect
alignment of the arc with the joint or by the
weld pool moving ahead of the arc.
• Maintain correct torch angle
This is a common problem when welding
materials with a high thermal conductivity
e.g. aluminium and copper.
• ensure joint faces are free of
excessive mill scale
Depending on the precise location in
the welded joint, this fault is often
characterised as follows:
• ensure correct weld process
gas selection
• lack of side fusion
• lack of inter-run fusion
• lack of root fusion
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• Adjust weld parameters to ensure
the arc is directed onto the leading
edge of the weld pool
• modify the joint design
