Four Position Welding Techniques

01 Backine welding

The molten metal falls due to gravity, and the shape and size of the molten pool can not be controlled.
The surface of welding parts should not be welded flat.
It is easy to have defects such as slag inclusion, non-penetration, welding tumor and poor weld formation.
Melting weld metal spatter diffusion, easy to cause scalding accident.
Backine welding is lower than other positions.

Weld metal mainly depends on the weight of the transition to the pool.
The shape of molten pool and molten pool metal are easy to maintain and control.
When welding the same thickness metal, the welding current at the flat welding position is larger than that at other welding positions, and the production efficiency is higher.
Slag and molten pool are easy to appear mixing phenomenon, especially when welding fillet weld, slag easily ahead of the formation of slag inclusion.
Welding parameters and improper operation, easy to form welding, undercut, welding deformation and other defects.
When the back of single-side welding is formed freely, the first weld is easy to produce the image of uneven penetration procedure and bad formation of the back.

The molten metal and slag are easily separated by the weight of the molten metal.
When the molten pool temperature is too high, the molten pool metal is easy to flow down to form defects such as welding nodule, undercut, slag inclusion, etc. .
T-joint weld root easy to form non-penetration.
Four Position Welding Techniques
The degree of penetration is easy to master.
The welding productivity is lower than the flat welding.

The molten metal is easy to fall on the groove due to its own weight, resulting in undercut defects on the upper side and tear-drop-shaped weldments or incomplete defects on the lower side.
Molten metal and slag easy to separate, slightly similar to vertical welding.

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