In the mechanical industry, there is a division standard for 1G, 2G, 3G, 4G, 5G and 6G, which is the division of weld position in the welding industry.

1. The position of groove weld is divided into: 1G, 2G, 3G, 4G, 5G and 6G, respectively representing flat welding, horizontal welding, vertical welding, overhead welding, horizontal fixed welding of pipeline, and inclined 45 ° fixed welding of pipeline.

2. Fillet weld of plate is divided into 1F, 2F, 3F and 4F, which are ship type weld, horizontal weld, vertical weld and overhead weld respectively.

3. Tube sheet or tube fillet welds are divided into: 1F, 2F, 2FR, 4F and 5F, which are respectively 45 ° rotary welding, transverse welding (tube axis vertical), horizontal (rotary) welding of tube axis, and horizontal (fixed) welding of overhead welded tube axis.

Introduction to flat welding: 1G is flat welding

Welding characteristics:

1. The fusion welding metal mainly depends on its own weight to transfer to the molten pool.

2. The shape and metal of the molten pool can be easily maintained and controlled.

3. When welding metals with the same thickness, the welding current at the flat welding position is higher than that at other welding positions, and the production efficiency is high.

4. The slag and molten pool are easy to mix, especially when welding the flat fillet weld, the slag is easy to lead and form slag inclusion.

*It is difficult to distinguish the slag of acid electrode from the molten pool; Alkaline electrode is relatively clear;

5. Inappropriate welding parameters and operations are easy to form weld beading, undercut, welding deformation and other defects.

6. When the back is free formed by single side welding, the first weld is easy to produce images such as uneven penetration procedure and poor back forming.

Introduction to transverse welding: 2G is transverse welding

Welding characteristics:

1. The molten metal is easy to fall on the groove due to its own weight, resulting in undercut defects on the upper side and teardrop type overlap or incomplete penetration defects on the lower side.

2. The molten metal and slag are easy to separate, slightly like vertical welding.

Introduction to vertical welding: 3G is vertical welding

Welding characteristics:

1. The molten pool metal and slag are easy to separate due to their own weight.

2. When the temperature of the molten pool is too high, the metal in the molten pool is easy to flow down to form defects such as weld beading, undercut and slag inclusion, and the weld is uneven.

3. The root of T-joint weld is easy to form incomplete penetration.

4. The degree of penetration is easy to master.

5. The welding productivity is lower than that of flat welding.

Introduction to overhead welding: 4G is overhead welding

Welding characteristics:

1. The molten metal falls due to gravity, and the shape and size of the molten pool should not be controlled.

2. It is difficult to transport the electrode, and the surface of the weldment should not be flat.

3. It is prone to defects such as slag inclusion, incomplete penetration, overlap and poor weld formation.

4. The molten weld metal splashes and spreads, which is easy to cause scalding accidents.

5. Overhead welding is less efficient than other positions.

The horizontal fixed port of the pipe is 5G

The 45 ° bevel weld of the pipe is the 6G position