Melting pole gas shielded welding, when the operator holds the welding torch in his right hand, welding from right to left, the welding torch nozzle and the welding direction are obtuse angle (>90 °) is called left welding method;
Welding from left to right, the welding torch nozzle and the welding direction are sharp angled (<90 °) is called right welding method.
If the operator holds the welding torch in his left hand and the welding direction is just opposite, Figure 1 is a schematic diagram of the left and right welding methods.
Figure 1 Schematic diagram of left and right soldering methods
The angle between the shaft of the welding torch and the surface of the weldment is the working angle;
In the plane where the welding torch axis and the welding direction are located, the angle between the welding torch axis and the straight line perpendicular to the welding direction is the walking angle.
Fig. 2(a) is a schematic diagram of the working angle and walking angle of the fillet weld, and Fig. 2(b) is a schematic diagram of the working angle and the walking angle of the butt weld. Usually, the working angle of the fillet weld is 45°, and the working angle of the butt weld is 90°;
Among them, the walking angle is different according to the welding direction, and there is a distinction between the forward inclination angle and the backward inclination angle, which is called the backward inclination angle when the right welding, and the forward inclination angle when the left welding.
Fig. 2 Schematic diagram of working angle and walking angle
Influence on weld forming
Welding direction and angle are not the same, arc and weldment mode of action is different, the right welding arc most of the direct action on the weldment, and the left welding arc most of the action on the liquid molten pool, therefore, in the same welding current, arc voltage, welding speed conditions, the resulting weld width and penetration depth is different, Figure 3 is the weld direction and angle and its weld forming influence schematic diagram.
(a) Schematic diagram of the influence of the welding direction and walking angle of the butt weld on the weld forming
(b) Schematic diagram of the influence of the welding direction and the walking angle on the weld forming
Fig. 3 Schematic diagram of welding direction and angle and its weld forming influence
In addition to the influence on weld forming, the welding direction and walking angle also have a certain impact on the welder's melt pool observation effect, the size of the splash and the gas protection effect.
When welding in the left direction, the operator's line of sight observes the welding arc and the welding pool from a 45° to 70° perspective on the side of the welding arc, which is easy to observe the melting situation and the change of the welding pool at the protruding end of the welding wire;
When welding to the right, the welding torch blocks the view of the operator and makes the operation difficult.
Figure 4 shows a schematic view of the operator's viewing angle for left-facing welding (flat solder position).
Fig. 4 Left-facing weld (flat solder position) operator perspective
Application of welding direction and angle
Since the welding direction and angle have an important impact on weld seam forming, splash size, gas protection effect, etc., in the actual welding production, according to different technical requirements and actual conditions, left welding and right welding have different applicable occasions, and the practical application of typical welding directions is shown in the attached table.
conclusion
The left welding method has the characteristics of shallow penetration depth and wide weld bead, which is suitable for thin plate welding; right welding method has the characteristics of large penetration depth and narrow weld bead, which is suitable for medium and thick plate welding.
When the walking angle is small, it has the characteristics of large molten depth and good protection effect of the molten pool; when the walking angle is large, it has the characteristics of small molten depth and poor protection effect of the molten pool, and when the walking angle is 10 ° ~ 15 °, the protection effect of the molten pool is good.