The difference between single-sided and double-sided welding of ssaw steel pipe

The influence of ssaw steel pipe production process factors on the quality of single-side welding double-sided forming welds mainly includes welding current, welding speed, number of welding layers, electrode type and electrode diameter.

Welding current:

The proper choice of the welding current size directly affects the final welding quality. Excessive welding current can increase the productivity and increase the penetration depth, but it is prone to defects such as biting and welding, and increases the tendency of stomata. In particular, when the vertical welding operation is difficult to control the molten pool, the occurrence of welding defects, arc length increases, the welding current is too small, the penetration depth is reduced, prone to defects such as incomplete penetration, poor fusion, slag inclusion, and disconnection. During the training, for those students who have just come into contact with welding, this is a difficult problem to grasp. During the single-sided welding of the board and board, the primary welding current is large, resulting in the back of our board there are many different sizes of welding. Bottom welding is too small, resulting in an unfused defect in our welding. This defect can directly lead to a significant reduction in weld quality, which is one of the important defects in industrial production.

Welding speed:

Welding speed is the main parameter to express the efficiency of welding production. Reasonable choice of welding courier is especially important for ensuring welding quality. The welding speed is too fast, so that the temperature of the bath is not enough, which may cause defects such as incomplete penetration, non-fusion, poor weld formation, and the like. The welding speed is too slow, so that the high temperature for a long time, the width of the heat affected zone increases, the grain of the welded joint becomes coarser, the mechanical properties decrease, the deformation of the weldment increases, and at the same time, the welding speed is too low and the thickness of each layer increases, resulting in slag backflow, the formation of slag inclusions and other defects. Cover welding speed.

Improper selection of welding layers.

The number of single-side welding double-sided forming welding layer also has a certain influence on the quality of the weld, each layer thickness is too large, the plasticity of the weld metal is detrimental, and the slag in the welding process is easy to reverse flow, resulting in slag and not Fusion and other defects, but the thickness of each layer is not too small, so as not to cause poor fusion on both sides of the weld.

The shape of the electrode and the diameter of the electrode.

The properties of the weld metal are mainly determined by the melting of the electrode and the weld metal. Therefore, whether the choice of wire type is appropriate or not is an important factor affecting the quality of the weld. In addition to the influence of the diameter of the electrode on the acoustic field rate, it also has a certain influence on the quality of the welding. The diameter of the electrode is too large and the underlying layer is under ground. The weld pool is difficult to control and it is easy to produce weld defects. What kind of base metal, choose the welding material with the same properties as the base metal. The choice of welding diameter is too large. We can hardly weld a good weld on the back of the test plate.