Factors Affecting the Shape and Performance of Submerged Arc Welding Seam

Submerged arc welding is mainly suitable for flat position welding. If certain tooling aids are used, corner welding and horizontal welding can be realized. The main factors affecting the shape and performance of submerged arc welding seam are welding process parameters and conditions. The welding process parameters affecting the shape and size of submerged arc welding seam include welding current, arc voltage, welding speed and wire diameter.

1.Welding current

When other conditions remain unchanged, the influence of increasing welding current on weld penetration is proportional to the change of welding current under normal welding conditions, that is, the influence of welding current is small, the depth of fusion is shallow, the reinforcement and width are insufficient, the current is too large, the depth of fusion is large, the reinforcement is too large, and high temperature cracks are easy to occur.

2.Arc voltage

The arc voltage is proportional to the arc length. At the same arc voltage and welding current, if the flux is different, the electric field strength in the arc space is different, and the arc length will be different. If other conditions remain unchanged, changing the influence of arc voltage on the weld shape, the arc voltage is low, the penetration is large, and the weld width is narrow, which is easy to produce hot cracks. When the arc voltage is high, the weld width increases, In submerged arc welding, the arc voltage is adjusted according to the welding current, that is, a certain welding current needs to maintain a certain arc length to ensure the stable combustion of welding arc, so the variation range of arc voltage is limited.

3.Welding speed

Welding speed has an effect on weld depth and width. Generally, the weld depth and width are larger when the welding speed is small and the weld pool is large. With the increase of welding speed, the weld depth and width will decrease, that is, they are inversely proportional to the welding speed. The influence of welding speed on the weld cross-section shape is that the welding speed is too small, the amount of molten metal is too large, the weld formation is poor, and the molten metal will melt when the welding speed is large In actual welding, in order to improve productivity, it is necessary to improve welding speed and arc power to ensure welding quality.

4.Welding wire diameter

When the welding current, arc voltage and welding speed are fixed, the weld shape will change with the diameter of the welding wire, and other conditions remain unchanged. The penetration is inversely proportional to the diameter of the welding wire, but this relationship weakens with the increase of the current density. This is because with the increase of the current density, the amount of molten metal in the molten pool increases, the molten metal is difficult to be discharged, and the penetration increases slowly, With the increase of the amount of molten metal, the reinforcement increases and the weld forming becomes worse. Therefore, it is necessary to increase the welding current and arc voltage to ensure the weld forming quality.