Welding process to reduce welding distortion

Ways to reduce shrinkage deformation:

1.Do not over weld

The more filler metal, the greater the deformation. Making the correct weld size can obtain small welding deformation and save welding time. The amount of filler metal in the weld should be small. Excessive welding metal will increase shrinkage force and welding deformation.

2.Intermittent weld

Using intermittent welding to reduce weld filler, such as welding stiffeners, can reduce weld filler by 75% to ensure the required strength.

3.Reduce weld bead

The welding deformation of less passes is less than that of more passes. The cumulative shrinkage caused by each weld of more passes increases the total shrinkage of the weld. The welding process effect of less passes and coarse electrodes is better.

4.Anti deformation technology

Before welding, the parts shall be bent in the opposite direction of welding deformation in advance, and the welding stress shall be offset by the reverse mechanical force. When preset, the shrinkage stress of the workpiece and the weld will have opposite deformation, and the post welding deformation will offset the pre welding deformation to form an ideal plane.

Placing and clamping the same welding workpiece relative to each other can also balance the shrinkage force, which can be used for pre bending. Before clamping, place the wedge at the appropriate position of the workpiece.

Special heavy welding workpieces can produce the required balance force. If not, other methods should be used to balance the welding shrinkage force to offset each other.

5.Welding sequence

The workpiece shrinks at the same position, double-sided groove is opened, multi-layer welding is adopted, intermittent welding is adopted for fillet weld, and the workpiece is fixed with fixture to increase rigidity and reduce deformation. It can be used to weld small workpieces.

6.Reduce welding time

The time factor also affects the deformation. Heating and cooling occur during welding, and the heat transfer takes time. Before the large workpiece is heated and expanded, the welding should be completed as soon as possible. The type of electrode, welding current and welding speed will affect the degree of shrinkage and deformation. The use of mechanized welding equipment reduces the welding time and deformation.