Design Measures to Reduce Residual Deformation of Welding

1. Reasonable selection of weld size

The length, width and thickness of the welded parts and other dimensions have a significant impact on the welding deformation. For example, the thickness of the plate for the corner weld corner deformation influence, when the thickness reaches a certain value (steel about 9mm) when the corner deformation is the largest. In the manufacture of T-shaped or work-shaped welded beams, due to the slender welded parts, so that the welding area shrinkage deformation caused by the weld bending deformation is a prominent problem. The best way to solve this problem is to carefully design the structural size parameters, (such as plate thickness, plate width, plate length and rib spacing, etc.) and welding parameters (such as unit line energy, etc.).

2. Reasonable choice of weld size and bevel form

The size of the weld seam is not only related to the welding workload but also has a greater impact on the welding deformation. Weld size is large, the welding volume is also large, filler metal consumption results in large welding deformation. Therefore, in the design of the weld seam size, under the condition of ensuring the load-bearing capacity of the structure, a smaller weld seam size should be used. Unilaterally increasing the size of the weld seam is extremely detrimental to reducing welding deformation. So the weld does not bear a lot of working stress, do not have to use a large size welding angle, as long as it can meet its strength requirements.

In addition, there is a reasonable design bevel type. For example, butt joints to use the best X-shaped bevel size for zero angular deformation. For the larger force T-shaped joints and cross joints, under the condition of ensuring the same strength, the use of open bevel welds than open bevel weld dynamic load strength, less weld metal, and reduced welding deformation is also beneficial, especially for thick plates, more in the sense.

3. Minimize unnecessary welds

In the design of welded structures, should strive to minimize the number of welds. In general, the design is often used to add a ribbed plate to improve the stability and stiffness of the structure, especially sometimes to reduce the weight of the main structure and the use of thinner plates, is bound to increase the number of ribs, thus greatly increasing the assembly and welding workload, the result is not only uneconomical, and the weld resulting in welding deformation is too large. So practice has proved that the reasonable choice of plate thickness, is appropriate to reduce the rib plate so that the weld is reduced, even though the structure may be slightly heavier, or more economical.

4. Reasonable arrangement of welding seam position

In order to avoid bending deformation of the welded structure, the design of the structure should strive to make the weld position symmetrical in the neutral axis of the material joint members or close to the neutral axis. Because of the weld symmetry in the neutral axis, it is possible to make the neutral axis on both sides of the bending deformation produced by the weld axis completely offset or largely offset. Because the weld is close to the neutral axis the weld shrinkage caused by the bending moment is reduced, so that the member bending deformation is also reduced. Therefore, when welding the structure should strive to make the structure symmetrical. Some cross-sectional shapes can not change the non-symmetrical structural parts, and can maintain the same cross-sectional shape, using the method of adjusting the distance between the center of gravity axis and the neutral axis of the weld to reduce deformation.