Page 77 - SSAB Welding Handbook Edition 2

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Welding handbook 13.0 Distortions in joints

Placement of the joint The influence of external joint restraint
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The closer the joints are situated to the center of A joint with a high degree of restraint will have less
gravity of the structure, the lower the bowing distortions compared to a joint with a lower degree
distortions are due to welding. This is because of constriction. External restraint can be applied
distortions lead to more bending as the distance by using fixtures, clamps or welding tack welds,
from the center of gravity increases, see fig. 13.4. as exemplified in fig. 13.6. However, a higher level
of restraint supports higher residual stresses in the
welded joint.
Moore distortions

Less distortions

Fig. 13.4: The bottom structure supports lower levels of bowing Fig. 13.6: Utilizing clamps in a joint.
distortions than the top structure.

Joints located symmetrically around the center of
gravity lower the level of bowing distortions since
the distortions from each joint counteract each other,
which is illustrated in fig. 13.5. If the joints on each
side of the center of gravity are welded simultaneously,
the distortions are additionally reduced compared to
welding the joints one at a time.

Fig. 13.5: The welded structure on the right favors lower bowing
distortions than the structure on the left.

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It is the responsibility of the user of this brochure to adapt the recommendations contained therein to the requirements of individual applications.