The measures to prevent and reduce the deformation of the steel structure

The steel structure processing company tells you the measures to prevent and reduce the deformation of the steel structure.

1) Reduce the cross-sectional area of the weld: on the premise of obtaining a good weld without exceeding the standard defect, the smaller groove size (angle and gap) should be used as much as possible.

2) For steels with a yield strength below 345MPa and weak hardenability, use a small heat input, do not preheat as much as possible or appropriately reduce the preheating and interlayer temperature; preferentially use welding methods with small heat input, such as CO2 gas protection weld.

3) For thick plate welding, use multi-layer welding instead of single-layer welding as much as possible.

4) For double-sided welding operations, double-sided symmetrical grooves should be used, and a welding sequence that is symmetrical to the central and axis of the component should be used for multi-layer welding.

5)When the thickness of the T-joint plate is large, the butt-weld of the beveled Angle is adopted

6) The anti-deformation method before welding is used to control the angular deformation after welding. This method is a common method in production, and the weldment is basically offset (compensated) in advance.

7) Rigid fixation method: also known as mandatory method. In actual production, the post-welding deformation of rigid components is generally less, and the rigidity of the components can be strengthened before welding, and the post-welding deformation will also be reduced. When using this method, you must wait for the welding to cool before removing the fixture and support. Several common methods include fixture method, support method, mold method, temporary fixation method (such as welding nail fixation and compression fixation method) , Positioning welding method.

8) Hammer welding seam method: This method is mainly suitable for the welding of thin plates. When the welding seam of the thin plate and its heat-affected zone have not completely cooled, the area is immediately hammered, and the thick plate is hit with an air gun.

9) Use the method of component reserved length to compensate for longitudinal shrinkage and deformation of the weld.

10) In the design, the number and size of welds should be reduced as much as possible; reasonable layout of welds, in addition to avoiding dense welds, the position of welds should be as close as possible to the neutral axis of the components, and the layout of the welds should be consistent with the components. The neutral axis is symmetrical.

11) Correctly choose the welding sequence. When there are butt welds and fillet welds in the steel structure, in principle, the butt welds and the reverse fillet welds should be welded first. For cross-shaped welds and T-shaped welds, the correct sequence should be adopted to avoid welding stress concentration and ensure the quality of joint welding. The welding of the neutral shaft symmetrical to the entire steel structure and the welding of the two sections from the middle phase are very beneficial to reduce deformation. For the welding of important parts with high strength requirements in the steel structure, the joints should be freely contracted as far as possible without restriction.