Metal Space frame Steel Structure building Prefab Warehouse

In the prefabricated warehouse engineering of metal space frame steel structure buildings, there are many cases where welding deformation directly affects the installation and functional use of steel components and steel structures. Therefore, controlling welding deformation is very important. Based on the causes and influencing factors of welding deformation, steel structures can take the following measures to control welding deformation:

1. When the design requirements are met, intermittent welding method can be used for the welding of longitudinal plates and transverse stiffeners.

2. For steel with yield strength below 345MPa and weak hardenability, small heat input should be used. Preheating should be avoided as much as possible or preheating and interlayer temperature should be appropriately reduced. Priority should be given to welding methods with small heat input, such as CO2 gas shielded welding.

3. Reduce the cross-sectional area of the weld seam: On the premise of obtaining intact and no excessive defects in the weld seam, try to use small groove sizes (angles and gaps) as much as possible

4. Steel structure thick plate welding should use multi-layer welding instead of single-layer welding as much as possible.

5. When both sides can be welded, double-sided symmetrical grooves should be used, and in multi-layer welding, the welding sequence should be symmetrical with the component and axis.

6. Using pre weld anti deformation method to control post weld corner deformation.

7. The steel structure adopts rigid fixture fixation method to control post weld deformation.

8. When the thickness of the T-shaped joint plate is large, beveled corner butt welds are used.

9. For the distortion of long components, the main approach is to improve the flatness of the plate and the assembly accuracy of the components, so as to ensure accurate groove angles and gaps, accurate arc direction or alignment, and to ensure that the weld seam angle deformation and longitudinal deformation values of the wing and web plates are consistent along the length direction of the components.

10. The component reservation length method is used to compensate for the longitudinal shrinkage deformation of the weld seam. For example, the longitudinal weld seam of H-shaped steel can be reserved with a length of 0.5mm-0.7mm per meter, and the corresponding length of each pair of transverse bars can be reserved with a length of 0.5mm. The reserved perimeter method is used to compensate for the longitudinal and transverse shrinkage deformation of the weld seam of cylindrical pipe components. If the plate thickness is greater than 10mm, each longitudinal and circumferential weld seam is reserved with a circumference of 2.0mm.