1. assembly

During assembly, there is no assembly jig for welding H steel, which results in the height width ratio specification error of H steel, and the web is deviated from the management center; after wing web connection, the weld is not leveled, and there is significant convex concave; the web of light steel structure is not leveled, and it is not corrected before assembly.

2.Cutting and blanking 

When cutting and blanking, the specification and width of flange plate are different, resulting in the specification of H-beam and corbel is inconsistent, and the left and right flange plates of steel column connected with corbel are shifted by about one plate thickness; there are deep cutting marks on the cutting edge, obvious dents on the plate edge, or deep zigzag marks on the cutting edge, the cutting surface roughness exceeds the standard, the cutting unevenness of the edge of the panel splicing method, the patching and staggering, etc。

3. electric welding

At the level of electric welding, the H-shaped steel wing plate of light steel structure is spliced after being cut. The weld is not installed with arc striking plate, resulting in the weld not being round, the edge has dents and no welding defects, etc., which is uneven with the butt weld. The specification of the welding hole of the column base and bracket is lower than the requirements of the design drawing, the fillet weld is in serious condition of edge collapse, the arc stopping place is widely smaller than the butt weld, and there are many air holes. It is necessary to The weld of CO2 welding is poor in forming, inconsistent in width, inconsistent in height, big or small; the weld of hand-made welding is bent, different in width, serious in staggered joint; the weld splashing is not eliminated 

If the structural quality of steel frame does not exceed the requirements, it will be mainly reflected in many aspects here

4. drilling

At the drilling level, it is not very good to review the engineering drawings in advance. In the area with single and double rows of holes, the single and double rows of holes have been opened, and the results remain on the prefabricated components without patching.For example, the H-shaped steel at the joint of the column and the bracket is a single double row hole, while the H-shaped steel of the same specification and model of the house beam and the secondary beam is a single double row hole, but the single double row holes are opened during the drilling, which endangers the compressive strength and appearance quality after installation.

5. whole welding process

During the whole welding process, the connection between the steel beam bracket and H-shaped steel beam shifted left and right, up and down, and the specification was not well controlled.

6.Anti-rust treatment and paint

Anti-rust treatment and paint layer: the anti-rust treatment is careless and does not exceed the level regulations, and the paint will return to rust and fall off soon; the thickness of paint layer is uneven, and the thickness of surface is wide and extra thick, reaching 250 μ m, but the back sun is usually above and below 90 μ m (the thickness of paint layer in the room is required to be 125 μ m); the residue before the paint is not removed, and there are many wastes, uneven, and wide flow hanging condition.