Welding is an important step of steel structure building. The quality of welding has a direct impact on the stability and stability of steel structure components, and determines the safety of the whole building. Therefore, the following points should be kept in mind in welding engineering:
1. Dimension out of tolerance
For the deviation of weld length, width, thickness, centerline deviation, bending, etc., the relative position and size of welding parts shall be strictly controlled, and the welding shall be allowed only after the welding is qualified, and the welding shall be carried out carefully.
2. Weld crack
In order to prevent cracks, suitable welding process parameters and welding procedures shall be selected to avoid large current and sudden flameout. The weld joint shall be 10-15mm long, and it is allowed to move and knock the weldment during welding.
3. Surface porosity
The welding rod shall be baked according to the specified temperature and time. The welding area must be cleaned up. During the welding process, appropriate welding current shall be selected to reduce the welding speed and make the gas in the molten pool escape completely.
4. Slag inclusion in weld
For multi-layer welding, the welding slag shall be removed layer by layer, the strip shall be transported correctly and the arc length shall be appropriate. Pay attention to the flow direction of the slag. When using the alkaline electrode, the slag must be left behind the slag.
In addition, attention should be paid not only to quality problems, but also to aesthetics during welding. The appearance of the weld should be smooth and beautiful without any welding defects, such as porosity, undercut, flowing, incomplete welding, incomplete wrapping angle, unsealed and so on.