1. Welders who are responsible for steel structure welding must hold the welder certificate for the corresponding welding project, and ensure that they can work only after passing the examination within the validity period.
2. The welding work should be carried out after the components are prefabricated and the geometric dimensions are checked. Before welding, the surface and surrounding oil, rust and other dirt should be removed. After welding, slag and spatter should be removed in time.
3. When one of the following situations occurs in the welding environment, effective protective measures must be taken, otherwise welding is prohibited.
4. During manual welding, the wind speed is greater than 10m/s;
5. The relative humidity is greater than 90%;
6. Rain and snow environment.
7. Weld surface quality
The following requirements should be met:
1. The weld seam is well formed. There shall be no defects such as cracks, slag inclusions, needle-shaped pores and arc craters on the surface of the weld, and no slag and spatter shall remain after the surface of the weld is cleaned;
2. The undercut depth on the surface shall not exceed 0.5mm, the continuous length of the undercut shall not exceed 100mm, and the cumulative length of the undercut on both sides of the weld shall not exceed 10% of the length of the weld.
3. The allowable deviation of the intermittent weld length is 0～+10mm.
4. The company's existing welding procedure qualification can meet the welding needs of this project.
Selection of steel structure welding materials: Q235 adopts J422 electrode, Q345 adopts J507 electrode, and between Q345 and Q235 adopts J427 electrode, and gas shielded welding adopts CHW-50C6. The overall dimensions of the weld shall meet the requirements of Table 4.3.6. Finally, regular inspections are carried out for reinforcement.
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