1. Material selection
Before processing, the factory qualification certificate, quality assurance certificate, batch number, chemical composition, mechanical properties, etc. of incoming materials shall be checked and accepted one by one, and sampling tests shall be carried out according to the current relevant national standards and construction specifications. It can be used only after passing the test. In addition, the welding materials used for structural welding must have the factory certificate, and have the relevant national regulations, and must also be compatible with the welded steel components.
2. Seam Welding
main weld. In particular, butt welds or welds required by design should be inspected in time after welding. Weld inspection methods mainly include appearance inspection and testing instrument inspection. Instrument inspection methods include ultrasonic, X-ray, magnetic powder, etc. Weld inspection adopts a strict three-level quality management system, including construction process inspection, construction unit self-inspection, and construction unit sampling inspection. Check whether the weld quality meets the design requirements, and rework the unqualified welds until they are qualified.
3. Derusting and anti-corrosion of bridge body
When painting, the surface of the steel is not allowed to have moisture and condensed water; the surface of the steel and concrete is not allowed to have loose objects, dust, oil and other attachments; it is not allowed to paint during the condensation period or other bad weather.
The type and amount of diluent should be compatible with the construction method and coating system, and should not be used indiscriminately; for the prepared coating, no diluent should be temporarily added on the construction
GB/T1591/GB/T3274 Q345D steel plate is -20 DEC impact low alloy high strength steel plates.site.
GB/T1591/GB/T3274 Q345D low temperature impact steel plates chemical composition:
Grade |
C % |
Si % |
Mn |
P % |
S % |
|
Q345D |
≤ 0.18 |
≤ 0.55 |
1.00-1.60 |
≤ 0.030 |
≤ 0.030 |
GB/T1591/GB/T3274 Q345D low temperature impact steel plates chemical composition:
Grade |
Thickness |
Yield Strength (Mpa) |
Tensile Strength |
Elongation |
Min Impact Energy |
|
(mm) |
(MPa) |
(%) |
|
Q345D |
≤16 |
345 |
470-630 |
22 |
-20 |
34J |
|
>16-35 |
325 |
470-630 |
22 |
-20 |
34J |
|
>35 |
295 |
470-630 |
22 |
-20 |
34J |
|
The min impact energy is longitudinal energy |
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