What is the common thickness range of Q355 steel plates in building construction?
Conventional steel structures: Beams and columns commonly use 12-30mm; long-span bridges and heavy components commonly use 20-50mm; curtain wall embedded parts and purlins commonly use 8-16mm.
7. Which building components must use Q355 steel plates?
High-rise building frame columns, steel beams, and core tube components.
Large-span spatial structures (gymnasiums, airport terminals) main beams and trusses.
Load-bearing components in areas with seismic fortification intensity of 8 degrees or higher.
Steel structures subjected to dynamic loads and low-temperature environments.
8. When is it necessary to select Z-direction performance Q355 steel plates (Z15/Z25/Z35)?
When the steel plate thickness is ≥40mm and subjected to tensile force along the plate thickness direction (such as thick-walled box columns and transfer layer nodes), Z-direction steel must be selected. For key nodes in high-rise buildings, Z25/Z35 steel is recommended, with section reduction rates ≥25% and 35% respectively.
9. What documents need to be checked during the acceptance inspection of Q355 steel plates upon arrival?
Factory quality certificate and certificate of conformity. The furnace batch number, chemical composition, mechanical properties, Z-direction properties (if applicable), and impact toughness report must be verified.
10. What are the batch divisions and items for the re-inspection of Q355 steel plates upon arrival?
Inspection batch: For the same grade, furnace batch number, and specification, every 60 tons constitutes one batch; less than 60 tons is considered one batch.
Re-inspection items: Yield strength, tensile strength, elongation, cold bending, impact toughness; for Z-direction steel, section reduction rate is also measured.