Q: Does Q355D contain chromium (Cr) and nickel (Ni)?
A: There are no mandatory requirements in the national standard. Standard grades do not contain Cr or Ni. For customized products requiring improved ultra-low temperature performance, a small amount can be added, but the composition needs to be confirmed separately.
Q: What standard governs the permissible deviation of the chemical composition of Q355D?
A: It follows GB/T 222-2006 "Permissible Deviation of Chemical Composition of Finished Steel," with deviations for each element within the reasonable range specified in the national standard.
Q: What is the conventional production process for Q355D steel plates?
A: The mainstream process is hot rolling. Some thinner specifications can be cold rolled. Thick plates (≥50mm) mostly use controlled rolling and controlled cooling (TMCP) processes to ensure uniform low-temperature toughness and strength.
Q: What is the standard thickness range for Q355D steel plates?
A: The standard thickness for hot-rolled plates is 3mm~200mm, and for cold-rolled plates, it is 1mm~6mm. Plates over 200mm can be customized, but separate scheduling with the steel mill is required.
Q: What are the standard widths and lengths of Q355D steel plates?
A: Standard widths are 1500mm, 1800mm, 2000mm, 2200mm, and 2500mm; lengths range from 6000mm to 12000mm. Custom lengths and cutting to size are available upon request.