Q235 steel coil: What are the main chemical components? What is the role of each element?
A: The core elements are C (carbon, ensuring strength) and Mn (manganese, strengthening ferrite and improving toughness), with a small amount of Si (silicon, deoxidizing). Impurities are P (phosphorus, causing cold brittleness) and S (sulfur, causing hot brittleness). It contains no alloying elements and belongs to ordinary carbon steel.
Q235 steel coil: What is the density? What is the reference value for calculating weight?
A: The density is 7.85 g/cm³, a commonly used calculation value for steel. The theoretical weight of a steel coil = thickness (mm) × width (m) × length (m) × 7.85.
Q235 steel coil: What is the tensile strength range?
A: The national standard requires a tensile strength of 370 MPa to 500 MPa, unaffected by thickness; only the yield strength decreases with increasing thickness.
Q235 steel coil: What is the elongation requirement? What property does it represent?
A: For thickness ≤ 16mm, the elongation should be ≥ 26%. The greater the thickness, the lower the elongation requirement. Elongation represents the plasticity of the steel; the higher the value, the better the cold bending and stamping formability.
What is the rule for the yield strength of Q235 steel coils as a function of thickness?
A: For thickness ≤ 16mm, the yield strength requirement is ≥ 235MPa; for 16~40mm, it is ≥ 225MPa; for 40~60mm, it is ≥ 215MPa; for 60~100mm, it is ≥ 205MPa. The greater the thickness, the lower the yield strength requirement.