What does the Q235 steel coil designation mean?
A: Q represents yield strength. 235 indicates that the yield strength of this steel is ≥235MPa. "Coil" indicates that the steel is hot-rolled/cold-rolled coil, a mainstream grade for general-purpose carbon structural steel.
What are the applicable standards for Q235 steel coils?
A: The mainstream national standard is GB/T 700-2006 (carbon structural steel). For hot-rolled coils, GB/T 3274-2017 is also relevant, and for cold-rolled coils, GB/T 11253-2022 is recommended.
What are some common sub-grades of Q235, and which type of coil is commonly used?
A: Q235 is subdivided into Q235A/Q235B/Q235C/Q235D. The core differences lie in impact toughness and carbon content. Q235B is the primary grade for coils, with Q235A as a secondary grade. Grades C/D are rarely used in coils due to their high cost.
What are the main chemical components of Q235 steel coil?
A: Core components (national standard range): C≤0.22%, Si≤0.35%, Mn≤1.40%, S≤0.045% (A/B grade), P≤0.045%. It contains no alloying elements and is a pure carbon steel.
What are the core differences between Q235B and Q235A steel coils?
A: ① Impact test: Q235B requires a room temperature (20℃) impact test, while Q235A has no such requirement; ② Carbon content: Q235B has slightly lower carbon content, resulting in better weldability; ③ Application: Q235B can be used in lightly stressed structures, while Q235A is only used for non-stressed components.