What is Q235 plate made of?
A: Q235 plate is a carbon structural steel plate specified in the Chinese national standard GB/T 700-2006. It belongs to low-carbon steel and is commonly known as "A3 steel".
What does the Q235 designation mean?
A: "Q" represents yield strength; "235" indicates a minimum yield strength ≥ 235 MPa (when plate thickness ≤ 16 mm).
Which national standards does Q235 comply with?
A: Material standard: GB/T 700-2006 "Carbon Structural Steel"
Steel plate standard: GB/T 3274 "Hot-rolled Steel Plates and Strips of Carbon Structural Steel and Low Alloy Structural Steel"
Dimensional tolerance: GB/T 709-2019
How many quality grades of Q235 are there? What are the differences? A: Q235 is classified into four grades: A, B, C, and D. The core differences lie in the impact temperature and sulfur and phosphorus content:
Q235A: No impact test required, S≤0.050%, P≤0.045%
Q235B: Impact test at 20℃, S≤0.045%, P≤0.045% (most commonly used)
Q235C: Impact test at 0℃, S≤0.040%, P≤0.040%
Q235D: Impact test at -20℃, S≤0.035%, P≤0.035% (for low-temperature use)
What are the main differences between Q235 and Q195, Q215, and Q355?
A: Yield strength increases in that order. Q235 offers the best cost-performance ratio and is the most widely used; Q355 has higher strength but is more expensive.