What is Chinese steel grade Q355B?
Q355B is a Chinese low-alloy, high-strength structural steel. It is known for its good weldability, high strength, and mechanical reliability, making it suitable for various engineering and construction applications.
Its typical chemical composition includes carbon, manganese, silicon, and trace amounts of phosphorus, sulfur, nickel, chromium, and nitrogen.
What is the chemical composition of Q355B steel?
Carbon (C): ≤ 0.20% (≤ 0.24% in some cases depending on thickness)
Manganese (Mn): 1.20–1.60%
Silicon (Si): 0.30–0.50%
Phosphorus (P): ≤ 0.035%
Sulfur (S): ≤ 0.035%
Nickel (Ni): ≤ 0.3%
Chromium (Cr): ≤ 0.3%
Nitrogen (N): ≤ 0.0012%
What are the mechanical properties of Q355B beams?
Yield Strength: ≥ 355 MPa (for thickness ≤ 16 mm)
Tensile Strength: 470–630 MPa
Impact Value (Akv): ≥ 34 J/cm²
What is the difference between Q355 and Q235 beams
Q235 beams are used where moderate strength and good weldability are sufficient. Q355 beams are selected for applications requiring higher strength, toughness, durability, and resistance to wear. Due to its enhanced properties and alloy content, Q355 is typically more expensive than Q235.
What are international equivalents of Q355B steel?
United States: ASTM A572 Grade 50
Europe: S355JR or S355J2
Japan: JIS G3106 SM490
India: IS 2062 E350 or IS 8500 FE 570
What applications are Q355B beams suitable for?
Q355B beams are ideal for high-rise buildings, bridges, heavy machinery, and structural components where superior strength and toughness are required. They are widely used in construction and engineering projects that demand reliable structural performance.
FAQ
What is the difference between Q355B and Q235 steel?
Q235 steel is used where moderate strength and good weldability are sufficient. Q355B is selected for applications requiring higher strength, toughness, and durability. Q355B is typically more expensive due to its superior mechanical properties and alloy content.
What are the international equivalents of Q355B steel?
United States: ASTM A572 Grade 50
Europe: S355JR or S355J2
Japan: JIS G3106 SM490
India: IS 2062 E350 or IS 8500 FE 570
What applications are suitable for Q355B beams?
Q355B beams are ideal for high-rise buildings, bridges, heavy equipment structures, and other demanding construction projects where high strength and toughness are required.
