Q295NH and Q235NH are Chinese (GB) standard weather-resistant (corten) steel plates, with the primary difference being their strength: Q295NH offers a higher minimum yield strength (around 295 MPa) than Q235NH (around 235 MPa), making Q295NH stronger for structural uses like bridges, containers, and buildings where atmospheric corrosion resistance and high strength are needed, with 'N' denoting normalisation and 'H' indicating a specific hardness or strength level.
Chemical Composition of Q235NH Steel Plate
|
Element |
Content (%) |
|---|---|
|
Carbon (C) |
≤ 0.13 |
|
Silicon (Si) |
0.10 - 0.40 |
|
Manganese (Mn) |
0.20 - 0.60 |
|
Phosphorus (P) |
≤ 0.030 |
|
Sulfur (S) |
≤ 0.030 |
|
Chromium (Cr) |
0.30 - 1.25 |
|
Nickel (Ni) |
≤ 0.65 |
|
Copper (Cu) |
0.25 - 0.55 |
Chemical Composition of Q295NH Steel Plate
|
Element |
Content (%) |
|---|---|
|
Carbon (C) |
≤ 0.15 |
|
Silicon (Si) |
0.10 - 0.40 |
|
Manganese (Mn) |
0.30 - 1.00 |
|
Phosphorus (P) |
≤ 0.035 |
|
Sulfur (S) |
≤ 0.035 |
|
Chromium (Cr) |
0.30 - 1.25 |
|
Nickel (Ni) |
≤ 0.65 |
|
Copper (Cu) |
0.25 - 0.55 |
Mechanical Properties and Performance
Q235NH steel plates deliver robust mechanical performance suitable for demanding welded applications. Key properties include:
Yield Strength: ≥ 235 MPa (for thicknesses up to 200mm)
Tensile Strength: 360 - 510 MPa
Elongation: ≥ 21% (ensuring ductility for forming and welding)
Impact Toughness: Excellent low-temperature performance, with Charpy V-notch tests available upon request
Q295NH plates provide solid mechanical attributes for welded fabrications, ensuring structural integrity under stress:
Yield Strength: ≥ 295 MPa (up to 100mm thickness)
Tensile Strength: 390 - 530 MPa
Elongation: ≥ 20% (promoting good formability)
Impact Toughness: Charpy V-notch tested for low-temperature resilience
Key Differences & Similarities:
Q235NH:
Strength: Lower strength, with a yield point around 235 MPa (similar to general structural steel like ASTM A36 or S235JR).
Application: Used where good formability and weldability are needed, often for simpler structures or parts needing corrosion resistance but not extreme strength.
Q295NH:
Strength: Higher strength, with a yield point of at least 295 MPa, making it more robust.
Application: Suited for more demanding structural components like trucks, shipping containers, and towers, where higher load-bearing capacity is required.
Both:
Type: Both are weather-resistant (Corten) steels, forming a protective rust-like patina for natural corrosion protection, www.alibaba.com notes www.alibaba.com.
Standard: Fall under Chinese GB standards for structural weather-resistant steel.
Properties: Offer improved atmospheric corrosion resistance, reduced consumption (can be used unpainted), and good weldability.
