Q460NH and Q355NH are Chinese standard (GB/T 4171) weathering (Corten) structural steels, known for atmospheric corrosion resistance, with 'Q' for yield strength, '355'/'460' indicating minimum yield strength (355 MPa / 460 MPa), and 'NH' signifying atmospheric corrosion resistance for welded structures, commonly used in construction, vehicles, and bridges due to their self-protecting rust patina, with Q460NH offering higher strength than Q355NH.
Q355NH steel plate Chemical composition
|
Grade |
Q355NH chemical composition(%) |
||||
|
C Max |
Si Max |
Mn |
P |
S Max |
|
|
China GB/T 4171 Q355NH |
0.16 |
0.5 |
0.5-1.5 |
0.030 |
0.030 |
Q460NH steel plate Chemical composition
|
C |
Si |
Mn |
P |
S |
Cu |
Ni |
Cr |
|
0.12 |
0.65 |
1.50 |
0.025 |
0.030 |
0.20-0.55 |
0.12-0.65 |
0.30-1.25 |
Q355NH steel plate Mechanical property
|
Grade |
Q355NH mechanical property |
|
||
|
Yield Strength(MPa) |
Tensile Strength(MPa) |
% Elongation min |
||
|
China GB/T 4171 Q355NH |
325-355 |
490-630 |
20 |
|
Q460NH steel plate Mechanical property
|
Thickness (mm) |
||||
|
Q460NH |
≤ 16 |
> 16 ≤ 40 |
> 40 ≤ 60 |
>60 |
|
Yield strength (≥Mpa) |
460 |
450 |
440 |
440 |
|
Tensile strength (Mpa) |
570-730 |
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Key Characteristics
Weathering Properties: Both form a stable, dense rust-like layer (patina) that protects the underlying steel from further corrosion, reducing maintenance.
High Strength: They are high-strength steels, with Q460NH having a higher yield strength (460 MPa minimum) compared to Q355NH (355 MPa minimum), making them suitable for structural applications.
Weldability: The 'H' designation indicates suitability for welded applications, achieved through controlled alloying elements like Cu, Cr, P, Ni, and Si.
Standard: Governed by GB/T 4171, similar to ASTM A588 or EN S355J2WP.
Common Applications
Bridges & Buildings: For structural elements needing durability and low maintenance.
Vehicles: Used in trucks, railway cars, and shipping containers.
Outdoor Structures: Sculptures, architectural facades, and storage containers.
Main Difference
Strength: Q460NH provides significantly higher yield strength and overall mechanical performance than Q355NH, catering to more demanding structural requirements.
