Q355NH and Q235NH are Chinese-standard, hot-rolled, weather-resistant (Corten-type) steel plates. Making Q355NH stronger, while both offer enhanced corrosion resistance for outdoor structures like bridges and containers, reducing need for paint but with Q355NH having better strength-to-weight for thicker applications.
Chemical composition
|
Grade |
Q235NH chemical composition(%) |
||||
|
C Max |
Si |
Mn |
P |
S Max |
|
|
China GB/T 4171 Q235NH |
0.13 |
0.1-0.4 |
0.20-0.60 |
0.030 |
0.030 |
|
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 |
Mechanical property
|
Grade |
Q235NH steel mechanical property |
||
|
Yield Strength(MPa) |
Tensile Strength(MPa) |
% Elongation min |
|
|
China GB/T 4171 Q235NH |
215-235 |
360-510 |
23 |
|
Grade |
Q355NH mechanical property |
|
||
|
Yield Strength(MPa) |
Tensile Strength(MPa) |
% Elongation min |
||
|
China GB/T 4171 Q355NH |
325-355 |
490-630 |
20 |
|
Strength: The primary difference is strength; Q355NH offers higher strength (355 MPa minimum yield) than Q235NH (235 MPa minimum yield), allowing for thinner sections or heavier loads.
Application: Both are used for outdoor structures (bridges, containers, architectural features) needing corrosion resistance, but Q355NH's higher strength suits thicker, high-performance needs.
Q235NH: Lower strength but good plasticity, cost-effective weathering steel.
Q355NH: Higher strength, excellent weldability, better low-temperature impact, suitable for demanding structural use.
