Q295NH and Q295GNH are Chinese standard (GB/T 4171) weathering (Corten) structural steel plates, known for good atmospheric corrosion resistance due to added copper, chromium, and nickel, offering similar mechanical properties (Yield Strength ~295 MPa) for outdoor structures like bridges, containers, and buildings, with 'G' often denoting specific processing or grade variations, both providing enhanced durability over regular carbon steel.
Q295NH Chemical composition
| C | Si | Mn | P | S | Cu | Ni | Cr |
| 0.15 | 0.10-0.50 | 0.30-1.00 | 0.030 | 0.030 | 0.25-0.55 | 0.65 | 0.40-0.80 |
Q295GNH Chemical composition
| C | Si | Mn | P | S | Cu | Cr | Ni |
| 0.12 | 0.10-0.40 | 0.20-0.50 | 0.07-0.12 | 0.02 | 0.20-0.45 | 0.30-0.65 | 0.25-0.50 |
Q295NH Mechanical Properties
| Thickness (mm) | ||||
| Q295NH | ≤ 16 | > 16 ≤ 40 | > 40 ≤ 60 | >60 |
| Yield strength (≥Mpa) | 295 | 285 | 275 | 255 |
| Tensile strength (Mpa) | 430-560 | |||
Q295GNH Mechanical Properties
|
Grade |
Thickness |
Yield |
Tensile |
Elongation |
Delivery state |
|
Q295GNH
|
mm |
Min Mpa |
Mpa |
Min % |
|
|
≤6 |
295 |
390 |
24 |
Hot rolling |
|
|
>6 |
|||||
|
≤2.5 |
260 |
390 |
27 |
Cold rolling |
Key Characteristics:
Standard: Both fall under the Chinese GB/T 4171 standard for weathering steel.
Material Type: They are weather-resistant structural steels (Corten steel).
Composition: Contain small amounts of alloying elements like Cu, Cr, Ni, P, and S, improving corrosion resistance.
Mechanical Properties: Minimum Yield Strength of 295 MPa (for certain thicknesses), with Tensile Strength typically 430-560 MPa, making them high-strength low-alloy (HSLA) steels.
Benefits: Better corrosion resistance than plain carbon steel, reduced maintenance, and aesthetic appeal as they form a protective rust layer.
Applications:
Construction: Exterior walls, roofs, bridges, and structural components.
Transportation: Trucks, railway engineering, shipping containers, and vehicle structures.
Industrial: Power plant chimneys, pipes, and agricultural facilities.
While very similar and often listed together, Q295GNH is sometimes specifically described as a "normalized" type, implying a controlled cooling process for improved properties, though both are essentially variations of high-performance weathering steel used for similar structural purposes.
