What is GBT 4171-2008 Weathering Structional Steel?
GB/T 4171-2008 Weathering Structural Steel is a Chinese national standard for bridge and structural applications. By adding Cu, Cr, Ni, and P, the steel forms a protective rust layer, offering 2–8 times higher corrosion resistance than carbon steel and about 30%–50% better performance than conventional structural steels, enabling reduced or no painting and lowering life-cycle maintenance costs by around 30%–50%.
Common grades include Q235NH (≈235 MPa), Q355NH (≈355 MPa), and Q460NH (≈460 MPa), which are widely used in weathering steel bridges, building structures, and landscape engineering.
As a professional supplier and manufacturer of weathering structural steel, GNEE exports products to more than 50 countries every year and has successfully supported over 70 bridge and steel structure projects worldwide.
We provide one-stop services ranging from raw material selection, cutting, and fabrication to corrosion protection and structural matching. Customized services such as fixed-length cutting, welding support, and third-party inspection are also available according to project requirements.
Our products are widely used in weathering steel bridges, building facades, and landscape structures. With excellent durability and long-term stability in exposed environments, they are an ideal material choice for sustainable, low-maintenance steel structure design.
We supply weathering steel plates, sections, and fabricated components with full size flexibility according to project requirements. Custom cutting, welding support, and structural fabrication services are available to meet different bridge and steel structure applications.
In addition, we provide EN 10204 3.1 material certificates, and upon request, can supply third-party inspection reports and welding documentation to ensure compliance with international engineering standards such as EN and ASTM.
Specification of GB/T 4171-2008 Weathering Structural Steel
| Item | Description |
|---|---|
| Product Name | Weathering Structural Steel Plate / Beam / Structural Sections |
| Standard | GB/T 4171-2008 |
| Material Grades | Q235NH / Q295NH / Q355NH / Q415NH / Q460NH |
| Chemical System | Cu, Cr, Ni, P alloyed weathering steel |
| Technique | Hot rolled / Controlled rolling / Normalized |
| Thickness | 1.5 mm – 200 mm (plate) |
| Width | 1000 mm – 4000 mm |
| Length | 3000 mm – 12000 mm or customized |
| Surface | Natural weathering surface / rust patina / optional coating |
| Corrosion Resistance | 2–8 times higher than carbon steel |
| Certifications | ISO / SGS / BV / EN 10204 3.1 available |
| MOQ | 1 ton or as per specification |
| Price Term | FOB / CIF / CFR / EXW |
| Payment Term | T/T, L/C (30% deposit, 70% before shipment) |
| Delivery Time | 7–30 days based on stock and order quantity |
| Sample | Available, freight cost borne by customer |
| Note | Cutting, welding, fabrication, and structural processing available |
Chemical Composition of GB/T 4171 Weathering Structural Steel for Bridge
| Grade | C (%) | Si (%) | Mn (%) | P (%) | S (%) | Cu (%) | Cr (%) | Ni (%) |
|---|---|---|---|---|---|---|---|---|
| Q235NH | ≤0.14 | 0.20–0.50 | 0.30–0.65 | 0.060–0.120 | ≤0.030 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
| Q265GNH | ≤0.14 | 0.20–0.50 | 0.40–0.80 | 0.060–0.120 | ≤0.030 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
| Q295NH | ≤0.13 | 0.20–0.50 | 0.50–1.00 | 0.060–0.120 | ≤0.030 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
| Q295GNH | ≤0.13 | 0.20–0.50 | 0.50–1.00 | 0.060–0.120 | ≤0.030 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
| Q310GNH | ≤0.13 | 0.20–0.50 | 0.60–1.20 | 0.060–0.120 | ≤0.030 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
| Q355NH | ≤0.12 | 0.20–0.50 | 0.80–1.50 | 0.060–0.120 | ≤0.030 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
| Q355GNH | ≤0.12 | 0.20–0.50 | 0.80–1.50 | 0.060–0.120 | ≤0.030 | 0.25–0.55 | 0.30–1.25 | ≤0.65 |
| Q415NH | ≤0.12 | 0.20–0.50 | 0.90–1.60 | ≤0.060 | ≤0.030 | 0.25–0.55 | 0.40–1.25 | ≤0.65 |
| Q460NH | ≤0.12 | 0.20–0.50 | 1.00–1.70 | ≤0.060 | ≤0.030 | 0.25–0.55 | 0.40–1.25 | ≤0.65 |
| Q500NH | ≤0.12 | 0.20–0.50 | 1.20–1.80 | ≤0.060 | ≤0.030 | 0.25–0.55 | 0.40–1.25 | ≤0.65 |
| Q550NH | ≤0.12 | 0.20–0.50 | 1.20–1.80 | ≤0.060 | ≤0.030 | 0.25–0.55 | 0.40–1.25 | ≤0.65 |
Mechanical Properties of GB/T 4171 Weathering Structural Steel for Bridge
| Grade | Yield Strength ReH (MPa) | Tensile Strength Rm (MPa) | Elongation A (%) | Impact Toughness |
|---|---|---|---|---|
| Q235NH | ≥235 | 360–500 | ≥26 | 20°C ≥ 27J |
| Q265GNH | ≥265 | 400–520 | ≥25 | 20°C ≥ 27J |
| Q295NH | ≥295 | 420–540 | ≥24 | 20°C ≥ 27J |
| Q295GNH | ≥295 | 420–540 | ≥24 | 20°C ≥ 27J |
| Q310GNH | ≥310 | 440–570 | ≥23 | 20°C ≥ 27J |
| Q355NH | ≥355 | 490–630 | ≥22 | 20°C ≥ 27J |
| Q355GNH | ≥355 | 490–630 | ≥22 | 20°C ≥ 27J |
| Q415NH | ≥415 | 520–680 | ≥20 | 20°C ≥ 27J |
| Q460NH | ≥460 | 550–720 | ≥19 | 20°C ≥ 27J |
| Q500NH | ≥500 | 610–760 | ≥17 | 20°C ≥ 27J |
| Q550NH | ≥550 | 620–780 | ≥16 | 20°C ≥ 27J |
What is the difference between GNH and NH weathering steel?
NH (e.g., Q235NH, Q355NH under GB/T 4171-2008) is weldable weathering structural steel with 2–8× higher corrosion resistance than carbon steel and about 30%–50% lower maintenance cost, widely used in bridges and general steel structures.
GNH refers to higher weathering grades designed for harsher environments, offering roughly 20%–50% better corrosion resistance than standard NH, making it more suitable for coastal, humid, or industrial pollution conditions.
Can GB/T 4171 Weathering Structural Steel be welded easily?
Yes, GB/T 4171 Weathering Structural Steel has good weldability and is suitable for common welding processes used in bridge and structural fabrication. We also supply equivalent grades under ASTM A588 and EN 10025-5 to meet international project requirements.
Application case of GB/T 4171 Weathering Structural Steel
East Don Trail Construction
North York, ON
Box Grove Community Park Pedestrian Bridge
Markham, ON
East Don Pedestrian Construction Project
North York, ON
Homer Watson Boulevard Improvements
Kitchener, ON
If you have requirements for the aforementioned items, you are welcome to place an order. GNEE can provide you with one-stop service.
Contact now to get your corten steel bridge project
We provide the following inspections to ensure quality:
Chemical Composition Testing: 100% spectrometric analysis to verify Cu, Cr, Ni, and P content complies with GB/T 4171-2008 requirements.
Mechanical Testing: Tensile strength, yield strength, and elongation tests to confirm mechanical properties meet specification requirements.
Impact Testing (if required): Charpy V-notch testing to verify low-temperature toughness performance.
Surface Inspection: 100% visual inspection to ensure uniform weathering surface quality and no defects such as cracks or laminations.
Corrosion Resistance Performance Check: Verification of weathering performance to ensure corrosion resistance is 2–8 times higher than carbon steel under atmospheric conditions.
We provide the following processing services to meet different project requirements:
Cutting Service: Laser cutting, plasma cutting, and flame cutting according to required dimensions.
Bending & Forming: Precision bending and shaping for structural components and customized designs.
Welding & Fabrication: Professional welding and assembly services for bridge and steel structure applications.
Surface Treatment: Natural weathering, pre-rusting treatment, and optional protective coating.
Custom Fabrication: Tailored solutions based on drawings, including structural components and finished assemblies.
We provide the following packaging and delivery solutions to ensure safe transportation:
Standard Export Packaging: Steel strips bundled with waterproof wrapping and anti-rust protection.
Seaworthy Packaging: Wrapped with plastic film and covered with waterproof paper, suitable for long-distance ocean shipping.(If you need)
Bundle Packing / Loose Packing: Available according to plate size and customer requirements.
Wooden Support / Pallet Packing: Used for cut-to-size plates and fabricated parts to ensure stability during transport.
Marking & Labeling: Clear heat number, grade, size, and standard marking for full traceability.
Delivery: Available by container (FCL/LCL), bulk shipment, or railway transport depending on order volume.
