09CuPCrNi-A corrosion resistant steel plate is a Chinese high-weather-resistance, low-alloy steel originally used for railway vehicles and other structures exposed to atmospheric environments.
It can be supplied as hot-rolled plate, sheet, strip or coil and has been widely used for railway wagons, containers, bridges, building façades, chimneys, industrial equipment and outdoor steel structures.
Unlike stainless steel, 09CuPCrNi-A is designed to form a protective rust-coloured patina rather than remain bright and rust-free. Copper, chromium, nickel and phosphorus promote the formation of a denser corrosion-product layer during repeated wet-and-dry exposure, reducing the rate at which oxygen and moisture reach the underlying steel.
Specification of 09CuPCrNi-A Weathering Steel Plate
09CuPCrNi-A has been produced in relatively thin hot-rolled plate and coil dimensions, particularly for railway vehicles and transportation equipment.
| Item | Typical Supply Range |
| Thickness | About 1.5–20 mm depending on mill and standard |
| Width | About 1000–2000 mm |
| Plate length | Commonly 2000–12000 mm or cut to length |
| Coil | Available for suitable thickness ranges |
| Surface | Hot rolled, shot blasted or processed as specified |
| Cutting | Laser, plasma, flame or shearing depending on thickness |
Chemical Composition of 09CuPCrNi-A Corten Steel Plate
| Element | Requirement wt.% |
| C | ≤0.12 |
| Si | 0.25–0.75 |
| Mn | 0.20–0.50 |
| P | 0.06–0.12 |
| S | ≤0.020 |
| Cu | 0.25–0.50 |
| Cr | 0.30–1.25 |
| Ni | 0.12–0.65 |
Mechanical Properties of 09CuPCrNi-A Corrosion Resistant Steel Plate
The mechanical-property requirements vary according to product form, thickness and rolling condition. Under TB/T 1979-2003, hot-rolled 09CuPCrNi-A provides a minimum yield strength of 345 MPa and minimum tensile strength of 480 MPa.
| Product Condition | Thickness | Yield Strength MPa | Tensile Strength MPa | Elongation |
| Hot rolled | t ≤ 6 mm | ≥345 | ≥480 | ≥24% |
| Hot rolled | t > 6 mm | ≥345 | ≥480 | ≥24% |
| Cold rolled | t ≤ 4 mm | ≥310 | ≥440 | ≥26% |
This means the minimum yield strength of hot-rolled 09CuPCrNi-A is approximately 38% higher than a 250 MPa-class structural steel when comparing nominal minimum yield values. Actual structural capacity, however, must be calculated according to thickness, section geometry, load combination and the applicable design code.
Impact Toughness and Bend Performance of 09CuPCrNi-A Corrosion Resistant Steel Sheet
For hot-rolled material covered by TB/T 1979-2003, impact requirements apply under specified thickness and test conditions.
| Test | Condition | Requirement |
| Charpy V-notch | t ≥ 12 mm, room temperature | ≥47 J |
| Charpy V-notch | t ≥ 12 mm, -40°C | ≥21 J |
| 180° bend / 180° | t ≤ 6 mm | d = a |
| 180° bend / 180° | t > 6 mm | d = 2a |
Here, d is the bend mandrel diameter and a is the steel thickness.
For impact testing, the standard uses the average value of three specimens. Specific requirements for reduced-size specimens and special low-temperature testing should be confirmed according to the purchase specification.
Atmospheric Corrosion Resistance Data of 09CuPCrNi-A Corten Steel Sheet
A particularly useful technical parameter for 09CuPCrNi-A is its relative corrosion rate. Under the corrosion test method associated with TB/T 1979-2003, Q235-A is taken as the reference material at 100%, while 09CuPCrNi-A is required to reach a relative corrosion rate of approximately 60% or lower under the specified 72-hour test conditions.
| Steel Grade | Relative Corrosion Rate |
| Q235-A | 100% |
| 09CuPCrNi-A | ≤60% |
| 09CuPCrNi-B | ≤60% |
| 05CuPCrNi | ≤60% |
| 09CuPTiRE-A | ≤65% |
A 60% relative corrosion rate does not mean that every outdoor structure will lose exactly 40% less material than Q235 steel during service. It is a controlled comparative laboratory parameter and should not be directly converted into a guaranteed service-life percentage.
With 09CuPCrNi-A weathering steel, Cu, Cr, Ni and P alter the composition and morphology of the corrosion products. Under suitable wet-dry cycling, a more compact and adherent rust layer develops, slowing further atmospheric corrosion.
dark grey → orange-brown → rust brown → dark reddish brown
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09CuPCrNi-A is often compared with Q345NQR2, SPA-H and S355J0WP because they occupy similar weathering-steel application areas. However, "similar" does not mean "automatically equivalent."
| Grade | Standard | Min. Yield Strength | Min. Tensile Strength | Main Positioning |
| 09CuPCrNi-A | TB/T 1979-2003 | 345 MPa hot rolled | 480 MPa | Railway and atmospheric corrosion-resistant structures |
| Q345NQR2 | TB/T 1979-2014 | 345 MPa-class | Depends on specification | Newer railway grade corresponding to old hot-rolled 09CuPCrNi-A |
| SPA-H | JIS G 3125 | ≥355 MPa for specified thinner range | ≥490 MPa | Containers, railway and weathering structures |
| S355J0WP | EN 10025-5 | S355-class / 355 MPa | Thickness dependent | European structural weathering steel |
For reference, JIS G 3125 SPA-H commonly specifies C≤0.12%, Cu 0.25–0.55%, Cr 0.30–1.25% and tensile strength ≥490 MPa, showing why it is frequently compared with 09CuPCrNi-A.
Typical Applications of 09CuPCrNi-A
Because 09CuPCrNi-A combines structural strength with atmospheric corrosion resistance, it has traditionally been used for railway and transportation structures and is also suitable for many outdoor fabricated products.
railway wagons and rolling-stock components
container side panels and structural members
bridges and exposed steel structures
architectural façades and decorative screens
chimneys and industrial enclosures
hoppers and atmospheric storage structures
Material selection should not be based only on the fact that a structure is outdoors. Exposure category, structural loads, drainage, chloride contamination, minimum design thickness and fabrication details must also be evaluated.
Fabrication of 09CuPCrNi-A Weathering Steel Plate
09CuPCrNi-A can be supplied not only as raw plate or coil but also as processed components. Typical fabrication services include cutting, bending, drilling, rolling and welding preparation.
| Processing | Typical Use |
| Laser cutting | Thin and medium plate with accurate profiles |
| Plasma cutting | Medium-thickness components |
| Flame cutting | Thicker plate |
| Bending | Panels, channels and boxes |
| Rolling | Cylinders, curved panels and landscape components |
| Drilling | Bolted structural connections |
| Welding preparation | Structural fabrication |
| Shot blasting | Scale removal and surface preparation |
| Pre-weathering | Architectural colour development |
For structural welding, welding procedure qualification, consumable selection, preheat requirements and heat input should be determined according to plate thickness, joint restraint, design code and project specification.
How to Specify 09CuPCrNi-A Correctly
A technical enquiry for 09CuPCrNi-A should contain enough information for the supplier and mill to confirm whether the material can meet the project requirements.
For old drawings specifying 09CuPCrNi-A, buyers should state whether strict supply to the old grade is required or whether an approved current-grade alternative such as Q345NQR2 or another project-specified weathering steel can be considered.
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If your project requires 09CuPCrNi-A corrosion resistant steel plate, 09CuPCrNi-A weathering steel plate, sheet or coil, send us the required grade, standard, thickness, width, length, quantity, destination and processing requirements.
We can prepare a technical and commercial quotation according to the requested specification and confirm available plate or coil dimensions, mill certification, batch traceability, cutting, bending, drilling, blasting, pre-weathering and other fabrication requirements.
