09CuPCrNi-A weathering steel sheet is a Chinese high-weather-resistance low-alloy steel historically used for railway vehicles, containers and other structures exposed to atmospheric corrosion.
It can be supplied as hot-rolled sheet, plate, strip or coil, while cold-rolled thin sheet may also be supplied where the applicable specification and mill capability permit.
Basic Specification of 09CuPCrNi-A
| Item | Specification |
| Grade | 09CuPCrNi-A |
| Material type | High-weather-resistance low-alloy steel |
| Historical standard | TB/T 1979-2003 |
| Earlier reference | GB 4171-1984 |
| Product form | Plate, sheet, strip, coil |
| Rolling condition | Hot rolled; cold rolled where applicable |
| Minimum hot-rolled yield strength | ≥345 MPa |
| Minimum hot-rolled tensile strength | ≥480 MPa |
| Hot-rolled elongation | ≥24% |
| Main alloying element | Cu, Cr, Ni, P |
| Relative corrosion rate | ≤60% of Q235-A reference under specified 72 h test |
| Typical use | Railway vehicles, containers, exposed structures |
Chemical Composition of 09CuPCrNi-A
One of the defining characteristics of 09CuPCrNi-A weathering steel sheet is its combination of relatively low carbon content with controlled phosphorus, copper, chromium and nickel additions.
| Element | Requirement,mass % |
| Carbon, C | ≤0.12 |
| Silicon, Si | 0.25–0.75 |
| Manganese, Mn | 0.20–0.50 |
| Phosphorus, P | 0.06–0.12 |
| Sulfur, S | ≤0.020 |
| Chromium, Cr | 0.30–1.25 |
| Copper, Cu | 0.25–0.50 |
| Nickel, Ni | 0.12–0.65 |
The approximately 0.25–0.50% Cu, 0.30–1.25% Cr and 0.12–0.65% Ni alloy ranges are important for atmospheric-corrosion resistance. These elements influence the composition, density and stability of the corrosion-product layer that develops during outdoor wet-dry cycles.
Phosphorus is relatively high compared with many conventional structural steels. It contributes to weathering performance but must also be considered when evaluating welding, forming and project-specific fabrication requirements.
The chemical analysis of the actual supplied heat should always be checked against the mill test certificate (MTC).
Mechanical Properties of 09CuPCrNi-A
The mechanical-property requirements differ between hot-rolled and cold-rolled products.
| Product | Thickness | Yield Strength | Tensile Strength | Elongation |
| Hot rolled | t ≤ 6 mm | ≥345 MP | ≥480 MPa | ≥24% |
| Hot rolled | t > 6 mm | ≥345 MPa | ≥480 MPa | ≥24% |
| Cold rolled | t ≤ 4 mm | ≥310 MPa | ≥440 MPa | ≥26% |
For hot-rolled material, the minimum yield strength of 345 MPa is approximately 38% higher than a 250 MPa-class structural steel when only the nominal minimum yield values are compared.
Impact Toughness and Bend Test
For applicable hot-rolled products under the historical TB/T 1979-2003 requirements, Charpy V-notch and bend tests may form part of the mechanical-property verification.
| Test | Thickness | 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 | t ≤ 6 mm | d = a | No specified cracking |
| 180° bend | t > 6 mm | d = 2a | No specified cracking |
Here:
d = bend mandrel diameter
a = steel thickness
When -40°C impact testing is carried out according to the historical specification, the room-temperature impact test may not be required. Impact acceptance is based on the prescribed sampling and averaging rules.
Atmospheric Corrosion Resistance of 09CuPCrNi-A Corten Steel
A useful technical indicator for 09CuPCrNi-A is the relative corrosion rate specified under the historical railway test system.
The atmospheric-corrosion resistance test uses Q235-A as the reference material at 100%. Under the specified 72-hour comparative test, the relative corrosion rate of 09CuPCrNi-A is required to be no more than approximately 60% of the Q235-A reference.
Relative Corrosion Rate Comparison
| Steel | Relative Corrosion Rate |
| Q235-A | 100% reference |
| 09CuPCrNi-A | ≤60% |
| 09CuPCrNi-B | ≤60% |
| 05CuPCrNi | ≤60% |
| 09CuPTiRE-A | ≤65% |
This is a controlled comparative corrosion-test value, not a direct prediction of field corrosion loss.
09CuPCrNi-A Dimensions and Supply Form
There is no single universal size range that applies to every 09CuPCrNi-A steel mill. Available thickness, width, length and coil weight depend on the rolling route, mill equipment, minimum order quantity and certification requirement.
| Product | Demonstrated Size |
| Hot-rolled coil | 4.0 × 1500 mm |
| Hot-rolled coil | 5.75 × 1000 mm |
| Hot-rolled coil | 5.75 × 2000 mm |
| Hot-rolled coil | 6.0 × 2000 mm |
What 09CuPCrNi-A Weathering Steel Dimensions Should Be Specified?
| Parameter | Recommended Information |
| Thickness | Nominal thickness + tolerance |
| Width | Width + tolerance |
| Edge | Mill edge or trimmed edge |
| Length | Cut length for plate/sheet |
| Coil supply | Coil ID, OD or weight where required |
| Flatness | Standard or special flatness class |
| Quantity | Pieces, coils or metric tonnes |
| Dimensional standard | State applicable standard |
For precision fabrication, dimensional tolerances should be agreed before cutting, bending or welding rather than after production.
Surface Quality of 09CuPCrNi-A Sheet
The steel surface should not contain harmful defects that make the product unsuitable for fabrication or service, such as serious cracks, folds, laminations, inclusions or other unacceptable defects.
For conventional structural use, surface acceptance is primarily based on the applicable material and dimensional standards.
However, architectural weathering-steel projects require additional visual controls because technical compliance does not necessarily guarantee uniform patina appearance.
Processing of 09CuPCrNi-A Corten Steel Sheet
09CuPCrNi-A steel can be processed using conventional fabrication methods when appropriate procedures are selected.
| Processing | Application |
| Laser cutting | Thin/medium precision parts |
| Plasma cutting | Medium plate |
| Oxy-fuel cutting | Thicker material |
| Bending | Panels and formed parts |
| Rolling | Curved panels, cylinders |
| Drilling | Bolted connections |
| Welding | Structural assembly |
| Shot blasting | Surface preparation |
| Pre-weathering | Architectural use |
09CuPCrNi-A vs Q345NQR2, SPA-H and S355J0WP
International material tables frequently place 09CuPCrNi-A close to SPA-H and S355J0WP, while the historical railway-standard relationship specifically links hot-rolled 09CuPCrNi-A with Q345NQR2.
| Grade | Standard | Yield Strength | Tensile Strength |
| 09CuPCrNi-A | TB/T 1979-2003 | ≥345 MPa HR | ≥480 MPa HR |
| Q345NQR2 | TB/T 1979-2014 | 345 MPa class | According to specificatio |
| SPA-H | JIS G 3125 | ≥355 MPa in applicable thickness | ≥490 MPa |
| S355J0WP | EN 10025-5 | 355 MPa class | Thickness dependent |
If you are purchasing 09CuPCrNi-A corten steel sheet, 09CuPCrNi-A weathering steel plate or 09CuPCrNi-A coil, provide the required standard, thickness, width, length, quantity, destination and inspection requirements.
We can check the available mill production route and confirm the applicable specification, MTC requirements, batch traceability and processing options such as cutting, bending, drilling, shot blasting and pre-weathering before quotation.
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