What is Copper-Nickel Alloy UNS C70600 / CuNi10Fe1Mn?
Copper-nickel alloys offer excellent resistance to biofouling and marine corrosion, combined with good fabricability. Adding nickel to copper significantly improves both strength and corrosion resistance.
UNS C70600 (also known as CuNi10Fe1Mn, ASTM B111 C70600, or 90/10 Copper-Nickel) is a widely used copper-nickel alloy that provides excellent corrosion resistance even in marine environments. This alloy possesses average high strength and good creep resistance at high temperatures. It is cost-effective compared to other copper alloys with similar mechanical properties.
What is the Chemical Composition of CuNi10Fe1Mn (UNS C70600)?
| Element | Content (%) |
|---|---|
| Copper (Cu) | Remaining (~88.7%) |
| Nickel (Ni) | 9.0 – 11.0 |
| Iron (Fe) | 1.0 – 1.8 (corrected from 13%) |
| Manganese (Mn) | ≤ 1.0 |
| Zinc (Zn) | ≤ 1.0 |
| Lead (Pb) | ≤ 0.05 |
Common alternative names: CuNi10Fe1Mn, 90/10 Cu-Ni, ASTM B151 C70600, ASME SB111 C70600.
What are the Physical Properties of 90/10 Copper-Nickel (C70600)?
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.94 g/cm³ | 0.323 lb/in³ |
What are the Mechanical Properties of UNS C70600 / CuNi10Fe1Mn?
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength | 303 – 414 MPa | 43,900 – 60,000 psi |
| Yield strength (depending on temper) | 110 – 393 MPa | 16,000 – 57,000 psi |
| Elongation at break (in 254 mm) | 42% | 42% |
| Elastic modulus | 117 GPa | 17,000 ksi |
| Poisson's ratio | 0.34 | 0.34 |
| Machinability (UNS C36000 = 100) | 20 | 20 |
| Shear modulus | 52.0 GPa | 7,540 ksi |
C70600 offers a yield strength range from 110 to 393 MPa – suitable for both moderate and high-strength applications.
What are the Thermal Properties of CuNi10Fe1Mn (C70600)?
| Property | Metric | Imperial |
|---|---|---|
| Thermal expansion co-efficient (@20-300°C) | 17.1 µm/m°C | 9.50 µin/in°F |
| Thermal conductivity (@20°C) | 40 W/mK | 278 BTU·in/hr·ft²·°F |
What are the Equivalent Designations to UNS C70600 / 90/10 Copper-Nickel?
| Standard | Equivalent Designation |
|---|---|
| ASTM | B111, B151, B122, B171, B359, B395, B432, B466, B469, B543, B608 |
| ASME | SB111, SB171, SB359, SB395, SB466, SB467, SB543 |
| DIN | 2.0872 |
| MIL | C-15726, T-15005, T-16420, T-22214 |
| SAE | J461, J463 |
| Common names | CuNi10Fe1Mn, 90/10 Cu-Ni, Copper-Nickel 90/10 |
How to Fabricate and Heat Treat UNS C70600 (CuNi10Fe1Mn)?
Machinability
The machinability rate of C70600 is 20 (relative to UNS C36000 = 100). Use sharp tools and adequate lubrication.
Welding
Suitable methods for 90/10 Copper-Nickel: soldering, brazing, oxyacetylene welding, gas shielded arc welding, coated metal arc welding, spot welding, seam welding, and butt welding.
Hot Working
Good capacity. Recommended temperature for CuNi10Fe1Mn: 760 – 816°C (1550 – 1750°F)
Cold Working
Good capacity. UNS C70600 responds well to cold forming.
Annealing
Temperature range for 90/10 Cu-Ni: 593 – 816°C (1100 – 1500°F)
What are the Applications of Copper-Nickel 90/10 (UNS C70600)?
UNS C70600 / CuNi10Fe1Mn is primarily used for:
Seawater service – forged and machined valve and pump components
Fittings and hardware for marine environments
Heat exchangers and condensers (ASTM B111 C70600 tubes)
Desalination plants
Boat hulls and offshore platforms
Applications requiring high corrosion resistance where chloride stress-corrosion cracking prevents use of stainless steels
FAQ
Q1: What is the difference between UNS C70600 (90/10 Copper-Nickel) and UNS C71500 (70/30 Copper-Nickel)?
A: UNS C70600 (CuNi10Fe1Mn) contains 90% copper and 10% nickel, while UNS C71500 (70/30 Cu-Ni) contains 70% copper and 30% nickel. C71500 offers higher strength and better corrosion resistance in high-velocity seawater, but C70600 is more cost-effective and widely used for general marine applications.
Q2: What are the equivalent European standards for UNS C70600 (CuNi10Fe1Mn)?
A: The main European equivalent for UNS C70600 is DIN 2.0872 (CuNi10Fe1Mn). It also matches CW352H under EN standards.
Q3: Can UNS C70600 (90/10 Copper-Nickel) be welded to stainless steel?
A: Yes, UNS C70600 can be welded to stainless steel using appropriate filler metals like AWS A5.7 ERCuNi or ERNiCu-7. However, galvanic corrosion protection should be considered in seawater service.
Q4: What is the maximum operating temperature for UNS C70600 (CuNi10Fe1Mn) in heat exchanger applications?
A: UNS C70600 can operate continuously up to 300°C (572°F) in heat exchanger services. Above this temperature, strength decreases significantly.
Q5: Does UNS C70600 (90/10 Copper-Nickel) require post-weld heat treatment?
A: No, UNS C70600 typically does not require post-weld heat treatment. However, stress relief annealing at 593-816°C may be beneficial for heavily welded sections.
Q6: What is the difference in corrosion resistance between UNS C70600 (90/10 Cu-Ni) and 316L stainless steel in seawater?
A: UNS C70600 offers superior resistance to chloride stress-corrosion cracking compared to 316L stainless steel. In stagnant or low-velocity seawater, 316L can pit, while C70600 performs reliably.
Q7: What product forms are available for UNS C70600 (CuNi10Fe1Mn)?
A: UNS C70600 is available as: seamless tubes (ASTM B111), pipes (ASTM B466/B467), plates (ASTM B171), sheets, bars (ASTM B151), forgings, fittings, and wire.
Q8: Can UNS C70600 (90/10 Copper-Nickel) be used for seawater piping systems?
A: Yes, UNS C70600 is one of the most popular materials for seawater piping on ships, offshore platforms, and desalination plants due to its excellent biofouling and corrosion resistance.
Q9: What filler metal should be used for TIG welding UNS C70600 (CuNi10Fe1Mn) to itself?
A: For TIG welding UNS C70600, use AWS A5.7 ERCuNi filler metal. It matches the alloy composition and provides good corrosion resistance.
Q10: How does the machinability of UNS C70600 (90/10 Copper-Nickel) compare to free-cutting brass (C36000)?
A: UNS C70600 has a machinability rating of 20, while free-cutting brass (C36000) is rated 100. So C70600 is more difficult to machine – use sharp carbide tools and ample coolant.
Quality Inspection for UNS C70600 (90/10 Copper-Nickel)
Every batch of UNS C70600 supplied by GNEE undergoes:
Chemical composition analysis (spectrometer)
Mechanical property testing (tensile, yield, elongation)
Flattening and expansion tests (for tubes – ASTM B111)
Hydrostatic or eddy current testing (for seamless tubes)
Intergranular corrosion test (when required)
Dimensional and visual inspection
All tests are documented with mill test reports (MTR) traceable to the heat number.
Packaging for UNS C70600 Copper-Nickel Tube (CuNi10Fe1Mn / 90/10 Tube)
| Step | Packaging Action | Purpose |
|---|---|---|
| 1 | Clean and dry the tube interior and exterior | Remove oil, moisture, and debris |
| 2 | Apply plastic end caps on both ends | Protect threads/bevels and prevent debris entry |
| 3 | Wrap each tube with VCI (vapor corrosion inhibitor) paper | Prevent oxidation and tarnishing |
| 4 | Bundle tubes in hexagonal or rectangular packs | Easy handling and space saving |
| 5 | Secure with rust-proof steel strapping (2-4 straps per bundle) | Prevent shifting during transport |
| 6 | Wrap bundle with woven polypropylene fabric or PE film | Protect from dust and moisture |
| 7 | Place in wooden crates or on plywood pallets | Structural protection for sea freight |
| 8 | Attach shipping marks (alloy, size, heat number, quantity) | Traceability and customs clearance |
Factory Equipment (GNEE Manufacturing Facility)
GNEE produces UNS C70600 using advanced equipment:
| Equipment | Function |
|---|---|
| 30T Induction Furnace | Melting and alloying |
| Horizontal Continuous Caster | Producing solid and hollow billets |
| Extrusion Press (2500T) | Forming tubes and profiles |
| Cold Drawing Bench (5-120mm) | Precision tube/bar drawing |
| Roller Straightening Machine | Straightening bars and tubes |
| Annealing Furnace (protective atmosphere) | Heat treatment |
| Eddy Current Tester | Non-destructive testing |
| Spectrometer (ARL iSpark) | Chemical analysis |
Product Range
GNEE supplies a full range of copper and copper alloy products. Buyers can order UNS C70600 in any of these forms:
| Product Category | Examples / Specifications |
|---|---|
| Copper-Nickel Alloys | UNS C70600 (90/10), UNS C71500 (70/30), CuNi30Fe |
| Copper Tubes | ASTM B280 (ACR), ASTM B88 (water), EN 1057 |
| Brass Products | C26000 (cartridge brass), C36000 (free-cutting brass), C37700 (forging brass) |
| Bronze Products | C51000 (phosphor bronze), C52100, C54400 |
| Copper Bars / Rods | C10100 (OFC), C11000 (ETP), C12200 (DHP) |
| Copper Plates / Sheets | C11000, C12200, C70600, C71500 |
| Copper Wire | C11000 bare wire, tinned copper wire |
| Custom Forgings & Castings | Per drawing or specification |
GNEE offers custom sizes, tempers, and third-party inspection (SGS/BV).
