C70600 Copper Nickel (90/10 Cupro Nickel / CuNi10Fe1Mn)

C70600, also known as 90/10 cupro nickel, CuNi10Fe1Mn, or CuNi10Fe1.6Mn, is a wrought copper-nickel alloy with additions of iron and manganese. These additions provide excellent corrosion resistance in fresh water and seawater, plus anti-biofouling properties.

Cupro nickel C70600 failures due to stress-corrosion cracking are unknown in seawater polluted with ammonia. The alloy is also immune to chloride and sulphide stress corrosion cracking.

Adding nickel to copper improves strength and corrosion resistance while retaining good ductility. C70600 has provided reliable service for several decades in marine environments.

GNEE supplies C70600 to meet all major global standards. Use this table for cross-referencing.

Common names: CuNi10Fe1Mn, CuNi10Fe1.6Mn, 90/10 Cu-Ni, Cupro Nickel 90/10, ASTM B151 C70600.

Key Features of C70600:

Excellent resistance to seawater corrosion

High inherent resistance to biofouling (prevents marine growth)

Immune to chloride and sulphide stress corrosion cracking

No known failures due to ammonia-induced stress-corrosion cracking

Good fabricability and weldability

Low magnetic permeability (1.01-1.69)

C70600 has good fabricability. Suitable methods include:

Soldering and brazing

Gas shielded arc welding (TIG/MIG)

Coated metal arc welding (MMA)

Spot, seam, and butt welding

Cold forming (good capacity)

Hot forming (good capacity)

Machinability rating: 20 (UNS C36000 free-cutting brass = 100). Use sharp carbide tools and ample coolant.

Q1: What is the difference between C70600 (90/10 Cupro Nickel) and C71500 (70/30 Cupro Nickel) for seawater piping?
A: C70600 (CuNi10Fe1Mn) contains 10% nickel and is more cost-effective. C71500 (70/30 Cu-Ni) contains 30% nickel, offering higher strength and better erosion resistance in very high-velocity seawater. For most seawater piping, C70600 is sufficient.

Q2: What is the European standard equivalent to ASTM B151 C70600 round bar?
A: The European equivalent to ASTM B151 C70600 is EN 12163 CW352H (CuNi10Fe1Mn) and DIN 2.0872.

Q3: Can C70600 (CuNi10Fe1Mn) be welded to carbon steel?
A: Yes, C70600 can be welded to carbon steel using appropriate filler metals like ERNiCu-7. However, galvanic corrosion protection (e.g., coating or cathodic protection) is required for seawater service.

Q4: What is the maximum operating temperature for C70600 (90/10 Cu-Ni) tube in heat exchangers?
A: C70600 tube can operate continuously up to 300°C (572°F). Above this temperature, strength decreases significantly.

Q5: Does C70600 (CuNi10Fe1Mn) require post-weld heat treatment?
A: No, C70600 typically does not require post-weld heat treatment. Stress relief annealing at 593-816°C may be beneficial for heavily welded sections or to relieve residual stresses.

Q6: Is C70600 (90/10 Cupro Nickel) resistant to ammonia stress-corrosion cracking?
A: Yes. C70600 failures due to stress-corrosion cracking are unknown in seawater polluted with ammonia, making it superior to many other copper alloys in this respect.

Q7: What is the magnetic permeability of C70600 (CuNi10Fe1Mn)?
A: C70600 has a relative magnetic permeability of 1.01 to 1.69 – it is considered low magnetic and suitable for applications requiring non-magnetic materials.

Q8: What filler metal should be used for TIG welding C70600 (CuNi10Fe1Mn) to itself?
A: For TIG welding C70600, use AWS A5.7 ERCuNi filler metal. It matches the alloy composition and provides good corrosion resistance.

Q9: Can C70600 (90/10 Cu-Ni) be used for fish farm net cages?
A: Yes, C70600 is widely used for fish farm net cages and seawater intake screens due to its excellent anti-biofouling properties – it resists marine growth naturally.

Q10: What is the difference between C70600 and C70620?
A: C70600 is the standard 90/10 copper-nickel alloy. C70620 is a modified version with tighter control on impurities (especially lead and zinc) for specific applications like potable water or nuclear service.

Q11: What product forms are available for ASTM B171 C70600 plate?
A: C70600 plate is available under ASTM B171 in thicknesses from 3/16" to 3". GNEE also supplies sheet, bar, tube, pipe, fittings, and flanges.

Q12: Is C70600 (CuNi10Fe1Mn) suitable for desalination plants?
A: Yes, C70600 is one of the most common materials for desalination plant tubing and piping due to its excellent resistance to chloride corrosion and biofouling.

Q13: What is the thermal conductivity of C70600 (90/10 Cupro Nickel)?
A: C70600 has a thermal conductivity of 50 W/mK (at room temperature). This is lower than pure copper but adequate for heat exchanger applications.

Q14: Can C70600 (CuNi10Fe1Mn) be cold formed into complex shapes?
A: Yes, C70600 has good cold forming capacity. Annealed temper is recommended for severe forming operations such as bending, flaring, or swaging.

Q15: How is ASTM B466 C70600 pipe inspected at GNEE?
A: Each C70600 pipe undergoes chemical analysis, tensile testing, hydrostatic testing, flattening test (for tube), dimensional inspection, and visual inspection. Mill test reports (MTR) are traceable to heat number.

Every batch of C70600 supplied by GNEE undergoes:

All tests documented with heat number traceable Mill Test Reports (MTR).
Third-party inspection (SGS, BV, TUV, Lloyds) available upon request.

GNEE packages C70600 seamless tube and pipe for export to prevent damage and corrosion during sea freight.

GNEE produces C70600 and other copper alloys using advanced equipment:

GNEE supplies a full range of copper and copper alloy products. C70600 is available in all forms below:

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