Copper Nickel Alloy

(Cu-Ni) Marine Grade Copper Nickel Materials Supplier

Copper Nickel Alloy (Cu-Ni) is a high-performance copper alloy with excellent seawater corrosion resistance, thermal stability and mechanical strength for marine and industrial applications.

What Is Copper Nickel Alloy (Cu-Ni)?

High Corrosion Resistant Copper Alloy for Marine Engineering, Heat Exchangers and Industrial Applications

Copper Nickel Alloy (Cu-Ni), also known as cupronickel, is a copper-based alloy containing nickel as the main alloying element. The addition of nickel significantly improves corrosion resistance, mechanical strength and stability in harsh environments.

Cu-Ni alloys are especially known for their excellent resistance to seawater corrosion, biofouling resistance and long-term performance in marine environments.

Sunny Steel supplies copper nickel alloy products including tubes, pipes, rods, bars, plates and customized components for marine engineering, shipbuilding, heat exchangers, desalination plants and industrial equipment.

Chemical Composition of Copper Nickel Alloy

Copper Nickel Alloy (Cu-Ni) is a copper-based alloy with nickel as the main alloying element. Nickel improves corrosion resistance, mechanical strength and stability, especially in seawater environments.

Element Typical Content (%)
Copper (Cu) Balance
Nickel (Ni) 10 - 30
Iron (Fe) Small amount depending on grade
Manganese (Mn) Small amount depending on grade
Other Elements Trace elements

90/10 Copper Nickel vs 70/30 Copper Nickel

Property 90/10 Cu-Ni 70/30 Cu-Ni
Nickel Content Approximately 10% Approximately 30%
Corrosion Resistance Excellent Superior
Mechanical Strength Good Higher
Marine Application Widely used Used for more demanding environments
Typical Applications Heat exchangers, seawater piping Offshore systems, marine equipment

Copper Nickel Alloy vs Stainless Steel

Property Copper Nickel Alloy Stainless Steel
Seawater Resistance Excellent Good to Excellent depending on grade
Biofouling Resistance Excellent Limited
Thermal Conductivity Higher Lower
Heat Transfer Performance Excellent Moderate
Marine Application Very suitable Depends on environment
Copper Nickel Bar

Applicable Grades

Cu-Ni solid-solution alloys for seawater and marine piping service.

Composition (ASTM B151)

UNS Cu Ni Fe Mn
C70600 88–90 9–11 1.0–1.8 ≤1.0
C71500 65–70 29–33 0.4–1.0 ≤1.0

Key Properties

  • Excellent seawater corrosion resistance (uniform & localized)
  • Natural biofouling resistance
  • Good ductility & weldability (TIG/MIG)
  • Single-phase FCC solid solution microstructure

Standards

ASTM B151 · EN 12163 (CW352H / CW354H) · BS 2874 · DEF STAN · EN 10204 3.1

Common Types of Copper-Nickel Alloys

Cu-Ni 90/10 (C70600)

Marine-grade alloy with ~10% nickel and controlled iron/manganese additions. Offers the best cost-to-performance ratio in seawater service, with good ductility and weldability.

Cu-Ni 70/30 (C71500)

Higher nickel content delivers increased mechanical strength and superior impingement resistance. Specified for high-velocity seawater piping, offshore sheathing and heavy-load applications.

Cu-Ni 80/20 (C71000)

Near-binary Cu-Ni alloy without iron modification. Provides balanced corrosion resistance and ductility, typically used for heat-exchanger tubing, wiring and architectural applications.

Cu-Ni 75/25 (C71300)

Optimized for non-structural applications requiring good ductility and aesthetic appeal. Commonly specified for coinage, decorative stamping and precision instrumentation.

Modified 70/30 (CuNi30Mn1Fe)

Enhanced version of 70/30 with optimized manganese and iron levels. Delivers excellent erosion-corrosion resistance for high-velocity seawater systems and pump casings.

Stocked Grades

Primary inventory consists of C70600 and C71500 solid round bars, supplied to ASTM B151, EN 12163 and DEF STAN specifications with EN 10204 3.1 certification.

Copper Nickel Alloy Product

Copper Nickel Alloy Product

Cu-Ni Grade Comparison

Side-by-side comparison of the three most specified cupronickel alloys for seawater service.

Property Cu-90/10
C70600		 Cu-70/30
C71500		 Modified 70/30
CuNi30Mn1Fe
Ni Content ~10% ~30% 29–33%
Fe / Mn 1.0–1.8 / ≤1.0 0.4–1.0 / ≤1.0 ~1.0 / ~1.0
Annealed Tensile (MPa) 275–380 380–520 400–550
Annealed Yield (MPa) 105–170 138–207 170–240
Impingement / Erosion Resistance Good Very Good Excellent
Biofouling Control Good Good Good
Weldability Excellent Excellent Excellent
Typical Use Condenser tubes, heat exchangers, bilge/brine systems Seawater piping, ship sheathing, valves High-velocity seawater piping, pump casings
Bar / Rod Standard ASTM B151 · EN 12163 (CW352H) ASTM B151 · EN 12163 (CW354H) ASTM B151 · EN 12163

Applications & Selection

Cu-Ni is specified for chloride-rich environments where corrosion resistance, fabricability and life-cycle cost outweigh initial material price.

Typical Applications

  • Marine Systems: Seawater piping, ship & offshore platform systems.
  • Thermal Equipment: Power plant condensers, heat exchangers, cooling-water systems.
  • Desalination: Reduced biofouling, extended service life.
  • Mechanical Components: Pump/valve bodies, shaftsleeves, offshore sheathing.

Material Selection Rationale

Material Seawater Performance Fabricability Initial Cost Life-Cycle Cost
Cupronickel Excellent High Moderate Low
Stainless Steel Good (velocity sensitive) Moderate Moderate–High Moderate
Titanium Superior Low High Moderate–High

Design Considerations

  • Velocity: Cu-Ni performs best at moderate flow velocities (1–3 m/s).
  • Chlorides: Superior resistance to localized corrosion in seawater.
  • Temperature: Suitable for typical seawater cooling temperatures.
  • Maintenance: Natural biofouling resistance reduces cleaning frequency.
Frequently Asked Questions
Copper Nickel Alloy (Cu-Ni), also known as cupronickel, is a copper-based alloy containing nickel as the main alloying element. It provides excellent seawater corrosion resistance, good mechanical strength and long-term stability in harsh environments.
The main advantages of Cu-Ni alloys include excellent seawater corrosion resistance, good thermal conductivity, resistance to biofouling, stable mechanical properties and excellent fabrication performance.
Copper Nickel Alloy is widely used in marine applications because it provides excellent resistance to seawater corrosion, good resistance to marine fouling and reliable long-term service performance.
The most common copper nickel alloys include 90/10 Cu-Ni and 70/30 Cu-Ni alloys. The suitable grade depends on corrosion conditions, mechanical requirements and application environment.
90/10 Copper Nickel Alloy contains approximately 90% copper and 10% nickel. It provides excellent corrosion resistance and is commonly used for seawater piping, heat exchangers and marine systems.
70/30 Copper Nickel Alloy contains approximately 70% copper and 30% nickel. Compared with 90/10 Cu-Ni, it provides higher nickel content and improved corrosion resistance for more demanding marine environments.
The main difference is nickel content. 70/30 Cu-Ni provides higher corrosion resistance and strength, while 90/10 Cu-Ni is widely used for general marine and heat exchanger applications.
Yes. Copper Nickel Alloy has excellent seawater corrosion resistance and is one of the preferred materials for seawater piping, marine equipment and offshore applications.
Yes. Copper Nickel Alloy tubes are widely used in heat exchangers and condensers because of their excellent corrosion resistance and good heat transfer performance.
Copper Nickel Alloy provides excellent seawater corrosion resistance, higher thermal conductivity and better biofouling resistance compared with many stainless steel grades in marine environments.
Yes. Copper Nickel Alloy has natural resistance to marine biological attachment, which makes it suitable for seawater cooling systems and marine piping applications.
Sunny Steel supplies copper nickel alloy tubes, pipes, rods, bars, plates and customized components according to customer requirements.
Yes. Copper Nickel Alloy tubes are widely used in desalination plants because of their excellent resistance to seawater and chloride-containing environments.
Yes. Cu-Ni alloys are commonly used in shipbuilding for seawater cooling systems, marine piping and heat exchanger equipment.
Yes. Copper Nickel Alloy can be welded and fabricated using suitable welding processes. Welding methods should be selected according to product design and service conditions.
Yes. Copper Nickel Alloy can be machined into various industrial components. Proper machining parameters should be selected according to alloy condition and product requirements.
Copper Nickel Alloy pipes are commonly used in seawater piping systems, offshore platforms, ship systems, power plants and industrial cooling equipment.
Copper Nickel Alloy plates are used for marine structures, corrosion-resistant components and industrial equipment requiring long-term durability.
Yes. Copper Nickel Alloy provides better thermal conductivity than many corrosion-resistant alloys, making it suitable for heat transfer applications.
Copper Nickel Alloy products are manufactured through melting, alloying, casting, hot working, cold working, heat treatment and machining processes.
Quality documents may include chemical composition reports, mechanical test reports, dimensional inspection reports and other documents required by customers.
Quality control includes raw material verification, chemical composition analysis, dimensional inspection, mechanical testing and final inspection before shipment.
Yes. Customized Cu-Ni components can be manufactured according to customer drawings, dimensions and technical requirements.
Copper Nickel Alloy is used in marine engineering, shipbuilding, offshore equipment, desalination plants, power generation and heat exchanger industries.
Sunny Steel supplies copper nickel alloy materials with various product forms, customized processing capability, quality control procedures and international export experience.

Copper Nickel 90/10

Copper nickel alloy bars with high ductility and toughness.

Copper Nickel 90/10 is a cupronickel alloy. While the basis of the alloy is 90% copper and 10% nickel, small amounts of iron and manganese are introduced during the alloying process to enhance performance.

Performance Characteristics

Copper Nickel 90/10 is an excellent choice for applications where erosion, stress-erosion and biofouling in saltwater atmospheres are considered. The alloy offers an attractive combination of toughness with high ductility. Mechanical properties are retained even at cryogenic temperatures, and resistance to hydrogen embrittlement is also high.

Stock Availability

Smiths Advanced Metals stock Copper Nickel 90/10 bars in the annealed condition. Bars of grade Copper Nickel 90/10 are available in various sizes.

Processing & Supply

We accurately cut your copper nickel bars to custom lengths and to close tolerances. We perform all these tasks in-house. Our products are supplied under ASTM, Euro Norm (EN) and DEF STAN specifications, supported by our UKAS Accredited Materials Testing Laboratory.

Iridium Unique Properties

A range of Copper Nickel Alloy Shapes

Sunny Steel supplies Copper Nickel Alloy materials in various forms to meet different industrial manufacturing requirements.

Copper Nickel Alloy Tube

Copper Nickel Alloy Rod

Copper Nickel Alloy Plate

Copper Nickel Alloy Coil

Copper Nickel Alloy Foil

Copper Nickel Alloy Sheet

Copper Nickel Alloy Bar

Copper Nickel Alloy Components

Copper Nickel Alloy Wire

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