Copper-Nickel 70/30: Complete Properties & Application Guide

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Overview

Copper-Nickel 70/30 (UNS C71500) is a cupronickel alloy with excellent resistance to seawater corrosion and biofouling. The 30% nickel content provides higher strength and corrosion resistance compared to 90/10 Cu-Ni, making it ideal for demanding marine applications.

Chemical Composition

The chemical composition of Copper-Nickel 70/30 is carefully controlled to achieve its unique combination of properties and performance characteristics.

Element	Min %	Max %
Copper (Cu)	Balance	Balance
Nickel (Ni)	29.0	33.0
Iron (Fe)	0.40	1.00
Manganese (Mn)	—	1.0
Zinc (Zn)	—	1.0
Carbon (C)	—	0.05
Lead (Pb)	—	0.05

Mechanical Properties at Room Temperature

The mechanical properties of Copper-Nickel 70/30 vary depending on product form and heat treatment condition. The data below represents typical values for solution-annealed material.

Property	Value
Tensile Strength	380 MPa
Yield Strength (0.2% offset)	125 MPa
Elongation in 2 inches	45%
Density	8.94 g/cm3
Melting Point	1240 °C
Max Service Temperature	300 °C

Corrosion Resistance

Outstanding resistance to seawater corrosion, including pitting, crevice corrosion, and stress corrosion cracking. Excellent resistance to biofouling due to the natural formation of a protective copper oxide film. Good resistance to ammonia stress corrosion cracking and dezincification.

Applications

The unique combination of properties makes Copper-Nickel 70/30 suitable for a wide range of demanding applications:

• Marine Engineering: Seawater piping, heat exchanger tubing, and condenser tubes.
• Offshore Platforms: Riser systems, ballast water systems, and firewater piping.
• Power Generation: Condenser tubing in coastal power plants.
• Shipbuilding: Seawater cooling systems, heat exchangers, and piping.
• Desalination: Heat rejection and recovery tubing in desalination plants.

Available Product Forms

Hangbo Alloy Group manufactures and supplies Copper-Nickel 70/30 in the following product forms, conforming to ASTM, AMS, and ASME specifications:

• Round Bars: Diameters from 6 mm to 300 mm, hot-finished or cold-drawn, solution annealed.
• Seamless Tubes & Pipes: Sizes from 6 mm OD to 219 mm OD, various wall thicknesses.
• Plates & Sheets: Thicknesses from 0.5 mm to 50 mm, hot-rolled or cold-rolled.
• Forgings: Custom flanges, rings, discs, and complex shapes per customer drawing.
• Welding Wire: Diameters 0.8 mm to 5.0 mm, precision-wound coils and spools.

Related Standards

Standard	Description
ASTM B111	Condenser Tube
ASTM B466	Seamless Pipe
ASTM B467	Welded Pipe
ASTM B122	Plate, Sheet, and Strip
ASTM B151	Bar and Rod
ASTM B171	Plate

Contact Us for Copper-Nickel 70/30

Hangbo Alloy Group maintains extensive inventory of Copper-Nickel 70/30 in all standard product forms. We can provide mill test certificates, third-party inspection reports (SGS, TUV), and custom processing services.

For quotations, material certifications, or technical consultation, contact our sales team or call +86-136-1165-6360. We typically respond within 10 minutes.