C7060 Copper

Grade Designation & Standards

Standard Grade: C7060 (Iron-White Copper Alloy)

International Equivalents:

China GB/T 4423-1992: BFe30-1-1

UNS (USA): C71500 (similar composition, verification required)

Applicable Standards:

GB/T 4423-1992 (China Iron-White Copper Standard)

JIS H3250 (Japanese Standard for Copper and Copper Alloy Rods, subject to actual specifications)

Key Features

1. Corrosion Resistance: Excellent resistance in seawater, freshwater, and steam, especially in high-salinity environments (corrosion rate ≤0.01 mm/a).

2. Mechanical Properties: Tensile strength ≥490 MPa, balancing high strength and ductility.

3. High-Temperature/High-Pressure Stability: Operates reliably at ≤400°C and under high pressure, ideal for condensers and heat exchangers.

4. Workability: Supports cold/hot working, welding, and surface treatments (e.g., plasma nitriding), but machinability is limited.

5. Conductive & Thermal Properties: Electrical conductivity ~5% IACS, thermal conductivity 40 W/(m·K), suitable for applications requiring both conductivity and corrosion resistance.

Common Product Forms & Specifications

Product Form	Size Range	Delivery Condition
Rod	Diameter: 5–150 mm; Length: 1–6 m	Annealed, Cold-drawn
Sheet/Strip	Thickness: 0.5–12 mm; Width ≤1200 mm	Soft (O), Hard (H)
Tube	OD: 10–200 mm; Wall Thickness: 1–15 mm	Annealed, Half-hard
Wire	Diameter: 0.5–10 mm	Coiled or Straight
Custom Profiles	As per technical drawings	Tailored processing states
Note: Size ranges reference Chinese standards; adjust per JIS H3250 for Japan.

Chemical Composition

Element	Cu	Ni	Fe	Mn	Other Impurities
Content	Balance	29.0–32.0%	0.5–1.0%	0.5–1.2%	Zn≤0.3%, Pb≤0.02%
Typical total impurities ≤0.7% (including Si, C, S, etc.).

Physical Properties

Property	Value	Remarks
Density	8.9 g/cm³	High density for structural stability
Melting Point	1330–1350°C (cast)	Suitable for high-temperature casting
Electrical Conductivity	~5% IACS	Low conductivity, typical for Cu-Ni alloys
Thermal Conductivity	40 W/(m·K)	Moderate heat dissipation
Thermal Expansion Coefficient	17.1×10⁻⁶/°C (20–200°C)	Excellent dimensional stability at high temperatures

Mechanical Properties

Property	Annealed (Soft)	Cold-Worked (Hard)
Tensile Strength (Rm)	≥280 MPa	≥480 MPa
Yield Strength (Rp0.2)	≥130 MPa	≥450 MPa
Elongation (A50)	≥30%	≥8%
Hardness (HV)	75–110	150–220
Note: Data based on GB/T 4423-1992; Japanese standards may vary.

Core Advantages

1. Marine-Grade Corrosion Resistance: Superior resistance to pitting and biofouling compared to stainless steel.

2. High-Temperature Stability: Long-term operation at ≤400°C, ideal for heat exchangers and marine power systems.

3. Surface Modification Potential: Plasma nitriding enhances surface hardness to HV 800–1000, significantly improving wear resistance.

Product Applications

• Shipbuilding: Condenser tubes, thermostats, seawater pump components.

• Chemical Equipment: Reactor linings, acid-resistant pipelines, storage tanks.

• Energy & Power: Power plant condensers, desalination equipment.

• Mechanical Engineering: Gears, bearing bushings (requires surface hardening).

Processing Guidelines

1. Welding:

Use TIG or laser welding; avoid overhead welding.

Interpass temperature ≤100°C to prevent hot cracking.

2. Machining:

Employ carbide tools with sulfur-based coolant; cutting speed ≤60 m/min.

3. Heat Treatment:

Stress relief annealing: 780–810°C; low-temperature annealing: 250–300°C for dimensional stability.

Key Application Scenarios

• Seawater Cooling Systems: Piping and heat exchangers for ships and coastal power plants.

• Deep-Sea Equipment: Submersible housings, high-pressure valves (requires nitriding).

• Chemical Reactors: Liners and agitators for corrosive media.

FAQs

Q1: How does C7060 differ from C70600 (Cu-Ni alloy)?

A1: C7060 (iron-white copper, ~30% Ni) emphasizes corrosion resistance and high-temperature strength; C70600 (Cu-Ni, ~10% Ni) is cost-effective but less corrosion-resistant.

Q2: How to enhance C7060’s wear resistance?

A2: Plasma nitriding increases surface hardness to HV 800+, suitable for gears and bearings.

Q3: How to prevent edge cracking in cold-rolled sheets?

A3: Limit rolling reduction to ≤20% per pass, ensure lubrication, and anneal post-processing.

Standard References

• Chemical Composition: GB/T 4423-1992 (China), JIS H3250 (Japan).

• Mechanical Testing: ISO 6892-1 (Metallic Materials – Tensile Testing).

• Processing: ASTM B543 (Cu-Ni Alloy Seamless Condenser Tubes).

Note: This specification integrates data from GB/T 4423-1992. Parameters under JIS standards require further verification. Actual performance may vary slightly due to manufacturing processes. Refer to supplier test reports for precise specifications.