CuNi18Zn20 Copper

Designation

• Name: Nickel-Zinc Cupronickel CuNi18Zn20

• International Designation: CW411J (European Standard), DIN 2.0530, C76900

• Standards: DIN 17666, EN 12165, ISO 1636.

Key Features

1. Superior Corrosion Resistance: Excellent resistance to seawater, salt spray, and weak acids.

2. High Strength & Ductility: Balanced tensile strength (500–700 MPa) with cold/hot forming capability.

3. Anti-Biofouling: Smooth surface minimizes marine organism adhesion.

4. Conductivity: Ideal for precision electronics and thermal management.

5. Aesthetic & Wear Resistance: Silver-white luster for luxury and wear-resistant parts.

Common Forms & Dimensions

Form	Dimensions
Round Bar	Diameter: Φ5.0mm–300mm
Plate	Thickness: 0.5–120mm
Tube	Seamless tubes per EN 12449 (Wall ≤18mm)
Wire	Diameter: 0.3mm–5.0mm
Forged Parts	Custom shapes (e.g., marine fittings, flanges)
Note: Confirm feasibility for non-standard sizes.

Chemical Composition (wt%)

Element	Cu	Ni	Zn	Pb	Fe	Mn	Impurities
Range	60–63	17–19	19–21	≤0.3	≤0.5	≤0.5	≤0.5
Data based on DIN 17666.

Physical Properties

Property	Value/Description
Density	8.7 g/cm³
Thermal Conductivity	27 W/m·K (at 20°C)
Electrical Resistivity	0.32 μΩ·m (at 20°C)
Conductivity	~13% IACS
Magnetism	Slightly magnetic (Ni influence)

Mechanical Properties

Property	Range/Typical Value
Tensile Strength (Rm)	500–700 MPa (varies by temper)
Yield Strength (Rp0.2)	220–420 MPa
Elongation (A)	18–35%
Brinell Hardness (HB)	130–210
Note: Hard temper (H) offers higher tensile strength.

Core Advantages

• All-Environment Resistance: Suitable for marine, chemical, and freshwater corrosion.

• Versatile Processing: Compatible with cold rolling, stamping, welding, and casting.

• Long Service Life: Low maintenance with anti-fouling and wear resistance.

Applications

• Marine Engineering: Seawater pumps, ship condensers, deep-sea pipelines.

• Energy & Chemical: Acid-resistant pipelines, heat exchanger linings.

• Electronics: High-precision connectors, resistor substrates.

• Luxury Goods: Cutlery, architectural trim, watch cases.

Processing Guidelines

1. Cold Working: Limit deformation to ≤25% per pass; anneal at 680–750°C.

2. Welding: Use TIG welding; post-weld passivation required.

3. Machining: Carbide tools with low speed and lubricants.

4. Surface Treatment: Electro-polishing or palladium plating for enhanced finish.

Key Application Scenarios

• Deep-Sea Equipment: High-pressure corrosion-resistant valves.

• Nuclear Power Plants: Chloride-resistant heat transfer tubes.

• Luxury Watchmaking: Sweat-resistant watch cases.

FAQs of CuNi18Zn20 Material

Q1: How does CuNi18Zn20 differ from CuNi18Zn27?

A: CuNi18Zn20 has lower Zn content (19–21% vs. 25–28%), offering slightly better corrosion resistance but lower strength.

Q2: Suitable for high-temperature/pressure environments?

A: Long-term use ≤170°C; short-term tolerance up to 230°C (pressure-dependent).

Q3: How to prevent cracking during processing?

A: Control cold deformation rate and anneal promptly.

Standards Reference

• DIN 17666: Chemical and mechanical specifications.

• EN 12165: Rod and wire processing standards.

• ISO 1636: Corrosion resistance testing.