C6870 Brass

Grade Name

C6870 Aluminum Brass (Corrosion-Resistant Brass)

Key Features

• Superior Corrosion Resistance: Aluminum (1.8–2.5%) and arsenic (0.02–0.10%) prevent dezincification, ideal for seawater environments.

• High Strength & Workability: Tensile strength ≥380 MPa (annealed), adaptable to cold/hot working and welding.

• Thermal Conductivity: 100 W/(m·K), suitable for heat exchangers.

• Eco-Compliance: RoHS-compliant (Pb ≤0.05%), meets ASTM B111 standards.

Product Forms & Dimensions

Form	Size Range	Standards
Rod	Diameter 5–300mm, Length 1–12m	ASTM B124M
Plate	Thickness 1.0–50mm, Width 200–2000mm	JIS H3300
Tube	OD 10–300mm, Wall Thickness 1.0–30mm	EN 12449:1999
Strip	Thickness 0.2–3.0mm, Width ≤300mm	ASTM B134
Wire	Diameter 0.5–12mm, Coil ≥5kg	DIN 17660

Chemical Composition

Element	Content (%)	Standard Range
Cu	76.0–79.0	Main Component (ASTM B111)
Al	1.8–2.5	Corrosion Resistance
As	0.02–0.10	Dezincification Inhibitor
Zn	Balance	Balancing Component
Pb	≤0.05	RoHS Limit
Fe+Sn	≤0.5	Impurity Control
Impurities	≤0.5	Total Limit

Physical Properties

Property	Value/Description
Density	8.40 g/cm³
Electrical Conductivity	28% IACS (20℃)
Thermal Conductivity	100 W/(m·K)
Thermal Expansion	19.5×10⁻⁶/℃ (20–300℃)

Mechanical Properties

Condition	Tensile Strength (MPa)	Elongation (%)	Hardness (HV)
Annealed (O)	380–450	≥25	80–100 HV
Half-Hard (H02)	450–550	≥15	120–150 HV
Hard (H)	≥550	≥8	≥160 HV

Core Advantages

1. Marine-Grade Durability: 3–5x longer service life in seawater vs. standard brass.

2. Efficient Heat Dissipation: Ideal for high thermal load applications.

3. Processing Flexibility: Compatible with cold rolling, hot forging, and welding.

Applications

• Marine Engineering: Ship condenser tubes, desalination equipment.

• Energy Systems: Heat exchangers in power plants.

• Chemical Industry: Corrosive fluid pipelines, valve liners.

• Electronics: Heat sinks for high-power devices.

Processing Guidelines

• Hot Working: 700–750℃, avoid 300–600℃ brittleness zone.

• Post-Cold Working: Low-temperature annealing (250–350℃) to prevent stress corrosion.

• Welding: Use TIG/MIG welding, followed by acid cleaning.

FAQs

Q1: Differences between C6870 and C4430?

A: C4430 (tin brass) has lower strength; C6870 offers higher strength and thermal conductivity.

Q2: Suitability for seawater exposure?

A: Yes, but monitor surface condition and limit flow velocity ≤2 m/s.

Standards

• ASTM B111M: U.S. condenser and heat exchanger tube standard.

• JIS H3300-2018: Japanese copper alloy tube standard.

• DIN 17660: European copper alloy composition standard.