1. Chemical Composition and Standards

HSi80-3’s chemical composition (according to GB/T 5231-2012 "Copper and Copper Alloys for Processing") is as follows:

Cu (Copper)：79.0–81.0%

Si (Silicon)：2.5–4.0%

Zn (Zinc)：Balance (~15–18%)

Mn (Manganese)：0.5–1.5%

Fe (Iron)：≤0.6%

Pb (Lead)：≤0.2%

• Comparable international grades:

China (GB): HSi80-3 (formerly ZCuZn16Si4)

USA (ASTM): C87600 (silicon bronze, similar but slightly different composition)

EU (EN): CW721R (CuZn16Si4)

Japan (JIS): CAC702 (silicon brass)

2. Physical and Mechanical Properties

(1) Physical Properties

Density: 8.3–8.5 g/cm³

Melting Point:900–950°C (lower than pure copper’s 1083°C)

Electrical Conductivity:~20% IACS (lower than pure copper but better than ordinary brass)

Thermal Conductivity:~70–90 W/(m·K)

Thermal Expansion Coefficient:18–20 ×10⁻⁶/°C

(2) Mechanical Properties (Annealed Condition)

Tensile Strength (Rm):350–450 MPa

Yield Strength (Rp0.2):150–250 MPa

Elongation (A):≥15%

Hardness (HB):100–130

Impact Toughness (Akv):Good (better than ordinary brass)

3. Material Characteristics and Advantages

(1) High Strength
Silicon forms Cu₅Si strengthening phases, significantly increasing hardness and tensile strength by 20–30% compared to ordinary brass. Suitable for parts under heavy mechanical loads, such as gears and bearings.

(2) Wear Resistance
The combined effect of silicon and manganese provides good wear resistance, ideal for friction parts like valves and pump bodies.

(3) Corrosion Resistance
Performs better than ordinary brass (e.g., H62) in seawater and mildly acidic environments, close to aluminum bronze levels. Widely used in corrosion-resistant components for shipbuilding and chemical equipment.

(4) Casting and Machining Performance
Good fluidity, suitable for precision casting (sand casting, metal mold casting).
Machinability is improved by small amounts of lead (Pb), but welding is slightly more challenging (requires low-zinc brass welding wires).

4. Main Application Fields

(1) Mechanical Manufacturing
Wear-resistant parts: bearings, gears, worm gears, valve cores.
High-strength structural parts: ship propeller blades, high-pressure pump housings.

(2) Shipbuilding and Marine Engineering
Seawater pipeline fittings: corrosion-resistant valves and flanges.
Ship propulsion systems: propellers, rudder components.

(3) Chemical and Energy
Corrosion-resistant pump bodies: pumps and impellers handling acid/alkali media.
Heat exchangers: condensers, cooling fins (with anti-fouling treatment).

(4) Construction and Decoration
High-strength decorative parts: antique-style copper door handles, sculptures (surface can be chrome/nickel plated).

5. Processing Guidelines

(1) Casting Process
Recommended methods: sand casting, metal mold casting.
Melting temperature: 1100–1200°C (covered with charcoal to prevent oxidation).
Heat treatment: annealing at 500–600°C to relieve internal stresses.

(2) Machining
Cutting speed: medium to low speed (silicon increases hardness, tool wear is higher).
Tool material: carbide or high-speed steel (HSS).

(3) Welding
Welding wires: HSi80-3 same-material wire or silicon bronze wire (ERCuSi-A).
Shielding gas: argon (TIG/MIG).
Preheat temperature: 200–300°C (to prevent zinc evaporation causing porosity).

6. Comparison with Other Brasses

(1) HSi80-3

Main Composition:Cu-Zn-Si-Mn

Characteristics:High strength, wear resistant, corrosion resistant

Typical Uses:Shipbuilding, chemical machinery

(2)H62 (ordinary brass)

Main Composition:Cu-Zn (60/40)

Characteristics:Low cost, good plasticity

Typical Uses:Hardware, plumbing

(3) HPb59-1 (lead brass)

Main Composition:Cu-Zn-Pb

Characteristics:Easy machining, moderate strength

Typical Uses:Screws, valves

(4) HA177-2 (aluminum brass)

Main Composition:Cu-Zn-Al

Characteristics:Seawater corrosion resistant

Typical Uses:Marine engineering

7. Common Issues and Solutions

(1) Casting Defects
Porosity: Zinc evaporation during melting → improve cover, control temperature.
Hot cracks: Excess silicon content → adjust Si ≤4%, optimize cooling rate.

(2) Welding Difficulties
Zinc evaporation causing porosity → use low-zinc welding wire, enhance shielding gas protection.

(3) Corrosion Protection
Dezincification (selective zinc dissolution) → add trace arsenic (As) or use low-zinc brass.

8. Summary

HSi80-3 is a high-strength silicon brass alloy that significantly enhances mechanical and corrosion properties of ordinary brass through alloying with silicon and manganese. It is widely used in wear- and corrosion-resistant components in shipbuilding, chemical, and mechanical industries. Processing requires attention to casting techniques and welding protection, but its overall performance surpasses traditional brass like H62.

9. About Suzhou Bolaibao

As a professional non-ferrous metal material supplier, Shanghai Bolaisheng Metal Co., Ltd. focuses on the research and supply of high-performance copper alloys. We offer stable supply of HSi80-3 silicon brass and various special copper alloy materials, supporting customized processing services. Our products serve shipbuilding, mechanical equipment, chemical and environmental protection industries. Contact us to jointly promote higher-quality and sustainable industrial manufacturing.

Bolaibao Metal – Solving Complex Problems with Specialized Materials, Empowering Critical Industries to Withstand Corrosion.

• Tel: +86 15366282159

• Email: sale@bolaibao1.com

• Website: www.blbszmetal.com