C44300 Brass

Grade Name

Item	Specification
UNS Number	C44300
Common Name	Tin Brass, Naval Brass (Arsenical Brass)
Chinese Designation	HSn70-1 (GB/T 5232-1985)
European Standard	CuZn28Sn1 (DIN 17660)
Primary Standards	ASTM B111/B135, SAE J463, GB/T 5231

Product Features

Exceptional Corrosion Resistance: Tin (0.8–1.3%) and arsenic (0.03–0.06%) synergistically inhibit dezincification (ASTM B858 compliant).
High Strength-Ductility Balance: Annealed tensile strength ≥310 MPa, elongation ≥40%; cold-worked strength up to 600 MPa.
Thermal Conductivity: 109 W/(m·K), electrical conductivity 28% IACS, ideal for heat exchange systems.
Stress Corrosion Sensitivity: Low-temp stress relief required after cold working to prevent cracking.
Process Compatibility: Supports cold bending, flaring, brazing; hot working range 700–800°C.

Common Product Forms & Dimensions

Form	Thickness/Dia. (mm)	Width/Length (mm)	Special Requirements
Tube	Wall: 0.5–10.0	OD: 6–300	Seamless/Welded condenser tubes
Bar	Φ3–200	Cut-to-length: 0.5–6m	Hex/Square bars available
Strip	0.08–2.5	Coil width: 10–600	Slitting tolerance ±0.1mm
Plate	0.5–80	1000–6000 (L) ×500–3000 (W)	Max. single plate: 5 tons

Note: Custom profiles available (MOQ: 500kg).

C44300 Chemical Composition

Element	Standard Range (wt%)	Typical (wt%)	Function
Cu	69.0–71.0	70.5	Matrix, ensures conductivity
Sn	0.8–1.3	1.0	Enhances corrosion resistance
As	0.03–0.06	0.04	Strengthens grain boundaries
Zn	Balance	28.0	Improves fluidity, reduces cost
Total Impurities	≤0.3	0.15	Fe≤0.10%, Pb≤0.05% strictly controlled

Physical Properties

Property	Value	Test Condition
Density (g/cm³)	8.53	20°C
Melting Point (°C)	900–930	–
Thermal Conductivity (W/(m·K))	109	20°C
Electrical Conductivity (%IACS)	28	Annealed
Thermal Expansion (×10⁻⁶/K)	20.2	20–300°C
Elastic Modulus (GPa)	117	–

Data per ASTM B193/E1225; values vary with processing.

Mechanical Properties

Condition	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)	Hardness (HB)
Annealed (O)	310–380	105–140	≥40	60–75
¼ Hard (H02)	400–460	250–310	18–25	100–125
Hard (H04)	500–600	≥390	≥5	≥150
Hot Rolled	450–550	350–400	10–20	120–140

Tube properties per ASTM B111 (min. wall thickness 0.5mm).

Core Advantages

1. Marine Corrosion Benchmark: Dezincification depth <0.1 mm/year (ASTM G48 seawater), service life >15 years.

2. Heat Exchange Efficiency: Condenser tube heat transfer coefficient ≥5200 W/m²·K, 30% better than stainless steel.

3. Forming Adaptability: Cold bending radius ≥2× wall thickness; compatible with Ag/Cu-P brazing.

4. Environmental Safety: As ≤0.06%, complies with EU REACH industrial exemption.

Product Applications

Marine Engineering: Ship condenser tubes, desalination pipelines, subsea valves.
Energy & Power: Thermal power plant condensers, nuclear cooling systems, refinery heat exchangers.
HVAC: AC refrigerant tubes, chlorinated hot water pipes.
Mechanical Parts: Deep-drawn pins/springs, corrosion-resistant bearing bushings.

Processing Guidelines

Process	Key Parameters	Risk Control
Hot Working	700–800°C (finish >550°C)	Control O₂ at 0.5–1.5% to prevent Zn volatilization
Welding	TIG: 80–120A	Argon purity ≥99.99% + preheat 150°C (prevents As porosity)
Annealing	Stress relief: 285°C×1h	N₂ atmosphere anti-oxidation
Cold Working	Deformation ≤50%	Intermediate annealing at 650°C
Surface Treatment	Pickling (HNO₃-H₂SO₄)	Tin plating after oxide removal

Key Application Scenarios

Mega Vessels: 200k DWT ship condenser tube bundles (seamless, wall 1.5mm).
Nuclear Plants: AP1000 coolant pipes (chloride resistance design).
Coastal Power Stations: Seawater cooling valves (forged + Ni-Cr coated).
Premium HVAC: Central AC evaporator tubes (brazing integrity required).

FAQs

Q1: Can it replace lead-free alloys in potable water systems?

A: Restricted! Arsenic leaching risk. Use C68700 aluminum brass instead; compliant for industrial cooling water.

Q2: How to resolve welding porosity?

A: Caused by As/Zn volatilization. Use ≥99.99% argon, preheat 150–200°C, post-weld stress relieve at 260°C×1h.

Q3: Causes and prevention of hot cracking?

A: Zn loss weakens grain boundaries. Control slightly oxidizing atmosphere (O₂: 0.5–1.5%), limit heating time ≤2h.

Q4: How to select vs. C68700?

A: C44300 offers superior seawater resistance & 15% lower cost; C68700 is arsenic-free for civilian use.

Standard References

Standard System	Code	Scope
US Standard	ASTM B111	Seamless Condenser & Heat Exchanger Tubes
US Standard	ASTM B135	Brass Strip Dimensions & Tolerances
International	SAE J463	Mechanical Properties of Wrought Cu Alloys
Chinese	GB/T 5231	Wrought Brass Specifications
European	DIN 17660	Cu Alloy Bars/Tubes (Designation: CuZn28Sn1)

Technical Note:

1. Data based on ASTM standard specimens. Actual properties subject to mill test certificates (MTC).

2. Critical applications require validation testing (e.g., ISO 9227 salt spray, ASME B96 brazing qualification).
Document Version: V2.0
Revision Date: 29 May 2025
Disclaimer: This document does not replace material test reports. FMEA analysis required for high-risk projects.

"The synergistic tin-arsenic anti-dezincification mechanism of C44300 remains a classic paradigm in corrosion-resistant brass design."
— Copper Alloys in Marine Engineering White Paper, 2024 Edition

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