"C68700" generally refers to the aluminum-arsenic brass alloy grade specified in ASTM B111/B111M.
ASTM B111 C68700 Pipe
Chemical Composition (typical range based on ASTM B111/B111M)
Copper (Cu): 76.0-79.0%
Aluminum (Al): 1.8-2.5% (core element, providing strength and corrosion resistance)
Arsenic (As): 0.02-0.10% (key additive, significantly improving dezincification corrosion resistance)
Zinc (Zn): Balance (typically approximately 18-21%)
Other Elements: Minor impurities such as iron, lead, tin, manganese, nickel, and silicon are generally limited to low levels.
Key Features
Excellent seawater corrosion resistance: This is its most prominent advantage. The addition of aluminum forms a protective oxide film, significantly improving corrosion resistance in environments such as seawater and brackish water, particularly against dezincification corrosion (the addition of arsenic further enhances this).
Good Strength: Higher strength and hardness than ordinary brass.
Good Thermal Conductivity: Copper alloys inherently possess excellent thermal conductivity.
Machinability: Can be hot or cold worked, and machined (although slightly more difficult than leaded brass).
Weldability: Can be soldered, brazed, and gas shielded welded (e.g., TIG, MIG) but not as weldable as pure copper or tin brass.
Erosion Corrosion Resistance: Has a certain resistance to seawater flow rates (but the upper limit of the flow rate should be observed).
Main Applications
Due to its excellent seawater corrosion resistance, C6871 is widely used in equipment that must withstand harsh marine environments:
Condenser and Heat Exchanger Tubes: Especially suitable for heat transfer tubes in condensers, steam generators, and coolers in power plants (thermal and nuclear), ships, offshore platforms, and desalination plants. This is its largest and most important application.
Marine hardware: Components exposed to seawater, such as propellers, valves, pump bodies, and pipe fittings.
Seawater piping systems: Pipes and fittings used to transport seawater or brackish water.
Chemical equipment: Heat exchangers and vessels used to handle certain corrosive media (such as chloride ion solutions).
Power industry: Ground rods, connectors, etc. (utilizing its corrosion resistance and electrical conductivity).
C68700 is a high-performance aluminum-arsenic brass. Its core value lies in its excellent resistance to seawater corrosion, particularly in preventing dezincification. It is virtually a standard material for heat transfer tubes in condensers and heat exchangers in marine environments and is widely used in the power generation, shipping, desalination, petrochemical, and other fields.
why choose us
Professional copper pipe supplier
As a professional enterprise dedicated to global copper product trade since 2008, GNEE Metal Group deeply recognizes the quality and responsibility embodied in the ASTM B111 standard. This standard not only specifies chemical composition and mechanical properties but also represents a comprehensive quality commitment spanning manufacturing processes to testing and verification. GNEE solemnly assures global customers that every ASTM B111-standard condenser tube and copper alloy tubing we supply will strictly adhere to its requirements for seamless manufacturing, annealing treatment, eddy current testing, and various mechanical performance tests.
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