Cupronickel or copper-nickel is an alloy of copper that contains nickel and strengthening elements, such as iron and manganese. Cupronickel is highly resistant to corrosion in seawater because its electrode potential is adjusted to be neutral with regard to seawater. Because of this, it is used for piping, heat exchangers, and condensers in seawater systems, as well as marine hardware, and sometimes for the propellers, crankshafts, and hulls of premium tugboats, fishing boats, and other working boats.
Copper nickel 70-30% 715 is one of the most corrosion-resistant and durable copper-base alloys for condenser and heat exchanger tubes in seawater. In high-pressure, high-temperature steam stations, copper-nickel 70-30% tubes are used in feedwater heaters regardless of the type of tube used in the main condensers.
Standards Available
ASME SB-111
ASME SB-466
ASTM B-111
ASTM B-466
MIL-T-15005f
c71500 chemical composition
C71500 Copper Nickel 70/30, also known as Cupronickel 70/30, has the following composition:
| Element | Content |
|---|---|
| Copper (Cu) | Approximately 65.0-71.5% |
| Nickel (Ni) | Approximately 29.0-33.0% |
| Iron (Fe) | Maximum 0.4% |
| Manganese (Mn) | Maximum 1.0% |
| Zinc (Zn) | Maximum 1.0% |
c71500 mechanical properties
| Property | Value |
|---|---|
| Tensile Strength | Typically 372-552 MPa (54,000-80,000 psi) |
| Yield Strength | Generally 138-483 MPa (20,000-70,000 psi) |
| Elongation | Typically 30-45% |
c71500 density and physical properties
c71500 density = Approximately 8.94 g/cm³ (0.323 lb/in³).
| Property | Value |
|---|---|
| Density | 8.94 g/cm³ (0.323 lb/in³) |
| Melting Point | Approximately 1170-1240°C (2140-2260°F) |
Corrosion Resistance
C71500 Copper Nickel 70/30 exhibits excellent resistance to corrosion in various environments, especially in seawater and brackish water. It provides high resistance to stress corrosion cracking and biofouling, making it suitable for marine and offshore applications.
Applications and Uses
C71500 Copper Nickel 70/30 tube and pipe are highly versatile and widely used in various industries due to their excellent corrosion resistance, high strength, and superior thermal conductivity.
Marine and Offshore Applications: C71500 Copper Nickel 70/30 tube and pipe are extensively used in marine environments for applications such as seawater cooling systems, heat exchangers, condensers, and shipbuilding components. Their exceptional resistance to seawater corrosion and biofouling make them an ideal choice for these demanding applications.
Oil and Gas Industry: Copper Nickel 70/30 tube and pipe are utilized in the oil and gas industry for various applications, including offshore platforms, subsea pipelines, and oil refineries. Their corrosion resistance and high mechanical strength make them suitable for handling corrosive fluids and withstanding high-pressure environments.
Power Generation: C71500 Copper Nickel 70/30 tube and pipe find application in power plants for heat exchangers, condensers, and steam generation systems. Their excellent thermal conductivity ensures efficient heat transfer, while their corrosion resistance makes them suitable for handling various cooling and heating fluids.
Desalination Plants: Copper Nickel 70/30 tube and pipe are used in desalination plants for seawater intake and brine discharge systems. Their resistance to corrosion and fouling by salts and marine organisms makes them ideal for these harsh environments.
Chemical Processing: Due to their excellent resistance to corrosive chemicals, C71500 Copper Nickel 70/30 tube and pipe are utilized in chemical processing plants for conveying and handling corrosive fluids, including acids, alkalis, and salt solutions.
HVAC and Refrigeration: These copper nickel tubes and pipes are employed in HVAC (heating, ventilation, and air conditioning) and refrigeration systems for their superior thermal conductivity and resistance to corrosion. They ensure efficient heat transfer and reliability in these applications.
Automotive and Transportation: Copper Nickel 70/30 tube and pipe find use in automotive and transportation industries for applications such as brake lines, fuel lines, and hydraulic systems due to their corrosion resistance and mechanical strength.
FAQ
Q1: What is the difference between C71500 and C70600 copper nickel?
C71500 has higher strength and better corrosion resistance than C70600. C71500 (70/30) contains 29-33% nickel with tensile strength 372-552 MPa. C70600 (90/10) contains 9-11% nickel with lower strength. For high-pressure, high-temperature steam stations and high-velocity seawater, choose C71500. For general marine use, C70600 is more economical.
Q2: What ASTM standards cover C71500 seamless tube and pipe?
ASTM B-111 and ASME SB-111 cover tube; ASTM B-466 and ASME SB-466 cover pipe. Military specifications include MIL-T-15005f and MIL-T-16420k (Class 200, 700, 1650, 3300, and 6000). For naval and critical applications, specify the appropriate MIL standard.
Q3: What is the density of C71500 material for weight calculation?
C71500 density is 8.94 g/cm³ (0.323 lb/in³). For pipe weight calculation: (OD - wall) × wall × 10.68 = lb/ft. For metric: (OD mm - wall mm) × wall mm × 0.028 = kg/m.
Q4: What is the tensile strength of C71500 tube?
Tensile strength typically ranges from 372 MPa (54,000 psi) to 552 MPa (80,000 psi). Yield strength is generally 138-483 MPa (20,000-70,000 psi) depending on temper. Elongation is typically 30-45%.
Q5: Why does C71500 have good corrosion resistance in seawater?
Because its electrode potential is adjusted to be neutral with regard to seawater. The alloy contains nickel, iron, and manganese as strengthening elements. This provides high resistance to stress corrosion cracking and biofouling, making it suitable for marine and offshore applications.
Q6: What are the common applications of C71500 tube and pipe?
Seawater cooling systems, heat exchangers, condensers, shipbuilding components, offshore platforms, subsea pipelines, oil refineries, power plant heat exchangers, desalination plants, chemical processing, HVAC, refrigeration, brake lines, fuel lines, and hydraulic systems. The page lists all these applications.
Q7: Is C71500 used in high-pressure, high-temperature steam stations?
Yes, C71500 tubes are used in feedwater heaters in high-pressure, high-temperature steam stations. The page states this applies "regardless of the type of tube used in the main condensers."
Q8: What is the melting point of C71500?
Melting point is approximately 1170-1240°C (2140-2260°F). This relatively high melting point allows the alloy to retain strength at elevated temperatures.
Q9: What is the machinability of C71500?
C71500 has good machinability, but its high strength and work hardening characteristics may require appropriate machining techniques and tools. Use sharp carbide tooling, appropriate cutting speeds, and adequate cooling. For complex components, consider finished machined parts.
Q10: Is C71500 suitable for desalination plants?
Yes, C71500 tube and pipe are used in desalination plants for seawater intake and brine discharge systems. Their resistance to corrosion and fouling by salts and marine organisms makes them ideal for these harsh environments.
Detection & Quality Control
| Test Method | Purpose | Acceptance Criteria |
|---|---|---|
| Optical Emission Spectrometry | Verify c71500 chemical composition | Cu 65.0-71.5%, Ni 29.0-33.0%, Fe ≤0.4%, Mn ≤1.0%, Zn ≤1.0% |
| Tensile Test | Confirm c71500 mechanical properties | UTS 372-552 MPa, Yield 138-483 MPa, Elong 30-45% |
| Flattening Test | Ductility for tube forming | No cracks when flattened |
| Hardness Test | Uniformity of temper | Per specification |
| Dimensional Check | OD, wall, length | Per ASTM B-466 |
| Hydrostatic Test | Leak tightness | Per specification |
| Eddy Current Test (when specified) | Detect pits and wall variations | Per ASTM E243 |
Packaging
c71500 copper pipe is packaged to prevent damage during transit:
| Packaging Type | Details |
|---|---|
| Hexagonal bundles | Steel straps, plywood separators, plastic end caps. Max bundle weight 2000 kg. |
| Wooden crates | ISPM-15 certified, foam-lined for finished components. |
| Steel reels | For coiled tube. Marked with heat number, size, length. |
Marking per bundle: Alloy (C71500 / 70/30), heat number, size (OD × wall), length, quantity, PO number, net/gross weight.
Moisture protection: Desiccant bags for tropical or long-term storage.
Factory Equipment
| Equipment | Role in C71500 Pipe Production |
|---|---|
| Induction melting furnaces | Precise control of Cu 65.0-71.5%, Ni 29.0-33.0%, Fe ≤0.4%, Mn ≤1.0% |
| Continuous casting | Produces solid billet |
| Extrusion press | Pierces billet to hollow shell |
| Cold pilger mills | Reduces OD and wall thickness |
| Draw benches | Final sizing, smooth finish |
| Annealing furnaces | Softening after cold work |
| Straightening machines | Achieves straightness |
| Hydrostatic testers | Pressure testing |
| Metallurgical lab | OES, tensile, hardness verification |
Our Full Product Range
| Product Form | Common Standards | Typical Alloy Grades | Size Range | Typical Applications |
|---|---|---|---|---|
| Copper Pipe & Tube (Seamless) | ASTM B-111, B-466, ASME SB-111, SB-466, MIL-T-15005f, MIL-T-16420k | C71500, C70600, C12200, C68700, C44300 | Per ASTM / MIL standard | Seawater cooling systems, heat exchangers, condensers, shipbuilding, feedwater heaters |
| Copper Rod & Bar | ASTM B151, MIL-C-15726, SAE J461, J463 | C71500, C70600, C36000, C46400 | Per ASTM standard | Marine hardware, propellers, crankshafts, hull components |
| Copper Sheet & Plate | ASTM B171, ASME SB171, MIL-C-15726 | C71500, C70600, C46400 | Per ASTM standard | Condenser plates, marine hardware |
| Copper Tube (Condenser) | ASTM B-111, ASME SB-111 | C71500, C70600 | Per ASTM standard | Power plant condensers, feedwater heaters |
| Copper Wire | MIL-C-15726 | C71500, C70600 | Per MIL standard | Welding filler, marine hardware |
| CNC Machined Components | Custom drawing | C71500, C70600, C36000, C63000, C17200 | Custom tolerances | Pump bodies, valve components, marine hardware |
