Copper Nickel Alloy C71500 is composed of 70 percent copper and 30 percent nickel, with a lower conductivity than C70600. C71500 Copper Nickel is used in oil and gas and marine defense applications where moderate-to-high sea water corrosion concern is present, for example, in pumps, valves, and high-pressure steam lines.
Benefits of C71500 Copper Nickel
High strength – Higher nickel content (30%) provides superior mechanical properties compared to C70600.
Excellent corrosion resistance – Performs reliably in seawater, brackish water, and high-pressure steam environments.
Moderate machinability – Can be machined into complex components like pumps and valves with proper tooling.
High impact resistance – Withstands shock loading and stress without cracking, important for marine defense applications.
Chemical Composition of C71500
| Element | Content (%) |
|---|---|
| Copper (Cu) | 70.0 (nominal) / Balance |
| Nickel (Ni) | 30.0 (nominal) / 29.0 – 33.0 |
| Iron (Fe) | 0.40 – 1.00 |
| Manganese (Mn) | ≤ 1.00 |
| Lead (Pb) | ≤ 0.05 |
| Zinc (Zn) | ≤ 1.00 |
Mechanical Properties of C71500
| Property | Annealed (O61) | Drawn / Half Hard (H80 / H02) |
|---|---|---|
| Tensile Strength (ksi) | 50 – 60 | 60 – 80 |
| Tensile Strength (MPa) | 345 – 414 | 414 – 552 |
| Yield Strength (ksi) | 18 – 25 | 35 – 50 |
| Yield Strength (MPa) | 124 – 172 | 241 – 345 |
| Elongation (%) | 30 – 45 | 10 – 20 |
| Hardness (Rockwell B) | 35 – 45 | 60 – 80 |
| Property | Value |
|---|---|
| Machinability Rating (C360 = 100) | 20 |
| Modulus of Elasticity (Tension) | 22,000 ksi (152 GPa) |
| Modulus of Rigidity | 8,300 ksi (57 GPa) |
| Poisson's Ratio | 0.34 |
Physical Properties of C71500
| Property | Imperial | Metric |
|---|---|---|
| Density | 0.323 lb/in³ | 8.94 g/cm³ |
| Melting Point – Solidus | 2140°F | 1171°C |
| Melting Point – Liquidus | 2260°F | 1238°C |
| Specific Gravity | 8.94 | 8.94 |
| Electrical Conductivity | 4 – 5% IACS | 0.024 – 0.029 MS/cm |
| Electrical Resistivity | 225 ohm-cmil/ft | 37.4 microhm-cm |
| Specific Heat Capacity | 0.09 Btu/lb/°F at 68°F | 377 J/kg·K at 20°C |
Why Choose C71500 Over C70600?
| Property | C71500 (70/30) | C70600 (90/10) |
|---|---|---|
| Copper content | 70% | 90% |
| Nickel content | 30% | 10% |
| Conductivity | Lower | Higher |
| Strength | Higher | Moderate |
| Corrosion resistance | Excellent (better in high velocity) | Very good |
| Typical applications | High-pressure steam lines, marine defense, oil & gas | General seawater piping, heat exchangers |
Selection guidance: Choose C71500 when the application involves high-pressure steam, high-velocity seawater, or marine defense requirements. Choose C70600 when higher conductivity or lower cost is the priority.
Applications of C71500
Oil and Gas:
High-pressure steam lines
Pumps and valves in corrosive environments
Marine Defense:
Seawater piping systems
Pumps and valves on naval vessels
High-pressure steam systems on ships
Industrial:
Any application where moderate-to-high seawater corrosion concern is present
FAQ
Q1: C71500 vs C70600 – which one has higher strength?
C71500 has higher strength. C71500 contains 30% nickel while C70600 contains 10% nickel. This higher nickel content gives C71500 superior mechanical properties, making it suitable for high-pressure steam lines and marine defense applications where C70600 would not be strong enough.
Q2: What is C71500 used for in marine defense?
C71500 is used for pumps, valves, and high-pressure steam lines in marine defense applications. The alloy offers high impact resistance and excellent seawater corrosion resistance, both critical for naval vessels operating in harsh ocean environments.
Q3: What is the conductivity of C71500 compared to C70600?
C71500 has lower conductivity than C70600. This is noted directly in the alloy description. If electrical or thermal conductivity is the primary requirement, C70600 (90/10) may be a better choice. For corrosion resistance and strength, C71500 is superior.
Q4: Is C71500 used in oil and gas applications?
Yes, C71500 is used in oil and gas applications where moderate-to-high seawater corrosion concern is present. Examples include pumps, valves, and high-pressure steam lines. The alloy's high strength and corrosion resistance make it suitable for offshore and coastal oil and gas facilities.
Q5: What is the machinability of C71500?
C71500 has moderate machinability. The benefits list includes "moderate machinability" as a feature. For machining into pumps, valves, and other components, use sharp carbide tooling, appropriate cutting speeds, and adequate coolant.
Q6: What specifications cover C71500?
ASTM B-151, ASTM B-122, ASTM B-11, and MIL-C-15726 cover C71500. For naval and military applications, MIL-C-15726 is the relevant specification. For general commercial use, ASTM standards apply.
Q7: Does C71500 have high impact resistance?
Yes, high impact resistance is listed as a key benefit of C71500. This property is particularly important for marine defense applications where components may be subject to shock loading, wave impact, or underwater explosions.
Q8: What is the composition of C71500?
C71500 is composed of 70% copper and 30% nickel. This is stated in the alloy description. Typical specifications also require iron 0.4-1.0% and manganese up to 1.0% for corrosion resistance.
Q9: Why choose C71500 for high-pressure steam lines?
C71500 offers high strength and excellent corrosion resistance for high-pressure steam lines. The alloy is specifically listed for this application in the description. High-pressure steam environments require materials that can maintain mechanical properties at elevated temperatures without corroding.
Q10: What industries use C71500?
Oil and gas and marine defense are the primary industries for C71500. Within these industries, the alloy is used in pumps, valves, and high-pressure steam lines. Any application with moderate-to-high seawater corrosion concern is a potential use case.
Quality Control for C71500 Products
Chemical verification: Every batch of C71500 is tested to ensure composition meets ASTM B-151 or MIL-C-15726 requirements: 70% copper nominal, 30% nickel nominal, with proper iron and manganese levels.
Mechanical testing: Tensile, yield, and impact tests confirm high strength and high impact resistance before material is released.
Hardness testing: Verifies consistent processing and proper thermal treatment.
Dimensional inspection: Pipes, bars, plates, and other forms are checked against customer specifications.
Traceability: All test reports linked to heat number. Full documentation available for marine defense and oil & gas projects.
Packaging for C71500 Copper Pipe
C71500 copper pipe is packaged for safe transit:
Bundling: Pipes are strapped into hexagonal bundles with steel bands every 1.5 meters. Plywood separators prevent surface damage between layers.
End protection: Plastic caps are placed on both pipe ends to keep debris out and protect thread ends.
Cut length packaging: Shorter pipe lengths are packed into wooden crates with foam lining.
Coiled pipe: Long continuous lengths are wound onto steel reels. Reel flanges show heat number and size.
Labels on every package: Alloy (C71500 70/30), heat number, OD × wall, length, quantity, PO number, and weights are clearly marked.
Sea freight protection: Desiccant bags and moisture barrier liners added for overseas shipments.
Production Equipment for C71500 Copper Pipe
Melting: Induction furnaces with composition control for 70% copper, 30% nickel, Fe 0.4-1.0%.
Casting: Continuous caster produces billet for tube and pipe production.
Extrusion: Press pierces billet into hollow tube shell.
Cold pilgering: Multiple stands reduce OD and wall thickness to final dimensions.
Drawing: Draw benches achieve final size, smooth internal finish, and precise straightness.
Annealing: Furnaces at 1200-1500°F (650-815°C) produce desired temper.
Testing: Eddy current and hydrostatic testing per ASTM and MIL specifications.
Our Full Product Range
| Product Form | Alloy Grades | Standards | Typical Applications |
|---|---|---|---|
| Seamless Copper Pipe | C71500, C70600, C12200, C68700 | ASTM B466, MIL-C-15726 | High-pressure steam lines, seawater piping, marine defense |
| Seamless Copper Tube | C71500, C70600, C12200, C44300 | ASTM B111 | Condensers, heat exchangers |
| Copper Rod & Bar | C71500, C70600, C36000, C46400, C63000 | ASTM B151, ASTM B122, MIL-C-15726 | Pump shafts, valve stems, fasteners |
| Copper Plate & Sheet | C71500, C70600, C46400 | ASTM B122 | Valve bodies, pump components, flanges |
| Copper Wire | C71500, C70600, C10100, C11000 | MIL-C-15726 | Welding filler, fasteners |
| CNC Machined Components | C71500, C70600, C36000, C63000, C17200 | Custom drawing | Pumps, valves, custom fittings |
