UNS C71500 (70/30 cupronickel) is a copper-nickel alloy containing approximately 70% copper and 30% nickel, with controlled iron and manganese additions to enhance corrosion resistance and mechanical properties. This alloy offers medium-high strength, good creep resistance at elevated temperatures, and exceptional performance in high-velocity seawater, marine, and chemical environments. It is the preferred material for seawater cooler pipes, ship propellers, power plant condensers, and offshore platform components where maximum corrosion resistance is required .
1. Product Specifications & Physical DataUNS C71500 is available in multiple mill forms for severe marine and industrial applications requiring verified corrosion resistance and mechanical properties. Available Forms: Pipe, tube, plate, sheet, bar, forgings, and fittings . Specifications: ASTM B111, ASTM B151, ASTM B171, ASME SB-111, UNS C71500, EN CW354H .
| Chemical Composition (Weight %) | UNS C71500 Specification |
|---|
| Copper (Cu) | 65.0 min. (Balance) | | Nickel (Ni) | 29.0 - 33.0 | | Iron (Fe) | 0.40 - 1.0 | | Manganese (Mn) | 1.0 max. | | Carbon (C) | 0.05 max. | | Lead (Pb) | 0.05 max. | | Zinc (Zn) | 1.0 max. | | Sulfur (S) | 0.02 max. |
| Physical Properties | Metric | Imperial |
|---|
| Density | 8.9 g/cm³ | 0.323 lb/in³ | | Melting Range | 1170 - 1240°C | 2140 - 2265°F | | Modulus of Elasticity | 150 GPa | 21.8 × 10⁶ psi | | Thermal Conductivity (RT) | 29 W/m·K | 201 BTU·in/hr·ft²·°F | | Coefficient of Expansion (20-300°C) | 16.2 µm/m·°C | 9.0 µin/in·°F |
| Mechanical Properties (Annealed) | Metric | Imperial |
|---|
| Tensile Strength (min.) | 380 MPa | 55 ksi | | Yield Strength (0.2% offset, min.) | 140 MPa | 20 ksi | | Elongation (min.) | 30% | 30% | | Hardness (Rockwell B) | 70 - 90 | 70 - 90 |
2. Fabrication & Material ComparisonAnnealing: 649-816°C (1200-1500°F) × 15-60 minutes, air cool; relieves cold work stresses . Hot Working: 927-1038°C (1700-1900°F); good hot workability . Cold Working: Good cold workability using standard methods; 20% machinability rating . Machining: Machinability rate of 20; requires sharp tools and adequate lubrication; surface finish achievable up to Ra 0.1 μm . Welding: Excellent weldability using soldering, brazing, oxyacetylene, GTAW/TIG, GMAW/MIG, SMAW, spot, seam, and butt welding methods . Deep Drawing: Supports deep drawing for complex component fabrication .
| Material Comparison | UNS C71500 (70/30) | UNS C70600 (90/10) | 316L Stainless | Aluminum Bronze |
|---|
| Copper Content | 65-70% | 88% min. | — | 80-90% | | Nickel Content | 29-33% | 9-11% | 10-14% | — | | Tensile Strength (min.) | 380 MPa | 310 MPa | 485 MPa | 550-650 MPa | | High-Velocity Seawater | Excellent | Good | Moderate | Good | | Impingement Resistance | Superior | Good | Moderate | Good | | Chloride SCC Resistance | Excellent | Excellent | Poor | Good | | Creep Resistance at High Temp | Good | Moderate | Good | Good | | Relative Cost | Higher | Moderate | Moderate | Lower | | Primary Use | High-velocity seawater, condensers, nuclear | General seawater piping | General marine | Propellers, pumps |
3. ApplicationsMarine Engineering: Seawater cooler pipes, ship propellers, propeller sleeves, offshore platform components, seawater intake systems Power Generation: Nuclear plant condensers, steam surface condensers, heat exchangers, feedwater heaters Chemical Processing: Distillation towers, reactors, heat exchanger sleeves, process vessels for non-oxidizing media Aerospace: Engine components, hydraulic system pipelines, fuel systems Desalination: Evaporator tubing, heat exchangers for high-temperature brine service Industrial: High-temperature process equipment requiring creep resistance
Contact ZYTC Alloy for certified UNS C71500 (70/30) cupronickel with complete traceability, certificates, and competitive pricing. Available in pipe, tube, plate, sheet, bar, forgings, and fittings for marine, power generation, and chemical processing applications. Email: daisy@zytcsteel.com WhatsApp/WeChat: +86 17335753350 |
