Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Hiduron vs C71500 Cupronickel
Hiduron 130 (UNS C72400), Hiduron 191 (UNS C72420) and C71500 70/30 cupronickel share the cupronickel matrix and the seawater corrosion-resistance heritage, but they are different alloy classes that solve different problems. C71500 is a solid-solution-strengthened 70Cu-30Ni alloy specified primarily into seawater piping, condenser tube and heat-exchanger service where corrosion resistance and biofouling resistance are the decisive properties. Hiduron 130 and 191 are precipitation-hardened Cu-Ni-Al alloys that carry the same corrosion envelope plus the gamma-prime Ni3Al strengthening response that delivers tensile strengths above 740 MPa and a yield envelope acceptable for structural bolting. The two families occupy adjacent positions on the cupronickel selection table but do not substitute for each other.
At a Glance: Hiduron vs C71500
| Property | Hiduron 130 (C72400) | Hiduron 191 (C72420) | C71500 (70/30 Cu-Ni) |
|---|---|---|---|
| Family | Cu-Ni-Al precip-hardened | Cu-Ni-Mn-Al precip-hardened | Cu-Ni solid-solution |
| Strengthening | Gamma-prime Ni3Al | Gamma-prime Ni3Al + Mn solid solution | Cold work + solid solution |
| Tensile (Rm) | 740 to 850 MPa | 820 to 1000 MPa | 340 to 520 MPa (annealed to H10) |
| 0.2 percent proof | >=480 MPa | >=580 MPa | 125 to 380 MPa |
| Primary form | Bolting, machined components | Bolting, machined components | Seamless tube, plate, piping |
| NACE MR0175 hardness | n/a primary | <=286 HBW, qualified | Solid-solution; low hardness |
| Primary use case | Subsea hydraulic connectors | Naval bolting, splash zone | Seawater piping, condensers |
Chemistry Comparison
| Element | Hiduron 130 | Hiduron 191 | C71500 (70/30) |
|---|---|---|---|
| Cu | balance (~80 to 82) | balance (~76 to 78) | balance (~67 to 69) |
| Ni | 14.0 to 15.5 | 14.0 to 15.5 | 29.0 to 33.0 |
| Al | 2.7 to 3.4 | 1.5 to 2.5 | n/a |
| Mn | up to 0.75 | 4.0 to 5.0 | 0.40 to 1.0 |
| Fe | 1.0 to 2.0 | 0.5 to 1.5 | 0.40 to 1.0 |
When to Specify Hiduron vs C71500
- Specify Hiduron 130 or 191 when the application is bolting, fasteners or machined components and the design needs a yield above 480 MPa with seawater corrosion resistance. C71500 solid-solution yield does not carry the structural load.
- Specify Hiduron 191 when the application carries a NACE MR0175 sour-service requirement and a structural strength requirement in the same component. C71500 is solid-solution and low-hardness so the NACE compliance is implicit, but the strength envelope is not in scope.
- Specify C71500 when the application is seawater piping, condenser tube, heat-exchanger tube sheet or other low-stress, corrosion-driven service. C71500 is the established alloy for this envelope and is supplied in seamless tube, plate and flat-rolled product.
- Do not interchange the two families. The chemistry is in the same Cu-Ni neighbourhood but the strengthening mechanism and the form availability are different. Substituting one for the other risks under-design (Hiduron in a piping role with no commercial seamless tube source) or over-design (C71500 in a bolting role with no structural strength envelope).
Form Availability
Hiduron 130 and Hiduron 191 are supplied in the bolting and machined-component form range (round bar, stud bolts, hex bolts, heavy hex bolts, anchor bolts, U-bolts, threaded rod, nuts, heavy hex nuts, washers, forgings, machined components) detailed in the shared Forms block below. C71500 is supplied in seamless tube, welded tube, plate, sheet, flat-rolled product, rod and wire from adjacent mill sources for seawater piping and heat-exchanger applications.
Frequently Asked Questions
Q. Is Hiduron a substitute for C71500?
No. C71500 (70/30 cupronickel) is a solid-solution-strengthened alloy specified into seawater piping, condenser tube and heat-exchanger service. Hiduron 130 and 191 are precipitation-hardened Cu-Ni-Al alloys specified into bolting, fasteners and machined components. The chemistry is in the same Cu-Ni neighbourhood but the families are not interchangeable.
Q. Why does Hiduron carry higher strength than C71500?
Hiduron carries gamma-prime Ni3Al precipitates from the aluminium addition (1.5 to 3.4 percent) that strengthen the matrix on the solution-anneal plus age cycle. C71500 has no aluminium and relies on solid-solution and cold work for strength. The result is Hiduron tensile of 740 to 1000 MPa against C71500 tensile of 340 to 520 MPa.
Q. Both are non-magnetic; which to specify?
Both Hiduron 130, Hiduron 191 and C71500 are non-magnetic by alloy class. The selection between them is driven by the form-factor and the load envelope, not the magnetic response. Hiduron for bolting and machined components; C71500 for seawater piping and heat-exchanger service.
Q. Are both NACE MR0175 compliant?
Hiduron 191 is qualified to NACE MR0175 at the 286 HBW (28 HRC) hardness ceiling. C71500 in the solid-solution-annealed condition carries low hardness (typically 60 to 80 HRB) which is implicitly below the NACE ceiling, but the alloy is not the primary NACE Cu-Ni listing because the application is piping, not bolting.
Q. Do you supply both alloys?
TorqBolt supplies Hiduron 130 and Hiduron 191 in the bolting and machined-component form range. C71500 piping, tube and plate are sourced from adjacent mills for project supply when the cross-reference is required on the same purchase order. EN 10204 type 3.1 or 3.2 certification on either alloy.
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