Hiduron® 191
Hiduron® 191 is a high-strength copper-nickel alloy with outstanding seawater and biofouling resistance for marine service.
Hiduron® 191 is a Copper-Nickel alloy developed by Langley Alloys for outstanding resistance to corrosion in seawater and brackish water environments. The alloy combines the inherent biofouling resistance of copper alloys with improved strength and corrosion resistance compared to standard 70/30 Cu-Ni alloys.
Its resistance to impingement, cavitation, erosion-corrosion and biological fouling makes it particularly suitable for seawater handling equipment, desalination plant, offshore structures and naval applications. It is a precipitation-hardened alloy, supplied in the hot worked condition.
We stock bar in the UK and USA. Plate, tube and fittings are available on enquiry; forgings and castings to order.
- Outstanding resistance to corrosion in seawater and brackish water
- Inherent biofouling resistance
- Good resistance to impingement, cavitation and erosion-corrosion
- Good strength and ductility
- Suitable for naval and defence seawater applications
| Element | Min | Max |
|---|---|---|
| Copper (Cu) | Bal | |
| Nickel (Ni) | 13.50 | 16.50 |
| Manganese (Mn) | 3.50 | 5.50 |
| Aluminium (Al) | 1.00 | 2.00 |
| Iron (Fe) | 0.70 | 1.20 |
| Chromium (Cr) | - | 0.50 |
| Carbon (C) | - | 0.05 |
| Silicon (Si) | - | 0.15 |
| Phosphorus (P) | - | 0.01 |
| Sulphur (S) | - | 0.15 |
| Property | Imperial | Metric |
|---|---|---|
| 0.2% Proof stress (min) | 62.4 ksi | 430 N/mm² |
| Tensile strength (min) | 105.1 ksi | 725 N/mm² |
| Elongation (5.65√S0) | 18% | |
| Hardness (Brinell) | 163 min | |
| Impact strength (room temp) | 40 J min |
| Property | Imperial | Metric |
|---|---|---|
| 0.2% Proof stress (min) | 58 ksi | 400 N/mm² |
| Tensile strength (min) | 103 ksi | 710 N/mm² |
| Elongation (5.65√S0) | 18% | |
| Hardness (Brinell) | 170-280 | |
| Impact strength (room temp) | 40 J min |
| Property | Value |
|---|---|
| Density (kg/m³) | 8500 |
| Magnetic permeability (20°C) | < 1.01 |
| Young's modulus (kN/mm²) | 145 |
| Modulus of rigidity (kN/mm²) | 52 |
| Electrical conductivity, 20°C (mΩ/mm²) | 2.85 / (17% IACS) |
| Mean coefficient of thermal expansion, 20-300°C (m/m/°C) | 16.0 x 10⁻⁶ |
| Specific heat, 20°C (J/kg.K) | 435 |
| Thermal conductivity, 20°C (W/m.K) | 16.3 |
Equivalents & cross-references
Standard designations
- DEF STAN
- 02-835UK Defence Standard - confirmed in Langley datasheet
- NES
- 835Naval Engineering Standard
- NACE
- MR0175 / ISO 15156Sour service
Hiduron® 191 is also designated DEF STAN 02-835, NES 835 and NACE MR0175 / ISO 15156.
Common questions
What is Hiduron 191?
Hiduron 191 is a medium-strength precipitation-hardened cupronickel supplied in the hot worked condition, covered by DEF STAN 02-835 and NES 835, and listed in NACE MR0175/ISO 15156. It contains about 14.5% nickel and 4.5% manganese, strengthened by aluminium and iron. Langley Alloys stocks it as bar; plate, tube and fittings are available on enquiry, and forgings and castings are to order.
What is Hiduron 191 used for?
Hiduron 191 is used for naval and defence applications such as fasteners for ships and submarines, submarine control elements, pump shafts, mechanical seals, winch components, gears, weapons handling equipment, sonar components and propeller shafts; oil and gas subsea bolting, pump and valve shafts, valve spindles and hydraulic pistons; process industry impellers, pump shafts and valve components; and subsea mining hydraulic connectors and pressure couplings. It is approved as a named alloy by the world's most prestigious navies.
How does Hiduron 191 compare with nickel aluminium bronze and duplex stainless steel?
Hiduron 191 was developed to combine the corrosion resistance and anti-fouling of conventional cupronickels with superior tensile and toughness properties compared to aluminium bronzes. Its strength is comparable to 22% chrome duplex stainless steels, while its combination of tensile strength and toughness is far superior to that of nickel aluminium bronzes, and its marine corrosion resistance is superior to both. Its properties are largely independent of section size.
Is Hiduron 191 suitable for marine and sour service?
Yes. Hiduron 191 has excellent corrosion resistance in marine environments with good resistance to localised corrosion and impingement attack in seawater (corrosion rate 0.02 mm/year), and good bio-fouling resistance. It meets the requirements of NACE MR0175/ISO 15156, has excellent anti-galling properties against stainless steels, shows no loss of impact strength down to -196°C, and is virtually non-magnetic with galvanic compatibility with other copper alloys and stainless steels.
What is DEF STAN 02-835?
DEF STAN 02-835 (formerly NES 835) is a UK Defence Standard covering Hiduron® 191, a medium-strength precipitation-hardened cupronickel alloy supplied by Langley Alloys. It is used in marine propulsion, naval hardware, and subsea connectors.
What is the density of Hiduron 191?
Hiduron 191 has a density of approximately 8.50 g/cm³ (8500 kg/m³).
Is Hiduron 191 magnetic?
No. Hiduron 191 is non-magnetic, with a magnetic permeability below 1.01.
Datasheets
Hiduron® 191 is supplied in the hot worked condition; each bar is ultrasonically tested and visually inspected.
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