Cupronickel 70/30 CuNi 70/30

spore: profile
id: cupronickel-70-30
spore_version: 0.2
family: copper-alloys
name: Cupronickel 70/30
abbreviation: CuNi 70/30
role: seawater-resistant condenser and heat-exchanger tube alloy
category: metals
type: copper-alloys
summary: |
  Cupronickel 70/30 (UNS C71500, EN CuNi30Mn1Fe, DIN 2.0882) is a copper alloy with about 30 % nickel and small iron and manganese additions. Wieland gives a density of 8.94 g/cm3, a thermal conductivity of 29 W/(m·K) at 20 °C, and tensile strength of 358 to 414 MPa for soft-annealed rod up to 12 mm diameter. The alloy was developed for naval seawater condensers. In a sulphide-polluted seawater immersion test, its corrosion rate was 0.15 mm/a at first and settled near 0.09 mm/a after 168 h. No source read gives a maximum service temperature.
best_for: Seawater condenser, heat-exchanger and piping parts, where resistance to seawater matters more than strength or service temperature
weakest_at: 'Strength and rated temperature: soft rod gives 358 to 414 MPa, no maximum service temperature is printed, and sulphide-rich seawater still corrodes it at about 0.09 mm/a in the laboratory test'
identity:
  formula: Cu balance with 29.0 to 33.0 % Ni, 0.4 to 1.0 % Fe and up to 1.0 % Mn (C71500, CuNi30Mn1Fe)
  source: jtcopper-c71500
  where: Chemical Composition table, rows Ni 29.0-33.0, Fe 0.4-1.0, Mn up to 1.0. The copper row in that table reads 65.0-70.0, which does not fit with the other rows, so copper is taken as balance from the Wikipedia 70-30 row.
  designations:
    - system: UNS
      code: C71500
      source: wieland-c71500
      where: 'Designations list, UNS: C71500'
    - system: EN name
      code: CuNi30Mn1Fe
      source: wieland-c71500
      where: 'Designations list, EN: EN 12451 (CuNi30Mn1Fe, CW 354H)'
    - system: EN name
      code: CW354H
      source: wieland-c71500
      where: 'Designations list, EN: EN 12451 (CuNi30Mn1Fe, CW 354H)'
    - system: EN
      code: '2.0882'
      source: wieland-c71500
      where: 'Designations list, DIN: DIN 17664 (CuNi30Mn1Fe, 2.0882)'
    - system: JIS
      code: C7150
      source: wieland-c71500
      where: 'Designations list, JIS: JIS H 3320 (C7150)'
    - system: Trade name
      code: 70/30 copper nickel
      source: wieland-c71500
      where: 'Page title block: C71500 Copper Nickel, also called 70/30 Copper Nickel'
tags:
  environments: []
  applications:
    - thermal-control
    - structures
properties:
  - benchmark: density
    label: Density, C71500 as printed on the maker's page
    value: 8.94
    unit: g/cm3
    scope: material
    conditions:
      grade: C71500 (Wieland)
      temperature: not stated
    method: Value printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Physical Properties table, row Density, metric column
  - benchmark: melting_point
    label: Melting range, C71500
    value: 1170
    value_high: 1240
    bound: range
    unit: °C
    scope: material
    conditions:
      grade: C71500 (Wieland)
      pressure: not stated
    method: Range printed in a manufacturer product page (the imperial column prints a reversed range, 2260-2140 ºF, so the metric column is used)
    status: ground
    source: wieland-c71500
    where: Physical Properties table, row Melting Range, metric column
  - benchmark: specific_heat
    label: Specific heat at 20 °C, C71500
    value: 377
    unit: J/(kg·K)
    scope: material
    conditions:
      grade: C71500 (Wieland)
      temperature: 20 °C
    method: Value printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Physical Properties table, row Specific Heat, metric column (377 J/kg ºK @20 ºc)
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 20 °C, C71500
    value: 29
    unit: W/(m·K)
    scope: material
    conditions:
      grade: C71500 (Wieland)
      temperature: 20 °C (printed as 68 ºF in the imperial column)
    method: Value printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Physical Properties table, row Thermal Conductivity, metric column
  - benchmark: thermal_conductivity
    label: Thermal conductivity range, C71500
    value: 29
    value_high: 33
    bound: range
    unit: W/(m·K)
    scope: material
    conditions:
      grade: C71500 (JTCopper)
      temperature: not stated
    method: Range printed in a supplier product page
    status: ground
    source: jtcopper-c71500
    where: 'Physical Properties table, row Thermal Conductivity (remark: moderate heat dissipation)'
  - benchmark: electrical_resistivity
    label: Electrical resistivity, C71500
    value: 37.4
    unit: µΩ·cm
    scope: material
    conditions:
      grade: C71500 (Wieland)
      temperature: not stated
    method: Value printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Physical Properties table, row Electrical Resistivity, metric column (37.4 µΩcm)
  - benchmark: electrical_conductivity_iacs
    label: Electrical conductivity, C71500
    value: 5
    unit: '% IACS'
    scope: material
    conditions:
      grade: C71500 (Wieland)
      temperature: 68 ºF as printed (about 20 °C)
    method: Value printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Physical Properties table, row Electrical Conductivity, imperial column (5% IACS @68ºF)
  - benchmark: cte
    label: Coefficient of thermal expansion, 20 to 300 °C, C71500
    value: 13.2
    value_high: 16.2
    bound: range
    unit: ppm/K
    scope: material
    conditions:
      grade: C71500 (JTCopper)
      temperature: 20 to 300 °C
      unit_in_source: ×10⁻⁶/°C
    method: Range printed in a supplier product page; 10⁻⁶ per °C is the same as ppm/K, so the unit is converted and the printed unit is kept in conditions
    status: ground
    source: jtcopper-c71500
    where: Physical Properties table, row Thermal Expansion, remark (20-300°C)
  - benchmark: yield_strength
    label: 0.5 % yield strength, soft-annealed rod up to 12 mm
    value: 124
    value_high: 179
    bound: range
    unit: MPa
    scope: material
    conditions:
      product_form: rod and bar, diameter up to 12 mm
      temper: 060 soft anneal (ASTM B 151)
      offset: 0.5 %
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table (Rod and Bar, ASTM B 151, 060 soft anneal), row up to 0.5 in (up to 12 mm), column 0.5% Yield (N/mm2)
  - benchmark: yield_strength
    label: 0.5 % yield strength, soft-annealed rod 12 to 25.4 mm
    value: 124
    value_high: 165
    bound: range
    unit: MPa
    scope: material
    conditions:
      product_form: rod and bar, diameter 12 to 25.4 mm
      temper: 060 soft anneal (ASTM B 151)
      offset: 0.5 %
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table, row over 0.5 to 1 in (over 12 to 25.4 mm), column 0.5% Yield (N/mm2)
  - benchmark: yield_strength
    label: 0.5 % yield strength, soft-annealed rod over 25.4 mm
    value: 124
    value_high: 152
    bound: range
    unit: MPa
    scope: material
    conditions:
      product_form: rod and bar, diameter over 25.4 mm
      temper: 060 soft anneal (ASTM B 151)
      offset: 0.5 %
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table, row over 1 in (over 25.4 mm), column 0.5% Yield (N/mm2)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, soft-annealed rod up to 12 mm
    value: 358
    value_high: 414
    bound: range
    unit: MPa
    scope: material
    conditions:
      product_form: rod and bar, diameter up to 12 mm
      temper: 060 soft anneal (ASTM B 151)
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table (Rod and Bar, ASTM B 151, 060 soft anneal), row up to 0.5 in (up to 12 mm), column UTS (N/mm2)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, soft-annealed rod 12 to 25.4 mm
    value: 331
    value_high: 400
    bound: range
    unit: MPa
    scope: material
    conditions:
      product_form: rod and bar, diameter 12 to 25.4 mm
      temper: 060 soft anneal (ASTM B 151)
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table, row over 0.5 to 1 in (over 12 to 25.4 mm), column UTS (N/mm2)
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, soft-annealed rod over 25.4 mm
    value: 310
    value_high: 358
    bound: range
    unit: MPa
    scope: material
    conditions:
      product_form: rod and bar, diameter over 25.4 mm
      temper: 060 soft anneal (ASTM B 151)
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table, row over 1 in (over 25.4 mm), column UTS (N/mm2)
  - benchmark: elongation
    label: Elongation, soft-annealed rod up to 12 mm
    value: 30
    value_high: 45
    bound: range
    unit: '%'
    scope: material
    conditions:
      product_form: rod and bar, diameter up to 12 mm
      temper: 060 soft anneal (ASTM B 151)
      gauge_length: not stated on the page
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table, row up to 0.5 in (up to 12 mm), column Elong (%)
  - benchmark: elongation
    label: Elongation, soft-annealed rod 12 to 25.4 mm
    value: 30
    value_high: 42
    bound: range
    unit: '%'
    scope: material
    conditions:
      product_form: rod and bar, diameter 12 to 25.4 mm
      temper: 060 soft anneal (ASTM B 151)
      gauge_length: not stated on the page
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table, row over 0.5 to 1 in (over 12 to 25.4 mm), column Elong (%)
  - benchmark: elongation
    label: Elongation, soft-annealed rod over 25.4 mm
    value: 30
    value_high: 40
    bound: range
    unit: '%'
    scope: material
    conditions:
      product_form: rod and bar, diameter over 25.4 mm
      temper: 060 soft anneal (ASTM B 151)
      gauge_length: not stated on the page
    method: Range printed in a manufacturer product page
    status: ground
    source: wieland-c71500
    where: Mechanical Properties table, row over 1 in (over 25.4 mm), column Elong (%)
  - benchmark: corrosion_rate
    label: Immersion corrosion rate, early stage, sulphide seawater
    value: 0.15
    unit: mm/a
    scope: material
    conditions:
      solution: 3.5 % NaCl + 0.5 % Na2S (wt.%), pH 8.20
      temperature: 35 ±2 °C (methods section; the Figure 1 caption says room temperature)
      immersion_time: initial stage
    method: Value printed in the paper abstract (laboratory immersion test)
    status: ground
    note: Laboratory test in a sulphide-polluted solution, not natural seawater. The name corrosion_rate is not in the canonical property list.
    source: gao2022
    where: Abstract; Section 3.1 (Figure 1)
  - benchmark: corrosion_rate
    label: Immersion corrosion rate after 168 h, sulphide seawater
    value: 0.09
    unit: mm/a
    scope: material
    conditions:
      solution: 3.5 % NaCl + 0.5 % Na2S (wt.%), pH 8.20
      temperature: 35 ±2 °C (methods section)
      immersion_time: 168 h
    method: Value printed in the paper abstract (laboratory immersion test)
    status: ground
    note: The corrosion rate stabilised at about this value; the per-time values in Figure 1 were not extractable.
    source: gao2022
    where: Abstract
corrosion:
  - environment: Seawater containing sulphide (3.5 % NaCl and 0.5 % Na2S, pH 8.20)
    headline: In a sulphide-polluted immersion test the corrosion rate fell from 0.15 mm/a to about 0.09 mm/a over 168 h.
    effect: Gao and Liu measured the corrosion rate at 0.15 mm/a early in immersion, which then settled to about 0.09 mm/a after 168 h as a dark-brown film formed. The film was mainly Cu2S early on and Cu2O later. The test used a sulphide-rich solution, so the rate may not carry over to natural seawater.
    rating: moderate
    conditions:
      temperature: 35 ±2 °C (methods section)
      basis: laboratory immersion test with electrochemical tests; composition Ni 30.54, Mn 0.93, Fe 0.80 wt% (sample), balance Cu
    source: gao2022
    where: Section 2.1 (materials and solution), Section 3.1 and Figure 1, Section 3.6 (XRD), Conclusions
  - environment: Marine saltwater at ambient temperature
    headline: Wieland says the alloy has excellent corrosion resistance in marine saltwater and is insensitive to stress corrosion.
    effect: Wieland's page states excellent corrosion resistance, especially in marine saltwater environments, and insensitivity to stress corrosion. It also says iron additions refine the grain and improve erosion resistance in flowing seawater, and that the high copper content gives anti-biofouling properties. The page prints no corrosion rate or test data.
    rating: low
    conditions:
      basis: manufacturer statement, no test data printed
    source: wieland-c71500
    where: Description and Main features text
risks:
  hazards:
    - text: The nickel wire safety data sheet (NextSDS, CAS 7440-02-0, EC 231-111-4) lists H317 May cause an allergic skin reaction, H351 Suspected of causing cancer and H372 Causes damage to the lung, the kidneys and the liver through prolonged or repeated exposure, with signal word danger. That is the nickel metal classification, not a SDS for this alloy, and the alloy SDS was not opened. Nickel is about 30 % of the alloy.
      ghs:
        - H317
        - H351
        - H372
      source: nextsds-ni
      where: Hazard Classifications and Hazard Statements sections of the nickel wire SDS page
  failure_risks:
    - mode: Sulphide-rich seawater attack
      trigger: Seawater containing sulphide, as in the 3.5 % NaCl plus 0.5 % Na2S test
      consequence: Corrosion rate of 0.15 mm/a at the start of immersion, settling to about 0.09 mm/a after 168 h, with a film of Cu2S and later Cu2O. The test is a laboratory result, so the rate in natural seawater is not known from these sources.
      severity: moderate
      source: gao2022
      where: Abstract; Section 3.1 (Figure 1); Conclusions
    - mode: Use at elevated temperature
      trigger: Service above room temperature, where no maximum service temperature is printed
      consequence: Wieland says only that the alloy retains its strength well at moderately elevated temperatures, and the only temperature in its table is the hot working range of 925 to 1025 °C. No source read gives a service limit, so use above the rated range has no printed data.
      severity: low
      source: wieland-c71500
      where: Main features text; Physical Properties table, row Hot Working Range
    - mode: Large section size
      trigger: Rod or bar over 12 mm diameter in place of thin stock
      consequence: Tensile strength falls from 358 to 414 MPa for rod up to 12 mm to 310 to 358 MPa for rod over 25.4 mm, so the size sets the strength of the part.
      severity: low
      source: wieland-c71500
      where: Mechanical Properties table, Rod and Bar rows
  side_effects:
    - text: The alloy is about 30 % nickel, so its cost follows nickel supply and price. The USGS says the 2025 average LME nickel cash price fell by an estimated 11 % from 2024, and that the global primary nickel market has been in surplus since 2022.
      affects: Cost of the alloy
      source: usgs-ni-2026
      where: Events, Trends, and Issues section
  handling:
    - text: Specify the product form, size and temper when ordering. The Wieland mechanical data are for soft-annealed rod (ASTM B 151, 060 soft anneal), and the strength changes with size.
      source: wieland-c71500
      where: Mechanical Properties table
    - text: The nickel wire SDS lists skin sensitisation (H317) for the nickel component, so the supplier's SDS for the alloy should be read before handling.
      source: nextsds-ni
      where: Hazard Statements section
  mitigations: []
uses:
  - application: thermal-control
    device: Condenser and heat-exchanger tubes and tube plates, feed-water heaters and desalination plants
    example: Wieland lists tube and tube plates for heavy-duty water condensers, heat exchangers, desalination plants, and feed-water heaters and evaporators in power stations. The alloy was developed for naval seawater condensers in the 1920s, according to Wikipedia.
    source: wieland-c71500
    where: Applications, Chemical and Marine list; Details section
  - application: structures
    device: Cooling-water circuits, salt-water pumps and piping on ships and submarines
    example: Wieland lists cooling-water circuits and sanitary services on board ship, fire sprinkler systems for ships, and salt-water pumps and piping for submarines and naval surface ships.
    source: wieland-c71500
    where: Applications, Chemical and Marine list
  - application: structures
    device: Offshore platform cladding and underwater cages for fish farming
    example: Wieland lists cladding for offshore platforms and underwater cages for fish farming, and wave and tidal energy generation equipment.
    source: wieland-c71500
    where: Details section; Applications, Chemical and Marine list
supply:
  - subject: Copper (balance of the alloy), mine production 2025e
    producers:
      - country: Chile
        share_percent: 23
        year: 2025
      - country: Congo (Kinshasa)
        share_percent: 13.9
        year: 2025
      - country: Peru
        share_percent: 11.7
        year: 2025
      - country: China
        share_percent: 7.8
        year: 2025
      - country: Russia
        share_percent: 5.7
        year: 2025
    critical_lists:
      - list: U.S. Final 2025 List of Critical Minerals (copper added, per the USGS Mineral Commodity Summaries 2026)
        listed: true
    recycling: 'USGS: old scrap provided an estimated 160,000 tons of copper in 2025, and copper recovered from scrap contributed about 30% of the U.S. copper supply. Brass and wire-rod mills accounted for approximately 80% of the copper recovered from scrap.'
    substitutes:
      - 'USGS: aluminum substitutes for copper in automobile radiators, cooling and refrigeration tube, electrical equipment and power cable. Titanium and steel are used in heat exchangers.'
    source: usgs-cu-2026
    where: World Mine and Refinery Production and Reserves table, mine production 2025e column (world total 23,000 thousand t). Shares calculated from the printed values 5,300, 3,200, 2,700, 1,800 and 1,300 over 23,000. Critical list paragraph; Recycling and Substitutes sections.
  - subject: Nickel (about 30 % of the alloy), mine production 2025e
    producers:
      - country: Indonesia
        share_percent: 66.7
        year: 2025
      - country: Philippines
        share_percent: 6.9
        year: 2025
      - country: Russia
        share_percent: 5.1
        year: 2025
      - country: Canada
        share_percent: 3.6
        year: 2025
      - country: New Caledonia
        share_percent: 3.6
        year: 2025
    critical_lists: []
    recycling: 'USGS: nickel recovered from scrap accounted for approximately 60% of apparent consumption in 2025.'
    substitutes:
      - 'USGS: titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments. Low-nickel, duplex and ultrahigh-chromium stainless steels have been substituted for austenitic grades.'
    source: usgs-ni-2026
    where: World Mine Production and Reserves table, 2025e column (world total 3,900,000 t). Shares calculated from the printed values 2,600,000, 270,000, 200,000 and 140,000 (twice) over 3,900,000. Recycling and Substitutes paragraphs.
documents:
  - title: Wieland Diversified, C71500 Copper Nickel (70/30) product page
    type: datasheet
    url: https://www.wieland-diversified.com/copper-nickel/copper-nickel-c71500/
  - title: JTCopper, C71500 copper product page (chemical composition and physical properties)
    type: datasheet
    url: https://en.jtcopper.com/c71500-copper.html
  - title: Goodfellow, Copper/Nickel Cu70/Ni30 foil, material information
    type: datasheet
    url: https://www.goodfellow.com/usa/resources/copper-nickel-cu70-ni30-foil-material-information/
  - title: Gao X. and Liu M., Corrosion Behavior of High-Strength C71500 Copper-Nickel Alloy in Simulated Seawater with High Concentration of Sulfide (Materials, 2022, open access)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC9738436/
    year: 2022
  - title: USGS Mineral Commodity Summaries 2026, Copper
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
  - title: USGS Mineral Commodity Summaries 2026, Nickel
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: NextSDS, Nickel wire safety data sheet, CAS 7440-02-0, hazard classification
    type: sds
    url: https://nextsds.com/sds/en/281331501257788/nickel-wire
gaps:
  - Elastic modulus is not entered. The Wieland page prints 22 ksi and 152 N/mm2 under a table header marked 10³, so the scale is inconsistent and the unit cannot be confirmed.
  - 'Maximum service temperature: no source read gives one. Wieland gives only the hot working range (925 to 1025 °C), which is a fabrication range and not a service limit.'
  - 'Space and flight use: the NASA NTRS search found no cupronickel 70/30 record for spacecraft or heat exchangers in the sources read. No space use is recorded here.'
  - Nickel critical-list status is not confirmed. The USGS nickel chapter read in this run mentions critical minerals only in a policy paragraph, so no critical_lists entry is given for nickel.
  - 'Copper composition: the JTCopper table prints Cu 65.0 to 70.0, which does not fit with the other rows. Copper is taken as balance from the Wikipedia 70-30 row and no range is entered.'
  - Mean linear expansion printed on the Wieland page as 0.0162 with the unit ºc x10-3 is not entered, because the unit form is unusual. The JTCopper range 13.2 to 16.2 x10-6/°C is used instead.
  - Electrical conductivity is entered as an IACS value under the name electrical_conductivity_iacs, and corrosion rate as corrosion_rate. Neither name is in the canonical property list, so both need adding to it.
  - 'Hardness is not entered: no source read gave a hardness value for this grade.'
  - 'Yield strength: only soft-annealed rod (ASTM B 151, 060 soft anneal) has 0.5 % yield values in the sources read. No yield value for hard or half-hard temper was found.'
  - 'Corrosion data: the Gao and Liu Figure 1 per-time rates are not extractable from the text. The paper''s methods give 35 ±2 °C, but its Figure 1 caption says room temperature, so the temperature is recorded as the methods value.'
  - 'Alloy SDS: the supplier''s SDS for cupronickel 70/30 was not opened. The hazard entries use the nickel metal SDS only. PubChem returned a browser-check page, so no PubChem GHS summary was used.'
  - 'Designations: Wieland also prints UNS C71520, which is a different product number and is not called the same grade, so it is not entered. The ASTM specification numbers on the Wieland page are product standards, not grade codes, and are not entered as designations.'
  - Wikipedia is used for composition ranges and history only, not for property or failure values, as the brief requires.
  - MatWeb and MakeItFrom returned HTTP 403, and matmatch.com could not be resolved, so no values from them are used.
sources:
  wieland-c71500:
    title: Wieland Diversified, C71500 Copper Nickel (70/30) product page
    url: https://www.wieland-diversified.com/copper-nickel/copper-nickel-c71500/
    kind: datasheet
    license: Manufacturer product page, cited, not reproduced (page says values are a guide only)
  gao2022:
    title: Corrosion Behavior of High-Strength C71500 Copper-Nickel Alloy in Simulated Seawater with High Concentration of Sulfide
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC9738436/
    year: 2022
    kind: paper
    license: CC BY (Materials, MDPI, open access via PMC)
  jtcopper-c71500:
    title: JTCopper, C71500 copper product page
    url: https://en.jtcopper.com/c71500-copper.html
    kind: datasheet
    license: Supplier product page, cited, not reproduced
  goodfellow-cu70ni30:
    title: Goodfellow, Copper/Nickel Cu70/Ni30 foil, material information
    url: https://www.goodfellow.com/usa/resources/copper-nickel-cu70-ni30-foil-material-information/
    kind: datasheet
    license: Supplier web page, cited, not reproduced
  wikipedia-cupronickel:
    title: Wikipedia, Cupronickel
    url: https://en.wikipedia.org/wiki/Cupronickel
    kind: web
    license: CC BY-SA 4.0 (Wikipedia), cited, not reproduced
  usgs-cu-2026:
    title: Mineral Commodity Summaries 2026, Copper
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-ni-2026:
    title: Mineral Commodity Summaries 2026, Nickel
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  nextsds-ni:
    title: NextSDS, Nickel wire safety data sheet, CAS 7440-02-0, hazard classification
    url: https://nextsds.com/sds/en/281331501257788/nickel-wire
    kind: datasheet
    license: SDS summary page (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 19
  unreachable: 4
  caveats: 8
  note: 'Read by an AI assistant on 2026-10-26 from the Wieland, JTCopper, Goodfellow and Gao and Liu pages and the USGS 2026 copper and nickel PDFs. Unreachable: MatWeb, MakeItFrom, matmatch and PubChem. Caveats: the Wieland page prints a reversed imperial melting range and an inconsistent modulus scale, so modulus is left out; the 70/30 nickel shares are nominal; the corrosion rates come from a sulphide test, not natural seawater; the nickel hazard is the nickel metal classification; no service temperature or space record was found.'
story:
  risk_groups:
    - title: For people
      lead: The hazard of this alloy comes from its nickel. The opened sources classify nickel metal, not the alloy itself, and no alloy SDS was read.
      level: 1
      verdict: Nickel classification
      points:
        - label: Nickel in the alloy
          line: The nickel wire SDS lists H317 (allergic skin reaction), H351 (suspected of causing cancer) and H372 (damage to lungs, kidneys and liver through prolonged exposure). Nickel is about 30 % of the alloy.
        - label: Alloy SDS
          line: No SDS for cupronickel 70/30 was opened, so no H-codes for the alloy itself are recorded.
    - title: If it fails
      lead: The sources give corrosion rates and size limits, but no service temperature.
      points:
        - label: Sulphide seawater
          line: In a test with 3.5 % NaCl and 0.5 % Na2S at pH 8.20, corrosion ran at 0.15 mm/a at first and settled near 0.09 mm/a after 168 h. The film was mainly Cu2S early on and Cu2O later.
        - label: Large sections
          line: Soft-annealed rod up to 12 mm has 358 to 414 MPa tensile strength. Over 25.4 mm the range falls to 310 to 358 MPa (Wieland).
    - title: Handling and storage
      points:
        - label: Choose the form
          line: Name the product form, size and temper on the order. Wieland's mechanical data are for soft-annealed rod.
        - label: Check the SDS
          line: Read the supplier's SDS before handling, since the nickel component carries a skin-sensitisation classification (H317).
  why: Cupronickel 70/30 (UNS C71500) is a copper alloy with about 30 % nickel and small iron and manganese additions. It was developed for naval seawater condensers in the 1920s, according to Wikipedia. Wieland says it has excellent corrosion resistance in marine saltwater and is insensitive to stress corrosion. It is used where seawater meets the metal, in condenser and heat-exchanger tubing, seawater piping and marine hardware.
  uses:
    - where: Condensers and heat exchangers
      line: Wieland lists tube and tube plates for heavy-duty water condensers, heat exchangers, desalination plants, and feed-water heaters and evaporators in power stations.
    - where: Ships and submarines
      line: Wieland lists cooling-water circuits and sanitary services on board ship, fire sprinkler systems for ships, and salt-water pumps and piping for submarines and naval surface ships.
    - where: Offshore and aquaculture
      line: Wieland lists cladding for offshore platforms and underwater cages for fish farming.
  can_do:
    - label: Resist seawater
      value: 0.09 mm/a
      benchmark: corrosion_rate
      line: In a sulphide-polluted immersion test the corrosion rate settled near 0.09 mm/a after 168 h (Gao and Liu 2022). The test is a laboratory result, not natural seawater.
    - label: Carry heat
      value: 29 W/(m·K)
      benchmark: thermal_conductivity
      line: Wieland gives 29 W/(m·K) at 20 °C. JTCopper gives a range of 29 to 33 W/(m·K) with no temperature.
    - label: Strength in soft rod
      value: 358 to 414 MPa
      benchmark: ultimate_tensile_strength
      line: Soft-annealed rod up to 12 mm diameter has tensile strength 358 to 414 MPa and 0.5 % yield strength 124 to 179 MPa (Wieland).
    - label: Stretch
      value: 30 to 45 %
      benchmark: elongation
      line: Soft-annealed rod up to 12 mm elongates 30 to 45 % (Wieland).
    - label: Weight
      value: 8.94 g/cm3
      benchmark: density
      line: Density is 8.94 g/cm3 on the Wieland page, and JTCopper prints the same value.
  compare: 'Two suppliers give different thermal conductivities for the alloy: 29 W/(m·K) at 20 °C from Wieland, and 29 to 33 W/(m·K) from JTCopper with no temperature. Rod strength depends on size, from 358 to 414 MPa up to 12 mm diameter to 310 to 358 MPa above 25.4 mm. The table rows are examples from these sources and are not a ranking.'
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Tensile strength (soft rod)
      benchmark: ultimate_tensile_strength
  handling:
    - Name the product form, size and temper, because strength changes with diameter.
    - No maximum service temperature is printed in any source read, so do not assume one.
    - Read the supplier SDS before handling, since the nickel component carries H317, H351 and H372 in the nickel SDS.
  good_for:
    - Seawater condenser and heat-exchanger tubing, the maker's main marine application (Wieland).
    - Seawater piping and marine hardware, including ship and submarine systems (Wieland).
    - Resistance to marine saltwater, with stress-corrosion insensitivity stated by the maker (Wieland).
  watch_out:
    - 'Sulphide-rich seawater: the laboratory test corroded at 0.15 mm/a at first and about 0.09 mm/a after 168 h.'
    - No maximum service temperature is printed in any source read.
    - 'Nickel content: the nickel metal is classified H317, H351 and H372.'
    - 'Size: strength falls for bars over 25.4 mm, to 310 to 358 MPa.'
    - 'Supply: 66.7 % of 2025 world nickel mine output came from Indonesia (USGS, calculated from printed tonnages).'
  verdict: Cupronickel 70/30 is a copper-nickel alloy for seawater service, with 358 to 414 MPa tensile strength in soft rod and a density of 8.94 g/cm3. The maker's marine corrosion record is supported by a laboratory test, although that test used sulphide-rich solution. The sources give no maximum service temperature and no spacecraft record.
  recipe:
    line: Cupronickel 70/30 is a copper-nickel alloy with a face-centred cubic structure, nominally 70 % copper and 30 % nickel (Goodfellow). Iron and manganese are added in small amounts (JTCopper). A research sample measured 30.54 % Ni, 0.93 % Mn and 0.80 % Fe, with copper as the remainder (Gao and Liu 2022, Section 2.1). Wieland gives a hot working range of 925 to 1025 °C.
    parts:
      - name: Copper
        symbol: Cu
        share: balance of the alloy (Wikipedia 70-30 row)
        role: Base metal of the alloy. It forms the matrix in which the nickel is dissolved.
      - name: Nickel
        symbol: Ni
        share: 29.0 to 33.0 wt% (JTCopper); 30.54 wt% in the Gao and Liu sample
        role: Main alloying element. JTCopper says it enhances corrosion resistance and strength.
      - name: Iron
        symbol: Fe
        share: 0.4 to 1.0 wt% (JTCopper); 0.80 wt% in the Gao and Liu sample
        role: Refines grain and improves erosion resistance in flowing seawater (Wieland).
      - name: Manganese
        symbol: Mn
        share: up to 1.0 wt% (JTCopper); 0.93 wt% in the Gao and Liu sample
        role: Minor addition that improves machinability (JTCopper).