Haynes 188 UNS R30188

spore: profile
id: haynes-188
spore_version: 0.2
family: cobalt-alloys
name: Haynes 188
abbreviation: UNS R30188
role: high-temperature oxidation-resistant cobalt-nickel-chromium-tungsten wrought superalloy
category: metals
type: nickel-superalloys
summary: |
  Haynes 188 (UNS R30188) is a wrought cobalt-base superalloy with a nominal composition of 39 % cobalt, 22 % nickel, 22 % chromium and 14 % tungsten. Haynes International rates it for long-term continuous exposure up to 2000 °F (1095 °C) in air and combustion gases. Its room-temperature tensile strength is 991 MPa in hot-rolled and solution-annealed plate, but it falls to 188 MPa at 1800 °F (982 °C), and the 1008 h flowing-air test at 2100 °F (1150 °C) shows 8.6 mils (218 µm) of metal loss.
best_for: Hot combustor and hot-structure parts in oxidising gas up to about 1095 °C, where stress stays low above about 982 °C
weakest_at: Strength above about 1800 °F (982 °C), and oxidation at 2100 °F (1150 °C), where metal loss is 8.6 mils (218 µm) after 1008 h, against 0.5 mil (13 µm) at 2000 °F
identity:
  formula: Cobalt-base alloy, nominal Co 39 (balance), Ni 22, Cr 22, W 14, Fe max 3, Mn max 1.25, Si 0.35, C 0.10, La 0.03, B max 0.015, in wt %
  source: haynes-188-page
  where: Nominal Composition table (wt %); UNS R30188 in the Principal Features text
  designations:
    - system: UNS
      code: R30188
      source: haynes-188-page
      where: Principal Features text, HAYNES 188 alloy (UNS R30188)
    - system: Trade name
      code: HAYNES 188
      source: haynes-188-page
      where: Page title, HAYNES 188 alloy
tags:
  environments: []
  stresses:
    - extreme-heat
    - thermal-cycling
  applications:
    - propulsion-and-tanks
    - thermal-control
properties:
  - benchmark: density
    label: Density at 22 °C (72 °F), Haynes 188
    value: 8.98
    unit: g/cm3
    scope: material
    conditions:
      temperature: 22 °C (72 °F)
      unit_in_source: 0.324 lb/in3
    method: Value printed in a distributor technical data page
    status: ground
    source: hightempmetals-188
    where: Physical Properties table, Density row, 72 °F / 22 °C
  - benchmark: melting_point
    label: Melting temperature range, Haynes 188 (manufacturer)
    value: 1315
    value_high: 1410
    bound: range
    unit: °C
    scope: material
    conditions:
      basis: melting temperature as printed by the manufacturer
      unit_in_source: 2400 to 2570 °F
    method: Range printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Melting Temperature row
  - benchmark: melting_point
    label: Incipient fusion temperature range, Haynes 188 (distributor)
    value: 1302
    value_high: 1330
    bound: range
    unit: °C
    scope: material
    conditions:
      basis: incipient fusion, the onset of melting, not the full melting range; differs from the manufacturer melting range and both are kept
      unit_in_source: 2375 to 2425 °F
    method: Range printed in a distributor technical data page
    status: ground
    source: hightempmetals-188
    where: Physical Properties table, Incipient Fusion Temperature row, metric column
  - benchmark: electrical_resistivity
    label: Electrical resistivity at room temperature, Haynes 188
    value: 101
    unit: µohm-cm
    scope: material
    conditions:
      temperature: RT, 21 °C (70 °F)
      unit_in_source: 39.6 µohm-in
    method: Value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Electrical Resistivity row, RT, metric column
  - benchmark: thermal_conductivity
    label: Thermal conductivity at room temperature, Haynes 188
    value: 10.4
    unit: W/m-°C
    scope: material
    conditions:
      temperature: RT
      unit_in_source: 72 Btu-in/ft2-hr-°F
    method: Value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Thermal Conductivity row, RT, metric column
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 1000 °C, Haynes 188
    value: 27.6
    unit: W/m-°C
    scope: material
    conditions:
      temperature: 1000 °C (2000 °F)
      unit_in_source: 204 Btu-in/ft2-hr-°F at 2000 °F
    method: Value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Thermal Conductivity row, 2000 °F (1000 °C) column
  - benchmark: specific_heat
    label: Specific heat at room temperature, Haynes 188
    value: 0.096
    unit: Btu/lb-°F
    scope: material
    conditions:
      temperature: RT
      unit_in_source: customary units only; the metric value printed beside it is garbled and not used
    method: Value printed in a manufacturer product page, customary units as printed
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Specific Heat row, RT, British column
  - benchmark: cte
    label: Mean coefficient of thermal expansion, 25 to 100 °C, Haynes 188
    value: 12.1
    unit: µm/m-°C
    scope: material
    conditions:
      temperature: 25 to 100 °C (mean)
      unit_in_source: 6.7 µin/in-°F for 75 to 200 °F
    method: Mean value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Mean Coefficient of Thermal Expansion row, 25-100 °C
  - benchmark: cte
    label: Mean coefficient of thermal expansion, 25 to 900 °C, Haynes 188
    value: 16
    unit: µm/m-°C
    scope: material
    conditions:
      temperature: 25 to 900 °C (mean)
      unit_in_source: 9.1 µin/in-°F for 75 to 1800 °F
    method: Mean value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Mean Coefficient of Thermal Expansion row, 75-1800 °F
  - benchmark: elastic_modulus
    label: Dynamic modulus of elasticity at room temperature, Haynes 188
    value: 232
    unit: GPa
    scope: material
    conditions:
      temperature: RT
      unit_in_source: 33.7 x 10^6 psi
    method: Dynamic modulus printed in a manufacturer product page; a dynamic value, not a static tensile modulus
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Dynamic Modulus of Elasticity row, RT
  - benchmark: yield_strength
    label: Yield strength 0.2 % offset, hot-rolled and solution-annealed plate at room temperature
    value: 483
    unit: MPa
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: RT
      unit_in_source: 70.1 ksi
    method: Tensile test value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, RT row
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, hot-rolled and solution-annealed plate at room temperature
    value: 991
    unit: MPa
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: RT
      unit_in_source: 143.8 ksi
    method: Tensile test value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, RT row
  - benchmark: elongation
    label: Elongation, hot-rolled and solution-annealed plate at room temperature
    value: 50.6
    unit: '%'
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: RT
    method: Tensile test value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, RT row, elongation column
  - benchmark: yield_strength
    label: Yield strength 0.2 % offset, bright annealed sheet at room temperature
    value: 464
    unit: MPa
    scope: material
    conditions:
      form: bright annealed sheet, 0.029 to 0.050 in thick
      temperature: RT (70 °F / 21 °C)
      unit_in_source: 67.3 ksi
    method: Average tensile value printed in a distributor technical data page
    status: ground
    source: hightempmetals-188
    where: Average Tensile Data, Sheet table, row 70 °F (21 °C), yield column
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, bright annealed sheet at room temperature
    value: 946
    unit: MPa
    scope: material
    conditions:
      form: bright annealed sheet, 0.029 to 0.050 in thick
      temperature: RT (70 °F / 21 °C)
      unit_in_source: 137.2 ksi
    method: Average tensile value printed in a distributor technical data page
    status: ground
    source: hightempmetals-188
    where: Average Tensile Data, Sheet table, row 70 °F (21 °C), ultimate column
  - benchmark: elongation
    label: Elongation in 2 in, bright annealed sheet at room temperature
    value: 53
    unit: '%'
    scope: material
    conditions:
      form: bright annealed sheet, 0.029 to 0.050 in thick
      temperature: RT (70 °F / 21 °C)
    method: Average tensile value printed in a distributor technical data page
    status: ground
    source: hightempmetals-188
    where: Average Tensile Data, Sheet table, row 70 °F (21 °C), elongation column
  - benchmark: yield_strength
    label: Yield strength 0.2 % offset, hot-rolled and solution-annealed plate at 538 °C
    value: 315
    unit: MPa
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: 1000 °F (538 °C)
      unit_in_source: 45.7 ksi
    method: Elevated-temperature tensile value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, 1000 °F row
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, hot-rolled and solution-annealed plate at 538 °C
    value: 832
    unit: MPa
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: 1000 °F (538 °C)
      unit_in_source: 120.6 ksi
    method: Elevated-temperature tensile value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, 1000 °F row
  - benchmark: yield_strength
    label: Yield strength 0.2 % offset, hot-rolled and solution-annealed plate at 982 °C
    value: 132
    unit: MPa
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: 1800 °F (982 °C)
      unit_in_source: 19.2 ksi
    method: Elevated-temperature tensile value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, 1800 °F row
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, hot-rolled and solution-annealed plate at 982 °C
    value: 188
    unit: MPa
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: 1800 °F (982 °C)
      unit_in_source: 27.2 ksi
    method: Elevated-temperature tensile value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, 1800 °F row
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, hot-rolled and solution-annealed plate at 1093 °C
    value: 96
    unit: MPa
    scope: material
    conditions:
      form: hot-rolled and solution-annealed plate
      temperature: 2000 °F (1093 °C)
      unit_in_source: 13.9 ksi
    method: Elevated-temperature tensile value printed in a manufacturer product page
    status: ground
    note: The same table gives 188 MPa at 982 °C, so tensile strength falls by about half between 1800 °F and 2000 °F.
    source: haynes-188-page
    where: Tensile Properties table, Hot-Rolled and Solution-annealed Plate, 2000 °F row
  - benchmark: max_service_temp
    label: Long-term continuous exposure limit in air and combustion gases (oxidation)
    value: 1095
    unit: °C
    scope: material
    conditions:
      basis: oxidation limit for long-term continuous exposure, not a mechanical limit
      unit_in_source: 2000 °F
    method: Value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Oxidation Resistance section, first paragraph
  - benchmark: oxidation_metal_affected
    label: Average metal affected (metal loss plus internal penetration), flowing air at 1150 °C for 1008 h
    value: 272
    unit: µm
    scope: material
    conditions:
      environment: flowing air
      temperature: 2100 °F (1150 °C)
      time: 1008 h
      unit_in_source: 10.7 mils
    method: Comparative oxidation value printed in a manufacturer product page; the page footnote defines the figure as metal loss plus average internal penetration
    status: ground
    source: haynes-188-page
    where: Comparative Oxidation Resistance in Flowing Air, 1008 Hours table, 188 row, 2100 °F column, average metal affected
  - benchmark: oxidation_metal_loss
    label: Metal loss, flowing air at 1150 °C for 1008 h
    value: 218
    unit: µm
    scope: material
    conditions:
      environment: flowing air
      temperature: 2100 °F (1150 °C)
      time: 1008 h
      unit_in_source: 8.6 mils
    method: Comparative oxidation value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Comparative Oxidation Resistance in Flowing Air, 1008 Hours table, 188 row, 2100 °F column, metal loss
  - benchmark: oxidation_metal_loss
    label: Metal loss, flowing air at 1093 °C for 1008 h
    value: 13
    unit: µm
    scope: material
    conditions:
      environment: flowing air
      temperature: 2000 °F (1093 °C)
      time: 1008 h
      unit_in_source: 0.5 mils
    method: Comparative oxidation value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Comparative Oxidation Resistance in Flowing Air, 1008 Hours table, 188 row, 2000 °F column, metal loss
  - benchmark: creep_stress_1pct_1000h
    label: Stress for 1 % creep in 1000 h at 982 °C, hot-rolled and solution-annealed plate
    value: 17
    unit: MPa
    scope: material
    conditions:
      form: solution-annealed plate
      temperature: 1800 °F (982 °C)
      creep: 1 %
      time: 1000 h
      unit_in_source: 2.5 ksi
    method: Approximate creep stress printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Creep and Stress-Rupture table, 188 Plate, Solution-Annealed, 1800 °F row, 1 % creep, 1,000 h column
  - benchmark: creep_stress_1pct_1000h
    label: Stress for 1 % creep in 1000 h at 982 °C, solution-treated sheet
    value: 14
    unit: MPa
    scope: material
    conditions:
      form: solution-treated sheet
      temperature: 1800 °F (982 °C)
      creep: 1.0 %
      time: 1000 h
      unit_in_source: 2.1 ksi
    method: Average creep value printed in a distributor technical data page
    status: ground
    source: hightempmetals-188
    where: Average Creep Data, Sheet table, 1800 (982) row, 1.0 % creep, 1000 hrs column
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength at room temperature after 8000 h at 650 °C
    value: 1045
    unit: MPa
    scope: material
    conditions:
      condition: after 8000 h at 1200 °F (650 °C), then tested at room temperature
      unit_in_source: 151.6 ksi
    method: Value printed in a manufacturer product page, thermal stability table
    status: ground
    source: haynes-188-page
    where: Impact and Thermal Stability section, Thermal Exposure table, room temperature row, UTS column
  - benchmark: yield_strength
    label: Yield strength 0.2 % offset at room temperature after 8000 h at 650 °C
    value: 550
    unit: MPa
    scope: material
    conditions:
      condition: after 8000 h at 1200 °F (650 °C), then tested at room temperature
      unit_in_source: 79.7 ksi
    method: Value printed in a manufacturer product page, thermal stability table
    status: ground
    source: haynes-188-page
    where: Impact and Thermal Stability section, Thermal Exposure table, room temperature row, yield column
  - benchmark: poissons_ratio
    label: Poisson's ratio at room temperature, Haynes 188
    value: 0.3
    unit: '-'
    scope: material
    conditions:
      temperature: RT
    method: Value printed in a manufacturer product page
    status: ground
    source: haynes-188-page
    where: Physical Properties table, Poisson's Ratio row, RT
  - benchmark: thermal_emittance
    label: Thermal emittance of pristine surface, Haynes 188
    value: 0.11
    unit: '-'
    scope: material
    conditions:
      surface: pristine, as received
      note_on_range: surface treatments raised emittance to between 0.28 and 0.86 in the same study
    method: Optical property value stated in a NASA technical memorandum
    status: ground
    source: nasa-tm-106549
    where: Summary, first page, emittance of pristine Haynes 188
corrosion:
  - environment: Air and combustion gases, 1095 to 1150 °C
    headline: Haynes 188 shows very good oxidation resistance, rated for long-term continuous exposure up to 2000 °F (1095 °C).
    effect: After 1008 h in flowing air at 2100 °F (1150 °C), the average metal affected is 10.7 mils (272 µm) and the metal loss is 8.6 mils (218 µm). At 2000 °F (1093 °C) the same test gives 3.7 mils (94 µm) affected and 0.5 mil (13 µm) metal loss, per Haynes International.
    rating: moderate
    conditions:
      air_velocity: flowing air
      cycling: as printed in the table test method
    source: haynes-188-page
    where: Oxidation Resistance section and Comparative Oxidation Resistance in Flowing Air, 1008 Hours table, 188 row
  - environment: Long-term thermal exposure at 650 °C, then room-temperature tensile test
    headline: After 8000 h at 1200 °F (650 °C), room-temperature strength stays high and ductility is retained.
    effect: Haynes International reports 550 MPa yield strength and 1045 MPa tensile strength after the 8000 h exposure, with 29.1 % elongation. A distributor page says the alloy keeps good ductility after 16,000 h at 1200, 1400 and 1600 °F (650, 760 and 870 °C).
    rating: low
    conditions:
      time: 8000 h at 1200 °F (650 °C)
    source: haynes-188-page
    where: Impact and Thermal Stability section, Thermal Exposure table; hightempmetals-188 Description
  - environment: Oxidising gas at high temperature above 1093 °C
    headline: The loss rises sharply between 2000 °F and 2100 °F in the same flowing-air test.
    effect: The metal loss increases from 0.5 mil (13 µm) at 2000 °F to 8.6 mils (218 µm) at 2100 °F after 1008 h, so the protection is not stable across that 100 °F step.
    rating: moderate
    conditions:
      time: 1008 h
    source: haynes-188-page
    where: Comparative Oxidation Resistance in Flowing Air, 1008 Hours table, 188 row, 2000 °F and 2100 °F columns
risks:
  hazards:
    - text: 'PubChem aggregated GHS for cobalt metal, from 2768 reports: H317 in more than 99.9 % of reports that give a code, H334 in more than 99.9 %, H341 in 65.8 %, H350 in 64.5 %, H360Fd in 61.6 %, H302 in 65.2 %, H330 in 23.4 %, H319 in 40.8 %, H413 in 54.9 %. Signal word Danger. These codes are for cobalt metal; the alloy is about 39 % cobalt, and nickel and chromium codes were not added.'
      ghs:
        - H317
        - H334
        - H341
        - H350
        - H360Fd
        - H302
        - H330
        - H319
        - H413
      source: pubchem-cobalt
      where: Safety and Hazards, GHS Classification, aggregated ECHA C&L notification block (2768 reports)
  failure_risks:
    - mode: Loss of strength at high temperature
      trigger: Use under stress above about 1800 °F (982 °C)
      consequence: Plate tensile strength falls from 991 MPa at room temperature to 188 MPa at 982 °C and 96 MPa at 1093 °C. One percent creep takes 17 MPa for 1000 h at 982 °C in plate.
      severity: moderate
      source: haynes-188-page
      where: Tensile Properties table (plate rows RT, 1800 °F and 2000 °F) and Creep and Stress-Rupture table
    - mode: Oxidation metal loss above 2000 °F
      trigger: Long exposure in flowing air at 2100 °F (1150 °C)
      consequence: Metal loss reaches 8.6 mils (218 µm) after 1008 h, against 0.5 mil (13 µm) at 2000 °F, so wall thinning is far faster at 2100 °F.
      severity: high
      source: haynes-188-page
      where: Comparative Oxidation Resistance in Flowing Air, 1008 Hours table, 188 row
    - mode: Low ductility near 760 °C
      trigger: Service or cycling near 760 °C
      consequence: NASA reports that Haynes 188 has a ductility minimum around 760 °C, and that low-cycle fatigue resistance follows ductility, so the cyclic strain capacity is also lowest near that temperature.
      severity: moderate
      source: nasa-n90-28642
      where: Results discussion, paragraph on tensile ductility minimum around 760 °C
    - mode: Low-cycle fatigue in actively cooled panels
      trigger: Panel walls up to 650 °C with high thermal gradients and high-pressure hydrogen, repeated runs
      consequence: NASA Glenn states that actively cooled combustor walls of this alloy could challenge low-cycle fatigue durability in repeated runs. The presentation is the objective of the test program; no result is entered here.
      severity: moderate
      source: nasa-gabb-2011
      where: Statement of Problem and Objective slides
  side_effects: []
  handling:
    - text: Solution heat treat at 2125 to 2175 °F (1163 to 1191 °C), then cool rapidly. Forging hold is 2150 °F (1175 °C).
      source: haynes-188-page
      where: Heat Treatment and Fabrication section
    - text: Solution treatment at 2150 °F ±25 °F (1177 °C ±14 °C) is the stated heat treatment; cold-worked parts are aged near 1000 °F (540 °C) for 4 to 16 hours.
      source: hightempmetals-188
      where: Heat-Treatment and Cold-Work and Aging section
uses:
  - application: propulsion-and-tanks
    device: Combustion cans in military and commercial gas turbine engines
    example: Haynes International says the alloy is widely used in established military and commercial gas turbine engines for combustion cans, and in aerospace fabricated components. These are aircraft and land-based turbine uses.
    source: haynes-188-page
    where: Description and Principal Features text
  - application: propulsion-and-tanks
    device: Liquid oxygen injection tubes (IDX posts) in the main combustion chamber of the Space Shuttle Main Engine
    example: NASA lists the IDX posts as a space-related application of the alloy. This is a flown rocket-engine use described in a NASA technical memorandum.
    source: nasa-n90-28642
    where: Introduction, first page, space-related applications paragraph
  - application: thermal-control
    device: Thermal energy storage containment canisters and working-fluid tubes in a solar dynamic receiver
    example: NASA says Haynes 188 will be used for TES containment canisters in the 2 kW solar dynamic ground test demonstrator, and that the canisters need high emittance so they radiate heat away from hot spots. This is a planned ground-demonstrator design, not a flight record.
    source: nasa-tm-106549
    where: Summary and Introduction, paragraphs on TES containment canisters
  - application: propulsion-and-tanks
    device: Actively cooled, hydrogen-cooled combustor wall panels in NASA's Durable Combustor Rig
    example: NASA Glenn assessed low-cycle fatigue of Haynes 188 for actively cooled combustor walls at 25 and 650 °C in hydrogen and helium. This is a test-rig use, not a flight record.
    source: nasa-gabb-2011
    where: Statement of Problem and Objective slides
supply:
  - subject: Cobalt (mine production, 2025)
    producers:
      - country: Congo (Kinshasa)
        share_percent: 73
        year: 2025
      - country: Indonesia
        share_percent: 14
        year: 2025
    critical_lists: []
    recycling: 'USGS: cobalt content of purchased scrap was 25 % of estimated cobalt consumption in 2025.'
    substitutes:
      - 'USGS: depending on the application, substitution for cobalt could cause a loss in product performance or increased cost.'
    source: usgs-mcs2026-cobalt
    where: 'Events, Trends, and Issues (73 % and 14 % of world total); World Mine Production table, 2025 column (230,000 and 44,000 of 310,000 t, so the table gives about 74 % for Congo). Domestic Production and Use: 51 % of US cobalt consumed in superalloys, mainly aircraft gas turbine engines.'
  - subject: Nickel (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
    critical_lists: []
    recycling: 'USGS: nickel recovered from scrap accounted for approximately 60 % of 2025 apparent consumption.'
    substitutes:
      - 'USGS: titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments.'
    source: usgs-mcs2026-nickel
    where: World Mine Production and Reserves table, 2025e column; shares calculated from the printed tonnages (Indonesia 2,600,000, Philippines 270,000 and Russia 200,000 of 3,900,000 t)
  - subject: Chromium (chromite ore mine production, 2025e)
    producers:
      - country: South Africa
        share_percent: 45.1
        year: 2025
      - country: Turkey
        share_percent: 17.6
        year: 2025
      - country: Kazakhstan
        share_percent: 13.7
        year: 2025
    critical_lists: []
    recycling: 'USGS: recycled chromium in reported stainless-steel scrap receipts accounted for 21 % of 2025 apparent consumption.'
    substitutes:
      - 'USGS: chromium has no substitute in superalloys, the major strategic end use.'
    source: usgs-mcs2026-chromium
    where: World Mine Production and Reserves table, 2025e column; shares calculated from the printed tonnages (South Africa 23,000, Turkey 9,000 and Kazakhstan 7,000 of 51,000 t). Substitutes paragraph.
  - subject: Tungsten (mine production, 2025)
    producers:
      - country: China
        share_percent: 78.8
        year: 2025
      - country: Vietnam
        share_percent: 3.5
        year: 2025
      - country: Russia
        share_percent: 2.4
        year: 2025
    critical_lists: []
    recycling: 'USGS: the quantity of secondary tungsten produced in 2025 was withheld to avoid disclosing proprietary data.'
    substitutes:
      - 'USGS: potential substitutes for cemented tungsten carbides include molybdenum, niobium and titanium carbides, ceramics, cermets and tool steels, which mostly reduce rather than replace tungsten use.'
    source: usgs-mcs2026-tungsten
    where: World Mine Production and Reserves table, 2025 column; shares calculated from the printed tonnages (China 67,000, Vietnam 3,000 and Russia 2,000 of 85,000 t); Events, Trends, and Issues on China's export controls
documents:
  - title: HAYNES 188 alloy product page, Haynes International (composition, physical, tensile, creep, oxidation and thermal stability tables)
    type: datasheet
    url: https://haynesintl.com/en/alloys/alloy-portfolio/high-temperature-alloys/haynes-188/
  - title: HAYNES 188 technical data, High Temp Metals (type analysis, physical properties, sheet tensile and creep tables)
    type: datasheet
    url: https://www.hightempmetals.com/techdata/hitempHaynes188data.php
  - title: 'PubChem: Cobalt (CID 104730), GHS classification (PUG View JSON)'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/104730/JSON?heading=GHS+Classification
  - title: 'Mineral Commodity Summaries 2026: Cobalt (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
    year: 2026
  - title: 'Mineral Commodity Summaries 2026: Nickel (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: 'Mineral Commodity Summaries 2026: Chromium (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
  - title: 'Mineral Commodity Summaries 2026: Tungsten (USGS)'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf
    year: 2026
  - title: High Temperature Fatigue Behavior of Haynes 188, NASA Lewis (Halford, Saltsman, Kalluri), NTRS N90-28642
    type: report
    url: https://ntrs.nasa.gov/api/citations/19900019326/downloads/19900019326.pdf
    year: 1990
  - title: Fatigue Life of Haynes 188 Superalloy in Hydrogen, NASA Glenn (Gabb et al.), presented 2011
    type: report
    url: https://ntrs.nasa.gov/api/citations/20150010332/downloads/20150010332.pdf
    year: 2011
  - title: Performance and Durability of High Emittance Heat Receiver Surfaces for Solar Dynamic Power Systems, NASA TM-106549 (de Groh)
    type: report
    url: https://ntrs.nasa.gov/api/citations/19940024331/downloads/19940024331.pdf
    year: 1994
gaps:
  - 'Specific heat: the manufacturer page prints 0.096 Btu/lb-°F at room temperature, but the metric value printed beside it is garbled, so only the customary value is entered.'
  - 'Melting range differs by source: the manufacturer gives 1315 to 1410 °C as the melting temperature, the distributor gives 1302 to 1330 °C as incipient fusion. Both are entered; no third source was found.'
  - 'AMS specification for HAYNES 188 itself: not found in any source we hold. The AMS numbers on the manufacturer page belong to filler products for other alloys.'
  - 'Product forms: sheet, plate and bar appear in the manufacturer''s tables; wire is implied by the filler section only. A full list of forms and sizes: not found in any source we hold.'
  - 'Creep and rupture: one stress and time point per form is entered. The full creep and rupture tables, and the low-cycle fatigue curves (images with no extractable text), are not entered.'
  - 'Charpy V-notch impact from -300 °F to 1300 °F, and hardness values: printed on the manufacturer page, but no canonical property name exists for them, so they are not entered.'
  - 'Corrosion beyond air and combustion-gas oxidation: the manufacturer page has sulfidation, corrosion and water-vapour tables that were not extracted into this profile. Aqueous corrosion data: not found in any source we hold.'
  - 'Safety data sheet for solid HAYNES 188 stock: not found in any source we hold. Hazard codes come from the PubChem cobalt metal record only; nickel and chromium codes were not added.'
  - 'Critical-mineral list status: the USGS 2026 summaries read here print no critical-list status for cobalt, nickel, chromium or tungsten, so critical_lists is empty.'
  - 'Flight record: the Shuttle main engine use is a flown application. The solar-receiver canister and the Durable Combustor Rig panels are planned or test-rig uses, and the Orbital Maneuvering Engine combustion chamber is described only as a potential use. None is counted as a flight record here.'
  - 'Custom benchmark names: oxidation_metal_affected, oxidation_metal_loss, creep_stress_1pct_1000h and thermal_emittance are not in the canonical list. Each is used as printed in the source.'
  - 'Tungsten recycling: USGS withheld the 2025 secondary tungsten figure, so no recycling share is given.'
sources:
  haynes-188-page:
    title: HAYNES 188 alloy, Haynes International product page
    id: UNS R30188
    url: https://haynesintl.com/en/alloys/alloy-portfolio/high-temperature-alloys/haynes-188/
    kind: datasheet
    license: Manufacturer product page (cited, not reproduced)
  hightempmetals-188:
    title: HAYNES 188 technical data, High Temp Metals
    id: Haynes 188 type analysis and technical data
    url: https://www.hightempmetals.com/techdata/hitempHaynes188data.php
    kind: datasheet
    license: Distributor technical data page (cited, not reproduced)
  pubchem-cobalt:
    title: 'PubChem: Cobalt (CID 104730), GHS classification'
    id: PubChem CID 104730, aggregated ECHA C&L notifications
    url: https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/104730/JSON?heading=GHS+Classification
    kind: database
    license: PubChem (NIH), public domain
  usgs-mcs2026-cobalt:
    title: 'Mineral Commodity Summaries 2026: Cobalt'
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-cobalt.pdf
    year: 2026
    kind: report
    license: Public domain (USGS)
  usgs-mcs2026-nickel:
    title: 'Mineral Commodity Summaries 2026: Nickel'
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: Public domain (USGS)
  usgs-mcs2026-chromium:
    title: 'Mineral Commodity Summaries 2026: Chromium'
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
    kind: report
    license: Public domain (USGS)
  usgs-mcs2026-tungsten:
    title: 'Mineral Commodity Summaries 2026: Tungsten'
    id: USGS MCS 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-tungsten.pdf
    year: 2026
    kind: report
    license: Public domain (USGS)
  nasa-n90-28642:
    title: High Temperature Fatigue Behavior of Haynes 188, NASA Technical Memorandum (Halford, Saltsman, Kalluri)
    id: NTRS N90-28642
    url: https://ntrs.nasa.gov/api/citations/19900019326/downloads/19900019326.pdf
    year: 1990
    kind: report
    license: NASA public domain
  nasa-gabb-2011:
    title: Fatigue Life of Haynes 188 Superalloy in Hydrogen, NASA Glenn (Gabb et al.)
    id: NTRS 20150010332
    url: https://ntrs.nasa.gov/api/citations/20150010332/downloads/20150010332.pdf
    year: 2011
    kind: report
    license: NASA public domain
  nasa-tm-106549:
    title: Performance and Durability of High Emittance Heat Receiver Surfaces for Solar Dynamic Power Systems, NASA TM-106549
    id: NASA TM-106549, NTRS 19940024331
    url: https://ntrs.nasa.gov/api/citations/19940024331/downloads/19940024331.pdf
    year: 1994
    kind: report
    license: NASA public domain
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 31
  unreachable: 0
  caveats: 6
  note: 'Values were read by an AI assistant on 2026-11-01 from the Haynes International HAYNES 188 product page, the High Temp Metals Haynes 188 data page, NASA NTRS papers N90-28642 and TM-106549, the 2011 NASA Glenn Gabb presentation, the PubChem cobalt GHS record and the USGS MCS 2026 cobalt, nickel, chromium and tungsten summaries. The oxidation and tensile values were read twice in this run. Caveats: the manufacturer and distributor pages are summarised text, the sheet and plate tensile data are different product forms, the melting ranges differ between sources, the hazard codes are for cobalt metal, and the NASA uses are older or planned.'
story:
  recipe:
    line: Haynes 188 is a wrought cobalt-base superalloy with a nominal composition of 39 % cobalt (balance), 22 % nickel, 22 % chromium and 14 % tungsten, with small manganese, silicon, carbon, lanthanum and boron additions (Haynes International). It is supplied hot-rolled and solution-annealed, with a solution heat treatment at 2125 to 2175 °F (1163 to 1191 °C) (Haynes International).
    parts:
      - name: Cobalt
        symbol: Co
        share_percent: 39
        share_note: nominal, balance (Haynes International)
        role: Matrix of the alloy
      - name: Nickel
        symbol: Ni
        share_percent: 22
        share_note: nominal (Haynes International)
        role: Austenitic matrix element
      - name: Chromium
        symbol: Cr
        share_percent: 22
        share_note: nominal (Haynes International)
        role: Oxide-scale former for oxidation resistance
      - name: Tungsten
        symbol: W
        share_percent: 14
        share_note: nominal (Haynes International)
        role: Solid-solution strengthener
      - name: Iron
        symbol: Fe
        share_percent: 3
        share_note: maximum (Haynes International)
        role: Impurity-level element
      - name: Manganese
        symbol: Mn
        share_percent: 1.25
        share_note: maximum (Haynes International)
        role: Deoxidiser and minor element
      - name: Silicon
        symbol: Si
        share_percent: 0.35
        share_note: nominal (Haynes International)
        role: Minor element
      - name: Carbon
        symbol: C
        share_percent: 0.1
        share_note: nominal (Haynes International)
        role: Carbide former
      - name: Lanthanum
        symbol: La
        share_percent: 0.03
        share_note: nominal (Haynes International)
        role: Trace element that improves oxide-scale adhesion
      - name: Boron
        symbol: B
        share_percent: 0.015
        share_note: maximum (Haynes International)
        role: Trace element
  risk_groups:
    - title: For people
      lead: The alloy is a solid metal. Its cobalt content carries the hazard codes in the PubChem cobalt metal record.
      level: 1
      verdict: Cobalt codes apply
      points:
        - label: Solid alloy
          line: The PubChem aggregated cobalt record lists skin sensitisation (H317 in more than 99.9 % of reports that give a code), respiratory sensitisation (H334 in more than 99.9 %), suspected genetic defects (H341 in 65.8 %), may cause cancer (H350 in 64.5 %) and may damage fertility (H360Fd in 61.6 %). Signal word Danger.
        - label: Fume and dust
          line: The sources read give no safety data for welding fume or grinding dust from this alloy. Treat them as cobalt fume until a safety data sheet is found.
    - title: If it fails
      lead: These failure routes come from the manufacturer's test data and NASA test notes.
      points:
        - label: Strength at high temperature
          line: Plate tensile strength falls from 991 MPa at room temperature to 188 MPa at 982 °C and 96 MPa at 1093 °C.
        - label: Oxidation at 2100 °F
          line: Metal loss is 8.6 mils (218 µm) after 1008 h at 2100 °F, against 0.5 mil (13 µm) at 2000 °F.
        - label: Ductility near 760 °C
          line: NASA reports a ductility minimum around 760 °C, where the cyclic strain capacity is also lowest.
    - title: Handling and storage
      points:
        - label: Heat treatment
          line: Solution heat treat at 2125 to 2175 °F (1163 to 1191 °C), then cool rapidly. Cold-worked parts are aged near 1000 °F (540 °C) for 4 to 16 hours.
  why: Haynes 188 is a cobalt-base superalloy used for gas-turbine combustion cans and hot parts that must resist oxidation. Haynes International gives its nominal composition as 39 % cobalt, 22 % nickel, 22 % chromium and 14 % tungsten. The USGS reports that an estimated 51 % of US cobalt consumption in 2025 went to superalloys, mainly for aircraft gas turbine engines.
  uses:
    - where: Gas-turbine combustion cans
      line: Haynes International says the alloy is widely used in military and commercial gas turbine engines for combustion cans.
    - where: Space Shuttle Main Engine
      line: NASA lists the liquid oxygen injection tubes (IDX posts) in the main combustion chamber of the Space Shuttle Main Engine as a space-related use.
    - where: Solar dynamic thermal storage
      line: NASA says the alloy will be used for thermal energy storage containment canisters in a 2 kW solar dynamic ground demonstrator. This is a planned design, not a flight record.
    - where: Hydrogen-cooled combustor panels
      line: NASA Glenn assessed low-cycle fatigue of the alloy for actively cooled combustor walls at 25 and 650 °C in hydrogen and helium, in the Durable Combustor Rig.
  can_do:
    - label: Resist oxidation
      value: up to 2000 °F (1095 °C)
      benchmark: max_service_temp
      line: Haynes International rates the alloy for long-term continuous exposure up to 2000 °F (1095 °C) in air and combustion gases.
    - label: Carry heat
      value: 10.4 W/m-°C
      benchmark: thermal_conductivity
      line: Thermal conductivity is 10.4 W/m-°C at room temperature and 27.6 W/m-°C at 1000 °C, per Haynes International.
    - label: Weight
      value: 8.98 g/cm3
      benchmark: density
      line: Density is 8.98 g/cm3 at 22 °C (72 °F), per High Temp Metals.
    - label: Melting
      value: 1315 to 1410 °C
      benchmark: melting_point
      line: The manufacturer gives a melting temperature range of 1315 to 1410 °C (2400 to 2570 °F).
    - label: Strength at room temperature
      value: 483 MPa yield
      benchmark: yield_strength
      line: Hot-rolled and solution-annealed plate has a room-temperature 0.2 % yield strength of 483 MPa and a tensile strength of 991 MPa.
  compare: Within the manufacturer's flowing-air test, Haynes 188 loses 0.5 mil (13 µm) at 2000 °F and 8.6 mils (218 µm) at 2100 °F after 1008 h, so its oxide protection drops sharply across that 100 °F step. Its plate tensile strength halves from 991 MPa at room temperature to 188 MPa at 982 °C, and 96 MPa at 1093 °C. This profile gives no numbers for other alloys, because none were read in the sources held for this run.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Yield strength
      benchmark: yield_strength
  handling:
    - Specify the temper and form, because the tensile values differ between plate and sheet.
    - Keep restrained welds and hot-worked parts within the solution heat treatment range, then cool rapidly.
    - Do not hold the alloy under high stress above about 1800 °F (982 °C), where its strength is low.
  good_for:
    - Oxidation resistance up to 2000 °F (1095 °C) for long-term continuous exposure, per Haynes International.
    - Hot combustor parts and actively cooled hot-structure panels, per Haynes International and NASA.
    - Thermal storage canisters that need a high-emittance surface, where a surface treatment can raise emittance from 0.11 to between 0.28 and 0.86, per NASA.
  watch_out:
    - 'Strength falls sharply above about 1800 °F (982 °C): plate tensile strength is 188 MPa at 982 °C and 96 MPa at 1093 °C.'
    - Oxidation loss rises from 0.5 mil (13 µm) at 2000 °F to 8.6 mils (218 µm) at 2100 °F after 1008 h.
    - NASA reports a ductility minimum around 760 °C, where cyclic strain capacity is lowest.
    - The cobalt content carries the PubChem hazard codes, including skin and respiratory sensitisation.
  verdict: Haynes 188 is a cobalt-base superalloy for hot oxidising gas up to 2000 °F (1095 °C) in combustion parts and hot structure. It keeps useful tensile strength to about 1800 °F (982 °C) and loses oxide protection quickly at 2100 °F. Its spaceflight record is limited to a Shuttle engine use, and its solar and combustor uses are planned or tested.