A-286 iron-based superalloy (UNS S66286, Grade 660) UNS S66286

spore: profile
id: a286
spore_version: 0.2
family: iron-superalloys
name: A-286 iron-based superalloy (UNS S66286, Grade 660)
abbreviation: UNS S66286
role: age-hardenable iron-nickel-chromium superalloy for fasteners, springs and jet engine hardware
category: metals
type: nickel-superalloys
summary: |
  A-286 (UNS S66286, also Grade 660 and W. Nr. 1.4980) is an age-hardenable iron-nickel-chromium superalloy. ATI gives its density as 7.92 g/cm3 solution treated and 7.94 g/cm3 solution treated and aged, with a melting range of 1370 to 1430 °C. Rolled Alloys gives a minimum yield strength of 85 ksi and a minimum tensile strength of 130 ksi for ASTM A453 Grade 660 Class B, and a 1000 h stress-rupture strength of 46 ksi at 649 °C.
best_for: Non-magnetic, high-strength fasteners, springs and jet engine parts that run from cryogenic temperature to about 700 °C (ATI and Rolled Alloys)
weakest_at: 'Hot strength above about 650 °C: the 1000 h stress-rupture strength is 46 ksi at 649 °C (Rolled Alloys), and ATI says creep and stress rupture are the limiting design criteria at elevated temperature'
identity:
  formula: 'Iron-nickel-chromium austenitic superalloy, age hardenable. Limiting composition (wt%, Upmet table): Fe balance, Ni 24.0 to 27.0, Cr 13.5 to 16.0, Mo 1.00 to 1.50, Ti 1.90 to 2.35, V 0.10 to 0.50, Al 0.35 max, B 0.003 to 0.010, C 0.08 max, Mn 2.00 max, Si 1.00 max, P 0.025 max, S 0.025 max. ATI typical analysis (wt%): C 0.04, Mn 0.20, P 0.015, S 0.002, Si 0.20, Cr 14.5, Ni 25.0, Mo 1.25, Ti 2.10, V 0.30, Al 0.15, B 0.006, Fe balance.'
  source: ati-a286
  where: Page 2, Composition (Typical) table; limiting ranges from the Upmet A286 Chemical Composition table; UNS S66286 from the ATI title block
  designations:
    - system: UNS
      code: S66286
      source: ati-a286
      where: Title block, page 1 (ATI A286 Iron-Based Superalloy (UNS S66286))
    - system: EN
      code: '1.4980'
      source: rolled-a286
      where: Specifications table, row UNS S66286 and W. Nr./EN 1.4980
    - system: ASTM
      code: A453
      note: bolting, Grade 660 Class A and Class B
      source: rolled-a286
      where: Specifications table, row ASTM A 453 Grade 660 Class B
    - system: ASTM
      code: A638
      note: forgings, forging stock and bar
      source: ati-a286
      where: Specifications list, ASTM A638
    - system: ASME
      code: SA-638
      note: forgings, forging stock and bar
      source: ati-a286
      where: Specifications list, ASME SA-638
    - system: AMS
      code: '5525'
      note: sheet, strip and plate
      source: ati-a286
      where: Specifications list, AMS 5525
    - system: AMS
      code: '5731'
      note: bar, forgings, tubing and rings
      source: ati-a286
      where: Specifications list, AMS 5731
    - system: AMS
      code: '5732'
      note: bar, forgings, tubing and rings
      source: ati-a286
      where: Specifications list, AMS 5732
    - system: AMS
      code: '5858'
      note: sheet, strip and plate, restricted analysis designed for welding
      source: ati-a286
      where: Specifications list, AMS 5858, and the Welding and Brazing section
    - system: Trade name
      code: ATI A286
      source: ati-a286
      where: Title block, page 1
tags:
  environments: []
  stresses:
    - extreme-cold
  applications:
    - structures
    - propulsion-and-tanks
    - mechanisms
properties:
  - benchmark: density
    label: Density, solution treated
    value: 7.92
    unit: g/cm3
    scope: material
    conditions:
      treatment: solution treated
      unit_in_source: 0.286 lb/in3
      basis: typical value
    method: Typical value printed in the ATI datasheet, Physical Properties table
    status: ground
    source: ati-a286
    where: Page 3, Physical Properties, row Density, Solution Treated
  - benchmark: density
    label: Density, solution treated and aged
    value: 7.94
    unit: g/cm3
    scope: material
    conditions:
      treatment: solution treated and aged
      unit_in_source: 0.287 lb/in3
      basis: typical value
    method: Typical value printed in the ATI datasheet, Physical Properties table
    status: ground
    source: ati-a286
    where: Page 3, Physical Properties, row Density, Solution Treated and Aged
  - benchmark: melting_point
    label: Melting range
    value: 1370
    value_high: 1430
    bound: range
    unit: °C
    scope: material
    conditions:
      unit_in_source: 2500-2600 °F
    method: Range printed in the ATI datasheet, Physical Properties table
    status: ground
    source: ati-a286
    where: Page 3, Physical Properties, row Melting Range
  - benchmark: specific_heat
    label: Specific heat
    value: 420
    unit: J/kg-°K
    scope: material
    conditions:
      temperature: not stated in the datasheet
      unit_in_source: 0.10 Btu/lb-°F
    method: Typical value printed in the ATI datasheet, Physical Properties table
    status: ground
    source: ati-a286
    where: Page 3, Physical Properties, row Specific Heat
  - benchmark: magnetic_permeability
    label: Magnetic permeability, solution treated
    value: 1.01
    unit: '-'
    scope: material
    conditions:
      treatment: solution treated
    method: Typical value printed in the ATI datasheet, Physical Properties table
    status: ground
    source: ati-a286
    where: Page 3, Physical Properties, row Magnetic Permeability, Solution Treated
  - benchmark: magnetic_permeability
    label: Magnetic permeability, solution treated and aged
    value: 1.007
    unit: '-'
    scope: material
    conditions:
      treatment: solution treated and aged
    method: Typical value printed in the ATI datasheet, Physical Properties table
    status: ground
    source: ati-a286
    where: Page 3, Physical Properties, row Magnetic Permeability, Solution Treated and Aged
  - benchmark: electrical_resistivity
    label: Electrical resistivity at 25 °C
    value: 91
    unit: microhm-cm
    scope: material
    conditions:
      temperature: 25 °C (77 °F)
      treatment: not stated in the datasheet
    method: Typical value printed in the ATI datasheet, Electrical Resistivity table
    status: ground
    source: ati-a286
    where: Page 4, Electrical Resistivity table, row 77 °F / 25 °C
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 150 °C
    value: 15.1
    unit: W/m-K
    scope: material
    conditions:
      temperature: 150 °C (302 °F)
      treatment: not stated in the datasheet
      unit_in_source: 8.7 Btu-ft/ft2-h-°F
    method: Typical value printed in the ATI datasheet, Thermal Conductivity table
    status: ground
    source: ati-a286
    where: Page 4, Thermal Conductivity table, row 302 °F / 150 °C
  - benchmark: thermal_conductivity
    label: Thermal conductivity at 600 °C
    value: 23.9
    unit: W/m-K
    scope: material
    conditions:
      temperature: 600 °C (1112 °F)
      treatment: not stated in the datasheet
      unit_in_source: 13.8 Btu-ft/ft2-h-°F
    method: Typical value printed in the ATI datasheet, Thermal Conductivity table
    status: ground
    source: ati-a286
    where: Page 4, Thermal Conductivity table, row 1112 °F / 600 °C
  - benchmark: cte
    label: Linear coefficient of thermal expansion, 21 to 316 °C
    value: 17
    unit: 10^-6/°C
    scope: material
    conditions:
      temperature_range: 21 to 316 °C (70 to 600 °F)
      treatment: solution treated and aged (the datasheet heading for the CTE test)
      unit_in_source: 9.47 10^-6/°F
    method: Linear CTE test printed in the ATI datasheet
    status: ground
    source: ati-a286
    where: Page 4, Linear Coefficient of Thermal Expansion table, row 21-316 °C
  - benchmark: cte
    label: Linear coefficient of thermal expansion, 21 to 760 °C
    value: 18.6
    unit: 10^-6/°C
    scope: material
    conditions:
      temperature_range: 21 to 760 °C (70 to 1400 °F)
      treatment: solution treated and aged (the datasheet heading for the CTE test)
      unit_in_source: 10.32 10^-6/°F
    method: Linear CTE test printed in the ATI datasheet
    status: ground
    source: ati-a286
    where: Page 4, Linear Coefficient of Thermal Expansion table, row 21-760 °C
  - benchmark: elastic_modulus
    label: Modulus of elasticity (dynamic) at 24 °C
    value: 201
    unit: GPa
    scope: material
    conditions:
      temperature: 24 °C (75 °F)
      method_in_source: dynamic
      unit_in_source: 29.1 x 10^6 psi
    method: Dynamic modulus printed in the ATI datasheet, Elastic Modulus table
    status: ground
    source: ati-a286
    where: Page 4, Elastic Modulus table, row 75 °F / 24 °C
  - benchmark: elastic_modulus
    label: Modulus of elasticity (dynamic) at 871 °C
    value: 130
    unit: GPa
    scope: material
    conditions:
      temperature: 871 °C (1600 °F)
      method_in_source: dynamic
      unit_in_source: 18.9 x 10^6 psi
    method: Dynamic modulus printed in the ATI datasheet, Elastic Modulus table
    status: ground
    source: ati-a286
    where: Page 4, Elastic Modulus table, row 1600 °F / 871 °C
  - benchmark: yield_strength
    label: Yield strength, room temperature, solution treated at 1800 °F
    value: 275
    unit: MPa
    scope: material
    conditions:
      treatment: solution treated at 1800 °F (982 °C)
      temperature: room temperature
      unit_in_source: 40,000 psi
    method: Typical room temperature tensile value printed in the ATI datasheet; the chart on the same page is an image and was not read
    status: ground
    note: Smith Metal gives 720 N/mm2 for solution annealed material (see its row below). The two sources are not reconciled here.
    source: ati-a286
    where: Page 5, Mechanical Properties, typical room temperature tensile properties
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, room temperature, solution treated at 1800 °F
    value: 620
    unit: MPa
    scope: material
    conditions:
      treatment: solution treated at 1800 °F (982 °C)
      temperature: room temperature
      unit_in_source: 90,000 psi
    method: Typical room temperature tensile value printed in the ATI datasheet
    status: ground
    note: Smith Metal gives 1000 N/mm2 for solution annealed material (see its row below).
    source: ati-a286
    where: Page 5, Mechanical Properties, typical room temperature tensile properties
  - benchmark: elongation
    label: Elongation, room temperature, solution treated at 1800 °F
    value: 40
    unit: '%'
    scope: material
    conditions:
      treatment: solution treated at 1800 °F (982 °C)
      temperature: room temperature
    method: Typical room temperature tensile value printed in the ATI datasheet
    status: ground
    source: ati-a286
    where: Page 5, Mechanical Properties, typical room temperature tensile properties
  - benchmark: yield_strength
    label: Yield strength, minimum, ASTM A453 Grade 660 Class B
    value: 85
    unit: ksi
    bound: lower
    scope: material
    conditions:
      standard: ASTM A453 Grade 660 Class B
      heat_treatment: anneal 1800 °F, age 1300 to 1400 °F for 16 hours
      product: bar and sheet to AMS 5732 (as printed in the table)
    method: Specification minimum printed in the Rolled Alloys data sheet
    status: ground
    source: rolled-a286
    where: Specifications table, row Grade 660 Class B, Yield Strength Min
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, minimum, ASTM A453 Grade 660 Class B
    value: 130
    unit: ksi
    bound: lower
    scope: material
    conditions:
      standard: ASTM A453 Grade 660 Class B
      heat_treatment: anneal 1800 °F, age 1300 to 1400 °F for 16 hours
    method: Specification minimum printed in the Rolled Alloys data sheet
    status: ground
    source: rolled-a286
    where: Specifications table, row Grade 660 Class B, Tensile Strength Min
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, sheet to AMS 5732, aged, 70 °F
    value: 145
    unit: ksi
    scope: material
    conditions:
      product_form: sheet, AMS 5732
      heat_treatment: 1800 °F solution treat, 1325 °F age
      temperature: 70 °F (21 °C)
    method: Representative value printed in the Rolled Alloys data sheet
    status: ground
    source: rolled-a286
    where: Mechanical Properties table, row Ultimate Tensile Strength, second 70 column (aged)
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, sheet to AMS 5732, aged, 1400 °F
    value: 64
    unit: ksi
    scope: material
    conditions:
      product_form: sheet, AMS 5732
      heat_treatment: 1800 °F solution treat, 1325 °F age
      temperature: 1400 °F (760 °C)
    method: Representative value printed in the Rolled Alloys data sheet
    status: ground
    source: rolled-a286
    where: Mechanical Properties table, row Ultimate Tensile Strength, 1400 column
  - benchmark: stress_rupture_1000h
    label: Stress-rupture strength for 1000 h at 538 °C
    value: 88
    unit: ksi
    scope: material
    conditions:
      temperature: 1000 °F (538 °C)
      duration: 1,000 hours
      heat_treatment: AMS 5732, 1800 °F / 1325 °F
    method: Typical stress-rupture value printed in the Rolled Alloys data sheet
    status: ground
    source: rolled-a286
    where: Typical Stress-Rupture Strength table, row 1,000 Hours, 1000 column
  - benchmark: stress_rupture_1000h
    label: Stress-rupture strength for 1000 h at 649 °C
    value: 46
    unit: ksi
    scope: material
    conditions:
      temperature: 1200 °F (649 °C)
      duration: 1,000 hours
      heat_treatment: AMS 5732, 1800 °F / 1325 °F
    method: Typical stress-rupture value printed in the Rolled Alloys data sheet
    status: ground
    source: rolled-a286
    where: Typical Stress-Rupture Strength table, row 1,000 Hours, 1200 column
  - benchmark: hardness_brinell
    label: Hardness, solution annealed
    value: 250
    value_high: 355
    bound: range
    unit: HB
    scope: material
    conditions:
      treatment: solution annealed
    method: Range printed in the Smiths Metal Centres data sheet
    status: ground
    source: smith-a286
    where: Mechanical Properties table, row Solution Annealed, Brinell HB column
  - benchmark: yield_strength
    label: 0.2% proof stress, solution annealed
    value: 720
    unit: N/mm2
    scope: material
    conditions:
      treatment: solution annealed
    method: Value printed in the Smiths Metal Centres data sheet under 0.2% Proof Stress
    status: ground
    note: Smith Metal gives 720 N/mm2 for solution annealed material, against 275 MPa for solution treated material in the ATI datasheet. Both are kept here side by side.
    source: smith-a286
    where: Mechanical Properties table, row Solution Annealed, proof stress column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, solution annealed
    value: 1000
    unit: N/mm2
    scope: material
    conditions:
      treatment: solution annealed
    method: Value printed in the Smiths Metal Centres data sheet
    status: ground
    note: ATI gives 620 MPa tensile for material solution treated at 1800 °F. The Smith value is for a different heat treatment label and is kept side by side.
    source: smith-a286
    where: Mechanical Properties table, row Solution Annealed, tensile column
  - benchmark: charpy_impact_energy
    label: Charpy V-notch impact energy at -196 °C, aged
    value: 77
    unit: J
    scope: material
    conditions:
      temperature: '-320 °F (-196 °C)'
      test: full size Charpy V-notch
      treatment: solution treated at 1800 °F and aged at 1325 °F for 16 hours
      unit_in_source: 57 ft-lbs
    method: Value printed in the ATI datasheet, Charpy V-Notch Impact Energy table
    status: ground
    source: ati-a286
    where: Page 6, Charpy V-Notch Impact Energy table, row -320 °F / -196 °C
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength at -423 °F, solution treated
    value: 168000
    unit: psi
    scope: material
    conditions:
      temperature: '-423 °F (about -253 °C)'
      treatment: solution-treated A-286 bar, as the report describes its material
    method: Value stated in the text of the NASA-funded Martin report, section Tension Properties (the Figure 13 chart was not read)
    status: ground
    source: nasa-cr65-70
    where: Printed page 84, Section 1 Tension Properties
  - benchmark: yield_strength
    label: Yield strength at 70 °F, solution treated
    value: 46000
    unit: psi
    scope: material
    conditions:
      temperature: 70 °F
      treatment: solution treated A-286
    method: Value stated in the text of the NASA-funded Martin report, section Tension Properties
    status: ground
    note: ATI gives 275 MPa (40,000 psi) for solution treated material at room temperature, so the two sources differ and are shown side by side.
    source: nasa-cr65-70
    where: Printed page 84, Section 1 Tension Properties
corrosion:
  - environment: Boiling 10% sulfuric acid
    headline: In boiling 10% sulfuric acid, A-286 corroded at 29.5 mils per year, against more than 500 mils per year for Type 304.
    effect: ATI's typical corrosion-rate table gives 29.5 mils per year (0.75 mm/a) for the Altemp A286 column, tested solution treated, and more than 500 mils per year (over 12 mm/a) for Type 304.
    rating: moderate
    conditions:
      test: boiling solution, typical corrosion rate in mils per year (mm/a in brackets)
      treatment: solution treated, per the datasheet footnote
    source: ati-a286
    where: Page 3, Typical Corrosion Rate table, row 10% Sulfuric Acid
  - environment: Boiling 1% hydrochloric acid
    headline: In boiling 1% hydrochloric acid, A-286 corroded at 84.1 mils per year, against 107 mils per year for Type 304.
    effect: ATI's typical corrosion-rate table gives 84.1 mils per year (2.14 mm/a) for A-286 and 107 mils per year (2.72 mm/a) for Type 304.
    rating: moderate
    conditions:
      test: boiling solution, typical corrosion rate in mils per year
      treatment: solution treated, per the datasheet footnote
    source: ati-a286
    where: Page 3, Typical Corrosion Rate table, row 1% Hydrochloric Acid
  - environment: Boiling 20% phosphoric acid
    headline: In boiling 20% phosphoric acid, A-286 corroded faster than Type 304, at 12.8 mils per year against 0.2 mils per year.
    effect: ATI's typical corrosion-rate table gives 12.8 mils per year (0.33 mm/a) for A-286 and 0.2 mils per year (under 0.01 mm/a) for Type 304, so the austenitic stainless steel does better in this acid.
    rating: moderate
    conditions:
      test: boiling solution, typical corrosion rate in mils per year
      treatment: solution treated, per the datasheet footnote
    source: ati-a286
    where: Page 3, Typical Corrosion Rate table, row 20% Phosphoric Acid
  - environment: Boiling 42% magnesium chloride, U-bend stress test
    headline: In the 42% magnesium chloride U-bend test, A-286 cracked after 168 hours, against 8 hours for Type 304 and 24 hours for Type 316.
    effect: ATI reports cracks in its U-bend test in boiling 42% magnesium chloride after 168 hours for the Altemp A286 column, after 8 hours for Type 304 and after 24 hours for Type 316. Cracking in chloride solutions is therefore a real limit for this alloy.
    rating: moderate
    conditions:
      test: U-bend stressed specimen in 42% magnesium chloride
      treatment: not stated for the Altemp column
    source: ati-a286
    where: Page 2, Typical Performance table, row U-Bend Test in 42% Magnesium Chloride
  - environment: 5% neutral salt spray and jet-engine atmosphere
    headline: A-286 showed no rusting after 100 hours of 5% neutral salt spray and is excellent in jet-engine atmospheres to 1300 °F (704 °C).
    effect: ATI reports no rusting after 100 hours of 5% neutral salt spray for the Altemp A286 column, and says its corrosion resistance to jet-engine atmospheres is excellent to at least 1300 °F (704 °C). Rolled Alloys says its aqueous corrosion resistance is comparable to 316 and 316L stainless steel.
    rating: low
    conditions:
      test: 5% neutral salt spray, 100 hours
      basis: datasheet statements; no exposure rate given for jet-engine atmospheres
    source: ati-a286
    where: Page 2, Typical Performance table, row 5% Neutral Salt Spray; Corrosion and Oxidation Resistance paragraph
  - environment: Air oxidation at high temperature
    headline: A-286 oxidation resistance is high for continuous service to 1500 °F (816 °C) and intermittent service to 1800 °F (982 °C).
    effect: ATI says oxidation resistance is high for continuous service up to 1500 °F (816 °C) and intermittent service up to 1800 °F (982 °C). Rolled Alloys gives the same continuous and intermittent limits, and Upmet says oxidation performance is comparable to Type 310 stainless steel through about 1500 °F (816 °C).
    rating: low
    conditions:
      basis: qualitative datasheet statements; no oxidation rate given
      temperature: continuous 816 °C, intermittent 982 °C
    source: ati-a286
    where: Page 2, Corrosion and Oxidation Resistance paragraph
risks:
  hazards:
    - text: 'NIST safety data sheet for SRM 1230, High-Temperature Alloy A286 (disk form), dated 12 July 2016: the disk is not classified as a physical or health hazard under OSHA 29 CFR 1910.1200, has no hazard pictograms, hazard statements or signal word, and needs no safety data sheet because it is an article under the exemption in 1910.1200(c). The sheet covers the disk form only; no producer safety data sheet for A-286 bar, sheet or forgings was found.'
      ghs: []
      source: nist-srm1230-sds
      where: Page 1, Product Identifier and Exemption 1910.1200 (c)
  failure_risks:
    - mode: Hot cracking in welds
      trigger: Welding aged material or heavy sections
      consequence: ATI says the alloy is susceptible to hot cracking, particularly in the aged condition, and heavy sections are more difficult to weld for the same reason.
      severity: moderate
      source: ati-a286
      where: Page 8, Welding and Brazing
    - mode: Loss of titanium in welds
      trigger: Welding by methods other than inert gas
      consequence: ATI says inert gas methods must be used to prevent loss of titanium, which is important for the strength that develops on aging.
      severity: moderate
      source: ati-a286
      where: Page 8, Welding and Brazing
    - mode: Creep and stress rupture at high temperature
      trigger: Sustained stress at elevated temperature
      consequence: ATI says creep and stress-rupture properties, rather than short-time tensile properties, are the limiting design criteria for elevated-temperature service.
      severity: moderate
      source: ati-a286
      where: Page 7, Creep and Stress Rupture Properties
    - mode: Rapid work hardening during forming
      trigger: Cold forming or deep drawing without intermediate anneals
      consequence: Smith Metal says the alloy works harden rapidly and may need intermediate annealing in deep drawing or intricate forming. ATI says intermediate anneals at 1800 °F (982 °C) soften material when the deformation is extensive.
      severity: low
      source: ati-a286
      where: Page 7, Formability; Smiths Metal Centres data sheet, Formability
  side_effects: []
  handling:
    - text: Age at 1325 °F (718 °C) for 16 hours and air cool after solution treatment, which develops the high strength of the alloy (ATI). Solution treat at 1650 °F (899 °C) for finer grain or 1800 °F (982 °C) for better creep strength.
      source: ati-a286
      where: Page 8, Heat Treatment
    - text: Form and weld in the solution-treated condition. ATI says the soft solution-treated material is gummy to machine, so it is machined after aging or overaging, or after cold work.
      source: ati-a286
      where: Page 8, Welding and Brazing; Page 9, Machining
    - text: After heat treatment, loosen the tight oxide film in a reducing, oxidising or fused salt bath, then pickle in warm sulfuric and then nitric-hydrofluoric acid baths (ATI).
      source: ati-a286
      where: Page 9, Descaling and Pickling
    - text: Use the same techniques and equipment as for 18-8 stainless steels when machining (ATI).
      source: ati-a286
      where: Page 9, Machining
  mitigations: []
uses:
  - application: structures
    device: Bolts, screws and high-temperature fasteners
    example: Rolled Alloys lists high temperature fasteners as an application, Smiths Metal Centres lists screws, and Upmet lists bolts and fasteners.
    source: rolled-a286
    where: Features and Applications table, Applications list (jet engine components, high temperature fasteners, springs); see also the Smiths and Upmet application lists
  - application: propulsion-and-tanks
    device: Jet engine blades, turbine wheels and afterburner parts
    example: Smiths Metal Centres lists aerospace, gas turbines, jet engine blades, afterburner parts, exhaust parts and turbine wheels as typical applications.
    source: smith-a286
    where: Typical Applications list on page 1
  - application: mechanisms
    device: Springs
    example: Combined Metals lists springs and non-magnetic cryogenic equipment as applications for Incoloy A-286 strip, and Rolled Alloys lists springs.
    source: combmet-a286
    where: Description, Applications include list
  - application: structures
    device: Non-magnetic cryogenic structural parts
    example: ATI says the alloy keeps high strength and ductility for low-temperature use down to -320 °F (-196 °C) and is non-magnetic. A 1965 NASA-funded Martin report found its solution-treated tensile strength rises from 90,000 psi at room temperature to 168,000 psi at -423 °F.
    source: nasa-cr65-70
    where: Printed page 84, Section 1 Tension Properties; ATI Introduction paragraph
supply:
  - subject: Nickel (about 24 to 27 wt% of A-286)
    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 apparent consumption in 2025, and most secondary nickel is in the form of nickel content of stainless-steel scrap.'
    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 (world total 3,900,000 t; shares calculated by Space Mushroom from Indonesia 2,600,000 t, Philippines 270,000 t and Russia 200,000 t). Recycling and Substitutes paragraphs.
  - subject: Chromium (13.5 to 16.0 wt% of A-286)
    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 apparent consumption in 2025.'
    substitutes:
      - 'USGS: chromium has no substitute in stainless steel or in superalloys, the major strategic end use.'
    source: usgs-mcs2026-chromium
    where: World Mine Production and Reserves table, 2025e column (world total 51,000 t, rounded; shares calculated by Space Mushroom from South Africa 23,000 t, Turkey 9,000 t and Kazakhstan 7,000 t). Recycling and Substitutes paragraphs.
documents:
  - title: ATI A286 Iron-Based Superalloy (UNS S66286) Technical Data Sheet, version 1 (4/17/2012)
    type: datasheet
    url: https://www.atimaterials.com/Products/Documents/datasheets/nickel-cobalt/nickel-based/ati_286_ludlum_version_tds_en_v1.pdf
    year: 2012
  - title: Rolled Alloys A-286 Alloy data sheet, Bulletin No. 1286
    type: datasheet
    url: https://www.rolledalloys.com/wp-content/uploads/A-286_Data-sheet-rolled-alloys.pdf
    year: 2011
  - title: United Performance Metals, Alloy A286 datasheet (AMS 5525, 5731, 5732, 5737, 5858)
    type: datasheet
    url: https://www.upmet.com/sites/default/files/products/datasheet/a286-datasheet.pdf
    year: 2026
  - title: Smiths Metal Centres, A-286 technical datasheet
    type: datasheet
    url: https://www.smithmetal.com/pdf/stainless/ph/a-286.pdf
    year: 2023
  - title: Elgiloy Specialty Metals (Combined Metals), Incoloy alloy A-286 strip products datasheet (rev 8/26/2020)
    type: datasheet
    url: https://www.combmet.com/wp-content/uploads/2023/02/Strip-A286-Nickel-Alloy.pdf
    year: 2020
  - title: Martin Company, Determination of Low-Temperature Fatigue Properties of Structural Metal Alloys, report CR-65-70 for NASA George C. Marshall Space Flight Center (October 1965)
    type: report
    url: https://ntrs.nasa.gov/api/citations/19660001322/downloads/19660001322.pdf
    year: 1965
  - title: Mineral Commodity Summaries 2026, Nickel (U.S. Geological Survey)
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: Mineral Commodity Summaries 2026, Chromium (U.S. Geological Survey)
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
  - title: NIST Safety Data Sheet, Standard Reference Material 1230, High-Temperature Alloy A286 (disk form), dated 12 July 2016
    type: sds
    url: https://tsapps.nist.gov/srmext/MSDS/1230-MSDS.pdf
    year: 2016
gaps:
  - The only A-286 safety data sheet found is NIST's for the SRM 1230 disk form, which is not classified as a hazard under OSHA (see risks.hazards). No producer sheet for bar, sheet or forgings, and no PubChem or GHS record for the alloy, was found in this run, so the classification may not carry over to other forms.
  - No AISI number was found for A-286 in any source read in this run, so none is listed. The EN name (the X5NiCrTiMoVB25-15-2 style name) was printed only on a supplier marketing page that was not fetched as a datasheet, so it is left out.
  - Stress-rupture data beyond 1000 h and the ATI creep and tensile charts were images and were not read. Only the printed table values are used.
  - Hardness (hardness_brinell), charpy_impact_energy, stress_rupture_1000h and magnetic_permeability are not in the canonical property list, so they use short names as allowed by the brief.
  - 'The sources disagree on solution-treated strength: ATI gives 275 MPa (40,000 psi) yield and 620 MPa (90,000 psi) tensile, the NASA 1965 report gives 46,000 psi yield and 90,000 psi tensile at room temperature, and Smith Metal gives 720 N/mm2 proof stress and 1000 N/mm2 tensile for solution annealed material. All are kept side by side and none is reconciled.'
  - The ATI corrosion table prints the 316 result for 10% sulfuric acid as 636 mils per year with 5.74 mm/a, which repeats the 1% hydrochloric acid mm/a value. The 316 figure is therefore not used.
  - The Smith Metal elongation figure is printed with an N/mm2 header, so it is not used. The Upmet and Combined Metals datasheets give no melting range.
  - The USGS summaries read do not print a critical-mineral list status for nickel or chromium in the text read, so no critical_lists entry is given.
  - No A-286 atomic oxygen, outgassing, radiation or flight-test data were found in any source read in this run. The cryogenic tensile value is from a 1965 solution-treated test, not from a spacecraft qualification.
  - The 1965 NASA report and the datasheets describe typical values for specific forms, not design allowables.
sources:
  ati-a286:
    title: ATI A286 Iron-Based Superalloy (UNS S66286) Technical Data Sheet, version 1 (4/17/2012)
    url: https://www.atimaterials.com/Products/Documents/datasheets/nickel-cobalt/nickel-based/ati_286_ludlum_version_tds_en_v1.pdf
    year: 2012
    kind: datasheet
    license: Manufacturer datasheet, typical data for information (cited, not reproduced)
  rolled-a286:
    title: Rolled Alloys A-286 Alloy data sheet, Bulletin No. 1286
    url: https://www.rolledalloys.com/wp-content/uploads/A-286_Data-sheet-rolled-alloys.pdf
    year: 2011
    kind: datasheet
    license: Distributor datasheet, typical data (cited, not reproduced)
  upmet-a286:
    title: United Performance Metals, Alloy A286 datasheet (AMS 5525, 5731, 5732, 5737, 5858)
    url: https://www.upmet.com/sites/default/files/products/datasheet/a286-datasheet.pdf
    year: 2026
    kind: datasheet
    license: Distributor datasheet, technical data for information only (cited, not reproduced)
  smith-a286:
    title: Smiths Metal Centres, A-286 technical datasheet
    url: https://www.smithmetal.com/pdf/stainless/ph/a-286.pdf
    year: 2023
    kind: datasheet
    license: Distributor datasheet, approximate testing (cited, not reproduced)
  combmet-a286:
    title: Elgiloy Specialty Metals (Combined Metals), Incoloy alloy A-286 strip products datasheet, UNS S66286, W. Nr 1.4980 (rev 8/26/2020)
    url: https://www.combmet.com/wp-content/uploads/2023/02/Strip-A286-Nickel-Alloy.pdf
    year: 2020
    kind: datasheet
    license: Distributor datasheet, typical values (cited, not reproduced)
  nasa-cr65-70:
    title: Martin Company, Determination of Low-Temperature Fatigue Properties of Structural Metal Alloys, report CR-65-70 (October 1965), prepared for NASA George C. Marshall Space Flight Center
    url: https://ntrs.nasa.gov/api/citations/19660001322/downloads/19660001322.pdf
    year: 1965
    kind: report
    license: public domain (NASA)
  usgs-mcs2026-nickel:
    title: 'Mineral Commodity Summaries 2026: Nickel (U.S. Geological Survey)'
    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 (U.S. Geological Survey)'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  nist-srm1230-sds:
    title: NIST Safety Data Sheet, Standard Reference Material 1230, High-Temperature Alloy A286 (disk form), dated 12 July 2016
    url: https://tsapps.nist.gov/srmext/MSDS/1230-MSDS.pdf
    year: 2016
    kind: datasheet
    license: U.S. government document (NIST), linked not reproduced
license: CC-BY-4.0
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 28
  unreachable: 0
  caveats: 4
  note: 'Values were read by an AI assistant on 2026-11-01 from the pages and PDFs named in each entry (PDFs extracted with pdftotext). The ATI tensile, creep and CTE charts are images and were not read. Caveats: the datasheets disagree on solution-treated strength; the NASA report is from 1965 and covers solution-treated material; the Smith Metal elongation unit is printed wrongly; a NIST safety sheet for the A286 disk form was found and classifies it as not hazardous under OSHA; no producer sheet for bar, sheet or forgings was found.'
story:
  recipe:
    line: A-286 is an iron-base alloy made to a limiting composition in weight percent, with nickel, chromium, titanium and molybdenum as the main alloying elements. ATI says it can be produced by AOD refining or vacuum induction melting, and that vacuum arc or electroslag remelting may be used to refine it further. Titanium and aluminium give the age hardening.
    parts:
      - name: Iron
        symbol: Fe
        role: The base metal and the balance of the composition in every limit table read.
      - name: Nickel
        symbol: Ni
        share_percent: 24
        share_high: 27
        role: Austenite-forming element in the limits; ATI calls the alloy an austenitic alloy.
      - name: Chromium
        symbol: Cr
        share_percent: 13.5
        share_high: 16
        role: ATI says chromium, nickel and molybdenum give aqueous corrosion resistance comparable to austenitic stainless steels.
      - name: Titanium
        symbol: Ti
        share_percent: 1.9
        share_high: 2.35
        role: Age-hardening element; ATI says strength develops on aging and needs inert gas welding to avoid losing titanium.
      - name: Molybdenum
        symbol: Mo
        share_percent: 1
        share_high: 1.5
        role: Listed alloying element in the limits; the sources read give no separate role.
      - name: Vanadium
        symbol: V
        share_percent: 0.1
        share_high: 0.5
        role: Listed alloying element in the limits; the sources read give no separate role.
      - name: Aluminium
        symbol: Al
        share_percent: 0
        share_high: 0.35
        role: Maximum limit only; works with titanium in age hardening, per the ATI aging description.
      - name: Boron
        symbol: B
        share_percent: 0.003
        share_high: 0.01
        role: Listed limiting element; the sources read give no separate role.
  risk_groups:
    - title: For people
      lead: The only A-286 safety sheet read is NIST's for the disk form, which is not classified as a hazard under OSHA. No producer sheet for bar or sheet was found. The sources read also name processing hazards.
      level: 1
      verdict: Not classified for the disk form
      points:
        - label: Acid pickling
          line: ATI says the oxide film after heat treatment is removed by pickling in warm sulfuric acid and then nitric-hydrofluoric acid baths, so those acids are part of the handling.
    - title: If it fails
      lead: The failure routes in the sources are welding cracks, loss of strength at high temperature and rapid work hardening.
      points:
        - label: Weld cracking
          line: ATI says the alloy is susceptible to hot cracking, particularly in the aged condition, and heavy sections are harder to weld.
        - label: Stress rupture
          line: ATI says creep and stress-rupture strength, not short-time tensile strength, limit the alloy at elevated temperature.
        - label: Work hardening
          line: Smith Metal says the alloy work hardens rapidly, so intermediate annealing may be needed in deep drawing or intricate forming.
    - title: Handling and storage
      points:
        - label: Heat treatment order
          line: Solution treat, then age at 1325 °F (718 °C) for 16 hours and air cool, as ATI describes.
        - label: Machining
          line: ATI says the soft solution-treated material is gummy, so it is machined after aging or after cold work.
  why: A-286 is an iron-nickel-chromium alloy that is age hardened and non-magnetic, and that keeps strength to cryogenic temperatures. ATI gives its density as 7.92 g/cm3 solution treated and a melting range of 1370 to 1430 °C. Rolled Alloys gives a 1000 h stress-rupture strength of 88 ksi at 538 °C and 46 ksi at 649 °C. Smiths Metal Centres, Rolled Alloys and Combined Metals list jet engine parts, fasteners and springs among its uses.
  uses:
    - where: Fasteners and screws
      line: Rolled Alloys lists high temperature fasteners, and Smiths Metal Centres lists screws and Upmet lists bolts among its applications.
    - where: Jet engine parts
      line: Smiths Metal Centres lists jet engine blades, afterburner parts and turbine wheels as typical uses.
    - where: Springs
      line: Combined Metals and Rolled Alloys both list springs among its applications.
    - where: Cryogenic structures
      line: ATI describes non-magnetic use down to -196 °C, and a 1965 NASA-funded test report measured a tensile strength of 168000 psi at -423 °F for solution-treated material.
  can_do:
    - label: Hold stress when hot
      value: 46 ksi at 649 °C
      benchmark: stress_rupture_1000h
      line: Rolled Alloys gives a typical 1000 h stress-rupture strength of 46 ksi at 1200 °F (649 °C) and 88 ksi at 1000 °F (538 °C).
    - label: Strength when cold
      value: 168000 psi at -423 °F
      benchmark: ultimate_tensile_strength
      line: The 1965 NASA-funded Martin report gives a tensile strength of 168,000 psi at -423 °F for solution-treated material, up from 90,000 psi at room temperature.
    - label: Weight
      value: 7.92 g/cm3
      benchmark: density
      line: ATI gives a density of 7.92 g/cm3 solution treated and 7.94 g/cm3 solution treated and aged.
    - label: Stiffness
      value: 201 GPa at 24 °C
      benchmark: elastic_modulus
      line: ATI gives a dynamic modulus of elasticity of 201 GPa at 24 °C and 130 GPa at 871 °C.
    - label: Aged sheet strength
      value: 145 ksi tensile
      benchmark: ultimate_tensile_strength
      line: Rolled Alloys gives a representative tensile strength of 145 ksi at 70 °F for aged AMS 5732 sheet.
  compare: ATI says the aqueous corrosion resistance of A-286 is comparable to the austenitic stainless steels, and Rolled Alloys says comparable to 316 and 316L. In ATI's typical corrosion-rate table, A-286 corroded less than Type 304 in boiling 10% sulfuric acid and boiling 1% hydrochloric acid, and more than Type 304 in boiling 20% phosphoric acid. The rows below show density, elastic modulus and thermal expansion from the sources read here. The sources cover different heat treatments, so read the rows as examples, not as a ranking.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Elastic modulus
      benchmark: elastic_modulus
    - label: Thermal expansion
      benchmark: cte
  handling:
    - Solution treat, then age at 1325 °F (718 °C) for 16 hours and air cool.
    - Form and machine in the solution-treated condition, or after aging, because the soft material is gummy to machine.
    - Weld by inert gas methods to protect the titanium, and weld in the solution-treated condition where possible.
    - Pickle after heat treatment in sulfuric and nitric-hydrofluoric acid baths, as ATI describes.
  good_for:
    - 'Fasteners and springs that need high strength and non-magnetic behaviour: 85 ksi minimum yield strength for Grade 660 Class B (Rolled Alloys).'
    - 'Cryogenic structures: 77 J Charpy V-notch impact energy at -196 °C in the aged condition (ATI).'
    - 'Jet engine hardware in air to about 704 °C: excellent corrosion resistance in jet engine atmospheres to 1300 °F (ATI).'
  watch_out:
    - 'Welding: the alloy is susceptible to hot cracking, especially when aged, and needs inert gas methods to protect the titanium (ATI).'
    - 'Stress rupture: at 649 °C the 1000 h stress-rupture strength is 46 ksi, so high-stress parts need the stress-rupture data, not the room-temperature strength (Rolled Alloys).'
    - 'Chloride cracking: in the boiling 42% magnesium chloride U-bend test, A-286 cracked after 168 hours (ATI).'
    - The sources disagree on solution-treated strength (275 MPa and 620 MPa from ATI; 720 and 1000 N/mm2 from Smiths Metal Centres). Check the heat-treatment condition before design use.
    - No producer safety data sheet for bar or sheet, flight test or spacecraft qualification data were found in this run; the NIST sheet covers the disk form only.
  verdict: A-286 is an age-hardened iron-nickel-chromium superalloy with a density of 7.92 g/cm3 solution treated, a melting range of 1370 to 1430 °C, and a 1000 h stress-rupture strength of 46 ksi at 649 °C. It stays ductile and non-magnetic to cryogenic temperatures, and it is used for fasteners, springs and jet engine parts. The only safety sheet read is NIST's for the disk form, which is not classified under OSHA, and the sources read here give no spacecraft qualification data.