spore: profile
id: stainless-317l
spore_version: 0.2
family: stainless-austenitic
name: AISI 317L stainless steel
abbreviation: 317L
role: corrosion-resistant structural alloy
category: metals
type: steels-and-stainless
summary: |
  AISI 317L (UNS S31703, EN 1.4438) is a low-carbon, molybdenum-bearing austenitic stainless steel with 18 to 20 % chromium, 11 to 15 % nickel and 3 to 4 % molybdenum. It is used for chemical process vessels, petrochemical plant, pulp and paper equipment and power-plant condensers. ATI gives its minimum annealed strength as 205 MPa yield and 515 MPa tensile, with 40 % elongation, and its molybdenum content gives better pitting resistance than 316L.
best_for: Chloride pitting resistance in process equipment, with a low-carbon grade that limits sensitization in welds
weakest_at: Strength in the annealed state (205 MPa minimum yield) and chloride stress cracking above about 49 °C
identity:
  formula: 'Iron-based austenitic alloy, % by weight (ATI 317L limits): Cr 18-20, Ni 11-15, Mo 3-4, Mn 2.0 max, Si 0.75 max, C 0.03 max, N 0.10 max, P 0.045 max, S 0.03 max, Fe balance (UNS S31703)'
  source: ati-tds
  where: Percentage by weight table, ATI 317L column (ASTM A240 limits)
  designations:
    - system: UNS
      code: S31703
      source: ati-tds
      where: Specifications line and composition table, ATI 317L (S31703) column
    - system: AISI
      code: 317L
      source: virgamet-1-4438
      where: 'Chemical composition table, ASTM row: AISI 317L - UNS S31703'
    - system: EN
      code: '1.4438'
      source: virgamet-1-4438
      where: Page title and chemical composition table, EN row
    - system: EN name
      code: X2CrNiMo18-15-4
      source: virgamet-1-4438
      where: Chemical composition table, EN row
    - system: AFNOR
      code: Z3CND19-15-04
      source: virgamet-1-4438
      where: Chemical composition table, NF row
    - system: BS
      code: 317S12
      source: virgamet-1-4438
      where: Chemical composition table, BS row
    - system: ASTM
      code: A240
      note: plate, sheet and strip
      source: ati-tds
      where: 'Specifications: ASTM A 240 and ASME SA-240'
    - system: Trade name
      code: ATI 317L
      source: ati-tds
      where: Title line, ATI 317L trademark
tags:
  environments: []
  stresses: []
  applications:
    - structures
    - thermal-control
properties:
  - benchmark: density
    label: Density, 317L (ATI physical properties table)
    value: 8.027
    unit: g/cm3
    scope: material
    conditions:
      grade: 317L, annealed; table is shared by the four-grade ATI sheet and not split by grade
      temperature: not stated
      unit_in_source: 0.29 lb/in3
    method: Value printed in the physical properties table of the ATI sheet
    status: ground
    source: ati-tds
    where: Physical properties, Density row
  - benchmark: melting_point
    label: Melting range, 317L (ATI physical properties table)
    value: 1390
    value_high: 1440
    bound: range
    unit: °C
    scope: material
    conditions:
      grade: 317L; shared physical table of the four-grade ATI sheet
      unit_in_source: 2540-2630 °F
    method: Range printed in the physical properties table of the ATI sheet
    status: ground
    source: ati-tds
    where: Physical properties, Melting Range row
  - benchmark: elastic_modulus
    label: Modulus of elasticity in tension
    value: 200
    unit: GPa
    scope: material
    conditions:
      grade: 317L; shared physical table of the four-grade ATI sheet
      temperature: not stated
      unit_in_source: 29 x 10^6 psi
    method: Value printed in the physical properties table of the ATI sheet
    status: ground
    source: ati-tds
    where: Physical properties, Modulus of Elasticity in Tension
  - benchmark: yield_strength
    label: Yield strength, 0.2 % offset, minimum
    value: 205
    bound: lower
    unit: MPa
    scope: material
    conditions:
      grade: 317L (S31703)
      form: plate, sheet and strip
      temper: annealed
      standard: ASTM A240 / ASME SA-240 minimum
      unit_in_source: 30,000 psi
    method: Minimum mechanical property printed in the ATI 317L column of the ASTM A240 table
    status: ground
    source: ati-tds
    where: Room temperature tensile properties table, ATI 317L column, Yield Strength 0.2% offset
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, minimum
    value: 515
    bound: lower
    unit: MPa
    scope: material
    conditions:
      grade: 317L (S31703)
      form: plate, sheet and strip
      temper: annealed
      standard: ASTM A240 / ASME SA-240 minimum
      unit_in_source: 75,000 psi
    method: Minimum mechanical property printed in the ATI 317L column of the ASTM A240 table
    status: ground
    source: ati-tds
    where: Room temperature tensile properties table, ATI 317L column, Ultimate Tensile Strength
  - benchmark: elongation
    label: Elongation in 2 in or 51 mm, minimum
    value: 40
    bound: lower
    unit: '%'
    scope: material
    conditions:
      grade: 317L (S31703)
      form: plate, sheet and strip
      temper: annealed
      gauge: 2 in or 51 mm
    method: Minimum mechanical property printed in the ATI 317L column of the ASTM A240 table
    status: ground
    source: ati-tds
    where: Room temperature tensile properties table, ATI 317L column, Percent Elongation
  - benchmark: hardness_brinell
    label: Hardness, maximum (Brinell)
    value: 217
    bound: upper
    unit: HB
    scope: material
    conditions:
      grade: 317L (S31703)
      form: plate, sheet and strip
      temper: annealed
      standard: ASTM A240 maximum
    method: Maximum printed in the ATI 317L column of the ASTM A240 table (217 HB, shown as 95 HRB)
    status: ground
    source: ati-tds
    where: Room temperature tensile properties table, ATI 317L column, Hardness Max. Brinell
  - benchmark: yield_strength
    label: Yield strength, typical at 70 °F
    value: 36.7
    unit: ksi
    scope: material
    conditions:
      temperature: 70 °F (21 °C)
      basis: typical value, not a minimum; the source does not name the product form or temper
      unit_in_source: ksi
    method: Typical value printed in the Typical Tensile and Impact Properties table
    status: ground
    source: rolled-alloys-317l
    where: Typical Tensile and Impact Properties table, 70 °F column, 0.2% Yield Strength row
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, typical at 70 °F
    value: 81.8
    unit: ksi
    scope: material
    conditions:
      temperature: 70 °F (21 °C)
      basis: typical value, not a minimum; the source does not name the product form or temper
    method: Typical value printed in the Typical Tensile and Impact Properties table
    status: ground
    source: rolled-alloys-317l
    where: Typical Tensile and Impact Properties table, 70 °F column, Ultimate Tensile Strength row
  - benchmark: charpy_impact_energy
    label: Charpy V-notch impact energy, typical at 70 °F
    value: 65
    value_high: 100
    bound: range
    unit: ft-lbf
    scope: material
    conditions:
      temperature: 70 °F (21 °C)
      notch: Charpy V-notch
      basis: typical value, not a minimum
      unit_in_source: ft-lbd
    method: Typical value printed in the Typical Tensile and Impact Properties table
    status: ground
    source: rolled-alloys-317l
    where: Typical Tensile and Impact Properties table, 70 °F column, Charpy Impact V-notch row
  - benchmark: thermal_conductivity
    label: Thermal conductivity, 1.4438 datasheet
    value: 14
    unit: W/(m·K)
    scope: material
    conditions:
      temperature: 20 °C
      grade: 1.4438 (317L)
    method: Value printed in the physical properties table of the 1.4438 datasheet
    status: ground
    source: virgamet-1-4438
    where: Physical Properties 20 °C table, Thermal conductivity row
  - benchmark: thermal_conductivity
    label: Thermal conductivity, ATI table
    value: 14.6
    unit: W/(m·K)
    scope: material
    conditions:
      temperature: 20 to 100 °C
      grade: 317L; shared thermal table of the four-grade ATI sheet
      unit_in_source: 100.8 Btu·in/(hr·ft²·°F)
    method: Value printed in the thermal conductivity table of the ATI sheet
    status: ground
    source: ati-tds
    where: Thermal Conductivity table, 68-212 °F (20-100 °C) row
  - benchmark: thermal_conductivity
    label: Thermal conductivity, Rolled Alloys
    value: 7.8
    unit: Btu·ft/(ft²·hr·°F)
    scope: material
    conditions:
      temperature: 70 °F (21 °C)
      grade: 317L
      unit_in_source: Btu·ft/ft²·hr·°F
    method: Value printed in the physical properties table of the Rolled Alloys 317L bulletin
    status: ground
    source: rolled-alloys-317l
    where: Physical Properties table, Thermal Conductivity row, 70 °F column
  - benchmark: cte
    label: Coefficient of thermal expansion, 20 to 100 °C
    value: 16.5
    unit: 10^-6 cm/cm/°C
    scope: material
    conditions:
      temperature: 20 to 100 °C
      grade: 317L; shared table of the four-grade ATI sheet
    method: Value printed in the coefficient of linear thermal expansion table of the ATI sheet
    status: ground
    source: ati-tds
    where: Coefficient of Linear Thermal Expansion table, 20-100 °C row
  - benchmark: cte
    label: Coefficient of thermal expansion, 20 to 500 °C
    value: 18.2
    unit: 10^-6 cm/cm/°C
    scope: material
    conditions:
      temperature: 20 to 500 °C
      grade: 317L; shared table of the four-grade ATI sheet
    method: Value printed in the coefficient of linear thermal expansion table of the ATI sheet
    status: ground
    source: ati-tds
    where: Coefficient of Linear Thermal Expansion table, 20-500 °C row
  - benchmark: cte
    label: Coefficient of thermal expansion, 70 to 212 °F
    value: 9.2
    unit: 10^-6 in/(in·°F)
    scope: material
    conditions:
      temperature: 70 to 212 °F, measured from 70 °F
      grade: 317L
    method: Value printed in the coefficient of thermal expansion row of the Rolled Alloys 317L bulletin
    status: ground
    source: rolled-alloys-317l
    where: Physical Properties table, Coefficient of Thermal Expansion row, 212 °F column
  - benchmark: specific_heat
    label: Specific heat capacity, 20 °C
    value: 500
    unit: J/(kg·K)
    scope: material
    conditions:
      temperature: 20 °C
      grade: 1.4438 (317L)
    method: Value printed in the physical properties table of the 1.4438 datasheet
    status: ground
    source: virgamet-1-4438
    where: Physical Properties 20 °C table, Specific heat capacity row
  - benchmark: poissons_ratio
    label: Poisson's ratio
    value: 0.3
    unit: '-'
    scope: material
    conditions:
      temperature: not stated
      grade: 317L
    method: Value printed in the physical properties table of the Rolled Alloys 317L bulletin
    status: ground
    source: rolled-alloys-317l
    where: Physical Properties table, Poisson's Ratio
  - benchmark: electrical_resistivity
    label: Electrical resistivity
    value: 475
    unit: Ohm-circ mil/ft
    scope: material
    conditions:
      temperature: not stated
      grade: 317L
    method: Value printed in the physical properties table of the Rolled Alloys 317L bulletin
    status: ground
    source: rolled-alloys-317l
    where: Physical Properties table, Electrical Resistivity row
  - benchmark: elastic_modulus
    label: Modulus of elasticity at 400 °C
    value: 172
    unit: GPa
    scope: material
    conditions:
      temperature: 400 °C
      grade: 1.4438 (317L)
    method: Value printed in the temperature table of the 1.4438 datasheet
    status: ground
    source: virgamet-1-4438
    where: Temperature table, Modulus of elasticity E row, 400 °C column
  - benchmark: yield_strength
    label: Yield point Rp0.2 at 400 °C, minimum
    value: 115
    bound: lower
    unit: MPa
    scope: material
    conditions:
      temperature: 400 °C
      grade: 1.4438 (317L)
      basis: the datasheet prints a greater-than value
    method: Value printed in the temperature table of the 1.4438 datasheet
    status: ground
    source: virgamet-1-4438
    where: Temperature table, Yield point Rp0,2 row, 400 °C column
  - benchmark: yield_strength
    label: Yield point Rp0.2, minimum (EN datasheet)
    value: 200
    bound: lower
    unit: MPa
    scope: material
    conditions:
      temperature: 20 °C
      grade: 1.4438 (317L)
      basis: minimum as printed
    method: Value printed in the mechanical properties table of the 1.4438 datasheet
    status: ground
    source: virgamet-1-4438
    where: Mechanical properties 20 °C table, 0.2% yield strength Rp row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength Rm (EN datasheet)
    value: 500
    value_high: 700
    bound: range
    unit: MPa
    scope: material
    conditions:
      temperature: 20 °C
      grade: 1.4438 (317L)
    method: Range printed in the mechanical properties table of the 1.4438 datasheet
    status: ground
    source: virgamet-1-4438
    where: Mechanical properties 20 °C table, Tensile strength Rm row
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, typical (AZoM)
    value: 595
    unit: MPa
    scope: material
    conditions:
      basis: typical table value, no test temperature or condition stated by the source
      grade: 317L
    method: Value printed in the Mechanical Properties table of the AZoM 317L article
    status: ground
    source: azom-317l
    where: Mechanical Properties table, Tensile strength row
  - benchmark: yield_strength
    label: Yield strength, typical (AZoM)
    value: 260
    unit: MPa
    scope: material
    conditions:
      basis: typical table value, no test temperature or condition stated by the source
      grade: 317L
    method: Value printed in the Mechanical Properties table of the AZoM 317L article
    status: ground
    source: azom-317l
    where: Mechanical Properties table, Yield strength row
corrosion:
  - environment: Chloride water, pitting and crevice attack
    headline: 'Molybdenum and nitrogen raise the pitting index: ATI gives PREN 29.7 for 317 and 317L against 24.2 for 316 and 316L.'
    effect: ATI says the molybdenum-bearing grades resist pitting and crevice corrosion better than conventional 18-8 grades, and that 317 and 317L resist pitting better than 316. Its PREN formula is Cr + 3.3 Mo + 16 N. ATI does not recommend these alloys for seawater at 19,000 ppm chloride.
    rating: moderate
    conditions:
      basis: PREN calculation and laboratory data quoted by ATI; no test temperature stated for the PREN
    source: ati-tds
    where: Pitting and crevice corrosion section, PREN values and seawater statement
  - environment: Atmosphere and mild corrosive media
    headline: 317L resists mild corrosion better than 18-8 stainless steels, and performs like 317 in most media.
    effect: ATI says the 316, 316L, 317 and 317L grades are more resistant to atmospheric and other mild corrosion than the 18-8 stainless steels, and that media which do not corrode 18-8 will not attack them. Rolled Alloys says 317L has better general and localized corrosion resistance than 304L and 316L.
    rating: low
    conditions:
      basis: general statements, no test duration or concentration given
    source: ati-tds
    where: General corrosion section
  - environment: Highly oxidizing acids, such as nitric acid
    headline: Nitric acid is the known exception to the broad resistance of the molybdenum-bearing grades.
    effect: ATI names highly oxidizing acids such as nitric acid as the one known exception to the resistance of the molybdenum-bearing stainless steels to media that do not attack 18-8 grades.
    rating: moderate
    conditions:
      basis: general statement, no concentration or temperature given
    source: ati-tds
    where: General corrosion section
  - environment: Welds and heat-affected zones in corrosive media
    headline: The low-carbon 317L is preferred over 317 for welds, because it resists intergranular attack.
    effect: ATI says 317L is preferred over 317 in the welded condition in media aggressive enough to attack welds, because its low carbon limits chromium carbide precipitation in the 800 to 1500 °F (427 to 816 °C) range.
    rating: moderate
    conditions:
      range: 800 to 1500 °F (427 to 816 °C) for carbide precipitation
      grade: 317L against 317
    source: ati-tds
    where: Intergranular corrosion and sensitization section
  - environment: Chloride ions with tensile stress above about 49 °C
    headline: Chloride stress cracking is the main cracking route for the grade, and the low-carbon version gives no advantage in it.
    effect: ATI says austenitic stainless steels crack under stress in halide environments, with residual tensile stress and temperatures above about 120 °F (49 °C) as the triggers. It says the molybdenum grades are somewhat more resistant than 18-8 alloys, and that the L grades offer no advantage for this cracking.
    rating: moderate
    conditions:
      temperature: above about 120 °F (49 °C)
      stress: residual tensile stress from cold work or welding
    source: ati-tds
    where: Stress corrosion cracking section
risks:
  hazards:
    - text: The supplier safety data sheet says that, as shipped, the massive alloy has no known toxicological properties other than allergic reactions in people sensitive to its metals, such as nickel.
      ghs: []
      source: rolled-sds
      where: Section XI, Toxicological information
    - text: Welding, cutting and grinding fume contains oxides of iron, manganese, nickel and chromium. The same sheet says IARC has concluded that welding fumes are possibly carcinogenic to humans, and classes nickel as a Category 3 carcinogen.
      ghs: []
      source: rolled-sds
      where: Section X (fume constituents) and Section XI (toxicology)
    - text: Long-term welding fume inhalation may damage the lungs and airways, including fibrosis of the lung.
      ghs: []
      source: rolled-sds
      where: Section XI, Delayed effects
  failure_risks:
    - mode: Intergranular corrosion after sensitization
      trigger: Exposure at 800 to 1500 °F (427 to 816 °C), such as welding or stress relief, in a corrosive medium
      consequence: Chromium carbides form at the grain boundaries, leaving the steel open to intergranular attack. The low carbon of 317L limits this, which is why ATI prefers it for welds.
      severity: moderate
      source: ati-tds
      where: Intergranular corrosion and sensitization section
    - mode: Chloride stress corrosion cracking
      trigger: Chloride or other halide ions with residual tensile stress from cold work or welding, at temperatures above about 120 °F (49 °C)
      consequence: The steel can crack in service. ATI says the low-carbon L grades offer no advantage in this test, and that duplex grades resist chloride cracking better.
      severity: high
      source: ati-tds
      where: Stress corrosion cracking section
    - mode: Pitting in chloride water
      trigger: Chloride ions in crevices or under deposits, or water chloride above what the grade tolerates
      consequence: ATI does not recommend the molybdenum-bearing grades for seawater (19,000 ppm chloride). Its PREN values place 317L above 316L, and below AL-6XN (PREN 44.5), which is designed for seawater.
      severity: moderate
      source: ati-tds
      where: Pitting and crevice corrosion section, PREN values and seawater statement
    - mode: Work hardening during machining
      trigger: High cutting speeds or interrupted feed
      consequence: The alloy work-hardens, which raises tool wear and the risk of surface damage. Low speed and constant feed reduce this.
      severity: low
      source: azom-317l
      where: Manufacturing Process section
  handling:
    - text: Use fume extraction and a fume respirator when welding, cutting or grinding, and keep exposure below the limits in Section III of the safety data sheet.
      source: rolled-sds
      where: Section III composition and handling precautions
    - text: Weld with AWS E/ER 317L filler metal, and avoid oxyacetylene welding.
      source: azom-317l
      where: Manufacturing Process section
    - text: Machine at low speed with constant feed and use chip breakers, because the alloy work-hardens.
      source: azom-317l
      where: Manufacturing Process section
    - text: Specify the low-carbon 317L for welded parts, since the standard 317 grade is more exposed to intergranular attack after welding.
      source: ati-tds
      where: Intergranular corrosion and sensitization section
  mitigations:
    - text: Solution anneal at 1020 to 1100 °C after hot working. Forging and rolling are done between 1150 and 800 °C.
      source: virgamet-1-4438
      where: Process temperatures
    - text: Anneal or stress-relieve to reduce residual tensile stress, which lowers sensitivity to chloride stress cracking.
      source: ati-tds
      where: Stress corrosion cracking section
uses:
  - application: thermal-control
    device: Condensers in fossil and nuclear fuelled power generation stations
    example: AZoM lists condensers in fossil and nuclear fuelled power generation stations among the widely used applications of 317L.
    source: azom-317l
    where: Applications section
  - application: structures
    device: Chemical process vessels, petrochemical plant and flue gas desulfurization systems
    example: Rolled Alloys lists chemical process vessels, petrochemical plant, pulp and paper, condensers in power generation and FGD systems as applications of 317L.
    source: rolled-alloys-317l
    where: Applications list
supply:
  - subject: Nickel (11 to 15 % of 317L)
    abundance: 'USGS: world nickel resources are estimated to contain more than 350 million tons of nickel.'
    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: in 2025 nickel recovered from scrap accounted for approximately 60% of apparent consumption.'
    substitutes:
      - 'USGS: low-nickel, duplex or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction.'
    source: usgs-nickel-2026
    where: World Mine Production and Reserves table, 2025e column (world total 3,900,000 t); shares calculated by Space Mushroom from the printed tons; Recycling; Substitutes; World Resources
  - subject: Chromium (18 to 20 % of 317L)
    abundance: 'USGS: 2021 to 2024 imports of chromite ore and concentrates came 96% from South Africa.'
    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: in 2025 recycled chromium, contained in reported stainless-steel scrap receipts, accounted for 21% of apparent consumption.'
    substitutes:
      - 'USGS: chromium has no substitute in stainless steel, the leading end use.'
    source: usgs-chromium-2026
    where: World Mine Production and Reserves table, 2025e column (world total 51,000 t, gross weight); shares calculated by Space Mushroom from the printed tons; Import Sources; Recycling; Substitutes
  - subject: Molybdenum (3 to 4 % of 317L)
    producers:
      - country: China
        share_percent: 37.3
        year: 2025
      - country: Chile
        share_percent: 16.2
        year: 2025
      - country: Peru
        share_percent: 15
        year: 2025
    critical_lists: []
    recycling: 'USGS: molybdenum is recycled as a component of catalysts, ferrous scrap and superalloy scrap.'
    substitutes:
      - 'USGS: there is little substitution for molybdenum in steels; potential substitutes include boron, chromium, niobium and vanadium.'
    source: usgs-molybdenum-2026
    where: World Mine Production and Reserves table, 2025e column (world total 260,000 t of molybdenum content); shares calculated by Space Mushroom from the printed tons; Recycling; Substitutes
documents:
  - title: ATI 316, ATI 316L, ATI 317 and ATI 317L technical data sheet (version 1, 2012)
    type: datasheet
    url: https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/austenitic/ati_316_316l_317_317l_tds_en1.pdf
    year: 2012
  - title: Rolled Alloys 317L stainless steel data sheet, bulletin 1037U
    type: datasheet
    url: https://www.rolledalloys.com/wp-content/uploads/317L_stainless-steel-data-sheet-rolled-alloys.pdf
    year: 2011
  - title: 'AZoM: Stainless Steel Grade 317L (UNS S31703)'
    type: report
    url: https://www.azom.com/article.aspx?ArticleID=8262
  - title: 'VIRGAMET offer page: 1.4438, AISI 317L, UNS S31703 (X2CrNiMo18-15-4)'
    type: datasheet
    url: https://virgamet.com/offer/x2crnimo18154-1-4438-aisi-317l-uns-s31703-z3cnd191504-stainless-steel
  - title: Rolled Alloys general products safety data sheet (revised February 2025)
    type: sds
    url: https://www.rolledalloys.com/wp-content/uploads/2022/07/General-Product-Safety-Data-Sheet.pdf
    year: 2025
  - title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Chromium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Molybdenum'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
gaps:
  - 'Spacecraft, rocket or satellite use of 317L: no source found. The aerospace pages read here cover 300-series steel in general, not 317L, so no space use is recorded and no tags.environments are set.'
  - 'Space environment data for 317L (atomic oxygen, outgassing, cold welding, radiation, vacuum): none found or read.'
  - 'Cryogenic toughness and cold-temperature tensile data for 317L: not read.'
  - Hardness (Brinell) and Charpy impact energy are not canonical property names in spores/property-canon.yaml; the short snake_case names hardness_brinell and charpy_impact_energy are used and need adding to the canon.
  - 'W.Nr. number: 1.4438 is the German material number, but no fetched source labels it W.Nr., so no W.Nr. designation is listed.'
  - 'JIS: SUS317L appears only in a substitutes list on the 1.4438 datasheet page, not as a labelled JIS designation, so it is not listed.'
  - 'Grade-specific density: the ATI physical properties table covers the four-grade sheet and is not split by grade. The 1.4438 datasheet gives density only as 8 g/cm3, so it is not used.'
  - Electrical resistivity of 317 (79.0 microhm-cm in the ATI table) is for 317, not 317L, and is not used. The 317L value is the Rolled Alloys figure in its own unit.
  - 'Corrosion rates in mm per year for acids or chlorides: none printed in the sources read.'
  - 'GHS classification for the solid alloy: no fetched safety data sheet gives GHS codes for the massive form.'
  - 'Welding fume exposure limits: the Rolled Alloys SDS table gives PEL and TLV values, but the units are not in the extracted text, so they are not recorded.'
  - 'Critical-mineral list status for nickel, chromium and molybdenum: the USGS 2026 summaries read here do not state a critical-list entry for these metals, so critical_lists is empty.'
  - 'Recipe atomic weights: not read from a source in this run, so the recipe gives composition limits by weight only.'
  - 'Media: no openly licensed image was checked for this profile.'
  - 'Creep, stress-rupture and elevated-temperature corrosion data: not read beyond the 400 °C yield and modulus row.'
  - The Rolled Alloys bulletin is dated 2011 and was not checked against the current ASTM A240 revision.
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 25
  unreachable: 0
  caveats: 6
  note: 'Values were read by an AI assistant on 2026-10-26 from the pages and PDFs named in each entry (ATI and Rolled Alloys PDFs extracted to text; AZoM and the 1.4438 page read as web pages). Caveats: the ATI physical properties table covers four grades and is not split by grade; the 1.4438 page gives rounded values; the AZoM and 1.4438 values carry no test condition; the Rolled Alloys figures are from a 2011 bulletin; the chromium and molybdenum shares are calculated from printed tons.'
sources:
  ati-tds:
    title: 'ATI 316, ATI 316L, ATI 317 and ATI 317L Technical Data Sheet (Stainless Steel: Austenitic), version 1'
    id: UNS S31600, S31603, S31700, S31703; ASTM A240; ASME SA-240
    url: https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/austenitic/ati_316_316l_317_317l_tds_en1.pdf
    year: 2012
    kind: datasheet
    license: Manufacturer data sheet (cited, not reproduced)
  rolled-alloys-317l:
    title: 317L Stainless Steel data sheet, Rolled Alloys bulletin No. 1037U
    id: Bulletin No. 1037U
    url: https://www.rolledalloys.com/wp-content/uploads/317L_stainless-steel-data-sheet-rolled-alloys.pdf
    year: 2011
    kind: datasheet
    license: Manufacturer data sheet (cited, not reproduced)
  azom-317l:
    title: Stainless Steel Grade 317L (UNS S31703), AZoM
    url: https://www.azom.com/article.aspx?ArticleID=8262
    kind: web
    license: Web article (cited, not reproduced)
  virgamet-1-4438:
    title: 1.4438, AISI 317L, UNS S31703 stainless steel (X2CrNiMo18-15-4), VIRGAMET offer page
    id: EN 1.4438; X2CrNiMo18-15-4
    url: https://virgamet.com/offer/x2crnimo18154-1-4438-aisi-317l-uns-s31703-z3cnd191504-stainless-steel
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  rolled-sds:
    title: Rolled Alloys controlled document, general products safety data sheet (revised February 2025)
    url: https://www.rolledalloys.com/wp-content/uploads/2022/07/General-Product-Safety-Data-Sheet.pdf
    year: 2025
    kind: datasheet
    license: Safety data sheet (cited, not reproduced)
  usgs-nickel-2026:
    title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: Public domain (US government)
  usgs-chromium-2026:
    title: 'USGS Mineral Commodity Summaries 2026: Chromium'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
    kind: report
    license: Public domain (US government)
  usgs-molybdenum-2026:
    title: 'USGS Mineral Commodity Summaries 2026: Molybdenum'
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
    kind: report
    license: Public domain (US government)
license: CC-BY-4.0
story:
  risk_groups:
    - title: For people
      lead: Welding fume is the main hazard. The massive alloy, as shipped, has no known toxicity beyond allergy to its metals such as nickel.
      level: 1
      verdict: Fume, not solid metal
      points:
        - label: Solid metal
          line: The supplier safety data sheet says the massive alloy has no known toxicological properties other than allergic reactions in people sensitive to its metals.
        - label: Welding and grinding fume
          line: Fume contains oxides of iron, manganese, nickel and chromium. The same sheet says IARC has concluded that welding fumes are possibly carcinogenic to humans, and classes nickel as a Category 3 carcinogen.
    - title: If it fails
      lead: 'These are the failure routes found in the sources. None is a measured field result for 317L: the sources are a standard, a supplier test and the datasheets.'
      level: 2
      verdict: Weld and chloride routes
      points:
        - label: Sensitized welds
          line: Chromium carbides form in the 427 to 816 °C range. The low carbon of 317L limits this, and ATI prefers the L grade for welds in corrosive media.
        - label: Chloride cracking
          line: Chloride ions with residual tensile stress can crack the steel above about 49 °C (120 °F). ATI says the low-carbon grades give no advantage in that test.
    - title: Handling
      lead: Handling is mostly about fume control, welding filler and machining.
      level: 1
      verdict: Control fume and work hardening
      points:
        - label: Welding
          line: Use AWS E/ER 317L filler metal and avoid oxyacetylene welding, according to AZoM.
        - label: Machining
          line: Use low speed and constant feed, with chip breakers, because the alloy work-hardens.
  why: AISI 317L is a stainless steel for chloride-bearing service where ordinary 304 is not enough. The molybdenum content gives it a pitting index (PREN) of 29.7 in ATI's formula, against 24.2 for 316 and 316L, and the low carbon keeps welds from sensitizing. ATI gives its minimum annealed strength as 205 MPa yield and 515 MPa tensile. Its density is 8.027 g/cm3, so it is a heavy material, and its thermal conductivity of 14.6 W/(m·K) is low for a metal.
  uses:
    - where: Power plant condensers
      line: AZoM lists condensers in fossil and nuclear fuelled power generation stations among its widely used applications. ATI notes that the 18-8 stainless grades keep their surfaces clean, which often gives better heat transfer than other metals with higher conductivity.
    - where: Process plants
      line: Rolled Alloys lists chemical process vessels, petrochemical plant, pulp and paper equipment and flue gas desulfurization systems as applications.
  can_do:
    - label: Pitting resistance
      value: PREN 29.7
      line: ATI gives a pitting index of 29.7 for 317 and 317L, against 24.2 for 316 and 316L, from the formula Cr + 3.3 Mo + 16 N.
    - label: Strength when annealed
      value: 205 MPa yield, 515 MPa tensile
      line: The ATI minimum for annealed plate, sheet and strip is 205 MPa yield and 515 MPa tensile, with 40 % elongation in 2 in.
    - label: Hot strength
      value: 115 MPa yield at 400 °C
      line: The 1.4438 datasheet gives a yield point above 115 MPa at 400 °C, and a modulus of 172 GPa at the same temperature.
    - label: Weight
      value: 8.027 g/cm3
      line: Density is 8.027 g/cm3 in the ATI physical properties table. That makes it a heavy choice for static plant rather than light structures.
    - label: Conduction
      value: 14.6 W/(m·K)
      line: Thermal conductivity is 14.6 W/(m·K) at 20 to 100 °C in the ATI table, and 14 W/(m·K) at 20 °C in the 1.4438 datasheet. Heat spreads through it at this rate.
  compare: Compared with the lower-molybdenum 316L grade, 317L has more chromium, nickel and molybdenum, which gives it a higher pitting index (PREN 29.7 against 24.2 in ATI's table). It is heavier than the 316L family values in ATI's own table, and it conducts heat at 14.6 W/(m·K). Its strength is set by the ATI minimums for annealed sheet, so read the table rows as examples of this grade, not as a ranking of stainless steels.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Thermal conductivity
      benchmark: thermal_conductivity
    - label: Yield strength
      benchmark: yield_strength
  recipe:
    line: 317L is a wrought austenitic stainless steel, a solid solution of iron, chromium, nickel and molybdenum. Its carbon is kept at 0.03 % maximum to limit chromium carbide precipitation in welds. ATI gives the composition as percentage-by-weight limits, so the shares below are limits, not measured values.
    parts:
      - name: Iron
        symbol: Fe
        share_note: balance
        role: The matrix. Nickel keeps the iron-based structure austenitic at room temperature.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column
      - name: Chromium
        symbol: Cr
        share_percent: 18
        share_high: 20
        role: Forms the passive oxide film that protects against general corrosion.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column
      - name: Nickel
        symbol: Ni
        share_percent: 11
        share_high: 15
        role: Stabilizes the austenitic structure.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column
      - name: Molybdenum
        symbol: Mo
        share_percent: 3
        share_high: 4
        role: Raises resistance to pitting and crevice corrosion in chloride solutions.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column
      - name: Manganese
        symbol: Mn
        share_note: maximum 2.0
        role: Present in the grade up to the ATI maximum.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column
      - name: Silicon
        symbol: Si
        share_note: maximum 0.75
        role: Present in the grade up to the ATI maximum.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column
      - name: Carbon
        symbol: C
        share_note: maximum 0.03
        role: Kept low so that chromium carbides do not form at grain boundaries during welding, which is what the L in 317L means.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column
      - name: Nitrogen
        symbol: 'N'
        share_note: maximum 0.10
        role: Adds to the pitting index (16 N in the PREN formula) and to strength.
        source: ati-tds
        where: Percentage by weight table, ATI 317L column; PREN formula in the pitting section
  handling:
    - Specify the temper and product form, since the minimum strengths are for annealed plate, sheet and strip.
    - Use fume extraction and a fume respirator for welding, cutting and grinding.
    - Weld with 317L filler metal and avoid oxyacetylene welding.
    - Machine at low speed with constant feed to limit work hardening.
  good_for:
    - 'Chloride pitting in process plant: PREN 29.7 with a low-carbon grade for welds.'
    - Condensers and heat exchange in power plant, and pulp and paper equipment, as the sources list.
    - Annealed sheet, strip and plate where a 205 MPa minimum yield is enough.
  watch_out:
    - Chloride stress cracking above about 49 °C (120 °F) under tensile stress.
    - 'Not for seawater: ATI does not recommend the molybdenum grades at 19,000 ppm chloride.'
    - Not for highly oxidizing acids such as nitric acid.
    - Welding fume contains nickel and chromium compounds, and IARC classes welding fumes as possibly carcinogenic.
    - No space use or space-environment test is recorded for 317L in the sources read.
  verdict: AISI 317L is a low-carbon molybdenum stainless steel for chloride-bearing process plant, condensers and pulp and paper equipment. It resists pitting better than 316L (PREN 29.7 against 24.2) and does not sensitize in welds, but it cracks under chloride stress above about 49 °C, it is heavy at 8.027 g/cm3 and conducts heat at 14.6 W/(m·K), and no space-environment data for it were found.