spore: profile
id: stainless-316l
spore_version: 0.2
family: stainless-austenitic
name: Stainless steel 316L
abbreviation: 316L (UNS S31603)
role: corrosion-resistant structural alloy
category: metals
type: steels-and-stainless
summary: |
  Type 316L is the extra-low-carbon form of 316, an austenitic chromium-nickel stainless steel with 2 to 3 percent molybdenum added. The molybdenum improves resistance to chloride pitting, and the carbon limit of 0.030 percent maximum limits chromium carbide after welding. Datasheets give a minimum tensile strength of 485 MPa and a minimum yield strength of 170 MPa for sheet, plate and strip, and a density of 7.99 to 8.03 g/cm3. Its uses cited here are marine parts, aerospace structures and vacuum hardware. Its main limits are sensitization after slow cooling through 450 to 900 C and pitting in seawater.
best_for: Welded parts in chloride or marine service, and vacuum hardware that is vacuum-fired
weakest_at: Long holds near 650 C form sigma phase, and seawater service needs a pitting resistance equivalent number greater than 40 (Wikipedia)
identity:
  formula: Fe balance; 16.0 to 18.0 Cr, 10.0 to 14.0 Ni, 2.00 to 3.00 Mo, max 0.030 C, max 2.00 Mn, max 0.75 Si, max 0.045 P, max 0.030 S, max 0.10 N (wt%)
  source: cmc-316l
  where: Nominal Composition table of the Combined Metals data sheet (REV 2024 01 11); the UPMET 316/316L composition table gives the same limits
  designations:
    - system: UNS
      code: S31603
      source: cmc-316l
      where: Title and header of the Combined Metals data sheet (Alloy 316L Stainless Steel, UNS S31603)
    - system: EN
      code: '1.4404'
      source: outokumpu-quarto
      where: 'Supra 316L/4404 entry, ''EN: 1.4404'' with ''ASTM type: TYPE 316L / UNS S31603'''
    - system: EN
      code: '1.4435'
      source: alleima-list
      where: 'EN steel no. column, Alleima 3R60 row (S31603, 316L, 1.4435); Outokumpu Supra 316L/4435 also prints ''EN: 1.4435'''
    - system: EN name
      code: X2CrNiMo17-12-2
      source: alloys-intl-316l
      where: 316L entry, W.Nr 1.4404 followed by X2CrNiMo17-12-2
    - system: DIN
      code: X2CrNiMo 17 13 2
      source: totalmateria-en-1-4404
      where: EN 1.4404 international equivalents, row with standard DIN (free view, 15 of 1066 rows)
    - system: JIS
      code: SUS316L
      source: totalmateria-astm-a240-316l
      where: ASTM A 240 Type 316L international equivalents, row SUS316L with standard JIS (free view, 15 of 1059 rows)
    - system: ISO
      code: X2CrNiMo17-12-2
      source: totalmateria-en-1-4404
      where: EN 1.4404 international equivalents, last row, standard ISO (free view)
    - system: AISI
      code: 316L
      source: icast-astm-a240
      where: ICAST ASTM A240 UNS S31603 data sheet, cross reference table, row 316L with standard AISI
    - system: ASTM
      code: A240
      source: cmc-316l
      where: Applicable Specifications line of the Combined Metals 316L data sheet
    - system: ASTM
      code: A276
      source: carpenter-316l
      where: Applicable Specifications list on the Carpenter 316L page
    - system: ASTM
      code: A182
      source: carpenter-316l
      where: Applicable Specifications list on the Carpenter 316L page (the F316L form is not printed under ASTM)
    - system: ASTM
      code: A312 TP316L
      source: totalmateria-astm-a312-tp316l
      where: 'Page title ''ASTM A 312 TP316L'' with standard A312/A312M: 2025 (free view)'
    - system: ASME
      code: SA-182 F 316L
      source: totalmateria-astm-a240-316l
      where: ASTM A 240 Type 316L international equivalents, row SA-182 F 316L with standard ASME (free view)
    - system: BS
      code: 316S11
      note: nearest equivalent
      source: aalco-316l
      where: Aalco 1.4404 (316L) sheet and plate datasheet, same 'may not be a direct equivalent' list. Totalmateria (standard B.S.) and ICAST print 316 S 11 without the hedge.
tags:
  environments: []
  stresses: []
  applications:
    - structures
properties:
  - benchmark: density
    value: 8.03
    unit: g/cm3
    scope: material
    conditions:
      basis: density row, shown for plate, sheet and strip
      temperature: not stated
      form: plate, sheet, strip
    method: Physical properties row of the ATI table, value in g/cm3 as printed (the 0.29 lb/in3 entry is the imperial value)
    status: ground
    source: ati-316l
    where: Density row of the ATI 316L table
  - benchmark: density
    value: 8.027
    unit: g/cm3
    scope: material
    conditions:
      basis: physical properties table, no temperature stated
    method: Physical Properties table, printed as 0.29 lb/in3 (8.027 g/cm3)
    status: ground
    source: upmet-316l
    where: Physical Properties of 316/316L table, Density row
  - benchmark: density
    value: 7.99
    unit: g/cm3
    scope: material
    conditions:
      temperature: 20 C (printed as At 20oC)
      basis: Physical Properties table, metric column
    method: Physical Properties table, metric column as printed
    status: ground
    source: cmc-316l
    where: Physical Properties table, Density row
  - benchmark: elastic_modulus
    value: 193
    unit: GPa
    scope: material
    conditions:
      temperature: 20 C (printed as At 20oC)
      loading: tension
      unit_in_source: 193 x 10^3 MPa
    method: Physical Properties table, Modulus of Elasticity row, printed as 193 x 10 MPa in tension with the exponent garbled in the PDF text; 193 x 10^3 MPa equals 193 GPa
    status: ground
    source: cmc-316l
    where: Physical Properties table, Modulus of Elasticity (E) row
  - benchmark: elastic_modulus
    value: 200
    unit: GPa
    scope: material
    conditions:
      loading: tension
      basis: no temperature stated
      unit_in_source: 29 x 10^6 psi
    method: Physical Properties table, Modulus of Elasticity in Tension row, GPa value as printed in brackets
    status: ground
    source: upmet-316l
    where: Physical Properties of 316/316L table, Modulus of Elasticity in Tension row
  - benchmark: shear_modulus
    value: 82
    unit: GPa
    scope: material
    conditions:
      basis: no temperature stated
      unit_in_source: 11.9 x 10^6 psi
    method: Physical Properties table, Modulus of Shear row, GPa value as printed in brackets
    status: ground
    source: upmet-316l
    where: Physical Properties of 316/316L table, Modulus of Shear row
  - benchmark: melting_point
    value: 1390
    value_high: 1440
    unit: °C
    scope: material
    conditions:
      basis: melting range as printed
      unit_in_source: 2540 to 2630 F
    method: Physical Properties table, Melting Range row, range printed in C in brackets; minimum and maximum as printed
    status: ground
    source: upmet-316l
    where: Physical Properties of 316/316L table, Melting Range row
  - benchmark: specific_heat
    value: 450
    unit: J/kg °K
    scope: material
    conditions:
      temperature: 20 C (68 F)
    method: Specific Heat table, value at 20 C as printed in J/kg K
    status: ground
    source: upmet-316l
    where: Physical Properties of 316/316L table, Specific Heat row at 20 C
  - benchmark: thermal_conductivity
    value: 14.6
    unit: W/m·K
    scope: material
    conditions:
      temperature_range: 20 to 100 C (68 to 212 F)
    method: Thermal Conductivity table, value in W/m K as printed
    status: ground
    source: upmet-316l
    where: Physical Properties of 316/316L table, Thermal Conductivity row (20 to 100 C)
  - benchmark: thermal_conductivity
    value: 16.2
    unit: W/m·K
    scope: material
    conditions:
      temperature: 100 C (printed as 100oC)
    method: Physical Properties table, metric value at 100 C as printed
    status: ground
    source: cmc-316l
    where: Physical Properties table, Thermal Conductivity row
  - benchmark: cte
    value: 16.5
    unit: 10-6 cm/cm/°C
    scope: material
    conditions:
      temperature_range: 20 to 100 C (68 to 212 F)
      basis: mean coefficient over the range
    method: Linear Coefficient of Thermal Expansion table, mean value for 20 to 100 C printed as 16.5 x 10^-6 cm/cm/C
    status: ground
    source: upmet-316l
    where: Physical Properties of 316/316L table, linear CTE row for 20 to 100 C
  - benchmark: cte
    value: 16
    unit: μm/m·°C
    scope: material
    conditions:
      temperature_range: 0 to 100 C (printed as 0-100oC)
    method: Coefficient of Expansion row, metric value as printed in μm/m-oC
    status: ground
    source: cmc-316l
    where: Physical Properties table, Coefficient of Expansion row
  - benchmark: electrical_resistivity
    value: 74
    unit: μΩ·cm
    scope: material
    conditions:
      temperature: 20 C (printed as At 20oC)
    method: Electrical Resistivity row, metric value as printed in μ ohm.cm
    status: ground
    source: cmc-316l
    where: Physical Properties table, Electrical Resistivity row
  - benchmark: ultimate_tensile_strength
    value: 485
    unit: MPa
    scope: material
    conditions:
      form: plate, sheet, strip
      basis: minimum value as printed (ASTM A240 per the page)
      temper: not stated
    method: Mechanical properties table, tensile strength row, minimum as printed (70 ksi min, 485 min)
    status: ground
    source: ati-316l
    where: Mechanical properties table, Tensile Strength row
  - benchmark: ultimate_tensile_strength
    value: 485
    unit: MPa
    scope: material
    conditions:
      alloy: Type 316L (S31603) column
      basis: table value, minimum or typical not stated
      temper: not stated
      unit_in_source: 70,000 psi
    method: Mechanical Properties of 316/316L table, Ultimate Tensile Strength row, MPa value in the 316L column
    status: ground
    source: upmet-316l
    where: Mechanical Properties of 316/316L table, Ultimate Tensile Strength row, 316L column
  - benchmark: ultimate_tensile_strength
    value: 558
    unit: MPa
    scope: material
    conditions:
      temper: annealed
      basis: Annealed (Min) row of the typical room temperature table
      unit_in_source: 81 ksi
    method: Typical Room Temperature Mechanical Properties table, Annealed (Min) row, MPa as printed; the data sheet notes the values are based on ASTM A240
    status: ground
    source: cmc-316l
    where: Typical Room Temperature Mechanical Properties table, Annealed (Min) row
  - benchmark: yield_strength
    value: 170
    unit: MPa
    scope: material
    conditions:
      form: plate, sheet, strip
      basis: minimum value as printed; offset not stated on this page
      temper: not stated
    method: Mechanical properties table, yield strength row, minimum as printed (25 ksi min, 170 min)
    status: ground
    source: ati-316l
    where: Mechanical properties table, Yield Strength row
  - benchmark: yield_strength
    value: 170
    unit: MPa
    scope: material
    conditions:
      alloy: Type 316L (S31603) column
      offset: 0.2%
      basis: table value, minimum or typical not stated
      temper: not stated
      unit_in_source: 25,000 psi
    method: Mechanical Properties of 316/316L table, Yield Strength 0.2% Offset row, MPa value in the 316L column
    status: ground
    source: upmet-316l
    where: Mechanical Properties of 316/316L table, Yield Strength 0.2% Offset row, 316L column
  - benchmark: yield_strength
    value: 290
    unit: MPa
    scope: material
    conditions:
      temper: annealed
      offset: 0.2%
      basis: Annealed (Min) row of the typical room temperature table
      unit_in_source: 42 ksi
    method: Typical Room Temperature Mechanical Properties table, 0.2% YS column, Annealed (Min) row, MPa as printed; the same row is labelled typical in the header note
    status: ground
    source: cmc-316l
    where: Typical Room Temperature Mechanical Properties table, 0.2% YS column
  - benchmark: elongation
    value: 40
    unit: '%'
    scope: material
    conditions:
      form: plate, sheet, strip
      basis: minimum as printed
      gauge_length: not stated on this page
      temper: not stated
    method: Mechanical properties table, elongation row, as printed (40% min)
    status: ground
    source: ati-316l
    where: Mechanical properties table, Elongation row
  - benchmark: elongation
    value: 40
    unit: '%'
    scope: material
    conditions:
      alloy: Type 316L (S31603) column
      gauge_length: 2 in or 51 mm
      basis: table value, minimum or typical not stated
      temper: not stated
    method: Mechanical Properties of 316/316L table, Percent Elongation row, 316L column
    status: ground
    source: upmet-316l
    where: Mechanical Properties of 316/316L table, Percent Elongation row, 316L column
  - benchmark: elongation
    value: 50
    unit: '%'
    scope: material
    conditions:
      temper: annealed
      gauge_length: 2 in (50.8 mm)
      basis: Annealed (Min) row of the typical room temperature table
    method: Typical Room Temperature Mechanical Properties table, Elongation column, Annealed (Min) row, as printed
    status: ground
    source: cmc-316l
    where: Typical Room Temperature Mechanical Properties table, Elongation row
corrosion:
  - environment: Chloride-bearing water and submerged seawater
    headline: Chloride ions cause pitting and crevice corrosion in susceptible stainless steels; for submerged seawater a pitting resistance equivalent number greater than 40 is typically specified.
    effect: Wikipedia says 316 and 316L, although used commonly in marine applications, are not suitable for condenser tubes in seawater because they are susceptible to crevice and pitting corrosion. It calls 316L the preferred steel for marine environments because of its greater resistance to pitting corrosion than most other grades of steel without molybdenum.
    rating: moderate
    conditions:
      solution: chloride, seawater
      criterion: pitting resistance equivalent number greater than 40 for submerged service (Wikipedia)
    source: wiki-316
    where: 'Marine grade stainless article: Suitability for marine use, and the introduction'
  - environment: Sulfuric, hydrochloric, acetic, formic and tartaric acids; acid sulfates and alkaline chlorides
    headline: Combined Metals says corrosion resistance is improved against these acids and salts, and that molybdenum improves resistance to chloride pitting.
    effect: The data sheet says the molybdenum addition increases general corrosion resistance and improves resistance to pitting from chloride ion solutions. UPMET says the molybdenum-bearing 316 family is more resistant to general corrosion and pitting and crevice corrosion than Type 304. No corrosion rate or test result for 316L was read in this run.
    rating: low
    conditions:
      basis: qualitative datasheet statement, no test conditions given
    source: cmc-316l
    where: Introduction paragraph of the Combined Metals data sheet
  - environment: Heating or slow cooling through 450 to 900 C, as in a weld heat-affected zone
    headline: Chromium carbide forms at grain boundaries in this range; 316L limits carbon to 0.030 percent maximum to reduce it.
    effect: Thermal Processing says austenitic stainless steels become sensitized in the 450 to 900 C range, with chromium carbide precipitating at grain boundaries, and sensitization occurs when carbon is above about 0.02 percent. The L designation controls carbon to below 0.030 percent to improve weldability and limit chromium carbide. Deliberate sensitization is done by holding at 650 C for one to two hours, and testing follows ASTM A262.
    rating: moderate
    conditions:
      temperature: 450 to 900 C
      carbon_threshold: above about 0.02 percent
      carbon_limit_L: below 0.030 percent
      test: ASTM A262, deliberate 650 C hold for 1 to 2 h
    source: thermal-processing
    where: Sensitization of Austenitic Stainless Steels; Introduction (L grades); Testing for Sensitization
  - environment: Long isothermal holds at 650 C
    headline: Sigma phase forms at grain boundaries after long holds; the study saw it after 1000 h at 650 C.
    effect: A study of AISI 316L (0% cold work, and 40% cold work followed by annealing) found M23C6 carbide, chi and sigma phases precipitated at grain boundaries, with sigma in the 650 C for 1000 h condition. The authors say sigma kinetics are very slow, so it can take hundreds to thousands of hours to form, and that precipitation of carbides and sigma, chi and Laves phases causes sensitisation of the steel.
    rating: moderate
    conditions:
      temperature: 650 C
      time: 100, 300 and 1000 h annealing series
      material_condition: 0% cold work, and 40% cold work then annealing
    source: pmc-sigma-316l
    where: Results and discussion (650 C annealing series, sigma phase); Introduction (sigma kinetics)
risks:
  hazards:
    - text: 'PubChem aggregated GHS for elemental nickel (CID 935, signal Danger): H317 May cause an allergic skin reaction; H351 Suspected of causing cancer; H372 Causes damage to organs through prolonged or repeated exposure. PubChem reports that 0.1 percent (5 of 4,778) of company reports say it does not meet GHS criteria. The data cover the element, not the alloy.'
      ghs:
        - H317
        - H351
        - H372
      source: pubchem-nickel
      where: Safety and Hazards, GHS Classification (aggregated)
    - text: 'PubChem aggregated GHS for elemental chromium (CID 23976, signal Danger): H317 (20.7 percent of notifications) May cause an allergic skin reaction; H319 (19.1 percent) Causes serious eye irritation; H334 (20.3 percent) May cause allergy or asthma symptoms if inhaled. Half of 2,404 reports say it does not meet GHS criteria.'
      ghs:
        - H317
        - H319
        - H334
      source: pubchem-chromium
      where: Safety and Hazards, GHS Classification (aggregated)
    - text: 'PubChem notifications for elemental molybdenum (CID 23932) are mixed: H228 (30 percent) Flammable solid and H361 (29.5 percent) Suspected of damaging fertility or the unborn child for one group, and H315, H319 and H335 (skin, eye and respiratory irritation) for another. 57.4 percent of 1,523 reports say it does not meet GHS criteria.'
      ghs:
        - H228
        - H361
        - H315
        - H319
        - H335
      source: pubchem-molybdenum
      where: Safety and Hazards, GHS Classification (aggregated and per-notification entries)
  failure_risks:
    - mode: Intergranular (sensitization) corrosion after welding or slow cooling
      trigger: Slow cooling or holding through 450 to 900 C, as in a weld heat-affected zone
      consequence: Chromium carbide at grain boundaries leaves the boundary open to attack. The 0.030 percent carbon limit makes this much less likely than in the higher-carbon 316.
      severity: moderate
      source: thermal-processing
      where: Sensitization of Austenitic Stainless Steels
    - mode: Pitting and crevice corrosion in seawater or chloride service
      trigger: Submerged seawater or chloride-bearing water where the pitting resistance equivalent number is not above 40
      consequence: 316 and 316L are not suitable for seawater condenser tubes because they are susceptible to crevice and pitting corrosion (Wikipedia).
      severity: high
      source: wiki-316
      where: 'Marine grade stainless article: Suitability for marine use'
    - mode: Sigma phase precipitation after long holds near 650 C
      trigger: Hundreds to thousands of hours at 650 C, as in long service or slow cooling through the range
      consequence: The study reports that carbides and sigma, chi and Laves phases precipitate and cause sensitisation of the steel. The datasheets read here do not give a service temperature limit for this.
      severity: moderate
      source: pmc-sigma-316l
      where: Results and discussion; Introduction
  side_effects: []
  handling:
    - text: Specify 316L, not 316, for welded parts in corrosive service. UPMET lists 316 with up to 0.08 percent carbon and 316L with a 0.030 percent maximum.
      source: upmet-316l
      where: Chemical Composition tables, 316/316L
    - text: Avoid holding 316L between 450 and 900 C during fabrication or service, because chromium carbide and sigma phase form in that range.
      source: thermal-processing
      where: Sensitization of Austenitic Stainless Steels
    - text: The datasheets give ASTM A240 minimums for plate, sheet and strip, and separate annealed typical values. Check the mill certificate for the form and temper being bought.
      source: cmc-316l
      where: Typical Room Temperature Mechanical Properties table, note
  mitigations:
    - text: For vacuum service, vacuum-fire the parts at about 950 C for 24 hours under vacuum. In NIST's seven-chamber comparison, unfired 304L, 316L and 316LN chambers gave hydrogen outgassing of 4.0 to 8.0 x 10^-11 Pa L/s/cm2, while the vacuum-fired 316L-XHV chamber gave below 1 x 10^-11.
      source: nist-vacuum-2020
      where: Abstract; Results (hydrogen outgassing); chamber table (316L-XHV, vacuum-fired 950 C, 24 hours or more)
    - text: For submerged seawater service, a pitting resistance equivalent number greater than 40 is typically specified as the minimum (Wikipedia).
      source: wiki-316
      where: 'Marine grade stainless article: Suitability for marine use'
    - text: Use the low-carbon 316L rather than 316 wherever the part will be welded, so that carbide precipitation at the weld is limited.
      source: cmc-316l
      where: Opening paragraph (316L is an extra-low carbon version of Type 316 that minimizes harmful carbide precipitation due to welding)
uses:
  - application: structures
    device: Aerospace structures
    example: UPMET lists aerospace structures among the industry applications for 316 and 316L sheet, coil and bar. No flight or space test result is given on the datasheet.
    source: upmet-316l
    where: Industry Applications list, 316/316L datasheet
  - application: structures
    device: Parts exposed to marine atmospheres
    example: Combined Metals lists parts exposed to marine atmospheres among the industries supplied for 316L, alongside exhaust manifolds, heat exchangers, jet engine parts and pharmaceutical equipment.
    source: cmc-316l
    where: Industries supplied paragraph, opening of the Combined Metals data sheet
  - application: structures
    device: Ultra-high-vacuum chamber walls (laboratory)
    example: In a NIST comparison of seven similar vacuum chambers, the vacuum-fired 316L chamber had hydrogen outgassing below 1 x 10^-11 Pa L/s/cm2, in the same ultra-low class as the titanium and aluminium chambers.
    source: nist-vacuum-2020
    where: Abstract and hydrogen outgassing results
supply:
  - subject: Nickel
    abundance: Stainless and alloy steel plus nickel-containing alloys typically account for more than 85% of US domestic consumption. World reserves are more than 140,000,000 t, of which Indonesia holds 62,000,000 t (USGS 2026).
    producers:
      - country: Indonesia
        share_percent: 66.7
        year: 2025
        basis: 2,600,000 t of 3,900,000 t world mine production (estimated), computed
      - country: Philippines
        share_percent: 6.9
        year: 2025
        basis: 270,000 t of 3,900,000 t, computed
      - country: Russia
        share_percent: 5.1
        year: 2025
        basis: 200,000 t of 3,900,000 t, computed
      - country: New Caledonia
        share_percent: 3.6
        year: 2025
        basis: 140,000 t of 3,900,000 t, computed
      - country: Canada
        share_percent: 3.6
        year: 2025
        basis: 140,000 t of 3,900,000 t, computed
      - country: China
        share_percent: 3.1
        year: 2025
        basis: 120,000 t of 3,900,000 t, computed
    critical_lists: []
    recycling: Nickel recovered from scrap accounted for about 60% of US apparent consumption in 2025, and most recycled nickel goes into new alloys and stainless steel (USGS 2026).
    substitutes:
      - Low-nickel, duplex or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction (USGS 2026)
      - Titanium alloys can substitute for nickel or nickel-base alloys in corrosive environments (USGS 2026)
    source: usgs-nickel-2026
    where: Domestic Production and Use; World Mine Production and Reserves table (2025e); Recycling; Substitutes
  - subject: Nickel import reliance, United States
    abundance: US net import reliance was an estimated 41% of apparent consumption in 2025 (USGS 2026).
    producers: []
    critical_lists: []
    recycling: Recycled nickel was about 60% of apparent consumption in 2025.
    substitutes: []
    source: usgs-nickel-2026
    where: Salient Statistics (net import reliance row, 2025e)
  - subject: Chromium
    abundance: World resources are greater than 12 billion t of shipping-grade chromite, and 95% of world chromium resources lie in Kazakhstan and southern Africa (USGS 2026).
    producers:
      - country: South Africa
        share_percent: 45.1
        year: 2025
        basis: 23,000 of 51,000 thousand t gross weight (estimated), computed
      - country: Turkey
        share_percent: 17.6
        year: 2025
        basis: 9,000 of 51,000 thousand t, computed
      - country: Kazakhstan
        share_percent: 13.7
        year: 2025
        basis: 7,000 of 51,000 thousand t, computed
      - country: India
        share_percent: 5.9
        year: 2025
        basis: 3,000 of 51,000 thousand t, computed
      - country: Brazil
        share_percent: 3.9
        year: 2025
        basis: 2,000 of 51,000 thousand t, computed
      - country: Zimbabwe
        share_percent: 3.9
        year: 2025
        basis: 2,000 of 51,000 thousand t, computed
    critical_lists: []
    recycling: Recycled chromium in stainless-steel scrap receipts was 21% of US apparent consumption in 2025 (USGS 2026).
    substitutes:
      - Chromium has no substitute in stainless steel, the leading end use (USGS 2026)
    source: usgs-chromium-2026
    where: World Mine Production and Reserves table (2025e, gross weight); World Resources; Substitutes; Recycling
  - subject: Chromium import reliance, United States
    abundance: 'US net import reliance was 79% of apparent consumption in 2025 (estimated). Chromite imports 2021 to 2024: South Africa 96%, Turkey 3% (USGS 2026).'
    producers: []
    critical_lists: []
    recycling: Recycled chromium was 21% of apparent consumption in 2025.
    substitutes: []
    source: usgs-chromium-2026
    where: Salient Statistics (net import reliance row); Import Sources (2021 to 2024)
  - subject: Molybdenum
    abundance: Molybdenum is used principally as an alloying agent in cast iron, steel and superalloys (USGS 2026). World mine production was an estimated 260,000 t of molybdenum content in 2025.
    producers:
      - country: China
        share_percent: 37.3
        year: 2025
        basis: 97,000 of 260,000 t molybdenum content (estimated), computed
      - country: Chile
        share_percent: 16.2
        year: 2025
        basis: 42,000 of 260,000 t, computed
      - country: United States
        share_percent: 15.4
        year: 2025
        basis: 40,000 of 260,000 t, computed
      - country: Peru
        share_percent: 15
        year: 2025
        basis: 39,000 of 260,000 t, computed
      - country: Mexico
        share_percent: 6.5
        year: 2025
        basis: 17,000 of 260,000 t, computed
    critical_lists: []
    recycling: Molybdenum recycled as part of new and old steel and other scrap may be as much as 30% of apparent supply (USGS 2026).
    substitutes:
      - There is little substitution for molybdenum in steels and cast irons (USGS 2026)
    source: usgs-molybdenum-2026
    where: World Mine Production and Reserves table (2025e); Domestic Production and Use; Recycling; Substitutes
  - subject: Molybdenum export controls
    abundance: The Government of China imposed export controls on molybdenum powders in February 2025, and the United States and other countries have sought alternative sources (USGS 2026).
    producers: []
    critical_lists: []
    recycling: ''
    substitutes: []
    source: usgs-molybdenum-2026
    where: Events, Trends, and Issues
  - subject: Critical-mineral status
    abundance: Nickel and chromium are on the USGS 2025 List of Critical Minerals (60 minerals, November 2025). Molybdenum is not on the list.
    producers: []
    critical_lists:
      - list: 'USGS 2025 List of Critical Minerals: nickel'
        listed: true
      - list: 'USGS 2025 List of Critical Minerals: chromium'
        listed: true
      - list: 'USGS 2025 List of Critical Minerals: molybdenum'
        listed: false
    recycling: ''
    substitutes: []
    source: usgs-crit-2025
    where: About the 2025 List of Critical Minerals page (bulleted list); EU critical raw materials list not read
media: []
documents:
  - title: 'Combined Metals Company data sheet: Alloy 316L Stainless Steel, UNS S31603 (REV 2024 01 11)'
    type: datasheet
    url: https://www.combmet.com/wp-content/uploads/2024/01/316L-Alloy-Data-Sheet-CMC-2024-01-11.pdf
    year: 2024
  - title: 'UPMET datasheet: 316/316L Stainless Steel Sheet, Coil and Bar (AMS 5524, 5507, 5648)'
    type: datasheet
    url: https://www.upmet.com/sites/default/files/datasheets/316-316l.pdf
    year: 2026
  - title: 'ATI: 316L Austenitic Stainless Steel, UNS S31603 (product page)'
    type: datasheet
    url: https://atimaterials.com/Products/ati-316l
  - title: Influence of 40% Cold Working and Annealing on Precipitation in AISI 316L Austenitic Stainless Steel (PMC9505488)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC9505488/
  - title: 'Fedchak et al.: Outgassing rate comparison of seven geometrically similar vacuum chambers of different materials and heat treatments (arXiv:2009.10560)'
    type: paper
    url: https://arxiv.org/pdf/2009.10560
    year: 2020
  - 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
  - title: 'USGS: About the 2025 List of Critical Minerals'
    type: report
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
  - title: 'PubChem: Nickel (CID 935) GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/935
    year: 2026
  - title: 'PubChem: Chromium (CID 23976) GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23976
    year: 2026
  - title: 'PubChem: Molybdenum (CID 23932) GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23932
    year: 2026
  - title: 'Alleima: list of alloys (billets and blooms), grade table with UNS, ASTM and EN steel numbers'
    type: datasheet
    url: https://www.alleima.com/cz/products/billets-and-blooms/list-of-alloys
  - title: 'Aalco: Stainless Steel - Austenitic - 1.4404 (316L) Sheet and Plate (Quarto Plate and CPP)'
    type: datasheet
    url: https://www.aalco.co.uk/datasheets/Stainless-Steel-14404-316L-Sheet-and-Plate-Quarto-Plate--CPP-Plate_346.ashx
  - title: 'Carpenter Technology: 316L alloy page (UNS, applicable specifications)'
    type: datasheet
    url: https://www.carpentertechnology.com/alloy-finder/316L
  - title: 'Outokumpu: quarto plate page, Supra 316L/4404 and Supra 316L/4435 entries'
    type: datasheet
    url: https://www.outokumpu.com/en/products/flat-products/quarto-plate
  - title: 'ICAST Alloys: ASTM A240 UNS S31603 data sheet, cross reference table'
    type: datasheet
    url: https://www.icastllp.com/material_db_pdf/ASTM%20A240%20UNS%20S31603.pdf
  - title: 'Alloys International: stainless steel 316L page (W.Nr and EN names, specifications)'
    type: datasheet
    url: https://alloysintl.com/inventory/stainless-steel/stainless_steel316L/
  - title: 'Total Materia: EN 1.4404 international equivalent materials'
    type: database
    url: https://www.totalmateria.com/en-us/material/1055292
  - title: 'Total Materia: ASTM A 240 Type 316L international equivalent materials'
    type: database
    url: https://www.totalmateria.com/en-us/material/1261273
  - title: 'Total Materia: ASTM A 312 TP316L international equivalent materials'
    type: database
    url: https://www.totalmateria.com/en-us/material/1260779
gaps:
  - Medical implant use is recorded in the story only, because the application list has no medical value. Wikipedia calls 316L the preferred grade for medical implants.
  - No flight, space-thermal, radiation or cryogenic result for 316L was found in this run. The only vacuum source is a laboratory outgassing comparison of chambers, not a space test.
  - Poisson's ratio, hardness at temperature and cryogenic strength were not found in the pages read in this run.
  - The AZoM 316L page could not be located, the Ulbrich 316L page returned HTTP 403, and the ASM Alloy Digest is behind a paywall.
  - The Combined Metals (193 GPa) and UPMET (200 GPa) Young's moduli disagree. Both are kept with their conditions.
  - The UPMET electrical resistivity table labels its two columns with the wrong units, so it is not used. The Combined Metals value (74 microohm cm) is used instead.
  - The Combined Metals table labels the annealed row both as minimum and as typical. The yield and tensile values are kept as printed, with the label in conditions.
  - The PubChem compound web page returned a browser check to the fetch tool, so the hazard records were read from PubChem's REST data for the same CIDs. No 316L safety data sheet was read, and welding-fume hazard was not sourced.
  - The sigma-phase study uses 0% and 40% cold-worked 316L, not mill-annealed sheet, so the kinetics may differ for the product bought.
  - No pitting potential, critical temperature or mg/L chloride limit for 316L was found. Only the PREN above 40 rule and qualitative statements are used.
  - Critical-mineral status is from the USGS 2025 list only. The EU critical raw materials list was not read.
  - Nickel, chromium and molybdenum shares are mine production only. Refinery and smelting shares were not read.
  - Recycling and substitutes for 316L itself were not sourced beyond the element data.
  - The Wikipedia page used for marine and medical statements is titled Marine grade stainless. Its composition table was not used for any number.
  - 'Designations: the BGH 1.4435 datasheet link returned HTTP 404, so EN 1.4435 is cited from the Alleima and Outokumpu grade tables only.'
  - 'Designations: the F316L form is not printed under ASTM on any page read in this run. ASTM A182 is cited from the Carpenter page, and SA-182 F 316L (ASME) from Totalmateria.'
  - 'Designations: the ASTM A240 summary (store.astm.org, 2002 edition), the NZ Building Code Hub A240 and A276 summaries, and the BSI EN 10088-3:2023 summary print no 316L grade name, so none is cited for a designation.'
  - 'Designations: Totalmateria free views show 15 of about 1,000 equivalents per standard, so further national names may exist behind registration.'
  - 'Designations: names printed for 316L outside the requested systems were not added (GOST 03CH17N14M3, ASME SA-240, SA-312, SA-276 and SA-409, AMS and other ASTM product specifications, and GB, IS, AFNOR and CSN equivalents).'
  - 'Designations: the ICAST EN 1.4404 cross-reference rows for JIS, AISI and BS are misaligned (SUS 304L, 361L), so the ICAST ASTM A240 data sheet is used for those names.'
sources:
  ati-316l:
    title: 'ATI: 316L Austenitic Stainless Steel, UNS S31603 (product page)'
    id: ATI product page, 316L
    url: https://atimaterials.com/Products/ati-316l
    kind: datasheet
    license: ATI web page (cited, not reproduced)
  cmc-316l:
    title: 'Combined Metals Company data sheet: Alloy 316L Stainless Steel, UNS S31603, EN-DIN 1.4404'
    id: REV 2024 01 11
    url: https://www.combmet.com/wp-content/uploads/2024/01/316L-Alloy-Data-Sheet-CMC-2024-01-11.pdf
    year: 2024
    kind: datasheet
    license: supplier data sheet (cited, not reproduced)
  upmet-316l:
    title: 'UPMET datasheet: 316/316L Stainless Steel Sheet, Coil and Bar (AMS 5524, 5507, 5648)'
    id: UNS S31600 and S31603
    url: https://www.upmet.com/sites/default/files/datasheets/316-316l.pdf
    year: 2026
    kind: datasheet
    license: supplier data sheet (cited, not reproduced)
  wiki-316:
    title: 'Wikipedia: Marine grade stainless (316 and 316L; URL 316_stainless_steel)'
    id: Marine grade stainless
    url: https://en.wikipedia.org/wiki/316_stainless_steel
    kind: web
    license: CC BY-SA 4.0 (cited, not reproduced)
  thermal-processing:
    title: 'Thermal Processing: Intergranular Corrosion of Austenitic Stainless Steels'
    id: thermalprocessing.com
    url: https://thermalprocessing.com/intergranular-corrosion-of-austenitic-stainless-steels/
    kind: web
    license: web page (cited, not reproduced)
  pmc-sigma-316l:
    title: Influence of 40% Cold Working and Annealing on Precipitation in AISI 316L Austenitic Stainless Steel
    id: PMC9505488
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC9505488/
    kind: paper
    license: open-access article (cited, not reproduced)
  nist-vacuum-2020:
    title: 'Fedchak et al.: Outgassing rate comparison of seven geometrically similar vacuum chambers of different materials and heat treatments'
    id: arXiv:2009.10560
    url: https://arxiv.org/pdf/2009.10560
    year: 2020
    kind: paper
    license: arXiv preprint (cited, not reproduced)
  usgs-nickel-2026:
    title: 'USGS Mineral Commodity Summaries 2026: Nickel'
    id: mcs2026-nickel
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-nickel.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-chromium-2026:
    title: 'USGS Mineral Commodity Summaries 2026: Chromium'
    id: mcs2026-chromium
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-molybdenum-2026:
    title: 'USGS Mineral Commodity Summaries 2026: Molybdenum'
    id: mcs2026-molybdenum
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-crit-2025:
    title: 'USGS: About the 2025 List of Critical Minerals'
    id: 2025 List of Critical Minerals, November 2025
    url: https://www.usgs.gov/programs/mineral-resources-program/science/about-2025-list-critical-minerals
    year: 2025
    kind: web
    license: public domain (USGS)
  pubchem-nickel:
    title: 'PubChem: Nickel (CID 935), Safety and Hazards, GHS Classification'
    id: CID 935
    url: https://pubchem.ncbi.nlm.nih.gov/compound/935
    kind: database
    license: PubChem terms (public)
  pubchem-chromium:
    title: 'PubChem: Chromium (CID 23976), Safety and Hazards, GHS Classification'
    id: CID 23976
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23976
    kind: database
    license: PubChem terms (public)
  pubchem-molybdenum:
    title: 'PubChem: Molybdenum (CID 23932), Safety and Hazards, GHS Classification'
    id: CID 23932
    url: https://pubchem.ncbi.nlm.nih.gov/compound/23932
    kind: database
    license: PubChem terms (public)
  alleima-list:
    title: 'Alleima: list of alloys (billets and blooms), grade table with UNS, ASTM and EN steel numbers'
    id: Alleima list of alloys
    url: https://www.alleima.com/cz/products/billets-and-blooms/list-of-alloys
    kind: datasheet
    license: web page (cited, not reproduced)
  aalco-316l:
    title: 'Aalco: Stainless Steel - Austenitic - 1.4404 (316L) Sheet and Plate (Quarto Plate and CPP)'
    id: 1.4404 (316L) sheet and plate
    url: https://www.aalco.co.uk/datasheets/Stainless-Steel-14404-316L-Sheet-and-Plate-Quarto-Plate--CPP-Plate_346.ashx
    kind: datasheet
    license: supplier data sheet (cited, not reproduced)
  carpenter-316l:
    title: 'Carpenter Technology: 316L alloy page (UNS, applicable specifications)'
    id: 316L alloy finder page
    url: https://www.carpentertechnology.com/alloy-finder/316L
    kind: datasheet
    license: manufacturer web page (cited, not reproduced)
  outokumpu-quarto:
    title: 'Outokumpu: quarto plate page, Supra 316L/4404 and Supra 316L/4435 entries'
    id: quarto plate page
    url: https://www.outokumpu.com/en/products/flat-products/quarto-plate
    kind: datasheet
    license: manufacturer web page (cited, not reproduced)
  icast-astm-a240:
    title: 'ICAST Alloys: ASTM A240 UNS S31603 data sheet, cross reference table'
    id: ASTM A240 UNS S31603
    url: https://www.icastllp.com/material_db_pdf/ASTM%20A240%20UNS%20S31603.pdf
    kind: datasheet
    license: stockist data sheet (cited, not reproduced)
  alloys-intl-316l:
    title: 'Alloys International: stainless steel 316L page (W.Nr and EN names, specifications)'
    id: stainless_steel316L page
    url: https://alloysintl.com/inventory/stainless-steel/stainless_steel316L/
    kind: datasheet
    license: stockist web page (cited, not reproduced)
  totalmateria-en-1-4404:
    title: 'Total Materia: EN 1.4404 international equivalent materials'
    id: EN 1.4404 (free view)
    url: https://www.totalmateria.com/en-us/material/1055292
    kind: database
    license: database page, free view (cited, not reproduced)
  totalmateria-astm-a240-316l:
    title: 'Total Materia: ASTM A 240 Type 316L international equivalent materials'
    id: ASTM A 240 Type 316L (free view)
    url: https://www.totalmateria.com/en-us/material/1261273
    kind: database
    license: database page, free view (cited, not reproduced)
  totalmateria-astm-a312-tp316l:
    title: 'Total Materia: ASTM A 312 TP316L international equivalent materials'
    id: ASTM A 312 TP316L (free view)
    url: https://www.totalmateria.com/en-us/material/1260779
    kind: database
    license: database page, free view (cited, not reproduced)
license: CC-BY-4.0
updated: '2026-10-24'
review:
  status: draft
  method: assistant
  checked_values: 22
  unreachable: 3
  caveats: 1
  note: 'Written by an AI assistant on 2026-10-24 from pages fetched in that run: three datasheets, Wikipedia marine grade stainless, the Thermal Processing sensitization page, the PMC sigma-phase study, the NIST arXiv vacuum paper, USGS 2026 nickel, chromium and molybdenum, the USGS 2025 critical list, and PubChem GHS records for nickel, chromium and molybdenum. Unreachable in this run: AZoM 316L page, Ulbrich 316L page (HTTP 403), and the PubChem web page (browser check).'
story:
  recipe:
    line: 316L is an iron-based austenitic stainless steel. Its nominal composition, from the Combined Metals and UPMET data sheets, is 16 to 18 wt% chromium, 10 to 14 wt% nickel and 2 to 3 wt% molybdenum, with carbon held to 0.030 wt% maximum and iron as the balance. UPMET lists the product as coil, sheet, bar and precision strip. The NIST vacuum study fired its 316L-XHV chamber at about 950 C for 24 hours under vacuum.
    parts:
      - name: Iron
        symbol: Fe
        share_note: balance (the rest)
        role: The matrix of the alloy.
      - name: Chromium
        symbol: Cr
        share_percent: 16
        share_high: 18
        role: Forms the passive oxide film that gives corrosion resistance.
      - name: Nickel
        symbol: Ni
        share_percent: 10
        share_high: 14
        role: Holds the austenite structure.
      - name: Molybdenum
        symbol: Mo
        share_percent: 2
        share_high: 3
        role: Increases general corrosion resistance and resistance to chloride pitting (Combined Metals).
      - name: Carbon
        symbol: C
        share_percent: 0
        share_high: 0.03
        limit: maximum
        role: Kept low so that chromium carbide does not form at grain boundaries after welding.
      - name: Manganese
        symbol: Mn
        share_percent: 0
        share_high: 2
        limit: maximum
        role: Impurity and processing element held to a maximum.
      - name: Silicon
        symbol: Si
        share_percent: 0
        share_high: 0.75
        limit: maximum
        role: Held to a maximum.
      - name: Phosphorus
        symbol: P
        share_percent: 0
        share_high: 0.045
        limit: maximum
        role: Impurity held low.
      - name: Sulfur
        symbol: S
        share_percent: 0
        share_high: 0.03
        limit: maximum
        role: Impurity held low.
      - name: Nitrogen
        symbol: 'N'
        share_percent: 0
        share_high: 0.1
        limit: maximum
        role: Held to a maximum.
  risk_groups:
    - title: For people
      level: 0
      verdict: Not checked against a 316L safety data sheet
      lead: The PubChem records below are for elemental nickel, chromium and molybdenum, not for the finished alloy.
      points:
        - label: Nickel
          line: 'PubChem lists elemental nickel as Danger: H317 (skin sensitiser), H351 (suspected carcinogen) and H372 (organ damage on repeated exposure).'
        - label: Chromium
          line: PubChem lists elemental chromium with H317, H319 and H334 in notifications that carry hazard codes. Half of the 2,404 reports say it does not meet GHS criteria.
        - label: Molybdenum
          line: PubChem's notifications for the element are mixed. Some carry H228 (flammable solid) and H361 (suspected of damaging fertility or the unborn child); others carry H315, H319 and H335.
        - label: Workshop
          line: Cutting, grinding and welding stainless steel can release metal fume and dust. No fume source was read in this run, so check the supplier safety data sheet before work.
    - title: Welding and heat
      level: 1
      verdict: Use 316L for welded parts in corrosive service
      lead: Sensitization is the main fabrication risk, and the L grade is made low-carbon to limit it.
      points:
        - label: Range
          line: Holding or slow cooling between 450 and 900 C precipitates chromium carbide at grain boundaries (Thermal Processing).
        - label: Fix
          line: 316L limits carbon to 0.030 percent maximum. UPMET lists 316 with up to 0.08 percent carbon, so 316L is the welded choice.
    - title: In seawater
      level: 1
      verdict: Chloride is the watch point
      lead: Pitting and crevice corrosion are the main failure routes in chloride service.
      points:
        - label: Seawater
          line: Wikipedia says a pitting resistance equivalent number greater than 40 is typically specified for submerged seawater service.
        - label: Condenser tubes
          line: Wikipedia says 316 and 316L are not suitable for seawater condenser tubes because they are susceptible to crevice and pitting corrosion.
  why: Type 316L is the low-carbon version of 316. Adding 2 to 3 percent molybdenum to the chromium-nickel steel improves resistance to chloride pitting, and UPMET says the molybdenum-bearing 316 family is more resistant to pitting and crevice corrosion than Type 304. The 0.030 percent carbon limit reduces the carbide precipitation that follows welding. The datasheets list it for aerospace structures and parts exposed to marine atmospheres, and NIST tested vacuum-fired 316L for vacuum chambers.
  uses:
    - where: Marine parts
      line: Combined Metals lists parts exposed to marine atmospheres among the industries supplied. Wikipedia calls 316L the preferred steel for marine environments because of its greater resistance to pitting corrosion.
    - where: Aerospace structures
      line: UPMET lists aerospace structures among the industry applications for 316 and 316L sheet, coil and bar. The datasheet gives no flight or space test data.
    - where: Vacuum hardware
      line: In NIST's comparison of seven vacuum chambers, the vacuum-fired 316L chamber had hydrogen outgassing below 1 x 10^-11 Pa L/s/cm2, in the same ultra-low class as the titanium and aluminium chambers. The unfired 316L chamber was higher.
    - where: Medical implants
      line: Wikipedia says 316L is the preferred grade for medical implants because it resists sensitization. No space use is implied; it is recorded here for context.
  can_do:
    - label: Strength
      benchmark: ultimate_tensile_strength
      line: The minimum tensile strength is 485 MPa and the minimum yield is 170 MPa for plate, sheet and strip (ATI). Annealed typical values are 558 MPa tensile and 290 MPa yield (Combined Metals).
    - label: Stiffness
      benchmark: elastic_modulus
      line: Young's modulus is 193 GPa at 20 C (Combined Metals) or 200 GPa (UPMET).
    - label: Density
      benchmark: density
      line: Density is 7.99 g/cm3 at 20 C (Combined Metals), 8.027 g/cm3 (UPMET) or 8.03 g/cm3 (ATI).
    - label: Heat
      benchmark: melting_point
      line: The melting range is 1,390 to 1,440 C (UPMET). Combined Metals says the alloy is somewhat stronger at elevated temperatures than Type 304.
  compare: Combined Metals says that the properties of 316L are similar to Type 304 except that it is somewhat stronger at elevated temperatures. UPMET says the molybdenum-bearing 316 family is more resistant to general corrosion and to pitting and crevice corrosion than Type 304. No Type 304 numbers were read in this run, so the table below compares 316L only with itself across three properties.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Stiffness
      benchmark: elastic_modulus
    - label: Melting range
      benchmark: melting_point
  handling:
    - Specify 316L, not 316, for welded parts in corrosive service. UPMET lists 316 with up to 0.08 percent carbon and 316L with a 0.030 percent maximum.
    - Avoid holding 316L between 450 and 900 C during fabrication or service. Sigma phase forms over hundreds to thousands of hours near 650 C.
    - For vacuum service, vacuum-fire the parts at about 950 C for 24 hours under vacuum, which the NIST study found lowers hydrogen outgassing.
    - The datasheets give ASTM A240 minimums for plate, sheet and strip and separate annealed typical values. Check the mill certificate for the form and temper being bought.
  good_for:
    - Welded corrosion-resistant parts in chloride-bearing service, where the low-carbon grade limits sensitization.
    - Vacuum hardware that is vacuum-fired. The NIST study found its hydrogen outgassing in the ultra-low class.
    - Marine parts exposed to salt air, which Combined Metals lists as a use.
  watch_out:
    - Chloride pitting. A pitting resistance equivalent number above 40 is typically specified for submerged seawater, and 316 and 316L are not suitable for seawater condenser tubes.
    - Sigma phase. Long holds near 650 C form sigma, chi and Laves phases alongside the carbides, and sensitize the steel.
    - Strength is modest for a structural steel, with a minimum yield of 170 MPa on the ATI and UPMET datasheets, so the design must allow for it.
  verdict: 316L is the choice when a 304-type steel would pit in chloride service and the part must be welded. Its limits are its heat history and its chloride limit, so specify the low-carbon grade for welds and check a pitting resistance above 40 for seawater.