spore: profile
id: stainless-317lmn
spore_version: 0.2
family: stainless-austenitic
name: AISI 317LMN stainless steel
abbreviation: 317LMN
role: corrosion-resistant structural alloy
category: metals
type: steels-and-stainless
summary: |
  AISI 317LMN stainless steel (UNS S31726, EN 1.4439) has a density of 8.0 g/cm3 at room temperature in the ATI datasheet. ATI gives its ASTM A240 minimum strength for annealed plate, sheet and strip as 240 MPa yield and 550 MPa tensile. It is a low-carbon, molybdenum- and nitrogen-bearing austenitic grade with a pitting resistance equivalent (PRE) of 38 in ATI's formula, against 30 for 317L and 25 for 316. ATI intends it for severe service such as flue gas desulfurization systems. No spacecraft use or space-environment test was found for it.
best_for: 'Chloride and acid process service above 317L: PRE 38 against 30 in ATI''s formula, with a low-carbon grade for welds'
weakest_at: Chloride stress cracking under tensile stress, and embrittlement after prolonged exposure in the sigma and carbide range (ATI)
identity:
  formula: 'Iron-based austenitic alloy, % by weight (ATI 317LMN composition, per ASTM A240): Cr 17.0-20.0, Ni 13.5-17.5, Mo 4.0-5.0, N 0.10-0.20, Mn 2.00 max, Si 0.75 max, C 0.030 max, P 0.045 max, S 0.030 max, Fe balance (UNS S31726)'
  source: ati-317lmn-tds
  where: Chemical Composition in Weight Percent table, ATI 317LMN column (per ASTM A240)
  designations:
    - system: UNS
      code: S31726
      source: ati-317lmn-tds
      where: Title block and Chemical Composition table, UNS No. S31726 column
    - system: AISI
      code: 317LMN
      source: team-edelstahl-pdf
      where: Normen und Bezeichnungen table, AISI row
    - system: EN
      code: '1.4439'
      source: team-edelstahl-pdf
      where: Normen und Bezeichnungen table, EN row
    - system: EN name
      code: X2CrNiMoN17-13-5
      source: team-edelstahl-pdf
      where: Normen und Bezeichnungen table, DIN row
    - system: ASTM
      code: A240
      note: plate, sheet and strip
      source: ati-317lmn-tds
      where: Mechanical Properties section, minimum properties per ASTM A240
    - system: Trade name
      code: ATI 317LMN
      source: ati-317lmn-tds
      where: Title block, ATI 317LMN trademark
tags:
  environments: []
  stresses: []
  applications:
    - structures
properties:
  - benchmark: density
    label: Density, room temperature (ATI)
    value: 8
    unit: g/cm3
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 20 °C (68 °F), room temperature as stated in the physical properties section
      basis: ATI says its physical data are applicable to the 317LMN, 317LM and 317L class for all practical purposes
      unit_in_source: 0.29 lb/in3 and 8.0 g/cm3
    method: Value printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Density row, g/cm3 line
  - benchmark: elastic_modulus
    label: Modulus of elasticity (ATI)
    value: 200
    unit: GPa
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 20 °C (68 °F), room temperature
    method: Value printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Modulus of Elasticity row, GPa line
  - benchmark: melting_point
    label: Melting range (ATI)
    value: 1320
    value_high: 1400
    bound: range
    unit: °C
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      unit_in_source: 2410 to 2550 °F
    method: Range printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Melting Range row, °C line
  - benchmark: melting_point
    label: Melting range (Sandmeyer sheet)
    value: 1393
    value_high: 1443
    bound: range
    unit: °C
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      unit_in_source: 2540 – 2630°F
    method: Range printed on the Sandmeyer 317LMN specification sheet; it differs from the ATI range, both recorded
    status: ground
    source: sandmeyer-317lmn
    where: Physical Properties block, Melting Range row, °C line (1393 – 1443°C)
  - benchmark: thermal_conductivity
    label: Thermal conductivity, 20 to 100 °C (ATI)
    value: 14.6
    unit: W/(m·K)
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 20 to 100 °C (68 to 212 °F)
      unit_in_source: 14.6 Watts/m-K
    method: Value printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Thermal Conductivity row, 20 to 100 °C line
  - benchmark: thermal_conductivity
    label: Thermal conductivity, 20 °C (Team Edelstahl 1.4439 datasheet)
    value: 14
    unit: W/(m·K)
    scope: material
    conditions:
      grade: 1.4439
      temperature: 20 °C
      unit_in_source: 14 W/m K
    method: Value printed in the physikalische Eigenschaften table of the Team Edelstahl 1.4439 datasheet
    status: ground
    source: team-edelstahl-pdf
    where: Physikalische Eigenschaften bei 20°C table, Wärmeleitfähigkeit column
  - benchmark: specific_heat
    label: Specific heat capacity (ATI)
    value: 0.46
    unit: J/g-K
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 20 °C (68 °F), room temperature
      unit_in_source: 0.46 J/g-K
    method: Value printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Specific Heat row, J/g-K line
  - benchmark: specific_heat
    label: Specific heat capacity, 0 to 100 °C (Sandmeyer sheet)
    value: 502
    unit: J/(kg·K)
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 0 to 100 °C
      unit_in_source: 502 J/kg-°K (0 – 100°C)
    method: Value printed in the physical properties block of the Sandmeyer 317LMN specification sheet
    status: ground
    source: sandmeyer-317lmn
    where: Physical Properties block, Specific Heat row, J/kg-°K line
  - benchmark: cte
    label: Coefficient of thermal expansion, 25 to 100 °C (ATI)
    value: 16.5
    unit: 10^-6/°C
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 77 °F (25 °C) to 212 °F (100 °C)
      unit_in_source: 9.2 (16.5) 10-6 /°F (10-6 /°C)
    method: Value in brackets printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Coefficient of Thermal Expansion row, 212 °F (100 °C) line, °C value in brackets
  - benchmark: cte
    label: Coefficient of thermal expansion, 25 to 500 °C (ATI)
    value: 18.2
    unit: 10^-6/°C
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 77 °F (25 °C) to 932 °F (500 °C)
      unit_in_source: 10.1 (18.2) 10-6 /°F (10-6 /°C)
    method: Value in brackets printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Coefficient of Thermal Expansion row, 932 °F (500 °C) line, °C value in brackets
  - benchmark: electrical_resistivity
    label: Electrical resistivity (ATI)
    value: 0.79
    unit: μ-ohm-m
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 20 °C (68 °F), room temperature
      unit_in_source: 31.1 μ-ohm-in and 0.79 μ-ohm-m
    method: Value printed in the physical properties section of the ATI datasheet
    status: ground
    source: ati-317lmn-tds
    where: Physical Properties page, Electrical Resistivity row, μ-ohm-m line
  - benchmark: electrical_resistivity
    label: Electrical resistivity, 20 °C (Sandmeyer sheet)
    value: 85.1
    unit: Microhm-cm
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 20 °C
      unit_in_source: 85.1 Microhm-cm at 20°C
    method: Value printed in the physical properties block of the Sandmeyer 317LMN specification sheet; it differs from the ATI value, both recorded
    status: ground
    source: sandmeyer-317lmn
    where: Physical Properties block, Electrical Resistivity row, 85.1 Microhm-cm at 20°C line
  - benchmark: yield_strength
    label: Yield strength, 0.2% offset, minimum (ASTM A240, ATI)
    value: 240
    bound: lower
    unit: MPa
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      form: plate, sheet and strip
      temper: annealed
      standard: ASTM A240 minimum
      unit_in_source: 35 ksi (240 MPa)
    method: Minimum mechanical property printed in the ATI 317LMN column of the ASTM A240 table
    status: ground
    source: ati-317lmn-tds
    where: Minimum Mechanical Properties per ASTM A240 table, ATI 317LMN column, 0.2% Yield Strength row
  - benchmark: ultimate_tensile_strength
    label: Ultimate tensile strength, minimum (ASTM A240, ATI)
    value: 550
    bound: lower
    unit: MPa
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      form: plate, sheet and strip
      temper: annealed
      standard: ASTM A240 minimum
      unit_in_source: 80 ksi (550 MPa)
    method: Minimum mechanical property printed in the ATI 317LMN column of the ASTM A240 table
    status: ground
    source: ati-317lmn-tds
    where: Minimum Mechanical Properties per ASTM A240 table, ATI 317LMN column, Ultimate Tensile Strength row
  - benchmark: elongation
    label: Elongation in 2 in (5.1 cm), minimum (ASTM A240, ATI)
    value: 40
    bound: lower
    unit: '%'
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      form: plate, sheet and strip
      temper: annealed
      gauge: 2 in (5.1 cm)
    method: Minimum mechanical property printed in the ATI 317LMN column of the ASTM A240 table
    status: ground
    source: ati-317lmn-tds
    where: Minimum Mechanical Properties per ASTM A240 table, ATI 317LMN column, % Elongation in 2" row
  - benchmark: hardness_brinell
    label: Hardness, maximum, Brinell (ASTM A240, ATI)
    value: 223
    bound: upper
    unit: HB
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      form: plate, sheet and strip
      temper: annealed
      standard: ASTM A240 maximum
      unit_in_source: 223 BHN, 96 RB
    method: Maximum printed in the ATI 317LMN column of the ASTM A240 table
    status: ground
    source: ati-317lmn-tds
    where: Minimum Mechanical Properties per ASTM A240 table, ATI 317LMN column, Hardness Maximum row
  - benchmark: yield_strength
    label: Yield point Rp0.2, minimum at 20 °C (Team Edelstahl 1.4439 datasheet)
    value: 280
    bound: lower
    unit: N/mm2
    scope: material
    conditions:
      grade: 1.4439
      temperature: 20 °C
      basis: minimum printed in the German datasheet; product form not stated
    method: Value printed in the Mechanische Eigenschaften bei 20°C table of the Team Edelstahl 1.4439 datasheet
    status: ground
    source: team-edelstahl-pdf
    where: Mechanische Eigenschaften bei 20°C table, Dehngrenze Rp0,2 column, ≥ 280 N / mm² line
  - benchmark: ultimate_tensile_strength
    label: Tensile strength Rm, 20 °C (Team Edelstahl 1.4439 datasheet)
    value: 580
    value_high: 800
    bound: range
    unit: N/mm2
    scope: material
    conditions:
      grade: 1.4439
      temperature: 20 °C
      basis: range printed in the German datasheet; product form not stated
    method: Range printed in the Mechanische Eigenschaften bei 20°C table of the Team Edelstahl 1.4439 datasheet
    status: ground
    source: team-edelstahl-pdf
    where: Mechanische Eigenschaften bei 20°C table, Zugfestigkeit Rm column, 580 - 800 N / mm² line
  - benchmark: elongation
    label: Elongation A5.65, minimum at 20 °C (Team Edelstahl 1.4439 datasheet)
    value: 35
    bound: lower
    unit: '%'
    scope: material
    conditions:
      grade: 1.4439
      temperature: 20 °C
      gauge: A5,65 as printed
    method: Minimum printed in the Mechanische Eigenschaften bei 20°C table of the Team Edelstahl 1.4439 datasheet
    status: ground
    source: team-edelstahl-pdf
    where: Mechanische Eigenschaften bei 20°C table, Dehnung A5,65 column, ≥ 35% line
  - benchmark: hardness_brinell
    label: Hardness, maximum at 20 °C (Team Edelstahl 1.4439 datasheet)
    value: 250
    bound: upper
    unit: HB
    scope: material
    conditions:
      grade: 1.4439
      temperature: 20 °C
    method: Maximum printed in the Mechanische Eigenschaften bei 20°C table of the Team Edelstahl 1.4439 datasheet
    status: ground
    source: team-edelstahl-pdf
    where: Mechanische Eigenschaften bei 20°C table, Härte HB column, ≤ 250 line
  - benchmark: pitting_resistance_equivalent
    label: Pitting resistance equivalent, PRE (ATI 317LMN)
    value: 38
    unit: '-'
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      formula: PRE = Cr + 3.3Mo + 30N, as printed by ATI
      basis: calculated by ATI from the composition; not a test result
    method: Calculated value printed in the ATI Pitting Resistance Equivalents table
    status: calculated
    source: ati-317lmn-tds
    where: Pitting Resistance Equivalents table, ATI 317LMN row
  - benchmark: pitting_resistance_equivalent
    label: Pitting resistance equivalent, PRE (ATI 317L, comparison grade)
    value: 30
    unit: '-'
    scope: material
    conditions:
      grade: 317L (UNS S31703), comparison only
      formula: PRE = Cr + 3.3Mo + 30N, as printed by ATI
      basis: calculated by ATI from the composition; not a test result
    method: Calculated value printed in the ATI Pitting Resistance Equivalents table
    status: calculated
    source: ati-317lmn-tds
    where: Pitting Resistance Equivalents table, ATI 317L row
  - benchmark: pitting_resistance_equivalent
    label: Pitting resistance equivalent, PRE (ATI 316, comparison grade)
    value: 25
    unit: '-'
    scope: material
    conditions:
      grade: 316 (comparison only, not 317LMN)
      formula: PRE = Cr + 3.3Mo + 30N, as printed by ATI
      basis: calculated by ATI from the composition; not a test result
    method: Calculated value printed in the ATI Pitting Resistance Equivalents table
    status: calculated
    source: ati-317lmn-tds
    where: Pitting Resistance Equivalents table, ATI 316 row
  - benchmark: critical_crevice_corrosion_temperature
    label: Critical crevice corrosion temperature (ATI 317LMN)
    value: 24
    unit: °C
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      test: modified ASTM G48 B
      unit_in_source: 75 °F
    method: Value printed in the Critical Crevice Corrosion Temperatures table; onset temperature of crevice corrosion
    status: ground
    source: ati-317lmn-tds
    where: Critical Crevice Corrosion Temperatures table, ATI 317LMN row, °C column
  - benchmark: corrosion_rate
    label: Corrosion rate, 10 % sulfuric acid, boiling (ATI 317LMN)
    value: 4.01
    unit: mm/y
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      medium: 10 % sulfuric acid, boiling, annealed strip (ATI samples activated)
      unit_in_source: 158 mils per year (4.01 mm/y)
    method: Value in brackets printed in the Corrosion Resistance in Boiling Solutions and ASTM Tests table
    status: ground
    source: ati-317lmn-tds
    where: Corrosion Resistance in Boiling Solutions and ASTM Tests table, Sulfuric Acid 10% row, ATI 317LMN column
  - benchmark: corrosion_rate
    label: Corrosion rate, 10 % sulfuric acid, boiling (ATI 316L, comparison grade)
    value: 16.2
    unit: mm/y
    scope: material
    conditions:
      grade: 316L, comparison only
      medium: 10 % sulfuric acid, boiling, annealed strip (ATI samples activated)
      unit_in_source: 636 mils per year (16.2 mm/y)
    method: Value in brackets printed in the Corrosion Resistance in Boiling Solutions and ASTM Tests table
    status: ground
    source: ati-317lmn-tds
    where: Corrosion Resistance in Boiling Solutions and ASTM Tests table, Sulfuric Acid 10% row, ATI 316L column
  - benchmark: crevice_weight_loss_fgd_simulant
    label: Crevice weight loss in simulated FGD solution, 50 °C (ATI 317LMN)
    value: 0.0129
    unit: g/cm2
    scope: material
    conditions:
      grade: 317LMN (UNS S31726)
      temperature: 50 °C (122 °F)
      medium: simulated FGD system solution, 72-hour exposure based on ASTM G-48B, 7 vol.% H2SO4, 3 vol% HCl, 1 wt% CuCl2, 1 wt% FeCl3
      unit_in_source: g/Cm2
    method: Value printed in the Crevice Corrosion in a Simulated FGD System Environment table
    status: ground
    source: ati-317lmn-tds
    where: Crevice Corrosion in a Simulated FGD System Environment table, ATI 317LMN row, 50 °C column
  - benchmark: crevice_weight_loss_fgd_simulant
    label: Crevice weight loss in simulated FGD solution, 50 °C (ATI 317L, comparison grade)
    value: 0.0377
    unit: g/cm2
    scope: material
    conditions:
      grade: 317L, comparison only
      temperature: 50 °C (122 °F)
      medium: simulated FGD system solution, 72-hour exposure based on ASTM G-48B, 7 vol.% H2SO4, 3 vol% HCl, 1 wt% CuCl2, 1 wt% FeCl3
      unit_in_source: g/Cm2
    method: Value printed in the Crevice Corrosion in a Simulated FGD System Environment table
    status: ground
    source: ati-317lmn-tds
    where: Crevice Corrosion in a Simulated FGD System Environment table, ATI 317L row, 50 °C column
corrosion:
  - environment: Chloride solutions, pitting and crevice attack
    headline: 'Molybdenum and nitrogen raise the pitting index: PRE 38 for 317LMN, against 30 for 317L and 25 for 316 in ATI''s table.'
    effect: ATI says the combination of molybdenum and nitrogen is particularly effective in enhancing resistance to pitting and crevice corrosion, and that its PRE formula is Cr + 3.3Mo + 30N. ATI's critical crevice corrosion temperature for 317LMN is 24 °C in a modified ASTM G48 B test.
    rating: moderate
    conditions:
      basis: PRE calculated by ATI from composition; critical crevice temperature from a modified ASTM G48 B test
    source: ati-317lmn-tds
    where: Introduction; Pitting Resistance Equivalents table; Critical Crevice Corrosion Temperatures table
  - environment: Simulated flue gas desulfurization solution, crevice attack at 50 °C
    headline: In a simulated flue gas desulfurization solution at 50 °C, 317LMN lost 0.0129 g/cm2, against 0.0377 g/cm2 for 317L (ATI).
    effect: ATI reports that crevice corrosion in this simulated solution is less for 317LMN than for 317L at the same test temperature. Its 72-hour test is based on ASTM G-48B, and ATI names it as a case where these alloys are frequently used.
    rating: moderate
    conditions:
      temperature: 50 °C (122 °F)
      basis: single 72-hour test in one simulated solution; not a service life
    source: ati-317lmn-tds
    where: Crevice Corrosion in a Simulated FGD System Environment table
  - environment: Boiling 10 % sulfuric acid
    headline: In boiling 10 % sulfuric acid, 317LMN corroded at 4.01 mm/y, against 16.2 mm/y for 316L (ATI).
    effect: ATI says resistance to sulfuric acid increases with molybdenum content, and that the alloys resist sulfuric acid up to 5 percent at temperatures as high as 120°F (49°C). Higher concentrations at lower temperatures need service tests.
    rating: moderate
    conditions:
      medium: 10 % sulfuric acid, boiling, annealed strip
      basis: ATI boiling-solution table; samples activated as printed
    source: ati-317lmn-tds
    where: Corrosion Resistance in Boiling Solutions and ASTM Tests table; Corrosion Resistance 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 says that environments not corrosive to 18Cr-8Ni steels will not attack molybdenum-bearing alloys, with the exception of highly oxidizing acids such as nitric acid.
    rating: moderate
    conditions:
      basis: general statement; no concentration or temperature given
    source: ati-317lmn-tds
    where: Corrosion Resistance section, first paragraph
  - environment: Welds and prolonged heating in the sensitization range
    headline: The low carbon resists sensitization in welds, but long exposure in the sigma and carbide range can still harm intergranular corrosion resistance.
    effect: ATI says prolonged exposure in the range "800 to 1400°F (427-816°C)" can be detrimental to intergranular corrosion resistance and may cause sigma-phase embrittlement. Sandmeyer says the higher nitrogen of 317LMN retards sigma and carbide precipitation.
    rating: moderate
    conditions:
      basis: ATI low-carbon statement (less than 0.03%); Sandmeyer nitrogen statement
    source: ati-317lmn-tds
    where: Corrosion Resistance section, sensitization paragraph
  - environment: Chloride ions with tensile stress
    headline: Chloride stress cracking is still possible; 317LMN is only somewhat better than 304 and 304L.
    effect: Sandmeyer says 317LMN "is somewhat more resistant to stress corrosion cracking than 304/304L stainless steels" but "it is still susceptible".
    rating: moderate
    conditions:
      basis: general statement; no threshold temperature or stress given in the sources read
    source: sandmeyer-317lmn
    where: General Corrosion Resistance section, stress corrosion cracking paragraph
  - environment: Mild atmospheric and other mildly corrosive media
    headline: Media that do not attack 18Cr-8Ni steels will normally not attack 317LMN.
    effect: ATI says environments that are not corrosive to 18Cr-8Ni steels will not attack alloys containing molybdenum, with the exception of highly oxidizing acids.
    rating: low
    conditions:
      basis: general statement; no test duration or concentration given
    source: ati-317lmn-tds
    where: Corrosion Resistance section, first paragraph
risks:
  hazards:
    - text: The Rolled Alloys general SDS says that, as shipped, massive alloys have no known toxicological properties other than allergic reactions in people sensitive to the metals, such as nickel. It does not name 317LMN.
      ghs: []
      source: rolled-sds
      where: Section XI, Toxicological information
    - text: Welding and grinding fume contains oxides of iron, manganese, nickel and chromium. The same SDS says IARC has concluded that welding fumes are possibly carcinogenic to humans.
      ghs: []
      source: rolled-sds
      where: Section X (stability and reactivity, fume constituents) and Section XI (toxicology)
    - text: The same SDS says nickel and cobalt are classified as Category 3 carcinogens, with inhalation as the route of concern.
      ghs: []
      source: rolled-sds
      where: Section XI, Toxicological information, first paragraph
  failure_risks:
    - mode: Sigma-phase embrittlement and carbide precipitation
      trigger: Prolonged exposure in the range ATI prints as 800 to 1400°F (427-816°C), such as stress relief, forging or weld heat-affected zones
      consequence: Embrittlement and lower intergranular corrosion resistance. Sandmeyer says the nitrogen in 317LMN retards sigma phase as well as carbides, which lowers the risk but does not remove it.
      severity: moderate
      source: ati-317lmn-tds
      where: Corrosion Resistance section, sensitization paragraph
    - mode: Chloride stress corrosion cracking
      trigger: Chloride or other halide ions together with residual tensile stress from cold work or welding
      consequence: The steel can crack in service. Sandmeyer says the alloy is still susceptible, although somewhat more resistant than 304 and 304L.
      severity: high
      source: sandmeyer-317lmn
      where: General Corrosion Resistance section, stress corrosion cracking paragraph
    - mode: Pitting and crevice attack in chloride-bearing acid
      trigger: Chloride ions in crevices or under deposits, such as in flue gas desulfurization systems
      consequence: Local attack at crevices. ATI gives a critical crevice corrosion temperature of 24 °C in a modified ASTM G48 B test, so crevice attack can start at modest temperatures in severe crevices.
      severity: moderate
      source: ati-317lmn-tds
      where: Critical Crevice Corrosion Temperatures table; Crevice Corrosion in a Simulated FGD System Environment table
    - mode: Weld corrosion without an overalloyed filler
      trigger: Welding without an overalloyed filler metal, and no post-weld anneal and pickle, in a corrosive service
      consequence: The weld may resist attack less than the base metal. ATI says the optimum corrosion resistance of welds comes from post-weld annealing and pickling.
      severity: moderate
      source: ati-317lmn-tds
      where: Weldability section
    - mode: Work hardening during machining
      trigger: Machining with dull tools or light, interrupted cuts
      consequence: The alloy work-hardens, which raises tool wear and the risk of surface damage. Sandmeyer says it is less machinable than 410 stainless steel.
      severity: low
      source: sandmeyer-317lmn
      where: Machining section
  handling:
    - text: Use local exhaust ventilation and a fume respirator for welding, cutting and grinding, as the Rolled Alloys SDS recommends.
      source: rolled-sds
      where: Section VIII, Engineering controls and respiratory protection
    - text: Weld with an overalloyed filler metal, as ATI suggests for 317LMN, and post-weld anneal and pickle where the service needs the full corrosion resistance.
      source: ati-317lmn-tds
      where: Weldability section
    - text: Hot work and solution anneal at the temperatures printed in the Sandmeyer and Team Edelstahl sheets; do not work the alloy below the minimum that Sandmeyer prints.
      source: sandmeyer-317lmn
      where: Hot Forming section
    - text: Machine with sharp tools and a steady feed, because the alloy work-hardens (Sandmeyer machining section).
      source: sandmeyer-317lmn
      where: Machining section
  mitigations:
    - text: Team Edelstahl prints a solution-annealing range of "1020 - 1120°C" (Lösungsglühen, +AT) and a hot-forming range of "1120 - 900°C".
      source: team-edelstahl-pdf
      where: Thermische Behandlung table, page 2 (Lösungsglühen and Warmformgebung rows)
    - text: Post-weld annealing and pickling give the optimum corrosion resistance of autogenous welds, according to ATI.
      source: ati-317lmn-tds
      where: Weldability section
uses:
  - application: structures
    device: Flue gas desulfurization systems, stack liners, absorbers, ducts, dampers and fans
    example: Sandmeyer lists air pollution control, including flue gas desulfurization systems, stack liners, absorbers, ducts, dampers and fans, among the applications of 317LMN.
    source: sandmeyer-317lmn
    where: Applications list
  - application: structures
    device: Apparatus and vessel construction, chemical and petrochemical plant
    example: Team Edelstahl lists apparatus and vessel construction, chemical and petrochemical industry, food, paper, pump, and pulp and textile industries as markets for 1.4439.
    source: team-edelstahl-web
    where: Markets and Applications list
supply:
  - subject: Nickel (austenite former, in the ATI composition range)
    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 (main passive-film former, in the ATI composition range)
    abundance: 'USGS: world chromium resources are "greater than 12 billion tons of shipping-grade chromite".'
    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; World Resources; Recycling; Substitutes
  - subject: Molybdenum (4.0 to 5.0 % in the ATI composition range)
    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 and cast irons.'
    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 317LMN Technical Data Sheet (Stainless Steel: Austenitic), version 1, 2012'
    type: datasheet
    url: https://atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/austenitic/ati_317lmn_tds_en_v1.pdf
    year: 2012
  - title: 'Sandmeyer Steel, Specification Sheet: 317LMN (UNS S31726) W. Nr. 1.4439, rev 02/2023'
    type: datasheet
    url: https://www.sandmeyersteel.com/wp-content/uploads/Alloy317LMN-SpecSheet.pdf
    year: 2023
  - title: TEAM EDELSTAHL, 1.4439 material page (English)
    type: datasheet
    url: https://www.teamedelstahl.de/en/materials/1-4439/
  - title: TEAM EDELSTAHL, 1.4439 Werkstoff Datenblatt (German)
    type: datasheet
    url: https://www.teamedelstahl.de/wp-content/uploads/2021/04/1.4439.pdf
  - title: Rolled Alloys controlled document, 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 317LMN: no source found. No space use is recorded and tags.environments is empty.'
  - 'Space environment data for 317LMN (atomic oxygen, outgassing, cold welding, radiation, vacuum): none found or read.'
  - 'Cryogenic toughness and cold-temperature tensile data: not read.'
  - 'Minimum yield strength differs by source: ATI gives the ASTM A240 minimum for annealed plate, sheet and strip, and Team Edelstahl gives a minimum from its German datasheet with no product form. Both are recorded with their conditions.'
  - Melting range and electrical resistivity differ between ATI and Sandmeyer. Both are recorded with their units as printed and are not converted or averaged.
  - Sandmeyer thermal conductivity and mean coefficient of thermal expansion are printed in a garbled or exponent form in the PDF text, so they are not recorded.
  - Sandmeyer typical-value strength row is garbled in the PDF text, so it is not recorded and does not conflict with the ATI minimum in this profile.
  - Property names hardness_brinell, critical_crevice_corrosion_temperature, corrosion_rate, crevice_weight_loss_fgd_simulant and pitting_resistance_equivalent are not in spores/property-canon.yaml. Short snake_case names are used and need adding to the canon.
  - 'Elevated-temperature creep, stress-rupture and high-temperature strength: ATI describes higher strengths qualitatively; no values were read.'
  - 'Nitrogen supply and abundance: not covered by the USGS summaries read in this run. Nitrogen is listed only as a composition range.'
  - 'Critical-mineral list status for nickel, chromium and molybdenum: none of the USGS 2026 summaries read states a critical-list entry for these metals, so critical_lists is empty.'
  - 'Recipe atomic weights: not read in this run, so the recipe gives composition ranges by weight only.'
  - 'Safety data sheet: the only SDS read is the Rolled Alloys general products SDS, which covers a family of alloys and does not list 317LMN in its appendix. No 317LMN-specific safety data sheet was found.'
  - 'GHS classification for the massive alloy: none in the sources read.'
  - 'Welding fume exposure limits: the Rolled Alloys SDS gives limits in a table whose units were not in the extracted text, so none are recorded.'
  - A PRE value for 1.4439 found only in a search result snippet was not recorded, because no fetched page printed it.
  - Solution-annealing and hot-forming temperatures are recorded only as quoted source text in mitigations and handling, not as properties.
  - 'Media: no openly licensed image was checked for this profile.'
updated: '2026-11-01'
review:
  status: draft
  method: assistant
  checked_values: 28
  unreachable: 0
  caveats: 5
  note: 'Values were read by an AI assistant on 2026-11-01 from the ATI 317LMN datasheet (version 1, 2012, PDF extracted to text), the Sandmeyer 317LMN specification sheet (rev 02/2023, PDF), the Team Edelstahl 1.4439 datasheet (German PDF and English page), the Rolled Alloys general products SDS (revised February 2025) and the three USGS 2026 summaries. Caveats: the ATI physical properties are stated for the 317LMN, 317LM and 317L class; the Team Edelstahl values are minimums or ranges without product form; the Sandmeyer and ATI melting and resistivity values disagree and both are kept; the chromium and molybdenum shares are calculated from printed tons; the SDS is a family document that does not name 317LMN.'
sources:
  ati-317lmn-tds:
    title: 'ATI 317LMN Technical Data Sheet (Stainless Steel: Austenitic), version 1'
    id: UNS S31726; ASTM A240
    url: https://atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/austenitic/ati_317lmn_tds_en_v1.pdf
    year: 2012
    kind: datasheet
    license: Manufacturer data sheet (cited, not reproduced)
  sandmeyer-317lmn:
    title: 'Sandmeyer Steel, Specification Sheet: 317LMN (UNS S31726) W. Nr. 1.4439, rev 02/2023'
    id: UNS S31726; W. Nr. 1.4439
    url: https://www.sandmeyersteel.com/wp-content/uploads/Alloy317LMN-SpecSheet.pdf
    year: 2023
    kind: datasheet
    license: Manufacturer data sheet (cited, not reproduced)
  team-edelstahl-web:
    title: TEAM EDELSTAHL, 1.4439 material page (English)
    url: https://www.teamedelstahl.de/en/materials/1-4439/
    kind: datasheet
    license: Supplier web page (cited, not reproduced)
  team-edelstahl-pdf:
    title: TEAM EDELSTAHL, 1.4439 Werkstoff Datenblatt (German)
    id: EN 1.4439; X2CrNiMoN17-13-5; AISI 317LMN; UNS S31726
    url: https://www.teamedelstahl.de/wp-content/uploads/2021/04/1.4439.pdf
    kind: datasheet
    license: Supplier data sheet (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, according to the Rolled Alloys SDS.
      level: 1
      verdict: Fume, not solid metal
      points:
        - label: Solid metal
          line: The Rolled Alloys SDS says massive alloys have no known toxicological properties other than allergic reactions in people sensitive to their metals. It does not name 317LMN.
        - label: Welding and grinding fume
          line: Fume contains oxides of iron, manganese, nickel and chromium. The same SDS says IARC has concluded that welding fumes are possibly carcinogenic to humans.
    - title: If it fails
      lead: 'These are the failure routes found in the sources. None is a measured field result for 317LMN: the sources are a manufacturer datasheet, a supplier sheet, a safety sheet and USGS summaries.'
      level: 2
      verdict: Sigma phase and chloride cracking
      points:
        - label: Sigma phase and carbides
          line: Prolonged exposure in the sigma and carbide range can embrittle the alloy and lower its intergranular corrosion resistance. Sandmeyer says the nitrogen in 317LMN slows sigma phase as well as carbides.
        - label: Chloride cracking
          line: Chloride ions with residual tensile stress can crack the steel. Sandmeyer says 317LMN is somewhat more resistant than 304 and 304L, but it is still susceptible.
    - 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 an overalloyed filler metal, as ATI suggests, and post-weld anneal and pickle where the service needs full corrosion resistance.
        - label: Machining
          line: Use sharp tools and a steady feed, because the alloy work-hardens.
  why: AISI 317LMN is a stainless steel for chloride and acid service above 317L. Its molybdenum and nitrogen give a PRE of 38 in ATI's formula, against 30 for 317L and 25 for 316. ATI gives its minimum annealed strength as 240 MPa yield and 550 MPa tensile, and its density is 8.0 g/cm3 at room temperature.
  uses:
    - where: Flue gas desulfurization systems
      line: Sandmeyer lists flue gas desulfurization systems, stack liners, absorbers, ducts, dampers and fans among the applications of 317LMN. ATI says the grade is intended for severe service such as FGD systems.
    - where: Chemical and petrochemical plant
      line: Team Edelstahl lists apparatus and vessel construction and the chemical and petrochemical industry as markets for 1.4439, along with food, paper, pump, and pulp and textile industries.
  can_do:
    - label: Pitting resistance
      benchmark: pitting_resistance_equivalent
      line: ATI gives a PRE of 38 for 317LMN, calculated from its formula Cr + 3.3Mo + 30N, against 30 for 317L and 25 for 316.
    - label: Strength when annealed
      benchmark: yield_strength
      line: The ATI minimum for annealed plate, sheet and strip is 240 MPa yield and 550 MPa tensile, with 40 % elongation in 2 in.
    - label: Acid corrosion
      benchmark: corrosion_rate
      line: In boiling 10 % sulfuric acid, ATI measured 4.01 mm/y for 317LMN and 16.2 mm/y for 316L.
    - label: Weight
      benchmark: density
      line: Density is 8.0 g/cm3 at room temperature in the ATI datasheet, a heavy material for static plant rather than light structures.
  compare: Compared with 316L, 317LMN has more molybdenum and adds nitrogen, which gives it a PRE of 38 in ATI's formula against 25 for 316. In ATI's boiling 10 % sulfuric acid test, 317LMN corroded at 4.01 mm/y, against 16.2 mm/y for 316L. Its yield minimum of 240 MPa applies to annealed plate, sheet and strip under ASTM A240, so the strength rows describe that product form only.
  compare_rows:
    - label: Density
      benchmark: density
    - label: Pitting resistance equivalent
      benchmark: pitting_resistance_equivalent
    - label: Yield strength
      benchmark: yield_strength
  recipe:
    line: 317LMN is a wrought austenitic stainless steel, a solid solution of iron, chromium, nickel and molybdenum with a nitrogen addition. Carbon is kept low so that chromium carbides do not form at grain boundaries in welds. ATI gives the composition as percentage-by-weight ranges per ASTM A240, 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-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column
      - name: Chromium
        symbol: Cr
        share_percent: 17
        share_high: 20
        role: Forms the passive oxide film that protects against general corrosion.
        source: ati-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column
      - name: Nickel
        symbol: Ni
        share_percent: 13.5
        share_high: 17.5
        role: Stabilizes the austenitic structure.
        source: ati-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column
      - name: Molybdenum
        symbol: Mo
        share_percent: 4
        share_high: 5
        role: Raises resistance to pitting and crevice corrosion in chloride solutions.
        source: ati-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column
      - name: Nitrogen
        symbol: 'N'
        share_percent: 0.1
        share_high: 0.2
        role: Adds to the pitting index (30 N in the PRE formula) and increases strength.
        source: ati-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column; PRE formula in the Pitting Resistance Equivalents table
      - name: Manganese
        symbol: Mn
        share_note: maximum 2.00
        role: Present in the grade up to the ATI maximum.
        source: ati-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column
      - name: Silicon
        symbol: Si
        share_note: maximum 0.75
        role: Present in the grade up to the ATI maximum.
        source: ati-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column
      - name: Carbon
        symbol: C
        share_note: maximum 0.030
        role: Kept low so that chromium carbides do not form at grain boundaries during welding, which is what the L in 317LMN means.
        source: ati-317lmn-tds
        where: Chemical Composition in Weight Percent table, ATI 317LMN column
  handling:
    - Specify the temper and product form, since the minimum strengths are for annealed plate, sheet and strip.
    - Use local exhaust ventilation and a fume respirator for welding, cutting and grinding.
    - Weld with an overalloyed filler metal and post-weld anneal and pickle where the service needs full corrosion resistance.
    - Machine with sharp tools and a steady feed to limit work hardening.
  good_for:
    - Chloride pitting and crevice attack in process plant, with PRE 38 in ATI's formula.
    - Flue gas desulfurization systems, stack liners, absorbers, ducts and fans, as Sandmeyer lists.
    - Annealed plate, sheet and strip where a 240 MPa minimum yield is enough.
  watch_out:
    - Chloride stress cracking under tensile stress, which Sandmeyer says the grade is still susceptible to.
    - Highly oxidizing acids such as nitric acid, which ATI names as the known exception.
    - 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 317LMN in the sources read.
  verdict: AISI 317LMN (UNS S31726, EN 1.4439) is a low-carbon, molybdenum- and nitrogen-bearing stainless steel for chloride and acid process plant and FGD systems. It has a PRE of 38 in ATI's formula against 30 for 317L and 25 for 316, and it has 240 MPa minimum yield when annealed. It is heavy at 8.0 g/cm3, it can still crack under chloride stress, and no space-environment data for it were found.