{
  "spore": "profile",
  "id": "stainless-904l",
  "spore_version": "0.2",
  "family": "stainless-austenitic",
  "name": "Super-austenitic stainless steel 904L",
  "abbreviation": "904L (UNS N08904, EN 1.4539)",
  "role": "corrosion-resistant austenitic alloy",
  "category": "metals",
  "type": "steels-and-stainless",
  "summary": "904L (UNS N08904, EN 1.4539, sold by Outokumpu as Ultra 904L) is a super-austenitic stainless steel with about 20 percent chromium, 24 percent nickel, 4.3 percent molybdenum and 1.4 percent copper. Outokumpu's typical PRE is 34. Its minimum proof strength is 220 MPa for plate, sheet and strip to ASTM, and 240 MPa for cold-rolled strip to EN 10088-2. It is annealed at 1060 to 1140 °C and quenched. It is used for sulfuric and phosphoric acid plant, utility scrubbers, seawater heat exchangers, pulp and paper bleaching and pickling equipment. No spacecraft use is recorded in the sources read.\n",
  "best_for": "Sulfuric and phosphoric acid plant, seawater condensers and heat exchangers, and pulp bleaching, in annealed sheet, plate, strip and tube, where 316L or 317L would corrode",
  "weakest_at": "Halide-containing acids and boiling magnesium or lithium chloride, where ATI's U-bend test cracked the alloy, and crevices in chloride water (ATI G-48 onset at 18 °C)",
  "identity": {
    "formula": "Fe balance; Outokumpu typical 19.8 Cr, 24.2 Ni, 4.3 Mo, 1.4 Cu, 0.01 C (wt%); ASTM ranges 19 to 23 Cr, 23 to 28 Ni, 4 to 5 Mo, 1 to 2 Cu, max 0.02 C, 2 Mn, 1 Si (wt%)",
    "designations": [
      {
        "system": "UNS",
        "code": "N08904",
        "source": "outokumpu-ultra",
        "where": "Table 1, UNS column, row Ultra 904L"
      },
      {
        "system": "EN",
        "code": "1.4539",
        "source": "outokumpu-ultra",
        "where": "Table 1, EN column, row Ultra 904L"
      },
      {
        "system": "EN name",
        "code": "X1NiCrMoCu25-20-5",
        "source": "metalcor-1-4539",
        "where": "Designation table, EN Designation row"
      },
      {
        "system": "AISI",
        "code": "904L",
        "source": "metalcor-1-4539",
        "where": "Designation table, AISI/SAE row (printed as 904 L)"
      },
      {
        "system": "ASTM",
        "code": "A240",
        "note": "plate, sheet and strip",
        "source": "outokumpu-ultra",
        "where": "Table 11, ASTM A240 section, row Ultra 904L (EN 1.4539, UNS N08904)"
      },
      {
        "system": "ASTM",
        "code": "B625",
        "note": "plate, sheet and strip",
        "source": "ati-904l",
        "where": "Mechanical properties, ASTM and ASME coverage table, Plate, Sheet and Strip row"
      },
      {
        "system": "ASTM",
        "code": "B677",
        "note": "seamless pipe and tube",
        "source": "ati-904l",
        "where": "Mechanical properties, ASTM and ASME coverage table, Seamless Pipe and Tube row"
      },
      {
        "system": "BS",
        "code": "904S13",
        "source": "spacemat-904l",
        "where": "Equivalent Designations line, BS904S13"
      },
      {
        "system": "JIS",
        "code": "SUS 904L",
        "source": "wiki-sae904l",
        "where": "Infobox, other names"
      },
      {
        "system": "Trade name",
        "code": "Ultra 904L",
        "source": "outokumpu-ultra",
        "where": "Table 1 and Table 2, Outokumpu name column"
      },
      {
        "system": "Trade name",
        "code": "ATI 904L",
        "source": "ati-904l",
        "where": "Title block of the ATI technical data sheet"
      }
    ],
    "source": "outokumpu-ultra",
    "where": "Table 1 (chemical composition, typical values), row Ultra 904L. The ASTM ranges come from the Sandmeyer specification sheet, Chemical Analysis table."
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, 904L (ASTM datasheet)",
      "value": 7.95,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temperature": "not stated"
      },
      "method": "Value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Physical Properties, Density (7.95 g/cm3)",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, Ultra 904L (EN 10088-1 values)",
      "value": 8,
      "bound": "exact",
      "unit": "kg/dm3",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "20 °C",
        "basis": "EN 10088-1 table, rounded to one decimal"
      },
      "method": "Value printed in the physical properties table of the Outokumpu Ultra range datasheet",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 13, Physical properties, Density column, row Ultra 904L",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, Ultra 904L at 20 °C",
      "value": 195,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "20 °C"
      },
      "method": "Value printed in the physical properties table of the Outokumpu Ultra range datasheet",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 13, Physical properties, Modulus of elasticity at 20 °C column, row Ultra 904L",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, alloy 904L",
      "value": 190,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temperature": "not stated"
      },
      "method": "Value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Physical Properties, Modulus of Elasticity (190 GPa)",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, Ultra 904L at 20 °C",
      "value": 12,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "20 °C"
      },
      "method": "Value printed in the physical properties table of the Outokumpu Ultra range datasheet",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 13, Physical properties, Thermal conductivity at 20 °C column, row Ultra 904L",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, alloy 904L at 100 °C",
      "value": 12.9,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temperature": "100 °C",
        "unit_in_source": "6.8 BTU/ft h °F"
      },
      "method": "Value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Physical Properties, Thermal Conductivity 212°F (100°C) row",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, alloy 904L at 200 °C",
      "value": 15.2,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temperature": "200 °C",
        "unit_in_source": "8.8 BTU/ft h °F"
      },
      "method": "Typical value printed in a manufacturer data sheet (ATI, 2012 edition)",
      "status": "ground",
      "source": "ati-904l",
      "where": "Physical Properties, Thermal Conductivity table, 392°F (200°C) row",
      "source_detail": {
        "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
        "id": "ATI 904L TDS, version 1, 4/18/2012",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat capacity, Ultra 904L at 20 °C",
      "value": 450,
      "bound": "exact",
      "unit": "J/(kg·K)",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "20 °C"
      },
      "method": "Value printed in the physical properties table of the Outokumpu Ultra range datasheet",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 13, Physical properties, Thermal capacity at 20 °C column, row Ultra 904L",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of thermal expansion, Ultra 904L, 20 to 100 °C",
      "value": 15.8,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "20 to 100 °C"
      },
      "method": "Value printed in the physical properties table of the Outokumpu Ultra range datasheet (10-6/K)",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 13, Physical properties, Coefficient of thermal expansion 20 to 100 °C column, row Ultra 904L",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of thermal expansion, alloy 904L, 20 to 100 °C",
      "value": 15.3,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temperature": "20 to 100 °C",
        "unit_in_source": "8.5 x 10-6/°F (68 to 212 °F)"
      },
      "method": "Value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Mean Coefficient of Thermal Expansion table, 20 to 100 °C row",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Mean coefficient of thermal expansion, alloy 904L, 20 to 400 °C",
      "value": 16.5,
      "bound": "exact",
      "unit": "ppm/K",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temperature": "20 to 400 °C",
        "unit_in_source": "9.2 x 10-6/°F (68 to 750 °F)"
      },
      "method": "Typical value printed in a manufacturer data sheet (ATI, 2012 edition)",
      "status": "ground",
      "source": "ati-904l",
      "where": "Average Coefficient of Thermal Expansion table, 20-400°C row",
      "source_detail": {
        "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
        "id": "ATI 904L TDS, version 1, 4/18/2012",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity, alloy 904L at 20 °C",
      "value": 95.2,
      "bound": "exact",
      "unit": "µΩ·cm",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temperature": "20 °C",
        "unit_in_source": "95.2 microhm-cm at 20°C"
      },
      "method": "Value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Electrical Resistivity entry, 95.2 Microhm-cm at 20°C",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting range, alloy 904L",
      "value": 1300,
      "value_high": 1390,
      "bound": "range",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "unit_in_source": "2372 to 2534 °F"
      },
      "method": "Melting range printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Melting Range entry, 1300 to 1390 °C",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Proof strength Rp0.2, cold-rolled, minimum (EN 10088-2)",
      "value": 240,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "form": "cold-rolled coil and sheet",
        "temperature": "20 °C",
        "basis": "minimum, EN 10088-2"
      },
      "method": "Minimum value printed in the mechanical properties table, EN 10088-2 basis",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 10, Mechanical properties at 20 °C, Min. yield strength Rp0.2 column, row Ultra 904L, Cold rolled",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Proof strength Rp0.2, hot-rolled and plate, minimum (EN 10088-2)",
      "value": 220,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "form": "hot-rolled coil and sheet, and plate",
        "temperature": "20 °C",
        "basis": "minimum, EN 10088-2"
      },
      "method": "Minimum value printed in the mechanical properties table, EN 10088-2 basis",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 10, Mechanical properties at 20 °C, Min. yield strength Rp0.2 column, rows Ultra 904L Hot rolled and Plate",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength Rp0.2, annealed plate, sheet and strip, minimum (ASTM B625)",
      "value": 220,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "form": "plate, sheet and strip, annealed",
        "temperature": "20 °C",
        "basis": "minimum, ASTM and ASME specified properties",
        "unit_in_source": "31,000 psi"
      },
      "method": "Minimum value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Mechanical properties table, Yield Strength 0.2% Offset, 31,000 psi (220 MPa) row",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Yield strength Rp0.2, annealed, typical (ATI)",
      "value": 270,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temper": "annealed",
        "temperature": "20 °C",
        "basis": "typical, not a minimum",
        "unit_in_source": "39,500 psi"
      },
      "method": "Typical value printed in a manufacturer data sheet (ATI, 2012 edition)",
      "status": "ground",
      "source": "ati-904l",
      "where": "Mechanical Properties, Typical (and minimum) table, Yield Strength row, typical column",
      "source_detail": {
        "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
        "id": "ATI 904L TDS, version 1, 4/18/2012",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Proof strength Rp0.2 at 100 °C, minimum (EN 10088-2)",
      "value": 205,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "100 °C",
        "basis": "minimum, EN 10088-2"
      },
      "method": "Minimum value printed in the elevated temperature table",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 12, Mechanical properties at elevated temperatures, Proof strength Rp0.2 row, 100 °C column",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Proof strength Rp0.2 at 300 °C, minimum (EN 10088-2)",
      "value": 145,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "300 °C",
        "basis": "minimum, EN 10088-2"
      },
      "method": "Minimum value printed in the elevated temperature table",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 12, Mechanical properties at elevated temperatures, Proof strength Rp0.2 row, 300 °C column",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Proof strength Rp0.2 at 500 °C, minimum (EN 10088-2)",
      "value": 110,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "temperature": "500 °C",
        "basis": "minimum, EN 10088-2"
      },
      "method": "Minimum value printed in the elevated temperature table",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 12, Mechanical properties at elevated temperatures, Proof strength Rp0.2 row, 500 °C column",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength Rm, cold-rolled (EN 10088-2)",
      "value": 530,
      "value_high": 730,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "form": "cold-rolled coil and sheet",
        "temperature": "20 °C",
        "basis": "range printed as minimum-to-maximum, EN 10088-2"
      },
      "method": "Range printed in the mechanical properties table, EN 10088-2 basis",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 10, Mechanical properties at 20 °C, Tensile strength Rm column, row Ultra 904L, Cold rolled",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength Rm, annealed, minimum (ASTM B625)",
      "value": 490,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "form": "plate, sheet and strip, annealed",
        "temperature": "20 °C",
        "basis": "minimum, ASTM and ASME specified properties",
        "unit_in_source": "71,000 psi"
      },
      "method": "Minimum value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Mechanical properties table, Ultimate Tensile Strength row, 71,000 psi (490 MPa)",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength Rm, annealed, typical (ATI)",
      "value": 605,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temper": "annealed",
        "temperature": "20 °C",
        "basis": "typical, not a minimum",
        "unit_in_source": "88,000 psi"
      },
      "method": "Typical value printed in a manufacturer data sheet (ATI, 2012 edition)",
      "status": "ground",
      "source": "ati-904l",
      "where": "Mechanical Properties, Typical (and minimum) table, Tensile Strength row, typical column",
      "source_detail": {
        "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
        "id": "ATI 904L TDS, version 1, 4/18/2012",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation A, cold-rolled and hot-rolled, minimum (EN 10088-2)",
      "value": 35,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "form": "cold-rolled and hot-rolled",
        "temperature": "20 °C",
        "gauge": "A, L0 = 5.65 times the square root of S0 (thickness 3 mm or more)",
        "basis": "minimum, EN 10088-2"
      },
      "method": "Minimum value printed in the mechanical properties table",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 10, Mechanical properties at 20 °C, Min. elongation A column, row Ultra 904L, Cold rolled and Hot rolled",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation in 2 in, annealed, minimum (ASTM B625)",
      "value": 36,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "form": "plate, sheet and strip, annealed",
        "temperature": "20 °C",
        "gauge": "2 in",
        "basis": "minimum, ASTM and ASME specified properties"
      },
      "method": "Minimum value printed in a specification sheet for alloy 904L",
      "status": "ground",
      "source": "sandmeyer-904l",
      "where": "Mechanical properties table, Elongation in 2 in. row, 36 % minimum",
      "source_detail": {
        "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
        "id": "Alloy 904L 11/2014, rev 02/2023",
        "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
        "year": 2023,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Hardness HB 30, maximum at 20 °C (EN 1.4539)",
      "value": 230,
      "bound": "upper",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "grade": "1.4539 (EN)",
        "temperature": "20 °C",
        "basis": "maximum"
      },
      "method": "Maximum value printed in the mechanical properties table of the Metalcor 1.4539 datasheet",
      "status": "ground",
      "source": "metalcor-1-4539",
      "where": "Mechanical Properties at 20 °C table, Hardness HB 30 row",
      "source_detail": {
        "title": "Metalcor: 1.4539 (AISI 904 L / N08904) datasheet",
        "id": "Metalcor datasheet 32",
        "url": "http://www.metalcor.de/en/datenblatt/32/",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Hardness Brinell, annealed, typical (ATI)",
      "value": 150,
      "bound": "exact",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "grade": "904L (UNS N08904)",
        "temper": "annealed",
        "temperature": "20 °C",
        "basis": "typical, shown for information only"
      },
      "method": "Typical value printed in a manufacturer data sheet (ATI, 2012 edition)",
      "status": "ground",
      "source": "ati-904l",
      "where": "Mechanical Properties, Typical (and minimum) table, Hardness (Brinell) row",
      "source_detail": {
        "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
        "id": "ATI 904L TDS, version 1, 4/18/2012",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "pren",
      "label": "Pitting resistance equivalent PRE, Ultra 904L (Cr + 3.3 Mo + 16 N)",
      "value": 34,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "basis": "Outokumpu typical composition, PRE = %Cr + 3.3 x %Mo + 16 x %N"
      },
      "method": "Value printed in the PRE table of the Outokumpu Ultra range datasheet",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 7, PRE values, row Ultra 904L (Table 1 also prints 34)",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "critical_crevice_temperature",
      "label": "Critical crevice corrosion onset temperature, 10% ferric chloride, ASTM G-48",
      "value": 18,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "904L (ATI)",
        "test": "10% ferric chloride, ASTM G-48 (artificial crevices)",
        "unit_in_source": "65 °F"
      },
      "method": "Onset temperature printed in a manufacturer data sheet (ATI, 2012 edition)",
      "status": "ground",
      "source": "ati-904l",
      "where": "Pitting Corrosion section, G-48 onset table, row ATI 904L",
      "source_detail": {
        "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
        "id": "ATI 904L TDS, version 1, 4/18/2012",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
        "year": 2012,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Upper temperature for pressure-vessel approval",
      "value": 400,
      "bound": "upper",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "Ultra 904L (EN 1.4539)",
        "basis": "pressure vessel approval range is -196 to +400 °C; a design code limit, not a creep or oxidation limit"
      },
      "method": "Value printed in the typical temperatures table of the Outokumpu Ultra range datasheet",
      "status": "ground",
      "source": "outokumpu-ultra",
      "where": "Table 8, Typical temperatures, Pressure vessel approval column, row Ultra 904L",
      "source_detail": {
        "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
        "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
        "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
        "year": 2025,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Boiling sulfuric acid, 10 percent",
      "headline": "In boiling 10 percent sulfuric acid, 904L corrodes at 101 mpy (2.57 mm/a), against 636 mpy (16.2 mm/a) for ATI 316.",
      "effect": "ATI's laboratory table of boiling solutions gives typical rates. 904L is also rated by Sandmeyer as fully resistant to dilute sulfuric acid across the 0 to 100 percent range at up to 35 °C.",
      "rating": "moderate",
      "conditions": {
        "solution": "10% H2SO4 (boiling)",
        "comparison": "ATI 316 at 636 mpy",
        "basis": "typical, laboratory boiling test"
      },
      "source": "ati-904l",
      "where": "Boiling Solution table, row 10% Sulfuric Acid"
    },
    {
      "environment": "Ambient and wet process phosphoric acid",
      "headline": "In wet process phosphoric acid at 60 °C, 904L corrodes at 1.2 mm/year, against more than 5 mm/year for 316L.",
      "effect": "Outokumpu's wet-process test uses a 54 percent P2O5 acid with impurities. The table shows that 904L is much lower than standard 316L, though Ultra 254 SMO, at 0.05 mm/year, is lower still.",
      "rating": "low",
      "conditions": {
        "solution": "wet process phosphoric acid, 54% P2O5 with impurities",
        "temperature": "60 °C"
      },
      "source": "outokumpu-ultra",
      "where": "Table 4, Uniform corrosion in wet process phosphoric acid at 60 °C, row Ultra 904L"
    },
    {
      "environment": "Pickling acid, nitric and hydrofluoric",
      "headline": "In a pickling acid at 25 °C, 904L corrodes at 0.47 mm/year, against more than 6 mm/year for 316L.",
      "effect": "Sandmeyer's pickling table gives the same 0.47 mm/year for 904L and more than 6 mm/year for 316L in the same acid.",
      "rating": "low",
      "conditions": {
        "solution": "20% HNO3 + 4% HF",
        "temperature": "25 °C"
      },
      "source": "outokumpu-ultra",
      "where": "Table 5, Uniform corrosion in pickling acid at 25 °C, row Ultra 904L"
    },
    {
      "environment": "Fatty acid column for tall oil distillation",
      "headline": "In a tall oil fatty acid column at 235 °C, 904L corrodes at 0.06 mm/year, against 0.88 mm/year for 316L.",
      "effect": "Sandmeyer gives the same kind of result at 253 °C, with 0.06 mm/year for 904L and 0.29 for 317LMN. Outokumpu says the nickel content sets resistance in hot concentrated caustic.",
      "rating": "low",
      "conditions": {
        "temperature": "235 °C",
        "comparison": "Supra 316L/4404 at 0.88 mm/year"
      },
      "source": "outokumpu-ultra",
      "where": "Table 6, Corrosion rates in a fatty acid column, row Ultra 904L"
    },
    {
      "environment": "Chloride pitting and crevices in aerated seawater",
      "headline": "The alloy is not totally resistant to aerated seawater, but it resists pitting and crevices better than 316.",
      "effect": "ATI says 904L suits tubesheets in seawater heat exchangers and pulp bleach plant equipment where some attack can be tolerated. Outokumpu says the risk of crevice corrosion in non-chlorinated seawater is considerably lower, and that chlorination raises the corrosion potential of the steel.",
      "rating": "moderate",
      "conditions": {
        "medium": "aerated seawater",
        "comparison": "316 has an onset of 27 °F (-3 °C) in the G-48 test"
      },
      "source": "ati-904l",
      "where": "Pitting Corrosion section, first and second paragraphs"
    },
    {
      "environment": "Chloride stress corrosion cracking, boiling chloride solutions",
      "headline": "U-bend specimens cracked in boiling 42 percent magnesium chloride and 33 percent lithium chloride in 1000 hours, but not in 26 percent sodium chloride.",
      "effect": "ATI calls 904L much better than Type 304 for chloride cracking because of its 25 percent nickel and 4.5 percent molybdenum, but says it is not completely resistant to the boiling magnesium and lithium chloride tests.",
      "rating": "moderate",
      "conditions": {
        "test": "U-bend, boiling solutions, 1000 hours",
        "solutions": "42% MgCl2, 33% LiCl, 26% NaCl"
      },
      "source": "ati-904l",
      "where": "Chloride Stress Corrosion Cracking section, Performance Using U-Bend Samples table"
    },
    {
      "environment": "Intergranular attack after welding",
      "headline": "In the ASTM A262 practice B ferric sulfate and sulfuric acid test, 904L corrodes at 14.2 mpy, against 35.5 mpy for 316.",
      "effect": "Low carbon keeps 904L resistant to intergranular attack in the welded condition. Sandmeyer says segregation after welding is less evident in 904L than in 316L or 317LMN.",
      "rating": "low",
      "conditions": {
        "test": "ASTM A262 practice B, ferric sulfate-sulfuric acid",
        "comparison": "ATI 316 at 35.5 mpy"
      },
      "source": "ati-904l",
      "where": "Intergranular Corrosion Resistance table, Ferric Sulfate-Sulfuric Acid row"
    },
    {
      "environment": "Halide-containing acids",
      "headline": "Acids with halide ions can be very aggressive, and the corrosion resistance of 904L may be insufficient.",
      "effect": "Sandmeyer names 317L, 317LMN and 904L together as possibly insufficient in such acids. Outokumpu says all stainless steels are sensitive to hydrofluoric, hydrochloric and fluosilicic acids.",
      "rating": "moderate",
      "conditions": {
        "acids": "hydrofluoric, hydrochloric, fluosilicic, and other halide-containing acids"
      },
      "source": "sandmeyer-904l",
      "where": "Corrosion Resistance section, first paragraph"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem's GHS record for elemental nickel lists H317, H351 and H372 as statements without a percentage. These describe the element, not the alloy.",
        "ghs": [
          "H317",
          "H351",
          "H372"
        ],
        "source": "pubchem-nickel",
        "where": "GHS Classification, Hazard Statements list (CID 935)"
      },
      {
        "text": "PubChem's GHS record for elemental chromium lists H317, H334 and H335 as statements without a percentage. These describe the element, not the alloy.",
        "ghs": [
          "H317",
          "H334",
          "H335"
        ],
        "source": "pubchem-chromium",
        "where": "GHS Classification, Hazard Statements list (CID 23976)"
      },
      {
        "text": "PubChem's GHS record for elemental molybdenum lists H315, H319 and H335 as statements without a percentage. These describe the element, not the alloy.",
        "ghs": [
          "H315",
          "H319",
          "H335"
        ],
        "source": "pubchem-molybdenum",
        "where": "GHS Classification, Hazard Statements list (CID 23932)"
      },
      {
        "text": "PubChem's GHS record for elemental copper lists H400 and H410 as statements without a percentage. These describe the element, not the alloy.",
        "ghs": [
          "H400",
          "H410"
        ],
        "source": "pubchem-copper",
        "where": "GHS Classification, Hazard Statements list (CID 23978)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Chloride stress corrosion cracking in boiling chloride",
        "trigger": "Boiling magnesium or lithium chloride, or hot chloride brine under tensile stress",
        "consequence": "ATI's U-bend test cracked 904L in boiling 42 percent MgCl2 and 33 percent LiCl within 1000 hours, so the alloy is not immune in these tests.",
        "severity": "moderate",
        "source": "ati-904l",
        "where": "Chloride Stress Corrosion Cracking section, U-bend table"
      },
      {
        "mode": "Crevice and pitting attack in chloride water",
        "trigger": "Crevices in chloride water above about 18 °C under the G-48 test conditions",
        "consequence": "ATI gives the G-48 onset as 18 °C for 904L against 45 °C for AL-6XN. Crevices are a design limit in warm chloride water.",
        "severity": "moderate",
        "source": "ati-904l",
        "where": "Pitting Corrosion section, G-48 onset table"
      },
      {
        "mode": "Attack by halide-containing acids",
        "trigger": "Acids containing chloride or fluoride ions",
        "consequence": "Sandmeyer says 904L may not be resistant enough in these acids, which can be very aggressive.",
        "severity": "moderate",
        "source": "sandmeyer-904l",
        "where": "Corrosion Resistance section, first paragraph"
      },
      {
        "mode": "Higher forming loads and fast work hardening",
        "trigger": "Cold forming, bending or pressing sheet",
        "consequence": "904L is somewhat stronger than 304 and 316, so it needs higher loads to deform, and cold work hardens it quickly.",
        "severity": "low",
        "source": "ati-904l",
        "where": "Formability section"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Solution anneal at 1060 to 1140 °C and quench (Outokumpu Table 8; Sandmeyer heat treatment).",
        "source": "outokumpu-ultra",
        "where": "Table 8, Solution annealing column, row Ultra 904L"
      },
      {
        "text": "Hot working is done at 1150 to 850 °C (Outokumpu Table 8). Sandmeyer says hot forming that ends above 1100 °C, with the whole workpiece quenched directly, may be used without a further heat treatment; otherwise a solution anneal is needed.",
        "source": "sandmeyer-904l",
        "where": "Hot Forming section"
      },
      {
        "text": "Weld with low heat input. Outokumpu says the Ultra grades are more sensitive to hot cracking than conventional austenitic steels.",
        "source": "outokumpu-ultra",
        "where": "Welding section"
      },
      {
        "text": "Use a 20 25 5 Cu L filler. The covered electrode is 20 25 5 Cu L (ISO 3581 and 14172) and the wire is 20 25 5 Cu L (ISO 14343 and 18274). Sandmeyer gives 20 25 CuL as its filler.",
        "source": "outokumpu-ultra",
        "where": "Table 9, Welding consumables, row Ultra 904L"
      },
      {
        "text": "Sandmeyer says a filler of the same composition as the base metal is normal, and that welds in 904L segregate less than in 316L or 317LMN.",
        "source": "sandmeyer-904l",
        "where": "Welding section"
      },
      {
        "text": "Machining is harder than for 410 and 304 because of work hardening.",
        "source": "sandmeyer-904l",
        "where": "Machining section"
      },
      {
        "text": "Outokumpu says a post-fabrication treatment is often needed after welding to restore the surface and corrosion resistance, by brushing, blasting, grinding or pickling.",
        "source": "outokumpu-ultra",
        "where": "Welding section, post-fabrication treatment paragraph"
      }
    ],
    "mitigations": [
      {
        "text": "For welds in corrosive media, use a more highly alloyed austenitic filler, which ATI says gives the best weld corrosion properties.",
        "source": "ati-904l",
        "where": "Weldability section"
      },
      {
        "text": "Specify solution annealing and quenching after heavy hot work, so the material returns to its corrosion-resistant condition.",
        "source": "outokumpu-ultra",
        "where": "Table 8, Solution annealing column"
      },
      {
        "text": "Design out crevices in chloride water. ATI's G-48 onset of 18 °C shows that crevices can start attack at warm temperatures.",
        "source": "ati-904l",
        "where": "Pitting Corrosion section, G-48 table"
      }
    ]
  },
  "uses": [
    {
      "application": "structures",
      "device": "Seawater condensers, heat exchangers and piping",
      "example": "Sandmeyer lists condensers, heat exchangers and piping systems for seawater and brackish water. ATI lists tubesheets in seawater heat exchangers.",
      "source": "sandmeyer-904l",
      "where": "Applications list, Seawater and Brackish Water item"
    },
    {
      "application": "structures",
      "device": "Utility scrubbers and air pollution control equipment",
      "example": "Sandmeyer lists scrubbers for coal-fired power plants, and ATI lists utility scrubbers among its service environments.",
      "source": "sandmeyer-904l",
      "where": "Applications list, Air Pollution Control item"
    },
    {
      "application": "structures",
      "device": "Sulfuric and phosphoric acid process equipment",
      "example": "Outokumpu lists pipes, heat exchangers, tanks and reactor vessels for chemical and petrochemical industry, plus sulfuric acid handling, flanges and valves.",
      "source": "outokumpu-ultra",
      "where": "Table 2, Key Ultra grades, Ultra 904L row, Typical applications column"
    },
    {
      "application": "structures",
      "device": "Pulp and paper bleach plant equipment",
      "example": "ATI says 904L suits pulp and paper bleach plant equipment where resistance above that of 316 is wanted, though some attack can be tolerated.",
      "source": "ati-904l",
      "where": "Pitting Corrosion section"
    },
    {
      "application": "structures",
      "device": "Pickling equipment using sulfuric acid",
      "example": "Sandmeyer lists pickling equipment that uses sulfuric acid among its applications.",
      "source": "sandmeyer-904l",
      "where": "Applications list, Metallurgical Processing item"
    },
    {
      "application": "structures",
      "device": "Offshore process equipment for oil and gas production",
      "example": "Sandmeyer lists offshore process equipment in its oil and gas production application.",
      "source": "sandmeyer-904l",
      "where": "Applications list, Oil and Gas Production item"
    },
    {
      "application": "structures",
      "device": "Pharmaceutical process equipment",
      "example": "Sandmeyer lists process equipment for the pharmaceutical industry.",
      "source": "sandmeyer-904l",
      "where": "Applications list, Pharmaceutical Industry item"
    }
  ],
  "supply": [
    {
      "subject": "Nickel",
      "abundance": "World mine production 3,900,000 tons of nickel content in 2025 (estimated), with reserves above 140,000,000 tons (USGS 2026).",
      "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
        },
        {
          "country": "New Caledonia",
          "share_percent": 3.6,
          "year": 2025
        },
        {
          "country": "Canada",
          "share_percent": 3.6,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 3.1,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "Nickel recovered from scrap was about 60 percent of US apparent consumption in 2025, mostly from stainless-steel scrap.",
      "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": "World Mine Production and Reserves table, 2025e column (shares calculated from printed tonnages); Salient Statistics; Recycling; Substitutes"
    },
    {
      "subject": "Chromium",
      "abundance": "World mine production 51,000 thousand metric tons of ore, gross weight, in 2025 (estimated). World 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
        },
        {
          "country": "India",
          "share_percent": 5.9,
          "year": 2025
        },
        {
          "country": "Brazil",
          "share_percent": 3.9,
          "year": 2025
        },
        {
          "country": "Zimbabwe",
          "share_percent": 3.9,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "Recycled chromium in stainless-steel scrap receipts was 21 percent of US apparent consumption in 2025.",
      "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 column (shares calculated from printed tonnages); World Resources; Salient Statistics; Import Sources; Substitutes"
    },
    {
      "subject": "Molybdenum",
      "abundance": "World mine production 260,000 metric tons of molybdenum content in 2025 (estimated). China, Chile, the United States, Peru and Mexico produce 90 percent of the total.",
      "producers": [
        {
          "country": "China",
          "share_percent": 37.3,
          "year": 2025
        },
        {
          "country": "Chile",
          "share_percent": 16.2,
          "year": 2025
        },
        {
          "country": "United States",
          "share_percent": 15.4,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 15,
          "year": 2025
        },
        {
          "country": "Mexico",
          "share_percent": 6.5,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "Molybdenum is recycled from catalysts, ferrous scrap and superalloy scrap. Revert and new scrap are reused in the steel industry.",
      "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 column (shares calculated from printed tonnages); Events, Trends, and Issues; Recycling; Substitutes"
    },
    {
      "subject": "Copper",
      "abundance": "World mine production 23,000 thousand metric tons of copper content in 2025 (estimated). The US added copper to its 2025 list of critical minerals.",
      "producers": [
        {
          "country": "Chile",
          "share_percent": 23,
          "year": 2025
        },
        {
          "country": "Congo (Kinshasa)",
          "share_percent": 13.9,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 11.7,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 7.8,
          "year": 2025
        },
        {
          "country": "United States",
          "share_percent": 4.3,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "U.S. Final 2025 List of Critical Minerals (copper added in 2025)",
          "listed": true
        }
      ],
      "recycling": "Old scrap gave an estimated 160,000 tons of copper in 2025, and copper recovered from scrap was about 30 percent of US copper supply.",
      "substitutes": [
        "Aluminum substitutes for copper in several electrical and cooling uses (USGS 2026)."
      ],
      "source": "usgs-copper-2026",
      "where": "World Mine and Refinery Production table, 2025e column (shares calculated from printed tonnages); Critical Minerals paragraph; Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
      "type": "datasheet",
      "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
      "year": 2025
    },
    {
      "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
      "type": "datasheet",
      "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
      "year": 2012
    },
    {
      "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
      "type": "datasheet",
      "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
      "year": 2023
    },
    {
      "title": "Metalcor: 1.4539 (AISI 904 L / N08904) datasheet",
      "type": "datasheet",
      "url": "http://www.metalcor.de/en/datenblatt/32/"
    },
    {
      "title": "SpaceMat: AISI 904L entry",
      "type": "database",
      "url": "https://www.spacematdb.com/spacemat/datasearch.php?name=AISI+904L"
    },
    {
      "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 Mineral Commodity Summaries 2026: Copper",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf",
      "year": 2026
    },
    {
      "title": "PubChem: Nickel (CID 935), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/935/JSON",
      "year": 2026
    },
    {
      "title": "PubChem: Chromium (CID 23976), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON",
      "year": 2026
    },
    {
      "title": "PubChem: Molybdenum (CID 23932), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23932/JSON",
      "year": 2026
    },
    {
      "title": "PubChem: Copper (CID 23978), GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23978/JSON",
      "year": 2026
    }
  ],
  "gaps": [
    "No spacecraft, rocket or satellite use is recorded. SpaceMat rates the space experience of AISI 904L as \"Limited\" and names no flight, mission, outgassing or atomic-oxygen data, so tags.environments is empty and no space use is listed.",
    "Mechanical values differ by standard and product form. Outokumpu gives EN 10088-2 minima, the Sandmeyer sheet gives ASTM B625 minima, and the ATI values are typical (2012 edition). Each property states its basis in conditions.",
    "The EN 1.4539 composition in the Metalcor datasheet has narrower ranges than the ASTM ranges (19 to 21 Cr, 24 to 26 Ni, 4 to 5 Mo, 1.2 to 2.0 Cu, 0.02 max C). Only the ASTM ranges are quoted in identity.formula.",
    "The SpaceMat page prints the EN name as X1NiCrMoCuN25-20-5. Only the Metalcor form, X1NiCrMoCu25-20-5, is listed as a designation.",
    "Outokumpu Figures 8, 9 and 11 (critical pitting temperature, critical crevice temperature and drop-evaporation threshold) are graphs with no printed values, so no values are taken from them.",
    "Impact energy, fatigue strength and Poisson's ratio have no printed numbers in the sources used. ATI describes the impact behaviour only as excellent at sub-zero temperatures.",
    "The ATI sheet is the 2012 version. Its corrosion and physical values are typical, not minimum or maximum values.",
    "A tube supplier's page (Finetubes) gives a maximum service temperature of 450 °C. It is not used, because no basis is printed, and Outokumpu's pressure-vessel range is 400 °C.",
    "Supply shares are calculated from the 2025 estimated mine-production tonnages in each USGS table. They are mine output only, not refining or smelting.",
    "The US critical-minerals status is recorded only for copper, which the USGS copper summary says was added in the 2025 list. The 2026 nickel, chromium and molybdenum summaries do not state their status, so their critical_lists are empty.",
    "Hazard statements are PubChem element records for nickel, chromium, molybdenum and copper, taken from the statements that appear without a percentage. No safety data sheet for the alloy was checked.",
    "Critical pitting temperature and the ASTM G-48 method for Ultra 904L have no printed value in the Outokumpu datasheet, so only the ATI G-48 onset is recorded."
  ],
  "story": {
    "why": "904L is a super-austenitic stainless steel. Its 20 percent chromium, 24 percent nickel and 4.3 percent molybdenum, with 1.4 percent copper, give a PRE of 34 and good resistance to sulfuric and phosphoric acids and to chloride pitting. It was developed for dilute sulfuric acid. Its minimum proof strength is 220 MPa to ASTM and 240 MPa for EN cold-rolled strip. Sold for acid plant, seawater cooling and pulp bleaching, it is a standard grade in the 904L class.",
    "uses": [
      {
        "where": "Seawater and desalination",
        "line": "Sandmeyer lists condensers, heat exchangers and piping for seawater and brackish water, and ATI lists tubesheets in seawater heat exchangers."
      },
      {
        "where": "Acid and chemical plant",
        "line": "Outokumpu lists pipes, heat exchangers, tanks and reactor vessels for sulfuric acid and the chemical industry, with flanges and valves."
      },
      {
        "where": "Air pollution control",
        "line": "Sandmeyer lists scrubbers for coal-fired power plants, and ATI lists utility scrubbers."
      },
      {
        "where": "Pulp and paper bleaching",
        "line": "ATI says 904L suits pulp and paper bleach plant equipment where some attack is tolerable."
      }
    ],
    "can_do": [
      {
        "label": "Strength",
        "line": "Minimum proof strength is 220 MPa to ASTM B625 for plate, sheet and strip, and 240 MPa to EN 10088-2 for cold-rolled strip. Tensile strength is 490 MPa minimum to ASTM.",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Acid corrosion",
        "line": "In wet process phosphoric acid at 60 °C, 904L corrodes at 1.2 mm/year, against more than 5 for 316L. In pickling acid at 25 °C it corrodes at 0.47 mm/year, against more than 6 for 316L.",
        "benchmark": "corrosion_rate",
        "scope": "material"
      },
      {
        "label": "Pitting",
        "line": "Outokumpu gives a PRE of 34 for Ultra 904L. Its critical crevice temperature in ATI's G-48 test is 18 °C.",
        "benchmark": "pren",
        "scope": "material"
      },
      {
        "label": "Hot strength",
        "line": "Minimum proof strength (Rp0.2) at 100 °C is 205 MPa, falling to 145 MPa at 300 °C and 110 MPa at 500 °C (EN 10088-2).",
        "benchmark": "yield_strength",
        "scope": "material"
      }
    ],
    "compare": "Against 316L in the same tests, 904L corrodes at 0.47 mm/year against more than 6 in pickling acid at 25 °C, and at 101 against 636 mpy in boiling 10 percent sulfuric acid. ATI's G-48 onset temperature is 18 °C for 904L against -3 °C for 316. Its minimum proof strength for plate (220 MPa, EN 10088-2) is below the 300 MPa minimum that Outokumpu prints for Ultra 254 SMO plate.",
    "compare_rows": [
      {
        "label": "Proof strength (Rp0.2, minimum)",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Tensile strength (Rm, minimum)",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Pitting resistance (PRE)",
        "benchmark": "pren",
        "scope": "material"
      }
    ],
    "handling": [
      "Anneal at 1060 to 1140 °C and quench (Outokumpu Table 8; Sandmeyer hot forming).",
      "Weld with low heat input and a 20 25 5 Cu L filler (Outokumpu Table 9). Sandmeyer says the same-composition filler is normal.",
      "Machining is harder than for 304 or 410 because of work hardening (Sandmeyer)."
    ],
    "good_for": [
      "Sulfuric and phosphoric acid plant, where Outokumpu lists pipes, heat exchangers, tanks and reactor vessels.",
      "Seawater condensers and heat exchangers, where Sandmeyer lists tube and piping systems.",
      "Pickling equipment and pulp and paper bleach plant, where ATI and Sandmeyer name the uses."
    ],
    "watch_out": [
      "Chloride cracking can occur in boiling magnesium or lithium chloride (ATI U-bend test).",
      "Crevices start attack at 18 °C in ATI's G-48 test, so crevice design still matters in warm chloride water.",
      "Acids containing halide ions can be very aggressive, and 904L may be insufficient (Sandmeyer).",
      "No spacecraft flight use is recorded. SpaceMat rates the space experience as limited."
    ],
    "verdict": "904L is a strong, sound choice for sulfuric and phosphoric acid plant, seawater cooling and pulp bleaching. It resists general and pitting attack better than 316L, but it is not immune to chloride cracking in boiling chloride, or to crevice and halide attack in warm chloride service.",
    "recipe": {
      "line": "904L is an iron-based super-austenitic stainless steel. Outokumpu's typical recipe, in weight percent, is 19.8 chromium, 24.2 nickel, 4.3 molybdenum, 1.4 copper and 0.01 carbon, with iron as the balance. The ASTM ranges are 19 to 23 chromium, 23 to 28 nickel, 4 to 5 molybdenum and 1 to 2 copper. It is solution annealed at 1060 to 1140 °C and quenched to give a fully austenitic structure.",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Matrix of the alloy, fully austenitic after annealing.",
          "share_note": "balance"
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "Forms the passive film. With molybdenum and nitrogen it sets the PRE.",
          "share_percent": 19.8,
          "source": "outokumpu-ultra",
          "where": "Table 1, chemical composition, row Ultra 904L"
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Stabilises austenite and gives resistance to chloride cracking and to hot caustic.",
          "share_percent": 24.2,
          "source": "outokumpu-ultra",
          "where": "Table 1, chemical composition, row Ultra 904L"
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "Adds pitting and crevice resistance; weighted 3.3 in the PRE formula.",
          "share_percent": 4.3,
          "source": "outokumpu-ultra",
          "where": "Table 1, chemical composition, row Ultra 904L"
        },
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Adds resistance to reducing acids such as sulfuric and phosphoric.",
          "share_percent": 1.4,
          "source": "outokumpu-ultra",
          "where": "Table 1, chemical composition, row Ultra 904L"
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Kept low to limit chromium carbides in welds.",
          "share_note": "max 0.02",
          "source": "sandmeyer-904l",
          "where": "Chemical Analysis table, Carbon maximum"
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Deoxidiser in the melt.",
          "share_note": "max 2",
          "source": "sandmeyer-904l",
          "where": "Chemical Analysis table, Manganese maximum"
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Deoxidiser in the melt.",
          "share_note": "max 1",
          "source": "sandmeyer-904l",
          "where": "Chemical Analysis table, Silicon maximum"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The hazard data are PubChem records for the element nickel, chromium, molybdenum and copper, not a supplier classification of the alloy.",
        "points": [
          {
            "label": "Nickel",
            "line": "PubChem's record for elemental nickel lists H317, H351 and H372 as statements without a percentage."
          },
          {
            "label": "Chromium",
            "line": "PubChem's record for elemental chromium lists H317, H334 and H335."
          },
          {
            "label": "Copper",
            "line": "PubChem's record for elemental copper lists H400 and H410."
          }
        ],
        "level": 0,
        "verdict": "No safety data sheet for the alloy was checked"
      },
      {
        "title": "In chloride service",
        "lead": "Boiling chloride can crack the alloy, and crevices start attack at warm temperatures.",
        "points": [
          {
            "label": "Cracking",
            "line": "ATI's U-bend test cracked 904L in boiling 42 percent MgCl2 and 33 percent LiCl within 1000 hours."
          },
          {
            "label": "Crevice",
            "line": "ATI's G-48 onset for 904L is 18 °C, against -3 °C for 316."
          }
        ],
        "level": 1,
        "verdict": "Chloride cracking and crevices are the watch points"
      },
      {
        "title": "Fabrication",
        "lead": "Weld with low heat input and a matching or overmatched filler. Anneal after hot work.",
        "points": [
          {
            "label": "Welding",
            "line": "Outokumpu says Ultra grades are more sensitive to hot cracking, so low heat input is needed."
          },
          {
            "label": "Hot work",
            "line": "Hot working at 1150 to 850 °C, then a solution anneal at 1060 to 1140 °C (Outokumpu Table 8)."
          }
        ],
        "level": 0,
        "verdict": "Low heat input and a solution anneal"
      }
    ]
  },
  "updated": "2026-10-26",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 30,
    "unreachable": 0,
    "caveats": 4,
    "note": "Read by an AI assistant on 2026-10-26 from pages fetched in this run: Outokumpu Ultra range datasheet (PDF), ATI 904L technical data sheet (PDF, 2012), Sandmeyer Steel Alloy 904L specification sheet (PDF), Metalcor 1.4539 datasheet, Wikipedia SAE 904L article, SpaceMat AISI 904L entry, USGS Mineral Commodity Summaries 2026 for nickel, chromium, molybdenum and copper, and PubChem GHS records for nickel, chromium, molybdenum and copper. Each value carries its product form, temperature and basis in conditions."
  },
  "sources": {
    "outokumpu-ultra": {
      "title": "Outokumpu: Ultra range datasheet (Ultra 904L, EN 1.4539, UNS N08904)",
      "id": "Outokumpu Ultra range datasheet, outokumpu.com/ultra",
      "url": "https://www.outokumpu.com/-/media/files/products/ultra/outokumpu_ultra_range_datasheet.pdf?revision=5e1844a6-f25c-49d4-b15b-3d84c47c9c31&modified=20250120090629",
      "year": 2025,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "ati-904l": {
      "title": "ATI: ATI 904L technical data sheet, version 1 (2012)",
      "id": "ATI 904L TDS, version 1, 4/18/2012",
      "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/superaustenitic/ati_904l_tds_en_v1.pdf",
      "year": 2012,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "sandmeyer-904l": {
      "title": "Sandmeyer Steel: Alloy 904L specification sheet (rev 02/2023)",
      "id": "Alloy 904L 11/2014, rev 02/2023",
      "url": "https://www.sandmeyersteel.com/wp-content/uploads/Alloy904L-SpecSheet.pdf",
      "year": 2023,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "metalcor-1-4539": {
      "title": "Metalcor: 1.4539 (AISI 904 L / N08904) datasheet",
      "id": "Metalcor datasheet 32",
      "url": "http://www.metalcor.de/en/datenblatt/32/",
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "wiki-sae904l": {
      "title": "Wikipedia: SAE 904L stainless steel",
      "id": "SAE 904L stainless steel",
      "url": "https://en.wikipedia.org/wiki/SAE_904L_stainless_steel",
      "kind": "web",
      "license": "CC BY-SA 4.0 (cited, not reproduced)"
    },
    "spacemat-904l": {
      "title": "SpaceMat: AISI 904L entry",
      "id": "SpaceMat AISI 904L",
      "url": "https://www.spacematdb.com/spacemat/datasearch.php?name=AISI+904L",
      "kind": "database",
      "license": "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-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-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-copper-2026": {
      "title": "USGS Mineral Commodity Summaries 2026: Copper",
      "id": "mcs2026-copper",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-copper.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain"
    },
    "pubchem-nickel": {
      "title": "PubChem: Nickel (CID 935), GHS classification",
      "id": "CID 935",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/935/JSON",
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "pubchem-chromium": {
      "title": "PubChem: Chromium (CID 23976), GHS classification",
      "id": "CID 23976",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON",
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "pubchem-molybdenum": {
      "title": "PubChem: Molybdenum (CID 23932), GHS classification",
      "id": "CID 23932",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23932/JSON",
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "pubchem-copper": {
      "title": "PubChem: Copper (CID 23978), GHS classification",
      "id": "CID 23978",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23978/JSON",
      "kind": "database",
      "license": "PubChem terms (public)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/stainless-904l/"
}