{
  "spore": "profile",
  "id": "stainless-409",
  "spore_version": "0.2",
  "family": "stainless-ferritic",
  "name": "Stainless steel 409",
  "abbreviation": "409 (UNS S40900, EN 1.4512)",
  "role": "exhaust and muffler stainless steel",
  "category": "metals",
  "type": "steels-and-stainless",
  "summary": "Grade 409 (EN 1.4512) is a titanium-stabilised ferritic chromium steel with about 10.5 to 11.75 percent chromium. Aalco calls it muffler grade stainless steel because most of its bulk use is in automotive exhaust systems. Combined Metals also lists heat exchangers as a use, where corrosion protection is needed beyond carbon steel.",
  "best_for": "Automotive exhaust systems and heat exchangers, where corrosion protection is needed beyond carbon steel (Combined Metals)",
  "weakest_at": "Pitting and intergranular corrosion: Outokumpu prints a critical pitting temperature below 10 °C and N/N for intergranular corrosion, and Aalco limits welded sheet to about 2.5 mm thick",
  "identity": {
    "formula": "Fe balance; Cr 10.500 to 11.750, C max 0.080, Mn max 1.000, Si max 1.000, P max 0.045, S max 0.030, Mo max 0.350, Ni max 0.500, Cu max 0.350, Ti max 0.750 (wt%, ASTM A240 listing for UNS S40900, ICAST); Combined Metals sheet for UNS S40910, S40920 and S40930: C max 0.030, Cr 10.50 to 11.70, Mn max 1.0, Si max 1.00, P max 0.040, S max 0.020, Ni max 0.50, N max 0.030; EN 10088-2 limits (Aalco): Cr 10.50 to 12.50, Ti 0.0 to 0.65",
    "designations": [
      {
        "system": "UNS",
        "code": "S40900",
        "source": "icast-as409",
        "where": "Cross Reference Table, A240 UNS S40900 row"
      },
      {
        "system": "UNS",
        "code": "S40910",
        "note": "one of three UNS numbers on the 409 sheet",
        "source": "combmet-409",
        "where": "Header, UNS S40910/S40920/S40930"
      },
      {
        "system": "UNS",
        "code": "S40920",
        "note": "one of three UNS numbers on the 409 sheet",
        "source": "combmet-409",
        "where": "Header, UNS S40910/S40920/S40930"
      },
      {
        "system": "UNS",
        "code": "S40930",
        "note": "one of three UNS numbers on the 409 sheet",
        "source": "combmet-409",
        "where": "Header, UNS S40910/S40920/S40930"
      },
      {
        "system": "EN",
        "code": "1.4512",
        "source": "outokumpu-xref",
        "where": "Table 2, 4512 row, EN column"
      },
      {
        "system": "EN name",
        "code": "X2CrTi12",
        "source": "aperam-409a",
        "where": "Norms, alphanumerical designation"
      },
      {
        "system": "ASTM",
        "code": "A240",
        "note": "plate, sheet and strip",
        "source": "icast-as409",
        "where": "Cross Reference Table, A240 UNS S40900 row; specification title"
      },
      {
        "system": "ASME",
        "code": "SA-240",
        "note": "UNS S40900",
        "source": "icast-as409",
        "where": "Cross Reference Table, SA-240 UNS S40900 row"
      },
      {
        "system": "AISI",
        "code": "409",
        "source": "aperam-409a",
        "where": "Norms, AISI 409"
      },
      {
        "system": "JIS",
        "code": "SUS409",
        "source": "outokumpu-xref",
        "where": "Table 2, JIS column, 4512 row"
      },
      {
        "system": "JIS",
        "code": "SUH409",
        "source": "icast-as409",
        "where": "Cross Reference Table, JIS row (SUH 409)"
      },
      {
        "system": "BS",
        "code": "409S19",
        "source": "outokumpu-xref",
        "where": "Table 3, BS/UK column, 4512 row (409S 19)"
      },
      {
        "system": "AFNOR",
        "code": "Z3 CT12",
        "source": "outokumpu-xref",
        "where": "Table 3, NF/France column, 4512 row"
      },
      {
        "system": "Trade name",
        "code": "muffler grade stainless steel",
        "source": "aalco-1-4512",
        "where": "Introduction paragraph"
      }
    ],
    "source": "icast-as409",
    "where": "Chemical Composition table (Cr 10.500 to 11.750) and Cross Reference Table (A240 UNS S40900); Combined Metals Nominal Composition table; Aalco Chemical Composition table"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "structures",
      "thermal-control"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density at 20 C (Combined Metals)",
      "value": 7.75,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "409 sheet (Combined Metals data sheet, ASTM A240 basis)",
        "temperature": "20 C (At 20C column)"
      },
      "method": "Physical Properties table, At 20C column, printed as 7.75 g/cm3 (0.280 lb/in3 at 70 F)",
      "status": "ground",
      "source": "combmet-409",
      "where": "Physical Properties table (Density row, At 20C column)",
      "source_detail": {
        "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
        "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity at 20 C (Combined Metals)",
      "value": 208.22,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "409 sheet (Combined Metals data sheet)",
        "temperature": "20 C (At 20C column)",
        "unit_in_source": "208.22 x 10^3 MPa, printed as 208.22 x 103 MPa"
      },
      "method": "Physical Properties table, Modulus of Elasticity row, At 20C column; 208.22 x 10^3 MPa is the same number as 208.22 GPa",
      "status": "ground",
      "source": "combmet-409",
      "where": "Physical Properties table (Modulus of Elasticity row, At 20C column)",
      "source_detail": {
        "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
        "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at 20 C (Combined Metals)",
      "value": 60,
      "bound": "exact",
      "unit": "micro-ohm-cm",
      "scope": "material",
      "conditions": {
        "form": "409 sheet (Combined Metals data sheet)",
        "temperature": "20 C (At 20C column)"
      },
      "method": "Physical Properties table, Electrical Resistivity row, At 20C column, printed as 60 μ ohm.cm",
      "status": "ground",
      "source": "combmet-409",
      "where": "Physical Properties table (Electrical Resistivity row, At 20C column)",
      "source_detail": {
        "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
        "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Annealed minimum 0.2% yield strength (Combined Metals)",
      "value": 170,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "409 sheet, ASTM A240 basis (Combined Metals data sheet)",
        "temper": "annealed (Min)",
        "temperature": "room temperature (typical room temperature table)",
        "basis": "0.2 percent offset, minimum"
      },
      "method": "Typical Room Temperature Mechanical Properties table, Annealed (Min) row, 0.2% YS Min column, printed as 25 ksi (170 MPa)",
      "status": "ground",
      "source": "combmet-409",
      "where": "Typical Room Temperature Mechanical Properties table (Annealed (Min) row, 0.2% YS Min column)",
      "source_detail": {
        "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
        "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Annealed minimum tensile strength (Combined Metals)",
      "value": 380,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "409 sheet, ASTM A240 basis (Combined Metals data sheet)",
        "temper": "annealed (Min)",
        "temperature": "room temperature (typical room temperature table)"
      },
      "method": "Typical Room Temperature Mechanical Properties table, Annealed (Min) row, Tensile Strength Min column, printed as 55 ksi (380 MPa)",
      "status": "ground",
      "source": "combmet-409",
      "where": "Typical Room Temperature Mechanical Properties table (Annealed (Min) row, Tensile Strength Min column)",
      "source_detail": {
        "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
        "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Annealed minimum elongation in 2 in (Combined Metals)",
      "value": 20,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "409 sheet, ASTM A240 basis (Combined Metals data sheet)",
        "temper": "annealed (Min)",
        "temperature": "room temperature (typical room temperature table)",
        "gauge": "2 in (50.8 mm)"
      },
      "method": "Typical Room Temperature Mechanical Properties table, Annealed (Min) row, Elongation Min column, printed as 20% in 2 in (50.8 mm)",
      "status": "ground",
      "source": "combmet-409",
      "where": "Typical Room Temperature Mechanical Properties table (Annealed (Min) row, Elongation column)",
      "source_detail": {
        "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
        "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Annealed maximum hardness, Rockwell B (Combined Metals)",
      "value": 88,
      "bound": "upper",
      "unit": "HRB",
      "scope": "material",
      "conditions": {
        "form": "409 sheet, ASTM A240 basis (Combined Metals data sheet)",
        "temper": "annealed (row labelled Annealed (Min); hardness printed as a maximum)",
        "temperature": "room temperature (typical room temperature table)",
        "scale": "Rockwell B (HRBW printed)"
      },
      "method": "Typical Room Temperature Mechanical Properties table, Hardness Rockwell column, Annealed (Min) row, printed as 88 HRBW (Max)",
      "status": "ground",
      "source": "combmet-409",
      "where": "Typical Room Temperature Mechanical Properties table (Hardness Rockwell column, Annealed (Min) row)",
      "source_detail": {
        "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
        "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
        "year": 2024,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density (Aalco)",
      "value": 7.6,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "409 / 1.4512 sheet (Aalco datasheet, EN 10088-2:2005 basis, indicative)",
        "temperature": "not printed"
      },
      "method": "Physical Property table, Density row, printed as 7.6 g/cm³",
      "status": "ground",
      "source": "aalco-1-4512",
      "where": "Physical Property table (Density row)",
      "source_detail": {
        "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet",
        "id": "Stainless-Steel-14512-Sheet_313",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx",
        "kind": "datasheet",
        "license": "distributor data sheet, cited (states its data are indicative only)"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity (Aalco)",
      "value": 208,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "409 / 1.4512 sheet (Aalco datasheet, EN 10088-2:2005 basis, indicative)",
        "temperature": "not printed"
      },
      "method": "Physical Property table, Modulus of Elasticity row, printed as 208 GPa",
      "status": "ground",
      "source": "aalco-1-4512",
      "where": "Physical Property table (Modulus of Elasticity row)",
      "source_detail": {
        "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet",
        "id": "Stainless-Steel-14512-Sheet_313",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx",
        "kind": "datasheet",
        "license": "distributor data sheet, cited (states its data are indicative only)"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity (Aalco)",
      "value": 25.8,
      "bound": "exact",
      "unit": "W/m.K",
      "scope": "material",
      "conditions": {
        "form": "409 / 1.4512 sheet (Aalco datasheet, EN 10088-2:2005 basis, indicative)",
        "temperature": "not printed"
      },
      "method": "Physical Property table, Thermal Conductivity row, printed as 25.8 W/m.K",
      "status": "ground",
      "source": "aalco-1-4512",
      "where": "Physical Property table (Thermal Conductivity row)",
      "source_detail": {
        "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet",
        "id": "Stainless-Steel-14512-Sheet_313",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx",
        "kind": "datasheet",
        "license": "distributor data sheet, cited (states its data are indicative only)"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Proof stress minimum, sheet up to 8 mm (Aalco)",
      "value": 210,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "sheet up to 8 mm thick (EN 10088-2:2005)",
        "temperature": "not printed",
        "basis": "proof stress, minimum"
      },
      "method": "Mechanical Property table, sheet up to 8 mm, Proof Stress row, printed as 210 Min MPa",
      "status": "ground",
      "source": "aalco-1-4512",
      "where": "Mechanical Property table, sheet up to 8 mm (Proof Stress row)",
      "source_detail": {
        "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet",
        "id": "Stainless-Steel-14512-Sheet_313",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx",
        "kind": "datasheet",
        "license": "distributor data sheet, cited (states its data are indicative only)"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength range, sheet up to 8 mm (Aalco)",
      "value": 380,
      "value_high": 560,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "sheet up to 8 mm thick (EN 10088-2:2005)",
        "temperature": "not printed"
      },
      "method": "Mechanical Property table, sheet up to 8 mm, Tensile Strength row, printed as 380 - 560 MPa",
      "status": "ground",
      "source": "aalco-1-4512",
      "where": "Mechanical Property table, sheet up to 8 mm (Tensile Strength row)",
      "source_detail": {
        "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet",
        "id": "Stainless-Steel-14512-Sheet_313",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx",
        "kind": "datasheet",
        "license": "distributor data sheet, cited (states its data are indicative only)"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation A50 minimum, sheet up to 8 mm (Aalco)",
      "value": 25,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "sheet up to 8 mm thick (EN 10088-2:2005)",
        "temperature": "not printed",
        "gauge": "A50 mm"
      },
      "method": "Mechanical Property table, sheet up to 8 mm, Elongation A50 mm row, printed as 25 Min %",
      "status": "ground",
      "source": "aalco-1-4512",
      "where": "Mechanical Property table, sheet up to 8 mm (Elongation A50 mm row)",
      "source_detail": {
        "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet",
        "id": "Stainless-Steel-14512-Sheet_313",
        "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx",
        "kind": "datasheet",
        "license": "distributor data sheet, cited (states its data are indicative only)"
      }
    },
    {
      "benchmark": "density",
      "label": "Density at room temperature (Outokumpu)",
      "value": 7.7,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "temperature": "room temperature (RT)",
        "unit_in_source": "kg/dm3 (1 kg/dm3 = 1 g/cm3, so the number is unchanged)"
      },
      "method": "Table 12 (Physical properties), 4512 row, density RT column, printed as 7.7 kg/dm3",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 12, 4512 row, density RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity at room temperature (Outokumpu)",
      "value": 220,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "temperature": "room temperature (RT)"
      },
      "method": "Table 12, 4512 row, modulus of elasticity RT column, printed as 220 GPa",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 12, 4512 row, modulus of elasticity RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity at room temperature (Outokumpu)",
      "value": 25,
      "bound": "exact",
      "unit": "W/m°C",
      "scope": "material",
      "conditions": {
        "temperature": "room temperature (RT)"
      },
      "method": "Table 12, 4512 row, thermal conductivity RT column, printed as 25 W/m°C",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 12, 4512 row, thermal conductivity RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat at room temperature (Outokumpu)",
      "value": 460,
      "bound": "exact",
      "unit": "J/kg°C",
      "scope": "material",
      "conditions": {
        "temperature": "room temperature (RT)"
      },
      "method": "Table 12, 4512 row, thermal capacity RT column, printed as 460 J/kg°C",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 12, 4512 row, thermal capacity RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, 20 to 100 C (Outokumpu)",
      "value": 10.5,
      "bound": "exact",
      "unit": "10-6/°C",
      "scope": "material",
      "conditions": {
        "temperature": "20 C to 100 C (CTE between 20 C and T, 100 C column)"
      },
      "method": "Table 12, 4512 row, CTE between 20 C and 100 C column, printed as 10.5 (10-6 per C)",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 12, 4512 row, CTE 100 C column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "label": "Coefficient of thermal expansion, 20 to 400 C (Outokumpu)",
      "value": 12,
      "bound": "exact",
      "unit": "10-6/°C",
      "scope": "material",
      "conditions": {
        "temperature": "20 C to 400 C (CTE between 20 C and T, 400 C column)"
      },
      "method": "Table 12, 4512 row, CTE between 20 C and 400 C column, printed as 12.0 (10-6 per C)",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 12, 4512 row, CTE 400 C column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "electrical_resistivity",
      "label": "Electrical resistivity at room temperature (Outokumpu)",
      "value": 0.6,
      "bound": "exact",
      "unit": "μΩm",
      "scope": "material",
      "conditions": {
        "temperature": "room temperature (RT)"
      },
      "method": "Table 12, 4512 row, electrical resistivity RT column, printed as 0.60 μΩm",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 12, 4512 row, electrical resistivity RT column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Typical 0.2% proof stress, cold rolled sheet (Outokumpu)",
      "value": 255,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "cold rolled coil and sheet (Outokumpu product code C)",
        "temperature": "room temperature (RT)",
        "basis": "Outokumpu typical value, Rp0.2"
      },
      "method": "Table 6 (Mechanical properties, room temperature), 4512 row, product C, typical Rp0.2 column, printed as 255 MPa",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 6, 4512 row, typical Rp0.2 column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Typical tensile strength, cold rolled sheet (Outokumpu)",
      "value": 425,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "cold rolled coil and sheet (Outokumpu product code C)",
        "temperature": "room temperature (RT)",
        "basis": "Outokumpu typical value"
      },
      "method": "Table 6, 4512 row, product C, typical Rm column, printed as 425 MPa",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 6, 4512 row, typical Rm column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Typical elongation A5, cold rolled sheet (Outokumpu)",
      "value": 33,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "cold rolled coil and sheet (Outokumpu product code C)",
        "temperature": "room temperature (RT)",
        "gauge": "A5",
        "basis": "Outokumpu typical value"
      },
      "method": "Table 6, 4512 row, product C, typical A5 column, printed as 33 %",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 6, 4512 row, typical A5 column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "EN minimum 0.2% proof stress at room temperature (Outokumpu)",
      "value": 220,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "EN 10088 minimum values, mainly hot rolled plate in the transverse direction (Table 6 note)",
        "temperature": "room temperature (RT)",
        "basis": "EN minimum Rp0.2"
      },
      "method": "Table 6, 4512 row, EN min Rp0.2 column, printed as 220 MPa",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 6, 4512 row, EN min Rp0.2 column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "EN minimum 0.2% proof stress at 100 C (Outokumpu)",
      "value": 200,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "EN minimum values, mainly hot rolled plate (Table 8 note)",
        "temperature": "100 C",
        "basis": "EN minimum Rp0.2"
      },
      "method": "Table 8 (Mechanical properties, elevated temperatures), 4512 row, EN min Rp0.2 MPa, 100 C column, printed as 200",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 8, 4512 row, 100 C column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "EN minimum 0.2% proof stress at 200 C (Outokumpu)",
      "value": 190,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "EN minimum values, mainly hot rolled plate (Table 8 note)",
        "temperature": "200 C",
        "basis": "EN minimum Rp0.2"
      },
      "method": "Table 8 (Mechanical properties, elevated temperatures), 4512 row, EN min Rp0.2 MPa, 200 C column, printed as 190",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 8, 4512 row, 200 C column",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "critical_pitting_temperature",
      "label": "Critical pitting temperature, Avesta cell test (Outokumpu)",
      "value": 10,
      "bound": "upper",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "test": "potentiostatic at +700 mV SCE with the Avesta cell, footnote 7",
        "electrolyte": "1 M NaCl",
        "surface": "ground to P 320 (ASTM G 150)",
        "printed": "< 10"
      },
      "method": "Table 14 (Fabrication and use characteristics), 4512 row, CPT column, printed as < 10 °C; footnote 7 gives the test",
      "status": "ground",
      "source": "outokumpu-xref",
      "where": "Table 14, 4512 row, CPT column (footnote 7)",
      "source_detail": {
        "title": "Outokumpu: Steel Grades, Properties and Global Standards",
        "id": "outokumpu-steel-grades-properties-global-standards.pdf",
        "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "label": "Minimum yield strength, ASTM A240 listing for S40900 (ICAST)",
      "value": 205,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "plate, sheet and strip, ASTM A240 listing for UNS S40900 (AS 409 data sheet)",
        "temperature": "not printed",
        "basis": "minimum; heat treatment printed as annealing or hardening plus tempering, not tied to one condition"
      },
      "method": "Mechanical Properties table (AS 409 data sheet), Yield Strength in Mpa row, printed as 205 min.",
      "status": "ground",
      "source": "icast-as409",
      "where": "Mechanical Properties table (Yield Strength row)",
      "source_detail": {
        "title": "ICAST Alloys: AS 409 material data sheet (ASTM A240 listing, cross-reference table)",
        "id": "AS 409",
        "url": "https://www.icastllp.com/material_db_pdf/AS%20409.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Minimum tensile strength, ASTM A240 listing for S40900 (ICAST)",
      "value": 380,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "plate, sheet and strip, ASTM A240 listing for UNS S40900 (AS 409 data sheet)",
        "temperature": "not printed",
        "basis": "minimum; heat treatment printed as annealing or hardening plus tempering, not tied to one condition"
      },
      "method": "Mechanical Properties table (AS 409 data sheet), Tensile Strength in Mpa row, printed as 380 min.",
      "status": "ground",
      "source": "icast-as409",
      "where": "Mechanical Properties table (Tensile Strength row)",
      "source_detail": {
        "title": "ICAST Alloys: AS 409 material data sheet (ASTM A240 listing, cross-reference table)",
        "id": "AS 409",
        "url": "https://www.icastllp.com/material_db_pdf/AS%20409.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Minimum elongation, ASTM A240 listing for S40900 (ICAST)",
      "value": 20,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "plate, sheet and strip, ASTM A240 listing for UNS S40900 (AS 409 data sheet)",
        "temperature": "not printed",
        "basis": "minimum; heat treatment printed as annealing or hardening plus tempering, not tied to one condition"
      },
      "method": "Mechanical Properties table (AS 409 data sheet), Elongation in % row, printed as 20 min.",
      "status": "ground",
      "source": "icast-as409",
      "where": "Mechanical Properties table (Elongation row)",
      "source_detail": {
        "title": "ICAST Alloys: AS 409 material data sheet (ASTM A240 listing, cross-reference table)",
        "id": "AS 409",
        "url": "https://www.icastllp.com/material_db_pdf/AS%20409.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "label": "Minimum hardness, ASTM A240 listing for S40900 (ICAST)",
      "value": 80,
      "bound": "lower",
      "unit": "HB",
      "scope": "material",
      "conditions": {
        "form": "plate, sheet and strip, ASTM A240 listing for UNS S40900 (AS 409 data sheet)",
        "temperature": "not printed",
        "scale": "Brinell (HB printed)",
        "basis": "minimum; heat treatment printed as annealing or hardening plus tempering"
      },
      "method": "Mechanical Properties table (AS 409 data sheet), Hardness in HB row, printed as 80 min.",
      "status": "ground",
      "source": "icast-as409",
      "where": "Mechanical Properties table (Hardness row)",
      "source_detail": {
        "title": "ICAST Alloys: AS 409 material data sheet (ASTM A240 listing, cross-reference table)",
        "id": "AS 409",
        "url": "https://www.icastllp.com/material_db_pdf/AS%20409.pdf",
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "General use against carbon steel (no test data given)",
      "headline": "Combined Metals says 409 is used where corrosion protection is needed beyond carbon steel.",
      "effect": "Combined Metals says 409 stainless steel is used when corrosion protection is needed beyond a carbon steel capacity, and lists automotive exhaust systems and heat exchangers as its applications. The sheet gives no corrosion test data.",
      "rating": "unknown",
      "source": "combmet-409",
      "where": "Introduction text (Applications include)"
    },
    {
      "environment": "Chloride pitting (critical pitting temperature test)",
      "headline": "Outokumpu's test gives a critical pitting temperature below 10 °C for 409, the same mark it prints for 430 and 304.",
      "effect": "Outokumpu's Table 14 prints the critical pitting temperature (CPT) of 4512 as < 10 °C. Footnote 7 gives the method: potentiostatic testing at +700 mV SCE with the Avesta cell in 1 M NaCl, on surfaces ground to P 320 (ASTM G 150); other methods give other values. The same table prints < 10 for 430 (4016) and for 304 (4301). Table 2 gives typical chromium of 11.5 percent for 409, 16.2 for 430 and 18.1 for 304, and typical nickel of 0.2 for 409 and 8.1 for 304.",
      "rating": "moderate",
      "conditions": {
        "test": "potentiostatic, +700 mV SCE, Avesta cell",
        "electrolyte": "1 M NaCl",
        "surface": "ground to P 320 (ASTM G 150)"
      },
      "source": "outokumpu-xref",
      "where": "Table 14, 4512 row, CPT column (footnote 7); Table 2 typical composition"
    },
    {
      "environment": "Intergranular corrosion, delivery and welded condition (EN ISO 3651-2)",
      "headline": "Outokumpu prints N/N for 409 for intergranular corrosion, which its legend reads as no in both delivery and welded condition.",
      "effect": "Outokumpu's Table 14 prints N/N for 4512 in the intergranular corrosion column. Footnote 6 says the test follows EN 10088-2 and EN ISO 3651-2, and that Y means yes and N means no for the delivery and welded conditions. For 430 (4016) the same column prints Y/N, and for 304 (4301) Y/N*, where the Table 15 note says the asterisk means it may be multi-certified as Y/Y. The source does not explain the 409 marks, so they are reported as printed.",
      "rating": "moderate",
      "conditions": {
        "standard": "EN 10088-2, tested to EN ISO 3651-2",
        "condition": "delivery and welded"
      },
      "source": "outokumpu-xref",
      "where": "Table 14, 4512 row, intergranular corrosion column (footnote 6); Table 15 note (asterisk)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem's aggregated GHS notifications for elemental chromium (CID 23976) give H317 (20.7%), H319 (19.1%) and H334 (20.3%, signal word Danger), and also list H320, H335, H341, H371, H400 and H410. The record is for chromium, not for the 409 alloy.",
        "ghs": [
          "H317",
          "H319",
          "H320",
          "H334",
          "H335",
          "H341",
          "H371",
          "H400",
          "H410"
        ],
        "source": "pubchem-chromium",
        "where": "Safety and Hazards, GHS Classification (CID 23976)"
      },
      {
        "text": "PubChem says the chemical does not meet GHS hazard criteria for 50% (1202 of 2404) of the company reports.",
        "ghs": [],
        "source": "pubchem-chromium",
        "where": "Safety and Hazards, GHS Classification (CID 23976)"
      }
    ],
    "failure_risks": [
      {
        "mode": "Pitting in chloride solution",
        "trigger": "Chloride exposure, tested at +700 mV SCE in 1 M NaCl",
        "consequence": "Critical pitting temperature printed as below 10 °C for 409, and the same mark for 430 and 304 in the same table, so the test does not separate the grades.",
        "severity": "moderate",
        "source": "outokumpu-xref",
        "where": "Table 14, CPT column (footnote 7)"
      },
      {
        "mode": "Intergranular corrosion in delivery or welded condition",
        "trigger": "Delivery, or welding of 409",
        "consequence": "Outokumpu prints N (no) for both the delivery and welded condition in its intergranular corrosion column for 4512.",
        "severity": "moderate",
        "source": "outokumpu-xref",
        "where": "Table 14, intergranular corrosion column (footnote 6)"
      },
      {
        "mode": "Weld thickness limit",
        "trigger": "Welding material thicker than about 2.5 mm",
        "consequence": "Aalco says weldability is good up to about 2.5 mm thick and advises grade 1.4003 where thicker welded material is needed.",
        "severity": "moderate",
        "source": "aalco-1-4512",
        "where": "Weldability section"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Anneal at 800 ± 30 °C; A in the source means annealing (Outokumpu Table 14, heat treatment temperature column).",
        "source": "outokumpu-xref",
        "where": "Table 14, 4512 row, heat treatment temperature column (footnote 1)"
      },
      {
        "text": "Outokumpu lists 13 or 19 9L as welding consumables for 4512 (covered electrodes to ISO 3581 or ISO 14172).",
        "source": "outokumpu-xref",
        "where": "Table 14, welding consumables column (footnote 2)"
      },
      {
        "text": "Aalco says welding is good up to about 2.5 mm thick and advises grade 1.4003 for thicker material.",
        "source": "aalco-1-4512",
        "where": "Weldability section"
      }
    ],
    "mitigations": [
      {
        "text": "For thicker welded parts, use grade 1.4003, which Aalco says is available in thicker sheets and plates.",
        "source": "aalco-1-4512",
        "where": "Weldability section and supplied forms"
      },
      {
        "text": "Choose the welding consumable from the 13 or 19 9L group that Outokumpu lists for 4512.",
        "source": "outokumpu-xref",
        "where": "Table 14, welding consumables column"
      }
    ]
  },
  "uses": [
    {
      "application": "structures",
      "device": "Automotive exhaust systems, mufflers and pipes",
      "example": "Aalco calls 409 'muffler grade stainless steel' because the major bulk usage of the material is for automotive exhaust systems.",
      "source": "aalco-1-4512",
      "where": "Introduction paragraph"
    },
    {
      "application": "structures",
      "device": "Exhaust manifolds, down-pipes, converter casings and mufflers",
      "example": "Aperam's 409A (extra low carbon) product page lists automotive exhaust systems: manifolds, down-pipes, converter casings and mufflers. The list is cited for its 409A product.",
      "source": "aperam-409a",
      "where": "Applications section"
    },
    {
      "application": "thermal-control",
      "device": "Heat exchangers",
      "example": "Combined Metals lists automotive exhaust systems and heat exchangers as applications for its 409 sheet.",
      "source": "combmet-409",
      "where": "Introduction text (Applications include)"
    }
  ],
  "supply": [
    {
      "subject": "Chromium",
      "abundance": "World mine production 51,000 thousand t gross weight in 2025 (estimated, world total rounded); world resources greater than 12 billion tons of shipping-grade chromite, 95 percent in Kazakhstan and southern Africa. US net import reliance 79 percent of apparent consumption in 2025 (estimated).",
      "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
        },
        {
          "country": "Finland",
          "share_percent": 3.7,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "Recycled chromium in reported 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-cr-2026",
      "where": "World Mine Production and Reserves table (2025e, gross weight; shares calculated from the printed tonnage over the 51,000 world total); Salient Statistics (net import reliance); Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Combined Metals: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
      "type": "datasheet",
      "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
      "year": 2024
    },
    {
      "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet (datasheet page)",
      "type": "datasheet",
      "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx"
    },
    {
      "title": "Outokumpu: Steel Grades, Properties and Global Standards (Tables 2, 3, 6, 8, 12, 14 and 15)",
      "type": "datasheet",
      "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf"
    },
    {
      "title": "Aperam: 409A - 1.4512 product page (extra low carbon, norms and applications)",
      "type": "datasheet",
      "url": "https://www.aperam.com/product/409a-1-4512/"
    },
    {
      "title": "ICAST Alloys: AS 409 material data sheet (ASTM A240 listing, cross-reference table)",
      "type": "datasheet",
      "url": "https://www.icastllp.com/material_db_pdf/AS%20409.pdf"
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Chromium",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf",
      "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
    }
  ],
  "gaps": [
    "No safety data sheet for 409 was read in this run. The hazard entries rest on the PubChem record for elemental chromium, which is not the alloy. Welding fume and hexavalent-chromium hazards for 409 are not sourced.",
    "UNS numbers differ by source. Combined Metals prints S40910, S40920 and S40930 for its 409 sheet, Outokumpu prints a dash for UNS in its 4512 row, and ICAST prints S40900 for A240. The S40900 entry is taken from ICAST and Aperam's 409A norm list, and all UNS numbers are kept as printed.",
    "Carbon limit differs. ICAST prints 0.080 maximum for A240 UNS S40900, Combined Metals prints 0.030 maximum for its S40910/S40920/S40930 sheet, and Aalco prints 0.0 to 0.30, which is read as a probable typo and not used. Both maxima appear in identity.formula.",
    "Minimum yield strength differs. ICAST prints 205 MPa for the S40900 listing and Combined Metals prints 170 MPa for the annealed condition on the ASTM A240 basis. Both are recorded with their own conditions.",
    "Titanium: the sources give a titanium limit (ICAST maximum 0.750; Aalco EN 10088-2 0.0 to 0.65), but none explains its metallurgical role. No titanium supply entry is given, because no page read links titanium supply to this grade.",
    "Niobium stabilisation is not sourced for 409. No page read names niobium for this grade.",
    "Oxidation and maximum service temperature for 409 are not sourced. The Atlas Steels 409 data sheets (2008 and 2021) returned a bot-verification page and were not opened, and Outokumpu's Table 14 gives no maximum service temperature for 4512.",
    "Aperam's 409A page describes an extra-low-carbon product. Its typical composition and its oxidation statements are not used as 409 values. Only its norm list (AISI 409, EN 1.4512, X2CrTi12) and its exhaust application list are used.",
    "Outokumpu's typical values for 4512 are for cold rolled coil and sheet (product code C). Its EN minimum values are mainly for hot rolled plate in the transverse direction. Each value carries its own product condition.",
    "The intergranular corrosion marks (N/N for 409, Y/N for 430, Y/N* for 304) are reported as printed. The source does not explain the 409 marks.",
    "Critical-mineral status of chromium is not established. The USGS 2025 critical minerals page returned a stub, and the EU critical raw materials page read in this run does not name chromium, so critical_lists is empty.",
    "Low-temperature (impact) data for 409 are not in the sources read. Outokumpu's low-temperature table has no 4512 row.",
    "Fatigue strength, Poisson's ratio, shear and bulk modulus, creep strength and crystal structure are not printed by any source read for 409, so they are not in the file.",
    "Exhaust-condensate, road-salt and sea-water corrosion data for 409 were not found in the sources read.",
    "Hardness and critical_pitting_temperature are not in spores/property-canon.yaml. Hardness is written on the scale each source prints (HRB or HB), and critical_pitting_temperature is a snake_case name.",
    "The exhaust and heat-exchanger uses are not space applications. The closest listed slugs (structures, thermal-control) are used for them, so tags.applications does not describe a space use.",
    "Media: no photograph or micrograph of 409 was added, because no licensed image was fetched in this run.",
    "Sources that could not be used: Suppliers Online (503 error), Atlas Steels (bot check), Continental Steel and ULProspector (stub pages), a guessed Deutsche Edelstahlwerke 1.4512 datasheet URL (returned a general product page with no 1.4512 data), and the USGS 2025 critical minerals page (stub).",
    "Corrosion ratings are the assistant's reading of the printed marks. The sources give no rating scale for these marks.",
    "Aalco states that its data are indicative only and not to be relied on in place of the full specification. Its values are used with that caveat.",
    "Wikipedia is used only for the 10.5 percent chromium threshold for stainless steel, for the statement that Type 409 has the lower chromium content, and for the statement that it is mainly used in automotive exhaust systems."
  ],
  "story": {
    "why": "Grade 409 is a titanium-stabilised ferritic chromium steel. Aalco calls it muffler grade stainless steel because most of its bulk use is in automotive exhaust systems. Wikipedia's ferritic summary calls Type 409 the lower-chromium grade, mainly used in automotive exhaust systems. Combined Metals says it is used where corrosion protection is needed beyond carbon steel.",
    "uses": [
      {
        "where": "Automotive exhaust systems",
        "line": "Aalco calls 409 muffler grade stainless steel because most of its bulk use is in automotive exhaust systems. Aperam's 409A page lists manifolds, down-pipes, converter casings and mufflers."
      },
      {
        "where": "Heat exchangers",
        "line": "Combined Metals lists automotive exhaust systems and heat exchangers as applications of its 409 sheet."
      }
    ],
    "can_do": [
      {
        "label": "Strength",
        "line": "Annealed sheet has a minimum tensile strength of 380 MPa under ASTM A240 (Combined Metals). The EN 10088-2 range for sheet up to 8 mm is 380 to 560 MPa (Aalco).",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Yield",
        "line": "The minimum 0.2 percent proof stress is 170 MPa for annealed sheet in the Combined Metals table and 210 MPa for EN sheet up to 8 mm (Aalco). The typical room-temperature value for cold rolled sheet is 255 MPa (Outokumpu).",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Stiffness",
        "line": "Elastic modulus is 208 GPa (Aalco), 208.22 GPa at 20 °C (Combined Metals) and 220 GPa at room temperature in Outokumpu's table.",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Density",
        "line": "Density is 7.6 g/cm3 (Aalco), 7.7 kg/dm3 (Outokumpu) and 7.75 g/cm3 at 20 °C (Combined Metals).",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Heat",
        "line": "The EN minimum 0.2 percent proof stress falls from 220 MPa at room temperature to 200 MPa at 100 °C and 190 MPa at 200 °C (Outokumpu Table 8).",
        "benchmark": "yield_strength",
        "scope": "material",
        "value": "200 MPa at 100 °C, 190 MPa at 200 °C"
      }
    ],
    "compare": "Against Type 430, Outokumpu's table gives 11.5 percent chromium for 409 against 16.2 percent for 430, and Wikipedia calls 409 the lower-chromium grade. Both grades print a critical pitting temperature below 10 °C in the same test, but 409's intergranular corrosion mark is N/N where 430's is Y/N. Against Type 304 (18.1 percent chromium, 8.1 percent nickel), 409 has 0.2 percent nickel and the same below-10 °C pitting mark, and 304's intergranular mark is Y/N*. Outokumpu's table shows no test result for 409 that is better than 430 or 304 on pitting or intergranular corrosion, and the sources read do not compare exhaust-condensate or salt-spray performance.",
    "compare_rows": [
      {
        "label": "Tensile strength",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      }
    ],
    "handling": [
      "Anneal at 800 ± 30 °C (Outokumpu Table 14).",
      "Weld only sheet up to about 2.5 mm thick, or use grade 1.4003 for thicker welded parts (Aalco).",
      "Choose welding consumables from the 13 or 19 9L group that Outokumpu lists for 4512."
    ],
    "good_for": [
      "Automotive exhaust systems, mufflers and converter casings, which Aalco gives as the bulk use (Aalco; Aperam 409A page).",
      "Heat exchangers, where corrosion protection beyond carbon steel is needed (Combined Metals)."
    ],
    "watch_out": [
      "Pitting. The critical pitting temperature is below 10 °C in Outokumpu's test, the same as for 430 and 304.",
      "Intergranular corrosion. Outokumpu prints N/N for 409 in the delivery and welded conditions.",
      "Welded thickness. Aalco limits weldability to about 2.5 mm thick."
    ],
    "verdict": "Grade 409 is the titanium-stabilised exhaust grade. It is magnetisable and anneals at 800 ± 30 °C. Outokumpu's table marks its intergranular corrosion weaker than 430 and 304, and its pitting mark is no better than theirs in the same test.",
    "recipe": {
      "line": "Grade 409 is an iron-chromium steel with 10.5 to 11.75 percent chromium and a titanium addition (ICAST). Aalco and Outokumpu describe it as titanium-stabilised. Carbon, manganese, silicon, phosphorus and sulfur are held low, and nickel is 0.5 percent at most (ICAST).",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "The matrix of the alloy. Outokumpu marks the grade as magnetisable.",
          "share_note": "balance (the rest)"
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "The main alloying element. Wikipedia says a Fe-base alloy must contain at least 10.5 percent Cr to qualify as stainless steel.",
          "share_percent": 10.5,
          "share_high": 11.75,
          "source": "icast-as409",
          "where": "Chemical Composition table, Cr row (10.500 to 11.750)"
        },
        {
          "name": "Titanium",
          "symbol": "Ti",
          "role": "The stabilising addition. Aalco's EN 10088-2 limit is 0.0 to 0.65 percent.",
          "share_percent": 0,
          "share_high": 0.75,
          "source": "icast-as409",
          "where": "Chemical Composition table, Ti row (max 0.750)"
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Held low. The Combined Metals sheet for UNS S40910, S40920 and S40930 gives 0.030 maximum.",
          "share_percent": 0,
          "share_high": 0.08,
          "source": "icast-as409",
          "where": "Chemical Composition table, C row (max 0.080)"
        },
        {
          "name": "Nitrogen",
          "symbol": "N",
          "role": "Held low. Combined Metals gives 0.030 maximum.",
          "share_percent": 0,
          "share_high": 0.03,
          "source": "combmet-409",
          "where": "Nominal Composition table, N row (max 0.030)"
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Melt addition, held at 1.000 percent maximum.",
          "share_percent": 0,
          "share_high": 1,
          "source": "icast-as409",
          "where": "Chemical Composition table, Mn row (max 1.000)"
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Melt addition, held at 1.000 percent maximum.",
          "share_percent": 0,
          "share_high": 1,
          "source": "icast-as409",
          "where": "Chemical Composition table, Si row (max 1.000)"
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Held low. Outokumpu prints 0.2 as typical.",
          "share_percent": 0,
          "share_high": 0.5,
          "source": "icast-as409",
          "where": "Chemical Composition table, Ni row (max 0.500)"
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "Present in a small amount, 0.350 percent maximum.",
          "share_percent": 0,
          "share_high": 0.35,
          "source": "icast-as409",
          "where": "Chemical Composition table, Mo row (max 0.350)"
        },
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Present in a small amount, 0.350 percent maximum.",
          "share_percent": 0,
          "share_high": 0.35,
          "source": "icast-as409",
          "where": "Chemical Composition table, Cu row (max 0.350)"
        },
        {
          "name": "Phosphorus",
          "symbol": "P",
          "role": "Impurity held low.",
          "share_percent": 0,
          "share_high": 0.045,
          "source": "icast-as409",
          "where": "Chemical Composition table, P row (max 0.045)"
        },
        {
          "name": "Sulfur",
          "symbol": "S",
          "role": "Impurity held low.",
          "share_percent": 0,
          "share_high": 0.03,
          "source": "icast-as409",
          "where": "Chemical Composition table, S row (max 0.030)"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "No safety data sheet for 409 was read in this run. The PubChem record for elemental chromium is the only hazard source, and it is not a rating for the alloy.",
        "points": [
          {
            "label": "Chromium record",
            "line": "PubChem lists sensitisation codes H317 and H334 and eye codes H319 and H320 for elemental chromium in its aggregated notifications. Half of the 2404 company reports (1202) say it does not meet GHS criteria."
          }
        ],
        "level": 1,
        "verdict": "Chromium record, not the alloy"
      },
      {
        "title": "In the environment",
        "lead": "Outokumpu's pitting test marks 409 below 10 °C, the same mark it prints for 430 and 304.",
        "points": [
          {
            "label": "Pitting",
            "line": "Critical pitting temperature below 10 °C in the Avesta cell test in 1 M NaCl (Outokumpu)."
          },
          {
            "label": "Intergranular",
            "line": "Outokumpu prints N/N for 409 for intergranular corrosion in the delivery and welded conditions, where 430 is Y/N."
          }
        ],
        "level": 2,
        "verdict": "Pitting is the watch point"
      },
      {
        "title": "Welding",
        "lead": "Aalco says weldability is good up to about 2.5 mm thick and recommends grade 1.4003 for thicker welded material.",
        "points": [
          {
            "label": "Thickness",
            "line": "Usually available up to a maximum of 2.5 mm thick, and weldable to about that thickness (Aalco)."
          },
          {
            "label": "Filler",
            "line": "Outokumpu lists 13 or 19 9L covered electrodes for welding 409 (ISO 3581 or ISO 14172)."
          }
        ],
        "level": 2,
        "verdict": "Keep welded sheet below 2.5 mm"
      },
      {
        "title": "Heat",
        "lead": "Outokumpu gives the annealing temperature as 800 ± 30 °C. The sources read give no service temperature limit for 409.",
        "points": [
          {
            "label": "Annealing",
            "line": "A 800 ± 30 °C anneal, with A meaning annealing (Outokumpu Table 14)."
          }
        ],
        "level": 1,
        "verdict": "Anneal at 800 ± 30 °C"
      }
    ]
  },
  "updated": "2026-10-24",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 31,
    "unreachable": 0,
    "caveats": 8,
    "note": "Read by an AI assistant on 2026-10-24 from pages fetched in this run: Combined Metals 409 data sheet (rev. 2024 01 11), Aalco 1.4512 sheet page, Outokumpu Steel Grades, Properties and Global Standards (Tables 2, 3, 6, 8, 12, 14 and 15), Aperam 409A product page, ICAST AS 409 data sheet, USGS Mineral Commodity Summaries 2026 chromium, PubChem chromium record and Wikipedia ferritic stainless steel. Caveats: the Aalco values are indicative; the modulus and density rows are unit notation or conversions (kg/dm3 and 10^3 MPa); the Outokumpu typical values are for product C and the EN minimums are for hot rolled plate; the ICAST minima carry no single heat-treatment condition; the Aperam page is an extra-low-carbon product used only for designations and uses."
  },
  "sources": {
    "combmet-409": {
      "title": "Combined Metals Company: Alloy 409 Stainless Steel data sheet (rev. 2024 01 11)",
      "id": "409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
      "url": "https://www.combmet.com/wp-content/uploads/2024/01/409-Stainless-Steel-Alloy-Data-Sheet-2024-01-11.pdf",
      "year": 2024,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "aalco-1-4512": {
      "title": "Aalco: Stainless Steel - Ferritic - 1.4512 Sheet",
      "id": "Stainless-Steel-14512-Sheet_313",
      "url": "https://www.aalco.co.uk/datasheets/Stainless-Steel-14512-Sheet_313.ashx",
      "kind": "datasheet",
      "license": "distributor data sheet, cited (states its data are indicative only)"
    },
    "outokumpu-xref": {
      "title": "Outokumpu: Steel Grades, Properties and Global Standards",
      "id": "outokumpu-steel-grades-properties-global-standards.pdf",
      "url": "https://www.outokumpu.com/-/media/from-sharepoint/documents/product/outokumpu-steel-grades-properties-global-standards.pdf",
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "aperam-409a": {
      "title": "Aperam: 409A - 1.4512 product page (extra low carbon, norms and applications)",
      "id": "409a-1-4512",
      "url": "https://www.aperam.com/product/409a-1-4512/",
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "icast-as409": {
      "title": "ICAST Alloys: AS 409 material data sheet (ASTM A240 listing, cross-reference table)",
      "id": "AS 409",
      "url": "https://www.icastllp.com/material_db_pdf/AS%20409.pdf",
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "usgs-cr-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)"
    },
    "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",
      "year": 2026,
      "kind": "database",
      "license": "PubChem terms (public)"
    },
    "wiki-ferritic": {
      "title": "Wikipedia: Ferritic stainless steel (used for composition and the grade summary only)",
      "id": "Ferritic_stainless_steel",
      "url": "https://en.wikipedia.org/wiki/Ferritic_stainless_steel",
      "kind": "web",
      "license": "CC BY-SA (Wikipedia), cited"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/stainless-409/"
}