{
  "spore": "profile",
  "id": "stainless-2304",
  "spore_version": "0.2",
  "family": "stainless-duplex",
  "name": "Lean duplex stainless steel 2304",
  "abbreviation": "2304 (UNS S32304, EN 1.4362)",
  "role": "structural alloy",
  "category": "metals",
  "type": "steels-and-stainless",
  "summary": "Lean duplex 2304 is an austenite-ferrite stainless steel with about 23 percent chromium, 4 percent nickel and very little molybdenum (UNS S32304, EN 1.4362). ATI gives a typical PREN of 26 and a minimum 0.2 percent yield strength of 400 MPa for plate, and says its corrosion resistance is comparable to 316L in most environments with much higher strength. Alleima says it resists chloride stress corrosion cracking up to about 125 C in dilute oxygen-bearing chloride, where 304 and 316 are limited to 60 C.",
  "best_for": "Chloride-bearing process piping and heat exchangers, pulp and paper equipment, and strength-limited structures where 304 or 316 would crack or be too weak (Alleima, ATI)",
  "weakest_at": "Exposure above about 315 C (600 F), where 475 C embrittlement can follow (ATI); prolonged exposure above 280 C (Alleima); weld metal without an overmatched filler (ATI)",
  "identity": {
    "formula": "Fe balance, 21.5 to 24.5 Cr, 3.0 to 5.5 Ni, 0.05 to 0.60 Mo, 0.05 to 0.60 Cu, 0.05 to 0.20 N, max 0.030 C, max 2.50 Mn, max 1.00 Si, max 0.040 P, max 0.030 S (wt%, ASTM A240 UNS S32304)",
    "designations": [
      {
        "system": "UNS",
        "code": "S32304",
        "source": "ati-tds",
        "where": "Title block, ATI 2304 (UNS S32304)"
      },
      {
        "system": "EN",
        "code": "1.4362",
        "source": "alleima-saf2304",
        "where": "Standards list, EN Number"
      },
      {
        "system": "EN name",
        "code": "X2CrNiN23-4",
        "source": "alleima-saf2304",
        "where": "Standards list, EN Name"
      },
      {
        "system": "DIN",
        "code": "X 2 CrNiN 23 4",
        "source": "alleima-saf2304",
        "where": "Standards list, DIN"
      },
      {
        "system": "SS",
        "code": "2327",
        "source": "alleima-saf2304",
        "where": "Standards list, SS"
      },
      {
        "system": "AFNOR",
        "code": "Z 2 CN 23.04AZ",
        "source": "alleima-saf2304",
        "where": "Standards list, AFNOR"
      },
      {
        "system": "ASTM",
        "code": "A240",
        "note": "plate, sheet and strip",
        "source": "ati-tds",
        "where": "Specifications paragraph"
      },
      {
        "system": "ASTM",
        "code": "A276",
        "note": "bar and shape",
        "source": "ati-tds",
        "where": "Specifications paragraph"
      },
      {
        "system": "ASTM",
        "code": "A789",
        "note": "seamless and welded tube and pipe",
        "source": "alleima-saf2304",
        "where": "Product standards, tube and pipe"
      },
      {
        "system": "ASTM",
        "code": "A790",
        "note": "seamless and welded tube and pipe",
        "source": "alleima-saf2304",
        "where": "Product standards, tube and pipe"
      },
      {
        "system": "ASTM",
        "code": "A928",
        "note": "steel and pipe",
        "source": "icast-s32304",
        "where": "Cross Reference Table, A928 S32304"
      },
      {
        "system": "EN",
        "code": "10216-5",
        "note": "seamless tube and pipe",
        "source": "alleima-saf2304",
        "where": "Product standards, seamless tube and pipe"
      },
      {
        "system": "EN",
        "code": "10088-2",
        "note": "strip and sheet",
        "source": "alleima-saf2304",
        "where": "Product standards, strip and sheet"
      },
      {
        "system": "EN",
        "code": "10088-3",
        "note": "bar and forged billets",
        "source": "alleima-saf2304",
        "where": "Product standards, bar steel and forged billets"
      },
      {
        "system": "Trade name",
        "code": "ATI 2304",
        "note": "ATI",
        "source": "ati-tds",
        "where": "Title block, ATI 2304"
      },
      {
        "system": "Trade name",
        "code": "SAF® 2304",
        "note": "Alleima",
        "source": "alleima-saf2304",
        "where": "Datasheet title, SAF 2304"
      },
      {
        "system": "Trade name",
        "code": "PW 400",
        "note": "hydraulic tubing, Alleima",
        "source": "alleima-saf2304",
        "where": "Forms of supply, hydraulic tubing"
      }
    ],
    "source": "icast-s32304",
    "where": "Chemical Composition table (ASTM A240 UNS S32304)"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": [
      "structures",
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "value": 7.8,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate (TDS typical data)",
        "heat_treatment": "not printed",
        "temperature": "not printed"
      },
      "method": "Physical Properties table, printed as 0.28 lb/in3 (7.8 g/cm3); ATI says the data are typical, not maximum or minimum values",
      "status": "ground",
      "source": "ati-tds",
      "where": "Physical Properties, Density row",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "value": 200,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate (TDS typical data)",
        "heat_treatment": "not printed",
        "temperature": "not printed"
      },
      "method": "Physical Properties table, Elastic Modulus row, printed as 29 x 10^6 psi (200 GPa)",
      "status": "ground",
      "note": "An asterisk follows the printed value; its meaning is not explained in the fetched text",
      "source": "ati-tds",
      "where": "Physical Properties, Elastic Modulus row",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "value": 13,
      "bound": "exact",
      "unit": "W/m.K",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate (TDS typical data)",
        "heat_treatment": "not printed",
        "temperature": "20 to 100 C (68 to 212 F)"
      },
      "method": "Thermal Conductivity table, metric column (W/m.K), 20 to 100 C row printed as 13",
      "status": "ground",
      "source": "ati-tds",
      "where": "Thermal Conductivity table (metric, 20 to 100 C row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "value": 14,
      "bound": "exact",
      "unit": "W/m.K",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate (TDS typical data)",
        "heat_treatment": "not printed",
        "temperature": "20 to 300 C (68 to 572 F)"
      },
      "method": "Thermal Conductivity table, metric column (W/m.K), 20 to 300 C row printed as 14",
      "status": "ground",
      "source": "ati-tds",
      "where": "Thermal Conductivity table (metric, 20 to 300 C row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 13,
      "bound": "exact",
      "unit": "10-6/K",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate (TDS typical data)",
        "heat_treatment": "not printed",
        "temperature": "20 to 100 C mean",
        "unit_in_source": "10^-6 cm/cm C (printed as cm/cm°C x 10^-6)"
      },
      "method": "Thermal Expansion table, mean coefficient over range, metric column, 68 to 212 F (20 to 100 C) row printed as 13",
      "status": "ground",
      "source": "ati-tds",
      "where": "Thermal Expansion table (metric, 20 to 100 C row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 14,
      "bound": "exact",
      "unit": "10-6/K",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate (TDS typical data)",
        "heat_treatment": "not printed",
        "temperature": "20 to 300 C mean",
        "unit_in_source": "10^-6 cm/cm C (printed as cm/cm°C x 10^-6)"
      },
      "method": "Thermal Expansion table, mean coefficient over range, metric column, 68 to 572 F (20 to 300 C) row printed as 14",
      "status": "ground",
      "source": "ati-tds",
      "where": "Thermal Expansion table (metric, 20 to 300 C row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 400,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate, ASTM A240 minimum",
        "heat_treatment": "annealed (ASTM A240 minimum)",
        "temperature": "room temperature"
      },
      "method": "Minimum Room Temperature Mechanical Properties table for plate, 0.2 percent yield strength printed as 58 ksi and 400 MPa",
      "status": "ground",
      "source": "ati-tds",
      "where": "Minimum Room Temperature Mechanical Properties for Plate (Yield Strength row, ATI 2304)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 600,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate, ASTM A240 minimum",
        "heat_treatment": "annealed (ASTM A240 minimum)",
        "temperature": "room temperature"
      },
      "method": "Minimum Room Temperature Mechanical Properties table for plate, ultimate strength printed as 87 ksi and 600 MPa",
      "status": "ground",
      "source": "ati-tds",
      "where": "Minimum Room Temperature Mechanical Properties for Plate (Ultimate Strength column, ATI 2304 row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "value": 25,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate, ASTM A240 minimum",
        "heat_treatment": "annealed (ASTM A240 minimum)",
        "temperature": "room temperature",
        "gauge": "2 in or 50 mm"
      },
      "method": "Minimum Room Temperature Mechanical Properties table for plate, elongation in 2 in or 50 mm printed as 25 percent",
      "status": "ground",
      "source": "ati-tds",
      "where": "Minimum Room Temperature Mechanical Properties for Plate (Elongation column, ATI 2304 row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "value": 290,
      "bound": "upper",
      "unit": "BHN",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate, ASTM A240 limit",
        "heat_treatment": "annealed (ASTM A240 limit)",
        "temperature": "room temperature"
      },
      "method": "Minimum Room Temperature Mechanical Properties table for plate, hardness maximum printed as 290 BHN",
      "status": "ground",
      "source": "ati-tds",
      "where": "Minimum Room Temperature Mechanical Properties for Plate (Hardness Max BHN column, ATI 2304 row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "value": 32,
      "bound": "upper",
      "unit": "Rc",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate, ASTM A240 limit",
        "heat_treatment": "annealed (ASTM A240 limit)",
        "temperature": "room temperature"
      },
      "method": "Minimum Room Temperature Mechanical Properties table for plate, hardness maximum printed as 32 Rc",
      "status": "ground",
      "source": "ati-tds",
      "where": "Minimum Room Temperature Mechanical Properties for Plate (Hardness Max Rc column, ATI 2304 row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "pitting_resistance_equivalent",
      "value": 26,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "form": "ATI typical composition, PREN = %Cr + 3.3(%Mo) + 16(%N)",
        "heat_treatment": "not printed",
        "temperature": "not applicable"
      },
      "method": "Corrosion Resistance section, typical PREN table, ATI 2304 row printed as 26; Type 316L row printed as 24; ATI says the figures are typical, not minimum",
      "status": "ground",
      "note": "Typical ATI composition basis, not a minimum",
      "source": "ati-tds",
      "where": "Corrosion Resistance section, typical PREN table (ATI 2304 row)",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "pitting_resistance_equivalent",
      "value": 25,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "form": "nominal composition, Cr 22.5, Mo 0.3, N 0.1 (Alleima)",
        "heat_treatment": "not printed",
        "temperature": "not applicable"
      },
      "method": "Pitting section, PRE table, SAF 2304 row printed as 25 (PRE = % Cr + 3.3 x % Mo + 16 x % N); ASTM 316L row printed as 24 and ASTM 304L row as 18",
      "status": "ground",
      "note": "Nominal composition basis, against 26 typical from ATI; both kept",
      "source": "alleima-saf2304",
      "where": "Pitting section, PRE table (SAF 2304 row)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "value": 315,
      "bound": "upper",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate, ASME Section VIII Division 1",
        "heat_treatment": "not printed",
        "temperature": "600 F (315 C) upper limit"
      },
      "method": "Elevated Temperature Mechanical Properties text, printed as an upper temperature limit of 600°F (315°C) for use of ATI 2304 under the ASME Boiler and Pressure Vessel Code",
      "status": "ground",
      "source": "ati-tds",
      "where": "Elevated Temperature Mechanical Properties section",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "charpy_impact_energy",
      "value": 40,
      "bound": "lower",
      "unit": "J",
      "scope": "material",
      "conditions": {
        "form": "ATI 2304 plate",
        "heat_treatment": "not printed",
        "temperature": "-40 C",
        "test": "Charpy, type not printed"
      },
      "method": "Low-Temperature Impact Properties text: ATI says 2304 retains toughness to exceed the commonly required Charpy impact energy of 40 J at -40 C; 40 J is the requirement the alloy exceeds, not a measured result",
      "status": "ground",
      "note": "Lower bound from the statement that the alloy exceeds 40 J; no measured number is printed",
      "source": "ati-tds",
      "where": "Low-Temperature Impact Properties section",
      "source_detail": {
        "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
        "id": "ati_2304_tds_en_v1",
        "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
        "year": 2014,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "density",
      "value": 7.8,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe (SAF 2304 datasheet)",
        "heat_treatment": "not printed",
        "temperature": "not printed"
      },
      "method": "Physical properties, printed as Density 7.8 g/cm3, 0.28 lb/in3",
      "status": "ground",
      "source": "alleima-saf2304",
      "where": "Physical properties, Density line",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "value": 490,
      "bound": "exact",
      "unit": "J/(kg °C)",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe (SAF 2304 datasheet)",
        "heat_treatment": "not printed",
        "temperature": "20 C"
      },
      "method": "Specific heat capacity table, 20 C row printed as 490 J/(kg °C)",
      "status": "ground",
      "source": "alleima-saf2304",
      "where": "Specific heat capacity table (20 C row)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "value": 16,
      "bound": "exact",
      "unit": "W/(m °C)",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe (SAF 2304 datasheet)",
        "heat_treatment": "not printed",
        "temperature": "20 C"
      },
      "method": "Thermal conductivity table, metric, SAF 2304 row, 20 C column printed as 16 W/(m °C); ASTM 316L row printed as 14 at 20 C",
      "status": "ground",
      "note": "Differs from ATI 13 W/m.K at 20 to 100 C; both kept, not averaged",
      "source": "alleima-saf2304",
      "where": "Thermal conductivity table (metric, SAF 2304 row, 20 C column)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "cte",
      "value": 13.5,
      "bound": "exact",
      "unit": "10-6/K",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe (SAF 2304 datasheet)",
        "heat_treatment": "not printed",
        "temperature": "30 to 100 C mean",
        "unit_in_source": "x10-6 per C (printed as Per °C)"
      },
      "method": "Thermal expansion, mean values in temperature ranges, metric, SAF 2304 row, 30-100 C column printed as 13.5; ASTM 304L/316L row printed as 16.5",
      "status": "ground",
      "note": "Range and value differ from ATI 13 for 20 to 100 C; both kept",
      "source": "alleima-saf2304",
      "where": "Thermal expansion table (metric, SAF 2304 row, 30-100 C column)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "value": 180,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe (SAF 2304 datasheet)",
        "heat_treatment": "not printed",
        "temperature": "300 C",
        "unit_in_source": "x10^3 MPa (printed value 180)"
      },
      "method": "Modulus of elasticity table, 300 C row printed as 180 (x10^3 MPa), equal to 26.2 ksi at 600 F",
      "status": "ground",
      "source": "alleima-saf2304",
      "where": "Modulus of elasticity table (300 C row)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 400,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe, wall up to 20 mm",
        "heat_treatment": "solution annealed",
        "temperature": "20 C"
      },
      "method": "Mechanical properties table at 20 C, Rp0.2 printed as 400 MPa minimum; footnote c says tubes up to 25.4 mm OD are guaranteed at 450 MPa (ASTM A789)",
      "status": "ground",
      "note": "Footnote c: 450 MPa guaranteed for tube up to 25.4 mm OD",
      "source": "alleima-saf2304",
      "where": "Mechanical properties, 20 C table (Rp0.2 column)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "value": 630,
      "value_high": 820,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe, wall up to 20 mm",
        "heat_treatment": "solution annealed",
        "temperature": "20 C"
      },
      "method": "Mechanical properties table at 20 C, Rm printed as 630-820 MPa; footnote c says tubes up to 25.4 mm OD are guaranteed at 690 MPa minimum (ASTM A789)",
      "status": "ground",
      "source": "alleima-saf2304",
      "where": "Mechanical properties, 20 C table (Rm column)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "yield_strength",
      "value": 270,
      "bound": "lower",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe, wall above 4 mm",
        "heat_treatment": "solution annealed",
        "temperature": "300 C"
      },
      "method": "High temperature proof strength table, Rp0.2 minimum, metric, Wt > 4 mm column, 300 C row printed as 270",
      "status": "ground",
      "source": "alleima-saf2304",
      "where": "At high temperatures, proof strength table (300 C row, Wt > 4 mm)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "hardness",
      "value": 30,
      "bound": "upper",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "form": "seamless tube and pipe, wall up to 20 mm",
        "heat_treatment": "solution annealed",
        "temperature": "20 C"
      },
      "method": "Mechanical properties table at 20 C, HRC column printed as 30 maximum",
      "status": "ground",
      "source": "alleima-saf2304",
      "where": "Mechanical properties, 20 C table (HRC column)",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "value": 280,
      "bound": "upper",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "pressure vessel applications (VdTÜV-Wb 496)",
        "heat_treatment": "not printed",
        "temperature": "280 C (540 F) maximum for prolonged exposure"
      },
      "method": "At high temperatures section, printed: for pressure vessel applications 280 C (540 F) is required as a maximum according to VdTÜV-Wb 496",
      "status": "ground",
      "source": "alleima-saf2304",
      "where": "At high temperatures section",
      "source_detail": {
        "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
        "id": "SAF 2304 seamless tube and pipe",
        "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
        "year": 2026,
        "kind": "datasheet",
        "license": "cited, not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Chloride stress corrosion cracking, dilute oxygen-bearing chloride",
      "headline": "Resists SCC up to about 125 C; 304 and 316 limited to 60 C",
      "effect": "Alleima says SAF 2304 can be used in dilute oxygen-bearing chloride solutions up to about 125 C (260 F) without any risk of SCC (Figure 9, about 8 ppm oxygen, 1000 hours). It says ASTM 304/304L and 316/316L should not be used above 60 C (140 F) in such environments. ATI says the duplex structure gives greater chloride SCC resistance than 304L and 316L.",
      "rating": "low",
      "conditions": {
        "environment": "oxygen-bearing neutral chloride, about 8 ppm oxygen",
        "temperature": "up to 125 C (260 F) for SAF 2304; 60 C (140 F) limit for 304 and 316",
        "test": "Figure 9, 1000 hours, load above yield strength at test temperature"
      },
      "source": "alleima-saf2304",
      "where": "Stress corrosion and cracking section, Figure 9 text"
    },
    {
      "environment": "Chloride SCC in oxygen-bearing solution above 125 C",
      "headline": "Above 125 C with more than about 10 ppm chloride, do not use SAF 2304",
      "effect": "Alleima says at temperatures above 125 C, SAF 2304 should not be used in oxygen-bearing solutions with more than about 10 ppm Cl-, and it recommends SAF 2205, SAF 2507 or Sanicro 28 for such conditions. At low oxygen contents, considerably higher chloride and temperature are tolerated.",
      "rating": "moderate",
      "conditions": {
        "environment": "oxygen-bearing solution with more than about 10 ppm Cl-",
        "temperature": "above 125 C (260 F)"
      },
      "source": "alleima-saf2304",
      "where": "Stress corrosion and cracking section, Figure 9 text"
    },
    {
      "environment": "Chloride SCC in concentrated chloride (40 percent CaCl2)",
      "headline": "Threshold stress much higher than 304 and 316",
      "effect": "Alleima Figure 8 shows the threshold stress for SCC in 40 percent CaCl2 at 100 C is much higher for SAF 2304 than for ASTM 304/304L and 316/316L. The figure values are not printed in the text, so no number is recorded.",
      "rating": "low",
      "conditions": {
        "environment": "40 percent CaCl2, pH 6.5, aerated",
        "temperature": "100 C (210 F)"
      },
      "source": "alleima-saf2304",
      "where": "Stress corrosion and cracking section, Figure 8"
    },
    {
      "environment": "Chloride pitting and crevice corrosion",
      "headline": "PRE 25 nominal, comparable to 316L; crevice better than 304",
      "effect": "Alleima's PRE table gives 25 for SAF 2304 against 24 for ASTM 316L and 18 for ASTM 304L. Its critical pitting temperature is higher than 304L and comparable to 316L (Figure 7, potentiostatic test in neutral chloride; no number in the text). Crevice resistance is better than 304/304L and comparable to 316/316L. ATI gives a typical PREN of 26 and 24 for Type 316L.",
      "rating": "low",
      "conditions": {
        "environment": "neutral chloride solutions, pH 6 (Figure 7)",
        "temperature": "critical pitting temperature from Figure 7, not printed as a number"
      },
      "source": "alleima-saf2304",
      "where": "Pitting and Crevice corrosion sections, PRE table and Figure 7"
    },
    {
      "environment": "General corrosion in acids",
      "headline": "Excellent in acids (Alleima); comparable to 316L in most environments (ATI)",
      "effect": "Alleima says SAF 2304 has excellent corrosion resistance in acidic environments, with corrosion-rate tables for acetic, formic, hydrochloric, nitric, phosphoric and sulphuric acid mixtures and isocorrosion diagrams for sulphuric, formic and nitric acid (Figures 4 to 6). ATI says general corrosion resistance is comparable to Type 316L in most environments.",
      "rating": "low",
      "conditions": {
        "environment": "acetic, formic, hydrochloric, nitric, phosphoric and sulphuric acid mixtures",
        "temperature": "varies by table; not summarised as one value"
      },
      "source": "alleima-saf2304",
      "where": "General corrosion section, corrosion-rate tables and Figures 4 to 6"
    },
    {
      "environment": "Intergranular corrosion in welds and erosion corrosion",
      "headline": "Welds pass the Strauss test; very good erosion resistance",
      "effect": "Alleima says welded joints easily pass Strauss intergranular corrosion testing (SS-EN ISO 3651-2 Method A). It says 304/304L and 316/316L types can be attacked by erosion corrosion in abrasive flow, while SAF 2304 shows very good resistance.",
      "rating": "low",
      "conditions": {
        "environment": "welded joints (Strauss test); abrasive flowing media",
        "temperature": "not printed"
      },
      "source": "alleima-saf2304",
      "where": "Intergranular corrosion and Erosion corrosion sections"
    },
    {
      "environment": "Corrosion fatigue",
      "headline": "Better fatigue strength under corrosive conditions than austenitic steels",
      "effect": "Alleima says SAF 2304 has higher strength and better corrosion resistance than ordinary austenitic stainless steels, and so has considerably better fatigue strength under corrosive conditions. No fatigue number is printed in the text.",
      "rating": "low",
      "conditions": {
        "environment": "corrosive conditions (qualitative statement)",
        "temperature": "not printed"
      },
      "source": "alleima-saf2304",
      "where": "Corrosion fatigue section"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "PubChem GHS notifications for elemental nickel (CID 935) list H250, H317, H334, H341, H350, H351, H360, H360F, H370, H372, H411 and H412. These describe the element, not the 2304 alloy.",
        "ghs": [
          "H250",
          "H317",
          "H334",
          "H341",
          "H350",
          "H351",
          "H360",
          "H360F",
          "H370",
          "H372",
          "H411",
          "H412"
        ],
        "source": "pubchem-nickel",
        "where": "UN GHS Classification (PubChem record, CID 935)"
      },
      {
        "text": "PubChem GHS notifications for elemental chromium (CID 23976) list H317, H319, H320, H334, H335, H341, H371, H400 and H410. These describe the element, not the 2304 alloy.",
        "ghs": [
          "H317",
          "H319",
          "H320",
          "H334",
          "H335",
          "H341",
          "H371",
          "H400",
          "H410"
        ],
        "source": "pubchem-chromium",
        "where": "UN GHS Classification (PubChem record, CID 23976)"
      },
      {
        "text": "PubChem GHS notifications for elemental molybdenum (CID 23932) list H225, H228, H315, H319, H335 and H361, with signal words Danger and Warning. These describe the element, not the 2304 alloy.",
        "ghs": [
          "H225",
          "H228",
          "H315",
          "H319",
          "H335",
          "H361"
        ],
        "source": "pubchem-molybdenum",
        "where": "UN GHS Classification (PubChem record, CID 23932)"
      }
    ],
    "failure_risks": [
      {
        "mode": "885 F (475 C) embrittlement",
        "trigger": "Exposure at temperatures above about 600 F (315 C)",
        "consequence": "Embrittlement of the ferrite phase; ATI gives the ASME upper temperature limit of 600 F (315 C) for use of ATI 2304",
        "severity": "high",
        "source": "ati-tds",
        "where": "Elevated Temperature Mechanical Properties section"
      },
      {
        "mode": "Lower impact strength after prolonged high-temperature exposure",
        "trigger": "Prolonged exposure above 280 C (540 F)",
        "consequence": "The microstructure changes and impact strength falls; 280 C is the maximum for pressure vessels (VdTÜV-Wb 496)",
        "severity": "moderate",
        "source": "alleima-saf2304",
        "where": "At high temperatures section"
      },
      {
        "mode": "Chloride stress corrosion cracking",
        "trigger": "Oxygen-bearing solution above 125 C (260 F) with more than about 10 ppm Cl-",
        "consequence": "SCC risk rises; Alleima recommends SAF 2205, SAF 2507 or Sanicro 28 for these conditions",
        "severity": "high",
        "source": "alleima-saf2304",
        "where": "Stress corrosion and cracking section, Figure 9 text"
      },
      {
        "mode": "Stress corrosion after moderate cold bending",
        "trigger": "Moderate cold bending where the material reaches nearly 125 C (255 F) in a neutral oxygen-bearing environment with about 100 ppm Cl-",
        "consequence": "Heat treatment is recommended after bending, because the SCC risk starts to increase",
        "severity": "moderate",
        "source": "alleima-saf2304",
        "where": "Bending section"
      },
      {
        "mode": "Deleterious phase precipitation",
        "trigger": "Heat treatment not followed by rapid cooling",
        "consequence": "Deleterious phases precipitate (ATI)",
        "severity": "moderate",
        "source": "ati-tds",
        "where": "Heat Treatment section"
      },
      {
        "mode": "Weld phase imbalance",
        "trigger": "Welding without an overmatched (higher-nickel) filler metal, or with unsuitable parameters",
        "consequence": "The weld and heat-affected zone can lose phase balance, and deleterious phases can form (ATI)",
        "severity": "moderate",
        "source": "ati-tds",
        "where": "Welding section"
      },
      {
        "mode": "Higher ferrite content from high-temperature anneal",
        "trigger": "Annealing above the 1800 F (980 C) minimum",
        "consequence": "Ferrite content rises above the level from an anneal near 980 C (ATI)",
        "severity": "low",
        "source": "ati-tds",
        "where": "Heat Treatment section"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Solution anneal at 930 to 1050 C (1710 to 1920 F) and cool rapidly in air or water (Alleima). ATI gives a minimum annealing temperature of 1800 F (980 C) under ASTM A480 and says rapid cooling prevents deleterious phases.",
        "source": "alleima-saf2304",
        "where": "Heat treatment, Solution annealing"
      },
      {
        "text": "Weld without preheating, at a heat input of 0.5 to 2.5 kJ/mm and an interpass temperature below 150 C (300 F) (Alleima).",
        "source": "alleima-saf2304",
        "where": "Welding section"
      },
      {
        "text": "Use overmatched filler metals: ISO 14343 S 23 7 N L (Exaton 23.7.L) for TIG or MIG, and ISO 14343 S 22 9 3 N L or AWS A5.9 ER2209 (Exaton 22.8.3.L) (Alleima). ATI suggests overmatched fillers with more nickel than the base metal.",
        "source": "alleima-saf2304",
        "where": "Welding section, recommended filler metals"
      },
      {
        "text": "Cold bend to 25 percent deformation without subsequent heat treatment (Alleima). ATI suggests bend radii of at least two times the metal thickness.",
        "source": "alleima-saf2304",
        "where": "Bending section"
      },
      {
        "text": "Hot bend at 1100 to 950 C (2010 to 1740 F) and solution anneal afterwards (Alleima).",
        "source": "alleima-saf2304",
        "where": "Bending section"
      },
      {
        "text": "Expand tubes in one operation, because expansion needs higher initial force than austenitic steels (Alleima).",
        "source": "alleima-saf2304",
        "where": "Expanding section"
      },
      {
        "text": "Machine at about 25 percent lower cutting speed than 304L, with a tougher insert grade for semi-roughing (Alleima).",
        "source": "alleima-saf2304",
        "where": "Machining section"
      }
    ],
    "mitigations": [
      {
        "text": "Above 125 C in oxygen-bearing chloride with more than about 10 ppm Cl-, choose SAF 2205, SAF 2507 or Sanicro 28 (Alleima).",
        "source": "alleima-saf2304",
        "where": "Stress corrosion and cracking section"
      },
      {
        "text": "Use an overmatched filler metal so the weld keeps a phase balance close to the base metal (ATI).",
        "source": "ati-tds",
        "where": "Welding section"
      },
      {
        "text": "Rapid cooling after heat treatment prevents precipitation of deleterious phases (ATI).",
        "source": "ati-tds",
        "where": "Heat Treatment section"
      },
      {
        "text": "Heat treat after moderate cold bending where the SCC risk starts to increase (Alleima).",
        "source": "alleima-saf2304",
        "where": "Bending section"
      }
    ]
  },
  "uses": [
    {
      "application": "structures",
      "device": "Process heat exchangers and piping where chlorides are present",
      "example": "Alleima lists these as higher-SCC-resistance replacements for ASTM 304/304L and 316/316L, together with instrumentation tubing and steam tracing",
      "source": "alleima-saf2304",
      "where": "Applications table, process industry rows"
    },
    {
      "application": "structures",
      "device": "Pulp and paper digester preheaters and evaporators",
      "example": "Alleima lists digester preheaters and evaporators as a use where SAF 2304 gives higher resistance to SCC than 304 and 316",
      "source": "alleima-saf2304",
      "where": "Applications table, pulp and paper row"
    },
    {
      "application": "structures",
      "device": "Oil and gas coolers, piping and flowlines on and offshore, and offshore rig tensioning systems",
      "example": "Alleima lists these uses, citing optimal combination of strength, weldability, corrosion resistance and cost",
      "source": "alleima-saf2304",
      "where": "Applications table, oil and gas row"
    },
    {
      "application": "mechanisms",
      "device": "Beams and torque-transmitting shafts",
      "example": "Alleima lists high strength combined with excellent corrosion resistance, ease of fabrication and low cost for engineering use",
      "source": "alleima-saf2304",
      "where": "Applications table, engineering row"
    },
    {
      "application": "mechanisms",
      "device": "Hydraulic tubing, also sold as PW 400",
      "example": "Alleima lists excellent corrosion resistance and reduced installation cost, owing to easy cleaning, for hydraulic tubing",
      "source": "alleima-saf2304",
      "where": "Applications table, hydraulic system row; Forms of supply"
    }
  ],
  "supply": [
    {
      "subject": "Nickel production by country (USGS 2026)",
      "abundance": "World mine production 3,900,000 tons in 2025 (estimated). World reserves more than 140,000,000 tons, of which Indonesia holds 62,000,000 tons. Stainless and alloy steel and nickel-containing alloys typically account for more than 85% of domestic consumption. US net import reliance was 41% of apparent consumption in 2025 (estimated). Shares are computed from the printed 2025e tonnage divided by the printed world total of 3,900,000 tons.",
      "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 accounted for approximately 60% of US apparent consumption in 2025 (USGS).",
      "substitutes": [
        "Low-nickel, duplex, or ultrahigh-chromium stainless steels have been substituted for austenitic grades in construction (USGS 2026)"
      ],
      "source": "usgs-nickel-2026",
      "where": "World Mine Production and Reserves table; Salient Statistics; Recycling; Substitutes"
    },
    {
      "subject": "Chromium production by country (USGS 2026)",
      "abundance": "World mine production 51,000 thousand metric tons in 2025 (estimated, gross weight). World resources greater than 12 billion tons of shipping-grade chromite, 95% in Kazakhstan and southern Africa. US net import reliance was 79% of apparent consumption in 2025 (estimated). Shares are computed from the printed 2025e gross-weight tonnage of 51,000 thousand metric tons. The grade contains chromium at 21.5 to 24.5 percent (ASTM A240).",
      "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 contained in stainless-steel scrap receipts was 21% of US apparent consumption in 2025 (USGS).",
      "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; World Resources; Salient Statistics; Recycling; Substitutes"
    },
    {
      "subject": "Molybdenum production by country (USGS 2026)",
      "abundance": "World mine production 260,000 tons of molybdenum content in 2025 (estimated). China, Chile, the United States, Peru and Mexico accounted for 90% of world production. The grade contains 0.05 to 0.60 percent molybdenum (ICAST, ATI), so molybdenum supply applies. US net import reliance is shown as E (net exporter, USGS footnote). Shares are computed from the printed 2025e tonnage divided by the printed world total of 260,000 tons.",
      "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 recycled as part of new and old steel and other scrap may be as much as 30% of the apparent supply of molybdenum (USGS 2026).",
      "substitutes": [
        "Little substitution for molybdenum in steels and cast irons; potential substitutes include boron, chromium, niobium and vanadium in alloy steels (USGS 2026)"
      ],
      "source": "usgs-molybdenum-2026",
      "where": "World Mine Production and Reserves table; Recycling; Substitutes; Events, Trends, and Issues"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
      "type": "datasheet",
      "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
      "year": 2014
    },
    {
      "title": "ATI 2304 Duplex Stainless Steel product page (UNS S32304)",
      "type": "datasheet",
      "url": "https://atimaterials.com/Products/ati-2304"
    },
    {
      "title": "Alleima SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
      "type": "datasheet",
      "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
      "year": 2026
    },
    {
      "title": "ICAST Alloys: ASTM A240 UNS S32304 chemical composition and mechanical summary",
      "type": "datasheet",
      "url": "https://www.icastllp.com/material_db_pdf/ASTM%20A240%20UNS%20S32304.pdf"
    },
    {
      "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": "PubChem: Nickel (CID 935), UN GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/935/JSON"
    },
    {
      "title": "PubChem: Chromium (CID 23976), UN GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON"
    },
    {
      "title": "PubChem: Molybdenum (CID 23932), UN GHS classification",
      "type": "database",
      "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23932/JSON"
    }
  ],
  "gaps": [
    "No melting range is printed in the fetched 2304 sources, so melting_point is not filled.",
    "Electrical resistivity, Poisson ratio, sour-service (NACE) limits, a fatigue strength number and a CAS number are not printed in the fetched 2304 sources.",
    "Alleima's impact (Figure 2), critical pitting temperature (Figure 7), SCC threshold (Figure 8) and acid corrosion-rate tables are graphs or tables that did not parse as numbers in the text, so only their stated conclusions are recorded.",
    "The ATI TDS is version 1 dated 2014 with typical data, not limits; no newer ATI revision appeared in the search results.",
    "Thermal conductivity, expansion and modulus differ between ATI (2014, plate) and Alleima (2026, seamless tube and pipe) at the same temperatures; both are kept and not averaged.",
    "PREN basis differs: 26 typical from ATI against 25 on Alleima's nominal composition (Cr 22.5, Mo 0.3, N 0.1, which is not a specification range). None was calculated for this file.",
    "ATI gives no measured Charpy value. The 40 J figure is the requirement the alloy exceeds and is recorded as a lower bound.",
    "PREN, hardness and charpy_impact_energy are not in property-canon.yaml, so snake_case names are used. Critical pitting temperature has no printed number in the text.",
    "The USGS 2026 nickel, chromium and molybdenum texts print no critical-minerals list membership, so critical_lists are empty; the nickel text names critical minerals only in the Executive Order 14285 context.",
    "Hazards are PubChem records for the elements nickel, chromium and molybdenum. No safety data sheet for 2304 was read, so welding-fume hazards for this grade are not covered.",
    "Cryogenic data (4 K and 20 K) for 2304 were not found in the fetched sources, and no space source naming 2304 in a spacecraft part was found, so the space link is open.",
    "No Outokumpu, Aperam or Acerinox datasheet was fetched in this run. ASM Alloy Digest entries for ATI 2304 and Sandvik SAF 2304 are behind a login and were not read. Resellers and aggregators were not used for values."
  ],
  "story": {
    "why": "Lean duplex 2304 (UNS S32304, EN 1.4362) gives about twice the proof strength of austenitic stainless steels, with chloride stress corrosion resistance that ATI and Alleima both rate above the 304 and 316 grades. ATI says its general corrosion resistance is comparable to 316L in most environments, and its typical PREN is 26. Its limits are the 475 C embrittlement that ATI links to exposure above about 315 C (600 F), and Alleima's 280 C maximum for prolonged exposure in pressure vessels.",
    "uses": [
      {
        "where": "Process heat exchangers and piping where chlorides are present",
        "line": "Alleima lists these as higher-SCC-resistance replacements for 304 and 316."
      },
      {
        "where": "Pulp and paper digester preheaters and evaporators",
        "line": "Alleima lists these uses against 304 and 316."
      },
      {
        "where": "Oil and gas coolers, flowlines and offshore rig tensioning systems",
        "line": "Alleima lists these uses, citing strength, weldability, corrosion resistance and cost."
      }
    ],
    "can_do": [
      {
        "label": "Strength",
        "line": "Minimum 0.2 percent proof strength is 400 MPa for plate (ATI) and for tube and pipe up to 20 mm wall (Alleima). Alleima says the proof strength is about twice that of austenitic steels.",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Tensile",
        "line": "Minimum tensile strength is 600 MPa for plate (ATI). Alleima tube and pipe reaches 630 to 820 MPa.",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Chloride pitting",
        "line": "PREN is 26 typical (ATI) and 25 on Alleima's nominal composition, against 24 for 316L.",
        "benchmark": "pitting_resistance_equivalent",
        "scope": "material"
      },
      {
        "label": "Chloride SCC",
        "line": "Resists SCC in dilute oxygen-bearing chloride up to about 125 C (Alleima), where 304 and 316 are limited to 60 C.",
        "scope": "material"
      },
      {
        "label": "Density",
        "line": "Density is 7.8 g/cm3 (ATI, Alleima).",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Stiffness",
        "line": "Elastic modulus is 200 GPa (ATI) and 180 GPa at 300 C (Alleima).",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Expansion",
        "line": "Mean expansion is 13 x 10-6 per C from 20 to 100 C (ATI) and 13.5 x 10-6 per C from 30 to 100 C (Alleima), against 16.5 for 304L and 316L (Alleima).",
        "benchmark": "cte",
        "scope": "material"
      }
    ],
    "compare": "Against 316L and 304L, 2304 has the higher PREN: 25 on Alleima's nominal composition against 24 for 316L and 18 for 304L, and ATI's typical PREN of 26 against 24 for 316L. Its minimum strengths for plate (400 MPa yield and 600 MPa tensile, ATI) are well above the austenitic grades, and Alleima says its proof strength is about twice that of austenitic steels. Alleima says 304 and 316 should not be used above 60 C in dilute oxygen-bearing chloride, while 2304 is safe to about 125 C. The trade-off is the 475 C embrittlement band that ATI ties to exposure above about 315 C, and the 280 C limit for prolonged exposure in pressure vessels (Alleima).",
    "compare_rows": [
      {
        "label": "Pitting resistance (PREN)",
        "benchmark": "pitting_resistance_equivalent",
        "scope": "material"
      },
      {
        "label": "Yield strength (0.2 percent minimum)",
        "benchmark": "yield_strength",
        "scope": "material"
      },
      {
        "label": "Tensile strength (minimum)",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      }
    ],
    "handling": [
      "Solution anneal at 930 to 1050 C (1710 to 1920 F) and cool rapidly in air or water (Alleima); ATI gives a minimum of 980 C (1800 F).",
      "Weld without preheating, at a heat input of 0.5 to 2.5 kJ/mm and an interpass temperature below 150 C (Alleima).",
      "Use overmatched filler metal, such as ER2209 or the 23.7 types (Alleima, ATI).",
      "Cold bend to 25 percent deformation without heat treatment; use a bend radius of at least two times the thickness (Alleima, ATI).",
      "Expand tubes in one operation, since expansion needs higher initial force (Alleima)."
    ],
    "good_for": [
      "Chloride-bearing process heat exchangers and piping where 304 and 316 would crack (Alleima).",
      "Structures and tubing that need about twice the proof strength of austenitic steels (Alleima, ATI).",
      "Pressure parts up to 315 C under the ASME Section VIII Division 1 limit for plate (ATI), with prolonged exposure held to 280 C or below (Alleima)."
    ],
    "watch_out": [
      "Embrittlement after exposure above about 315 C (600 F), the 885 F (475 C) effect (ATI).",
      "Above 125 C in oxygen-bearing chloride with more than about 10 ppm Cl-, do not use it; choose SAF 2205, SAF 2507 or Sanicro 28 (Alleima).",
      "Welds need overmatched filler metal and controlled heat input, because the weld phase balance depends on them (ATI, Alleima)."
    ],
    "verdict": "Lean duplex 2304 is a strong, chloride-resistant duplex option, with a typical PREN of 26 (ATI) and a plate minimum yield of 400 MPa (ATI). Keep it under the 315 C ASME limit for plate, hold prolonged pressure-part exposure to 280 C or below (Alleima), and do not use it in oxygen-bearing chloride above 125 C with more than about 10 ppm Cl- (Alleima). No source in this file ties it to a space part, so the space link is open.",
    "recipe": {
      "line": "Lean duplex 2304 is an austenite-ferrite steel with a nearly equal mixture of the two phases (ATI). Composition limits in weight percent under ASTM A240 for UNS S32304 are chromium 21.5 to 24.5, nickel 3.0 to 5.5, molybdenum 0.05 to 0.60, copper 0.05 to 0.60, nitrogen 0.05 to 0.20, carbon 0.030 max, manganese 2.50 max, silicon 1.00 max, phosphorus 0.040 max, sulphur 0.030 max, and iron as the balance (ICAST, ATI). Alleima's nominal composition is Cr 22.5, Ni 4.5, Mo 0.3, Cu 0.3 and N 0.1. Seamless tube is delivered solution annealed and white pickled or bright annealed (Alleima).",
      "parts": [
        {
          "name": "Iron",
          "symbol": "Fe",
          "role": "Matrix of the alloy, with the austenite and ferrite phases",
          "share_note": "balance (the rest)",
          "source": "ati-product",
          "where": "Composition table, Fe Balance row"
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "Forms the passive film; with Mo and N it sets the PREN (ATI)",
          "share_percent": 21.5,
          "share_high": 24.5,
          "source": "ati-product",
          "where": "Composition table, Minimum and Maximum weight percent (Cr row)"
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Austenite-forming element; overmatched fillers carry more nickel (ATI)",
          "share_percent": 3,
          "share_high": 5.5,
          "source": "ati-product",
          "where": "Composition table, Minimum and Maximum weight percent (Ni row)"
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "Adds to the PREN (Cr + 3.3 Mo + 16 N, ATI)",
          "share_percent": 0.05,
          "share_high": 0.6,
          "source": "ati-product",
          "where": "Composition table, Minimum and Maximum weight percent (Mo row)"
        },
        {
          "name": "Nitrogen",
          "symbol": "N",
          "role": "Adds to the PREN (16 times the nitrogen weight percent, ATI)",
          "share_percent": 0.05,
          "share_high": 0.2,
          "source": "ati-product",
          "where": "Composition table, Minimum and Maximum weight percent (N row)"
        },
        {
          "name": "Copper",
          "symbol": "Cu",
          "role": "Alloying addition inside the ASTM A240 range; no role printed in the sources",
          "share_percent": 0.05,
          "share_high": 0.6,
          "source": "ati-product",
          "where": "Composition table, Minimum and Maximum weight percent (Cu row)"
        },
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Maximum limit (ASTM A240)",
          "share_percent": 0,
          "share_high": 0.03,
          "source": "ati-product",
          "where": "Composition table (C 0.030 row)"
        },
        {
          "name": "Manganese",
          "symbol": "Mn",
          "role": "Maximum limit (ASTM A240)",
          "share_percent": 0,
          "share_high": 2.5,
          "source": "ati-product",
          "where": "Composition table (Mn 2.50 row)"
        },
        {
          "name": "Silicon",
          "symbol": "Si",
          "role": "Maximum limit (ASTM A240)",
          "share_percent": 0,
          "share_high": 1,
          "source": "ati-product",
          "where": "Composition table (Si 1.00 row)"
        },
        {
          "name": "Phosphorus",
          "symbol": "P",
          "role": "Maximum limit (ASTM A240)",
          "share_percent": 0,
          "share_high": 0.04,
          "source": "ati-product",
          "where": "Composition table (P 0.040 row)"
        },
        {
          "name": "Sulphur",
          "symbol": "S",
          "role": "Maximum limit (ASTM A240)",
          "share_percent": 0,
          "share_high": 0.03,
          "source": "ati-product",
          "where": "Composition table (S 0.030 row)"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "PubChem lists hazards for elemental nickel, chromium and molybdenum. No 2304 safety data sheet was read.",
        "points": [
          {
            "label": "Nickel",
            "line": "PubChem lists H250, H317, H334, H341, H350, H351, H360, H360F, H370, H372, H411 and H412 for elemental nickel."
          },
          {
            "label": "Chromium",
            "line": "PubChem lists H317, H319, H320, H334, H335, H341, H371, H400 and H410 for elemental chromium."
          },
          {
            "label": "Molybdenum",
            "line": "PubChem lists H225, H228, H315, H319, H335 and H361 for elemental molybdenum."
          }
        ],
        "level": 0,
        "verdict": "Element records, not alloy tests"
      },
      {
        "title": "In the environment",
        "lead": "The PREN of 25 to 26 holds off pitting, but chloride SCC rises above 125 C in oxygen-bearing solutions with more than about 10 ppm chloride.",
        "points": [
          {
            "label": "Chloride",
            "line": "Alleima: safe to about 125 C without SCC in dilute oxygen-bearing chloride; above 125 C avoid oxygen-bearing solutions with more than about 10 ppm Cl-."
          },
          {
            "label": "Pitting",
            "line": "Critical pitting temperature is not printed as a number; Alleima says it is comparable to 316L."
          }
        ],
        "level": 1,
        "verdict": "Chloride and oxidising service are the watch points"
      },
      {
        "title": "Heat history",
        "lead": "The 475 C embrittlement and the prolonged-exposure limit both come from heat history.",
        "points": [
          {
            "label": "Band",
            "line": "ATI: 885 F (475 C) embrittlement follows exposure above about 600 F (315 C)."
          },
          {
            "label": "Prolonged",
            "line": "Alleima: prolonged exposure above 280 C (540 F) reduces impact strength."
          },
          {
            "label": "Fix",
            "line": "Solution anneal at 930 to 1050 C with rapid cooling (Alleima); rapid cooling also prevents deleterious phases (ATI)."
          }
        ],
        "level": 2,
        "verdict": "Heat history sets the embrittlement risk"
      }
    ]
  },
  "updated": "2026-10-24",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 25,
    "unreachable": 0,
    "caveats": 7,
    "note": "Read by an AI assistant on 2026-10-24 from pages fetched in this run: ATI 2304 TDS version 1 (2014), the ATI 2304 product page, the Alleima SAF 2304 seamless tube and pipe datasheet (updated 2026-02-11), the ICAST ASTM A240 UNS S32304 summary, USGS MCS 2026 nickel, chromium and molybdenum, and PubChem nickel, chromium and molybdenum GHS records. Composition ranges come from the ICAST and ATI product pages. ATI 2014 values are typical, not limits. Resellers and aggregators were not used for values."
  },
  "sources": {
    "ati-tds": {
      "title": "ATI 2304 Technical Data Sheet, version 1 (2014): Stainless Steel Duplex (UNS S32304)",
      "id": "ati_2304_tds_en_v1",
      "url": "https://www.atimaterials.com/Products/Documents/datasheets/stainless-specialty-steel/duplex/ati_2304_tds_en_v1.pdf",
      "year": 2014,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "ati-product": {
      "title": "ATI: 2304 Duplex Stainless Steel (UNS S32304), composition, density and mechanical table",
      "id": "ati-2304",
      "url": "https://atimaterials.com/Products/ati-2304",
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "alleima-saf2304": {
      "title": "Alleima: SAF 2304 tube and pipe, seamless datasheet (updated 2026-02-11)",
      "id": "SAF 2304 seamless tube and pipe",
      "url": "https://www.alleima.com/en/technical-center/material-datasheets/tube-and-pipe-seamless/saf-2304?show=pdf",
      "year": 2026,
      "kind": "datasheet",
      "license": "cited, not reproduced"
    },
    "icast-s32304": {
      "title": "ICAST Alloys: ASTM A240 UNS S32304 chemical composition and mechanical summary",
      "id": "ASTM A240 UNS S32304",
      "url": "https://www.icastllp.com/material_db_pdf/ASTM%20A240%20UNS%20S32304.pdf",
      "kind": "datasheet",
      "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"
    },
    "pubchem-nickel": {
      "title": "PubChem: Nickel (CID 935), UN 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), UN 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), UN 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)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/stainless-2304/"
}