{
  "spore": "profile",
  "id": "cronidur-30",
  "spore_version": "0.2",
  "family": "high-nitrogen-steels",
  "name": "Cronidur 30",
  "role": "bearing steel",
  "category": "tribology",
  "type": "bearing-materials",
  "summary": "Cronidur 30 is a high-nitrogen martensitic stainless steel, EN 1.4108 (X30CrMoN15-1) to SAE AMS 5898, that the producer sells for bearings, ball screws, pumps and valves. The producer gives a hardness above 58 HRC in the hardened condition, and a distributor prints Rockwell C above 60 for the AMS 5898 bar. The producer rates the steel 9 on a scale of 1 to 10 for corrosion. The one space application found in the sources read is the bearing rings of the Space Shuttle main engine turbopump, which Pratt and Whitney tested with Cronidur 30 and AISI 9310 steel.\n",
  "best_for": "Bearings and ball screws that need a hardness above 58 HRC together with corrosion resistance (producer datasheet)",
  "weakest_at": "Density, strength and toughness are not in the sources read here, and the tempering limit is printed as 475 °C by the producer but as 500 °C by a distributor",
  "identity": {
    "formula": "Iron-based martensitic stainless steel, wt%: C 0.25–0.35, Cr 14.0–16.0, Mo 0.85–1.10, N 0.30–0.50, Si max 1.00, Mn max 1.00, Ni max 0.5",
    "designations": [
      {
        "system": "UNS",
        "code": "S42027",
        "source": "gmh-datasheet",
        "where": "Available according to list, first page"
      },
      {
        "system": "EN",
        "code": "1.4108",
        "source": "gmh-datasheet",
        "where": "Mat.-no. line and Chemical Analysis table"
      },
      {
        "system": "EN name",
        "code": "X30CrMoN15-1",
        "source": "gmh-datasheet",
        "where": "Mat.-no. line and Chemical Analysis table"
      },
      {
        "system": "AMS",
        "code": "5898",
        "source": "righton-pdf",
        "where": "Title and Specifications box (AMS 5898)"
      },
      {
        "system": "ASTM",
        "code": "F899",
        "source": "gmh-datasheet",
        "where": "Available according to list (ASTM F 899)"
      },
      {
        "system": "Trade name",
        "code": "Cronidur 30",
        "source": "righton-pdf",
        "where": "Title (Bearing Steels, AMS 5898 Cronidur 30 Bar)"
      }
    ],
    "source": "gmh-datasheet",
    "where": "Chemical Analysis table, row 1.4108 X30CrMoN15-1, min and max values (wt.%, decimal commas in the source)"
  },
  "tags": {
    "environments": [
      "launch"
    ],
    "stresses": [],
    "applications": [
      "propulsion-and-tanks",
      "mechanisms"
    ]
  },
  "properties": [
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness, Rockwell C, AMS 5898 bar",
      "value": 60,
      "bound": "lower",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "grade": "AMS 5898 (Cronidur 30) bar",
        "heat_treatment": "not stated",
        "unit_in_source": "Rockwell C >60"
      },
      "method": "Value printed in a distributor datasheet",
      "status": "ground",
      "source": "righton-pdf",
      "where": "Mechanical properties table, row Hardness Rockwell C",
      "source_detail": {
        "title": "Righton Blackburns, Bearing Steels AMS 5898 (Cronidur 30) Bar datasheet, updated 28 July 2025",
        "id": "AMS 5898, Cronidur 30",
        "url": "https://www.rightonblackburns.co.uk/datasheets/view/Righton-Blackburns-Ltd_Bearing-Steels-AMS-5898-Cronidur-30-Bar_405.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "distributor document, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness, Rockwell C, hardened condition",
      "value": 58,
      "bound": "lower",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30",
        "heat_treatment": "hardened condition, treatment steps not stated in this line"
      },
      "method": "Value printed in the producer datasheet",
      "status": "ground",
      "source": "gmh-datasheet",
      "where": "Key Advantages, first bullet",
      "source_detail": {
        "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
        "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
        "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness after 2 x 180 °C temper",
      "value": 58,
      "value_high": 60,
      "bound": "range",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30",
        "heat_treatment": "austenitize 1030 °C, cryogenic -80 °C, temper 2 x 180 °C"
      },
      "method": "Range printed in the producer heat-treatment recommendations",
      "status": "ground",
      "source": "gmh-datasheet",
      "where": "Heat treatment recommendations, item 1",
      "source_detail": {
        "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
        "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
        "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness after 2 x 280 °C temper",
      "value": 52,
      "value_high": 57,
      "bound": "range",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30",
        "heat_treatment": "austenitize 1030 °C, cryogenic -80 °C, temper 2 x 280 °C"
      },
      "method": "Range printed in the producer heat-treatment recommendations",
      "status": "ground",
      "source": "gmh-datasheet",
      "where": "Heat treatment recommendations, item 2",
      "source_detail": {
        "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
        "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
        "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_rockwell_c",
      "label": "Hardness after 2 x 475 °C temper",
      "value": 58,
      "value_high": 60,
      "bound": "range",
      "unit": "HRC",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30",
        "heat_treatment": "austenitize 1030 °C, cryogenic -80 °C, temper 2 x 475 °C"
      },
      "method": "Range printed in the producer heat-treatment recommendations",
      "status": "ground",
      "source": "gmh-datasheet",
      "where": "Heat treatment recommendations, item 3",
      "source_detail": {
        "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
        "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
        "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "hardness_brinell",
      "label": "Hardness after soft annealing",
      "value": 250,
      "bound": "upper",
      "unit": "HBW",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30",
        "heat_treatment": "soft annealing at 780–820 °C, holding time 8 h",
        "holding_time_h": 8
      },
      "method": "Upper limit printed in the producer heat-treatment section",
      "status": "ground",
      "source": "gmh-datasheet",
      "where": "Heat treatment, Soft annealing paragraph (<250 HBW for 8 h holding time)",
      "source_detail": {
        "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
        "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
        "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "tempering_resistance_temperature",
      "label": "Tempering resistance, producer statement",
      "value": 475,
      "bound": "upper",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30"
      },
      "method": "Upper limit printed in the producer datasheet",
      "status": "ground",
      "source": "gmh-datasheet",
      "where": "Introduction text, left column (tempering resistance up to 475 °C)",
      "source_detail": {
        "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
        "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
        "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    },
    {
      "benchmark": "tempering_resistance_temperature",
      "label": "Tempering resistance, distributor statement",
      "value": 500,
      "bound": "upper",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "AMS 5898 Cronidur 30 bar",
        "unit_in_source": "High temper resistance up to 500 °C"
      },
      "method": "Upper limit printed in a distributor datasheet",
      "status": "ground",
      "note": "Differs from the producer's 475 °C. Both values are recorded and the sources are not reconciled.",
      "source": "righton-pdf",
      "where": "Characteristics list, item High temper resistance",
      "source_detail": {
        "title": "Righton Blackburns, Bearing Steels AMS 5898 (Cronidur 30) Bar datasheet, updated 28 July 2025",
        "id": "AMS 5898, Cronidur 30",
        "url": "https://www.rightonblackburns.co.uk/datasheets/view/Righton-Blackburns-Ltd_Bearing-Steels-AMS-5898-Cronidur-30-Bar_405.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "distributor document, cited not reproduced"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Modulus of elasticity, Cronidur 30 entry",
      "value": 190,
      "value_high": 215,
      "bound": "range",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "grade": "PROPRIETARY Cronidur 30 (equivalent 1.4108)",
        "temperature": "not stated; the page does not map the value to a temperature"
      },
      "method": "Range printed in a third-party materials database entry, not a producer datasheet",
      "status": "ground",
      "source": "totalmateria",
      "where": "Physical and mechanical properties table, row Modulus of Elasticity",
      "source_detail": {
        "title": "TotalMateria, PROPRIETARY Cronidur 30 Stainless steels",
        "id": "material 1451444",
        "url": "https://www.totalmateria.com/en-us/material/1451444",
        "kind": "database",
        "license": "database entry, cited not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity, Cronidur 30 entry",
      "value": 13.848,
      "value_high": 20.873,
      "bound": "range",
      "unit": "W/(m·°C)",
      "scope": "material",
      "conditions": {
        "grade": "PROPRIETARY Cronidur 30 (equivalent 1.4108)",
        "temperature": "not stated; the page does not map the value to a temperature"
      },
      "method": "Range printed in a third-party materials database entry, not a producer datasheet",
      "status": "ground",
      "source": "totalmateria",
      "where": "Physical and mechanical properties table, row Thermal Conductivity",
      "source_detail": {
        "title": "TotalMateria, PROPRIETARY Cronidur 30 Stainless steels",
        "id": "material 1451444",
        "url": "https://www.totalmateria.com/en-us/material/1451444",
        "kind": "database",
        "license": "database entry, cited not reproduced"
      }
    },
    {
      "benchmark": "pren",
      "label": "Pitting resistance equivalent number, producer statement",
      "value": 20,
      "value_high": 24,
      "bound": "range",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30",
        "basis": "approximately 20 to 24 as printed; the formula and element weights used are not stated"
      },
      "method": "Range printed in the producer FAQ; PREN is an index calculated from composition",
      "status": "calculated",
      "source": "gmh-web",
      "where": "FAQ 3, answer for Cronidur 30",
      "source_detail": {
        "title": "GMH Gruppe, high-nitrogen steels product page with Cronidur 30 FAQ",
        "url": "https://www.gmh-gruppe.de/en/products/high-nitrogen-steels",
        "kind": "web",
        "license": "supplier web page, cited not reproduced"
      }
    },
    {
      "benchmark": "austenitizing_temperature",
      "label": "Austenitizing temperature range",
      "value": 990,
      "value_high": 1030,
      "bound": "range",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "grade": "1.4108 Cronidur 30",
        "selection": "chosen to suit product requirements, as printed"
      },
      "method": "Range printed in the producer hardening section",
      "status": "ground",
      "source": "gmh-datasheet",
      "where": "Hardening section (990 to 1030 °C)",
      "source_detail": {
        "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
        "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
        "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier document, cited not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Hardened condition after 1030 °C austenitizing, -80 °C cryogenic treatment and 2 x 180 °C tempering",
      "headline": "The producer rates the 180 °C-tempered condition at 58 to 60 HRC with very good corrosion resistance.",
      "effect": "The producer's heat-treatment recommendation 1 pairs 1030 °C, -80 °C and 2 x 180 °C with very good corrosion resistance at 58 to 60 HRC. Its corrosion rating for the steel is 9 on a scale of 1 to 10, a relative score and not a measured value.",
      "rating": "low",
      "conditions": {
        "basis": "producer statement; no test method or exposure medium printed",
        "grade": "1.4108 Cronidur 30"
      },
      "source": "gmh-datasheet",
      "where": "Heat treatment recommendations, item 1; Properties box (Corrosion rating 9)"
    },
    {
      "environment": "Tempered at 2 x 280 °C instead of 2 x 180 °C",
      "headline": "A 280 °C temper keeps very good corrosion resistance but lowers hardness to 52 to 57 HRC.",
      "effect": "The producer states that the 1030 °C, -80 °C and 2 x 280 °C route gives very good corrosion resistance with increased ductility, at 52 to 57 HRC.",
      "rating": "low",
      "conditions": {
        "basis": "producer statement; hardness range as printed",
        "grade": "1.4108 Cronidur 30"
      },
      "source": "gmh-datasheet",
      "where": "Heat treatment recommendations, item 2"
    },
    {
      "environment": "Comparison with other stainless grades (distributor statement)",
      "headline": "A bar distributor states higher corrosion resistance than 1.2083, 1.4112, 1.4301 and 1.4571, and greater corrosion resistance than 440C.",
      "effect": "Righton Blackburns states superior corrosion resistance over 1.2083, 1.4112, 1.4301 and 1.4571 and greater corrosion resistance than 440C. It also states good wear resistance, higher than 1.4034, 1.2363 and 1.4528. The sheet gives no test method, medium or numbers, so the claims are not checked here.",
      "rating": "low",
      "conditions": {
        "basis": "distributor statement; no test conditions printed"
      },
      "source": "righton-pdf",
      "where": "Introductory description and Characteristics list (page 1)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "A generic stainless steel safety data sheet (GPT Industries, revision V1.0 dated 12.15.16) states that stainless steel is an article and not hazardous in its solid form. That sheet is not specific to the 1.4108 bar, so the bar's own classification is not confirmed here.",
        "ghs": [],
        "source": "gpt-stainless-sds",
        "where": "Section 2, Classification paragraph"
      },
      {
        "text": "The same sheet says that cutting, milling, grinding, melting and welding could emit hazardous materials. Its GHS table lists the classes for the elements that may be emitted: carcinogenicity Category 1B, respiratory sensitizer Category 1, STOT repeated exposure Category 1, toxic to reproduction Category 1B, acute oral toxicity Category 4, skin sensitizer Category 1, STOT single exposure Category 3 and eye irritation Category 2B.",
        "ghs": [],
        "source": "gpt-stainless-sds",
        "where": "Section 2, GHS classification table and hazard statements"
      },
      {
        "text": "The sheet says that processing byproducts may cause irritation, difficulty in breathing, coughing or wheezing, and may cause allergic skin reactions. It advises avoiding dust formation, and local exhaust ventilation during welding, brazing, grinding and machining.",
        "ghs": [],
        "source": "gpt-stainless-sds",
        "where": "Sections 4, 6 and 8"
      }
    ],
    "failure_risks": [
      {
        "mode": "Retained austenite after hardening above 1000 °C",
        "trigger": "Hardening above 1000 °C without an immediate cryogenic step",
        "consequence": "The producer says the nitrogen content strongly stabilizes retained austenite, so the steel must reach at least -80 °C and be held at least 60 minutes before tempering. The sources give no hardness figure for an untreated part.",
        "severity": "moderate",
        "source": "gmh-datasheet",
        "where": "Tempering section"
      },
      {
        "mode": "Nitrogen depletion or enrichment at the surface",
        "trigger": "Vacuum hardening without a nitrogen partial pressure of 100 to 200 mbar",
        "consequence": "The producer warns of nitrogen depletion or nitrogen enrichment in the surface layer and advises an all-round grinding allowance of about 0.2 mm when the furnace cannot hold the pressure.",
        "severity": "moderate",
        "source": "gmh-datasheet",
        "where": "Hardening section"
      }
    ],
    "side_effects": [
      {
        "text": "Tempering at 2 x 280 °C gives increased ductility and very good corrosion resistance at 52 to 57 HRC, against 58 to 60 HRC after 2 x 180 °C.",
        "affects": "Hardness of the finished part",
        "source": "gmh-datasheet",
        "where": "Heat treatment recommendations, items 1 and 2"
      }
    ],
    "handling": [
      {
        "text": "Soft anneal at 780–820 °C for 4 to 8 hours before machining. Hardness is below 300 HBW after 4 hours and below 250 HBW after 8 hours.",
        "source": "gmh-datasheet",
        "where": "Heat treatment, Soft annealing paragraph"
      },
      {
        "text": "Stress relieve at 600–650 °C after rough machining. Hold for about 2 hours, cool in the furnace to about 350 °C, then cool in still air.",
        "source": "gmh-datasheet",
        "where": "Heat treatment, Stress relief annealing paragraph"
      },
      {
        "text": "For vacuum hardening, keep a nitrogen partial pressure of 100 to 200 mbar. If the furnace cannot hold it, allow an all-round grinding allowance of about 0.2 mm.",
        "source": "gmh-datasheet",
        "where": "Hardening section"
      }
    ],
    "mitigations": [
      {
        "text": "Cool to at least -80 °C after hardening and hold for at least 60 minutes after complete cooling, then temper for 2 x 2 hours at the chosen temperature.",
        "source": "gmh-datasheet",
        "where": "Tempering section"
      }
    ]
  },
  "uses": [
    {
      "application": "propulsion-and-tanks",
      "device": "Bearing rings in the high-pressure oxygen turbopump of the Space Shuttle main engine",
      "example": "A 2010 NASA Marshall history of Shuttle main engine turbopump bearing tests states that Pratt and Whitney used Cronidur 30 and AISI 9310 steel for the bearing rings.",
      "source": "ntrs-gibson2010",
      "where": "Full report text, passage on Pratt and Whitney bearing materials (topics discussed in the summary of NTRS 20100023061)"
    },
    {
      "application": "mechanisms",
      "device": "High-precision ball and roller bearings, ball screw drives",
      "example": "The producer lists high-precision ball bearings, ball and roller bearings, ball screw drives, extruder screws, pumps and valves among its main application areas.",
      "source": "gmh-datasheet",
      "where": "Main application areas, first page"
    }
  ],
  "supply": [
    {
      "subject": "Chromium (chromite ore)",
      "producers": [
        {
          "country": "South Africa",
          "share_percent": 45.1,
          "year": 2025
        },
        {
          "country": "Turkey",
          "share_percent": 17.6,
          "year": 2025
        },
        {
          "country": "Kazakhstan",
          "share_percent": 13.7,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: in 2025 recycled chromium in reported stainless-steel scrap receipts accounted for 21% of apparent consumption.",
      "substitutes": [
        "USGS: chromium has no substitute in stainless steel, the leading end use."
      ],
      "source": "usgs-mcs2026-chromium",
      "where": "World Mine Production and Reserves table, chromite ore, 2025e (world total 51,000 thousand t; shares calculated by Space Mushroom from the country values 23,000, 9,000 and 7,000 thousand t); Recycling; Substitutes"
    },
    {
      "subject": "Molybdenum (mine production)",
      "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
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: molybdenum recycled as part of new and old steel and other scrap may be as much as 30% of apparent supply.",
      "substitutes": [
        "USGS: there is little substitution for molybdenum in steels; potential alloy-steel substitutes include boron, chromium, niobium and vanadium."
      ],
      "source": "usgs-mcs2026-molybdenum",
      "where": "World Mine Production and Reserves table, mine production 2025e (world total 260,000 t; shares calculated by Space Mushroom from the country values 97,000, 42,000, 40,000 and 39,000 t); Recycling; Substitutes"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "GMH Gruppe, Cronidur 30 product datasheet (EN, 2025 edition)",
      "type": "datasheet",
      "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
      "year": 2025
    },
    {
      "title": "Righton Blackburns, Bearing Steels AMS 5898 (Cronidur 30) Bar datasheet (28 July 2025)",
      "type": "datasheet",
      "url": "https://www.rightonblackburns.co.uk/datasheets/view/Righton-Blackburns-Ltd_Bearing-Steels-AMS-5898-Cronidur-30-Bar_405.pdf",
      "year": 2025
    },
    {
      "title": "GMH Gruppe, high-nitrogen steels product page with Cronidur 30 FAQ",
      "type": "datasheet",
      "url": "https://www.gmh-gruppe.de/en/products/high-nitrogen-steels"
    },
    {
      "title": "TotalMateria, PROPRIETARY Cronidur 30 Stainless steels (material 1451444)",
      "type": "database",
      "url": "https://www.totalmateria.com/en-us/material/1451444"
    },
    {
      "title": "Gibson et al., History of Space Shuttle Main Engine Turbopump Bearing Testing at the Marshall Space Flight Center (JANNAF 2010), NTRS 20100023061",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/20100023061",
      "year": 2010
    },
    {
      "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": "GPT Industries, Stainless Steel Safety Data Sheet (generic solid stainless steel, revision V1.0 dated 12.15.16)",
      "type": "sds",
      "url": "https://www.gptindustries.com/wp-content/uploads/2022/01/Stainless-Steel-Safety-Data-Sheet.pdf",
      "year": 2016
    }
  ],
  "gaps": [
    "Density is not in any source read here. The GMH datasheet prints no density, and TotalMateria shows density only as a gated placeholder.",
    "Tensile strength, yield strength and elongation against tempering temperature appear only as a chart in the GMH datasheet, and no numbers could be read from it.",
    "Charpy impact energy for Cronidur 30 was not found. The GMH text gives 350 J only for high-nitrogen steels in general, so it is not recorded as a Cronidur value.",
    "Specific heat, coefficient of thermal expansion and Poisson's ratio are gated on TotalMateria and absent from the datasheet.",
    "Brinell hardness of 200 to 240 HB from TotalMateria is not recorded, because the page does not map the test condition.",
    "No safety data sheet for the Cronidur 30 bar was read. The hazard entries use a generic stainless steel safety data sheet (GPT Industries, revision V1.0 dated 12.15.16), which is not specific to the 1.4108 bar. A PubChem GHS record for this alloy was not read.",
    "No corrosion test data (salt spray, immersion or pitting rate) was read in a fetched source. The OSTI paper on Cronidur 30 bearing performance refused connection, and a DTIC wear report returned 403.",
    "Rolling-contact fatigue or bearing life against 440C was not read. The NASA 2010 history names the material but gives no life figures.",
    "A space use beyond the Shuttle turbopump bearing rings was not verified. The ISS mechanism claim returned no source, and the 1995 first-flight date from a German article could not be read.",
    "Producer share of world supply for Cronidur 30 was not found. The producer named on the datasheet is Energietechnik Essen GmbH (GMH Gruppe), Essen, Germany.",
    "Critical-mineral list status for chromium and molybdenum is not printed in the USGS 2026 summaries read here, and the EU list was not opened.",
    "Nickel (maximum 0.5 wt%) is not profiled for supply.",
    "Hardness (Rockwell C and Brinell), tempering resistance, PREN and austenitizing temperature have no canonical name in spores/property-canon.yaml, so snake_case names are used.",
    "The knifesteelnerds article gives its composition table only as an image with no readable numbers, so it is not used as a source.",
    "Radiation, vacuum outgassing and cryogen compatibility were not searched.",
    "No abbreviation or media file was checked for this grade.",
    "The profile holds 12 properties against the 15 wanted by the lithium standard, because the readable sources give no density, strength or thermal expansion values."
  ],
  "story": {
    "why": "Cronidur 30 (EN 1.4108, X30CrMoN15-1, AMS 5898) is a martensitic stainless steel for parts that must be hard, wear resistant and corrosion resistant. The producer, Energietechnik Essen (GMH Gruppe) of Essen, Germany, says the nitrogen gives high strength, high fracture toughness, tempering resistance and corrosion resistance. The reason to choose it is the combination of hardness above 58 HRC with corrosion resistance. A distributor says it resists corrosion better than 440C, but gives no test conditions for that claim.",
    "uses": [
      {
        "where": "Space Shuttle main engine turbopump",
        "line": "A 2010 NASA Marshall history of Shuttle main engine turbopump bearing tests says that Pratt and Whitney used Cronidur 30 and AISI 9310 steel for the bearing rings. It is the one space application found in the sources read."
      },
      {
        "where": "Precision bearings and ball screws",
        "line": "The producer lists high-precision ball and roller bearings, ball screw drives, pumps and valves among its main application areas."
      }
    ],
    "can_do": [
      {
        "label": "Hardness",
        "line": "Hardened Cronidur 30 is above 58 HRC according to the producer, and a distributor prints Rockwell C above 60 for the AMS 5898 bar. Heat treatment changes the figure: 58 to 60 HRC after 2 x 180 °C tempering, and 52 to 57 HRC after 2 x 280 °C.",
        "scope": "material",
        "value": "58 HRC or more"
      },
      {
        "label": "Tempering resistance",
        "line": "The producer gives tempering resistance up to 475 °C, while the distributor prints up to 500 °C. The sources disagree, so the lower figure is the safer one to quote.",
        "scope": "material",
        "value": "Up to 475 °C"
      },
      {
        "label": "Stiffness",
        "line": "TotalMateria lists a modulus of elasticity of 190 to 215 GPa for Cronidur 30, with no test temperature printed.",
        "scope": "material",
        "value": "190 to 215 GPa"
      },
      {
        "label": "Thermal conductivity",
        "line": "TotalMateria lists thermal conductivity of 13.848 to 20.873 W/(m·°C), with no temperature printed.",
        "scope": "material",
        "value": "13.848 to 20.873 W/(m·°C)"
      },
      {
        "label": "Corrosion",
        "line": "The producer rates corrosion 9 on a scale of 1 to 10 and calls the hardened steel very corrosion resistant. These are relative scores, not test results.",
        "scope": "material",
        "value": "Rated 9 of 10"
      }
    ],
    "compare": "Cronidur 30 is a hard, corrosion resistant steel for bearings. A distributor says it wears longer and resists corrosion better than 440C, and better than 1.2083, 1.4112, 1.4301 and 1.4571. It also says its wear resistance is higher than 1.4034, 1.2363 and 1.4528. These claims come from one distributor's sheet and carry no test conditions, so they should be checked against a test report before a design decision. No 440C figures from a fetched source were found, so the modulus and thermal conductivity ranges are not set against 440C here.",
    "compare_rows": [
      {
        "label": "Elastic modulus",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Thermal conductivity",
        "benchmark": "thermal_conductivity",
        "scope": "material"
      },
      {
        "label": "Hardness (Rockwell C)",
        "benchmark": "hardness_rockwell_c",
        "scope": "material"
      }
    ],
    "handling": [
      "Soft anneal at 780–820 °C for 4 to 8 hours before machining. Hardness is below 250 HBW after 8 hours.",
      "Stress relieve at 600–650 °C after rough machining, then cool in the furnace to about 350 °C.",
      "For vacuum hardening, keep a nitrogen partial pressure of 100 to 200 mbar, or allow about 0.2 mm of grinding stock."
    ],
    "good_for": [
      "Bearings, ball screws and valves that need more than 58 HRC with corrosion resistance (producer datasheet).",
      "Aerospace parts. The Shuttle turbopump bearing rings are the one space use found in the sources read."
    ],
    "watch_out": [
      "Heat treatment sets both hardness and corrosion result. Skipping the -80 °C cryogenic step after hardening above 1000 °C leaves retained austenite (producer).",
      "The tempering limit is printed as 475 °C by the producer and as 500 °C by a distributor.",
      "The corrosion rating and the distributor's comparisons carry no test method."
    ],
    "verdict": "Cronidur 30 is a hard, corrosion resistant bearing steel whose heat treatment decides the result. The producer's figures support hardness above 58 HRC and very good corrosion resistance at 58 to 60 HRC after the 180 °C temper. Density, strength and corrosion test data are not in the sources read here.",
    "recipe": {
      "line": "Cronidur 30 is an iron-based martensitic stainless steel with about 14 to 16 wt% chromium, 0.85 to 1.10 wt% molybdenum and 0.30 to 0.50 wt% nitrogen. The producer alloys the nitrogen beyond its usual solubility limit by high-pressure electro-slag remelting (PESR), which gives a homogeneous microstructure with fine carbonitrides (GMH datasheet).",
      "parts": [
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Sets the hardness reached after quenching; the producer's composition table gives the range."
        },
        {
          "name": "Chromium",
          "symbol": "Cr",
          "role": "The main alloying element of the stainless group, in the producer's composition table."
        },
        {
          "name": "Molybdenum",
          "symbol": "Mo",
          "role": "An alloying element in the producer's table; its effect is not described in the sources read."
        },
        {
          "name": "Nitrogen",
          "symbol": "N",
          "role": "The distinguishing element. The producer says nitrogen enhances corrosion resistance and has a positive effect on mechanical properties."
        },
        {
          "name": "Silicon and manganese",
          "symbol": "Si, Mn",
          "role": "Minor elements held at the maximum in the producer's table."
        },
        {
          "name": "Nickel",
          "symbol": "Ni",
          "role": "Minor element held at the maximum in the producer's table."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The bar's own safety data sheet was not read. A generic stainless steel safety data sheet says the solid is not hazardous, but processing can release hazardous fumes and dust.",
        "points": [
          {
            "label": "Dust and swarf",
            "line": "The generic stainless steel sheet advises avoiding dust formation and using local exhaust ventilation during grinding, machining and welding. It says prolonged skin contact with dust may cause skin irritation in sensitive people. Check the bar supplier's own safety data sheet before machining or grinding."
          }
        ]
      },
      {
        "title": "In service",
        "lead": "The producer's figures describe the steel in its heat-treated condition.",
        "points": [
          {
            "label": "Hardness",
            "line": "The producer gives a hardness above 58 HRC in the hardened condition, and a distributor prints Rockwell C above 60. Tempering at 2 x 280 °C gives 52 to 57 HRC instead."
          },
          {
            "label": "Corrosion",
            "line": "The producer rates the steel 9 on a scale of 1 to 10 and calls its corrosion resistance very good. These are relative ratings, not measured test results."
          }
        ]
      },
      {
        "title": "Heat treatment",
        "lead": "Process steps from the producer's datasheet.",
        "points": [
          {
            "label": "Cryogenic step",
            "line": "After hardening above 1000 °C, the steel must reach at least -80 °C and be held at least 60 minutes before tempering, because the nitrogen strongly stabilizes retained austenite."
          },
          {
            "label": "Soft annealing",
            "line": "Anneal at 780–820 °C for 4 to 8 hours before machining. The hardness is then below 250 HBW after 8 hours."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 12,
    "unreachable": 2,
    "caveats": 1,
    "note": "Written by an AI assistant on 2026-11-01 from the producer datasheet, a distributor datasheet, a database entry, a NASA report and two USGS summaries fetched in this run. Hazard entries added from a generic stainless steel safety data sheet, not one for this grade. Density, strength and thermal expansion were not available in readable form."
  },
  "sources": {
    "gpt-stainless-sds": {
      "title": "GPT Industries, Stainless Steel Safety Data Sheet (generic solid stainless steel, not specific to Cronidur 30)",
      "id": "GHS product identifier STAINLESS STEEL; revision V1.0, 12.15.16",
      "url": "https://www.gptindustries.com/wp-content/uploads/2022/01/Stainless-Steel-Safety-Data-Sheet.pdf",
      "year": 2016,
      "kind": "datasheet",
      "license": "supplier document, cited not reproduced"
    },
    "gmh-datasheet": {
      "title": "Cronidur 30 product datasheet (EN), Energietechnik Essen GmbH, GMH Gruppe",
      "id": "Mat.-no. 1.4108, X30CrMoN15-1; file GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125",
      "url": "https://www.gmh-gruppe.de/wp-content/uploads/2025/11/GMH_ETE_Produktdatenblatt_Cronidur30_EN_1125.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "supplier document, cited not reproduced"
    },
    "gmh-web": {
      "title": "GMH Gruppe, high-nitrogen steels product page with Cronidur 30 FAQ",
      "url": "https://www.gmh-gruppe.de/en/products/high-nitrogen-steels",
      "kind": "web",
      "license": "supplier web page, cited not reproduced"
    },
    "righton-pdf": {
      "title": "Righton Blackburns, Bearing Steels AMS 5898 (Cronidur 30) Bar datasheet, updated 28 July 2025",
      "id": "AMS 5898, Cronidur 30",
      "url": "https://www.rightonblackburns.co.uk/datasheets/view/Righton-Blackburns-Ltd_Bearing-Steels-AMS-5898-Cronidur-30-Bar_405.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "distributor document, cited not reproduced"
    },
    "totalmateria": {
      "title": "TotalMateria, PROPRIETARY Cronidur 30 Stainless steels",
      "id": "material 1451444",
      "url": "https://www.totalmateria.com/en-us/material/1451444",
      "kind": "database",
      "license": "database entry, cited not reproduced"
    },
    "ntrs-gibson2010": {
      "title": "History of Space Shuttle Main Engine Turbopump Bearing Testing at the Marshall Space Flight Center (JANNAF Joint Propulsion Meeting, 2010)",
      "id": "NASA NTRS 20100023061; Gibson, Thom and Moore (NASA MSFC); Haluck (Pratt and Whitney Rocketdyne)",
      "url": "https://ntrs.nasa.gov/citations/20100023061",
      "year": 2010,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "usgs-mcs2026-chromium": {
      "title": "Mineral Commodity Summaries 2026, Chromium",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "usgs-mcs2026-molybdenum": {
      "title": "Mineral Commodity Summaries 2026, Molybdenum",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/cronidur-30/"
}