{ "spore": "profile", "id": "steel-4130", "spore_version": "0.2", "family": "carbon-and-alloy-steels", "name": "Alloy steel AISI 4130 (chromium-molybdenum)", "abbreviation": "4130 (UNS G41300)", "role": "structural alloy", "category": "metals", "type": "steels-and-stainless", "summary": "AISI 4130 is a low-alloy chromium-molybdenum steel (UNS G41300) that is widely used for aircraft tube, sheet and bar and for oil and gas parts. Its strength depends on heat treatment, so each value in this file carries its own condition. Hydrogen gas and salt solutions reduce its crack and fatigue resistance in laboratory tests.", "best_for": "Aircraft and motorsport tube, sheet and bar, and oil and gas parts, where weldability and strength after heat treatment both matter", "weakest_at": "Hydrogen gas and salt solutions: in one laboratory study the threshold stress intensity fell from 88 to 32 MPa√m as hydrogen pressure rose from 21 to 69 MPa, and salt solution cut corrosion-fatigue life", "identity": { "formula": "Fe balance; 0.28 to 0.33 C, 0.40 to 0.60 Mn, 0.15 to 0.35 Si, 0.80 to 1.10 Cr, 0.15 to 0.25 Mo, 0.035 max P, 0.040 max S (wt%, allowable ranges printed in Table 1.1.1 of the Sandia reference)", "designations": [ { "system": "UNS", "code": "G41300", "source": "aircraft-4130", "where": "Specifications list, UNS G41300" }, { "system": "AISI", "code": "4130", "source": "aircraft-4130", "where": "Specifications list, AISI 4130; page title" }, { "system": "SAE", "code": "4130", "source": "titanium-4130", "where": "Introduction: also known as AISI or SAE 4130" }, { "system": "SAE", "code": "J404", "source": "sandia-1211", "where": "Section 1.2, common names: SAE J404 (4130)" }, { "system": "ASTM", "code": "A29", "note": "grade 4130 (as printed)", "source": "sandia-1211", "where": "Section 1.2, common names: ASTM A29 (4130)" }, { "system": "ASTM", "code": "A322", "source": "aircraft-4130", "where": "Specifications list, ASTM A322" }, { "system": "ASTM", "code": "A331", "source": "aircraft-4130", "where": "Specifications list, ASTM A331" }, { "system": "ASTM", "code": "A519", "source": "matweb-4130", "where": "Key Words line, ASTM A519" }, { "system": "AMS", "code": "6350", "source": "aircraft-4130", "where": "Specifications list, AMS 6350 Sheet / Plate" }, { "system": "AMS", "code": "6360", "source": "matweb-4130", "where": "Key Words line, AMS 6360" }, { "system": "AMS", "code": "6370", "source": "aircraft-4130", "where": "Specifications list, AMS 6370 Bar" }, { "system": "AMS", "code": "6345", "source": "aircraft-4130", "where": "Specifications list, AMS 6345 Sheet / Plate, Normalised" }, { "system": "AMS", "code": "6346", "source": "aircraft-4130", "where": "Specifications list, AMS 6346 Bar, Hardened & Tempered" }, { "system": "AMS", "code": "6348", "source": "aircraft-4130", "where": "Specifications list, AMS 6348 Bar" }, { "system": "AMS", "code": "6371", "source": "aircraft-4130", "where": "Specifications list, AMS 6371 Tube" }, { "system": "AMS", "code": "6356", "source": "matweb-4130", "where": "Key Words line, AMS 6356" }, { "system": "AMS", "code": "6361", "source": "matweb-4130", "where": "Key Words line, AMS 6361" }, { "system": "AMS", "code": "6372", "source": "matweb-4130", "where": "Key Words line, AMS 6372" }, { "system": "AMS", "code": "6373", "source": "matweb-4130", "where": "Key Words line, AMS 6373" }, { "system": "MIL", "code": "MIL-S-6758", "source": "aircraft-4130", "where": "Specifications list, MIL-S-6758" }, { "system": "MIL", "code": "MIL-S-18729", "source": "aircraft-4130", "where": "Specifications list, MIL-S-18729" }, { "system": "MIL", "code": "MIL-T-67366", "source": "aircraft-4130", "where": "Specifications list, MIL-T-67366" }, { "system": "MIL", "code": "MIL-S-16974", "source": "matweb-4130", "where": "Key Words line, MIL SPEC MIL-S-16974" }, { "system": "SAE", "code": "J412", "source": "matweb-4130", "where": "Key Words line, SAE J412" }, { "system": "SAE", "code": "J770", "source": "matweb-4130", "where": "Key Words line, SAE J770" }, { "system": "EN", "code": "1.7218", "note": "nearest equivalent", "source": "saarstahl-25crmo4", "where": "Header: Werkstoff-Nr. 1.7218 on the 25CrMo4 datasheet" }, { "system": "EN name", "code": "25CrMo4", "note": "nearest equivalent", "source": "saarstahl-25crmo4", "where": "Page title: Saarstahl - 25CrMo4" }, { "system": "AFNOR", "code": "25 CD 4", "source": "matweb-4130", "where": "Key Words line, AFNOR 25 CD 4 (France)" }, { "system": "BS", "code": "CDS 110", "source": "matweb-4130", "where": "Key Words line, B.S. CDS 110 (UK)" }, { "system": "SS", "code": "14 2225", "source": "matweb-4130", "where": "Key Words line, SS14 2225 (Sweden)" }, { "system": "Trade name", "code": "Chromoly", "source": "materialwelding-4130", "where": "Heading: AISI 4130 Steel aka Chromoly Steel" } ], "source": "sandia-1211", "where": "Table 1.1.1, Allowable composition ranges (wt%) for Cr-Mo steels, row 4130 (UNS G41300)" }, "tags": { "environments": [ "launch" ], "stresses": [], "applications": [ "propulsion-and-tanks", "structures", "mechanisms" ] }, "properties": [ { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, quenched and tempered, temper about 635 C", "value": 820, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1144 K (about 871 C) for 120 min, oil quench, temper 908 K (about 635 C) for 120 min, air cool", "strength_level": "row 4130 [8] of Table 1.1.3", "test": "test temperature and environment not stated in Table 1.1.3" }, "method": "Table 1.1.3 as printed, Su column", "status": "ground", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [8] row, Su column", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "yield_strength", "label": "Yield strength (Sy), quenched and tempered, temper about 635 C", "value": 635, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1144 K (about 871 C) for 120 min, oil quench, temper 908 K (about 635 C) for 120 min, air cool", "strength_level": "row 4130 [8] of Table 1.1.3", "test": "test temperature and environment not stated in Table 1.1.3" }, "method": "Table 1.1.3 as printed, Sy column (Sy is the yield strength as the report names it)", "status": "ground", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [8] row, Sy column", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "reduction_of_area", "label": "Reduction of area, quenched and tempered, temper about 635 C", "value": 67, "bound": "exact", "unit": "%", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1144 K (about 871 C) for 120 min, oil quench, temper 908 K (about 635 C) for 120 min, air cool", "strength_level": "row 4130 [8] of Table 1.1.3" }, "method": "Table 1.1.3 as printed, RA column", "status": "ground", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [8] row, RA column", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "yield_strength", "label": "Yield strength (Sy), quenched and tempered, lower strength level", "value": 1050, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1116 K, water quench, temper between 523 K and 813 K (about 250 C to 540 C) for 120 min", "strength_level": "lower of the two Sy levels printed for 4130 [6, 7]", "test": "not stated in Table 1.1.3" }, "method": "Table 1.1.3 as printed; the two strength levels share one heat-treatment cell, and Figure 3.2.2.1 spans 1050 to 1330 MPa", "status": "ground", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [6, 7] rows, first Sy value", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, quenched and tempered, lower strength level", "value": 1140, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1116 K, water quench, temper between 523 K and 813 K (about 250 C to 540 C) for 120 min", "strength_level": "lower of the two strength levels printed for 4130 [6, 7]", "test": "not stated in Table 1.1.3" }, "method": "Table 1.1.3 as printed, Su column, paired with the first Sy value", "status": "ground", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [6, 7] rows, first Su value", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "yield_strength", "label": "Yield strength (Sy), quenched and tempered, high strength level", "value": 1330, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1116 K, water quench, temper between 523 K and 813 K (about 250 C to 540 C) for 120 min", "strength_level": "high strength level; Section 3.2.2 calls 1330 MPa high strength", "test": "not stated in Table 1.1.3" }, "method": "Table 1.1.3 as printed, second Sy value for 4130 [6, 7]", "status": "ground", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [6, 7] rows, second Sy value; Section 3.2.2 text", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, quenched and tempered, high strength level", "value": 1600, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1116 K, water quench, temper between 523 K and 813 K (about 250 C to 540 C) for 120 min", "strength_level": "high strength level", "test": "not stated in Table 1.1.3" }, "method": "Table 1.1.3 as printed, second Su value for 4130 [6, 7]", "status": "ground", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [6, 7] rows, second Su value", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "threshold_stress_intensity_factor", "label": "Threshold stress-intensity factor KTH in hydrogen gas, 21 MPa H2", "value": 88, "bound": "exact", "unit": "MPa√m", "scope": "material", "conditions": { "environment": "high-pressure hydrogen gas, 21 MPa H2", "temperature": "286 K (about 13 C)", "heat_treatment": "same reference and yield strength as the Table 1.1.3 row for 4130 [8]: austenitize 1144 K, oil quench, temper 908 K", "yield_strength": "635 MPa" }, "method": "Table 3.2.2.1 as printed, 4130 [8] row", "status": "ground", "source": "sandia-1211", "where": "Table 3.2.2.1, 4130 [8] row, 21 MPa H2 line", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "threshold_stress_intensity_factor", "label": "Threshold stress-intensity factor KTH in hydrogen gas, 41 MPa H2", "value": 68, "bound": "exact", "unit": "MPa√m", "scope": "material", "conditions": { "environment": "high-pressure hydrogen gas, 41 MPa H2", "temperature": "286 K (about 13 C)", "heat_treatment": "same reference and yield strength as the Table 1.1.3 row for 4130 [8]: austenitize 1144 K, oil quench, temper 908 K", "yield_strength": "635 MPa" }, "method": "Table 3.2.2.1 as printed, 4130 [8] row", "status": "ground", "source": "sandia-1211", "where": "Table 3.2.2.1, 4130 [8] row, 41 MPa H2 line", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "threshold_stress_intensity_factor", "label": "Threshold stress-intensity factor KTH in hydrogen gas, 62 MPa H2", "value": 45, "bound": "exact", "unit": "MPa√m", "scope": "material", "conditions": { "environment": "high-pressure hydrogen gas, 62 MPa H2", "temperature": "286 K (about 13 C)", "heat_treatment": "same reference and yield strength as the Table 1.1.3 row for 4130 [8]: austenitize 1144 K, oil quench, temper 908 K", "yield_strength": "635 MPa" }, "method": "Table 3.2.2.1 as printed, 4130 [8] row", "status": "ground", "source": "sandia-1211", "where": "Table 3.2.2.1, 4130 [8] row, 62 MPa H2 line", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "threshold_stress_intensity_factor", "label": "Threshold stress-intensity factor KTH in hydrogen gas, 69 MPa H2", "value": 32, "bound": "exact", "unit": "MPa√m", "scope": "material", "conditions": { "environment": "high-pressure hydrogen gas, 69 MPa H2", "temperature": "286 K (about 13 C)", "heat_treatment": "same reference and yield strength as the Table 1.1.3 row for 4130 [8]: austenitize 1144 K, oil quench, temper 908 K", "yield_strength": "635 MPa" }, "method": "Table 3.2.2.1 as printed, 4130 [8] row", "status": "ground", "source": "sandia-1211", "where": "Table 3.2.2.1, 4130 [8] row, 69 MPa H2 line", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "threshold_stress_intensity_factor", "label": "Threshold stress-intensity factor KTH in hydrogen gas, 97 MPa H2", "value": 52, "bound": "exact", "unit": "MPa√m", "scope": "material", "conditions": { "environment": "high-pressure hydrogen gas, 97 MPa H2", "temperature": "286 K (about 13 C)", "heat_treatment": "same reference and yield strength as the Table 1.1.3 row for 4130 [8]: austenitize 1144 K, oil quench, temper 908 K", "yield_strength": "635 MPa" }, "method": "Table 3.2.2.1 as printed, 4130 [8] row; this value is above the 69 MPa value, as printed", "status": "ground", "source": "sandia-1211", "where": "Table 3.2.2.1, 4130 [8] row, 97 MPa H2 line", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "fracture_toughness", "label": "Fracture toughness KIc, quenched and tempered, temper about 635 C", "value": 125, "bound": "exact", "unit": "MPa√m", "scope": "material", "conditions": { "condition": "quenched and tempered: austenitize 1144 K (about 871 C) for 120 min, oil quench, temper 908 K (about 635 C) for 120 min, air cool", "basis": "KIc column of Table 1.1.3, row 4130 [8]" }, "method": "Table 1.1.3 as printed; the report footnote says not reported as standardised KIc", "status": "ground", "note": "Sandia footnote: not reported as a standardised KIc measurement.", "source": "sandia-1211", "where": "Table 1.1.3, 4130 [8] row, KIc column, footnote marked with an asterisk", "source_detail": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, normalised at 870 C (1600 F)", "value": 670, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "normalised at 870 C (1600 F), as the MatWeb record title states", "test": "test temperature not stated" }, "method": "MatWeb datasheet printout, Mechanical Properties rows, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Tensile Strength Ultimate, 670 MPa (97200 psi)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "yield_strength", "label": "Yield strength, normalised at 870 C (1600 F)", "value": 435, "bound": "exact", "unit": "MPa", "scope": "material", "conditions": { "condition": "normalised at 870 C (1600 F), as the MatWeb record title states", "test": "test temperature not stated" }, "method": "MatWeb datasheet printout, Mechanical Properties rows, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Tensile Strength Yield, 435 MPa (63100 psi)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "elongation", "label": "Elongation at break, normalised at 870 C (1600 F)", "value": 25.5, "bound": "exact", "unit": "%", "scope": "material", "conditions": { "condition": "normalised at 870 C (1600 F), as the MatWeb record title states", "gauge": "50 mm, as printed" }, "method": "MatWeb datasheet printout, Mechanical Properties rows, value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Elongation at Break, 25.5 % in 50 mm", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "reduction_of_area", "label": "Reduction of area, normalised at 870 C (1600 F)", "value": 60, "bound": "exact", "unit": "%", "scope": "material", "conditions": { "condition": "normalised at 870 C (1600 F), as the MatWeb record title states" }, "method": "MatWeb datasheet printout, Mechanical Properties rows, value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Reduction of Area, 60 %", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "hardness_brinell", "label": "Hardness, Brinell, normalised at 870 C (1600 F)", "value": 197, "bound": "exact", "unit": "HB", "scope": "material", "conditions": { "condition": "normalised at 870 C (1600 F), as the MatWeb record title states" }, "method": "MatWeb datasheet printout, Brinell hardness row as printed (the other scales are converted by MatWeb)", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Hardness, Brinell, 197", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "density", "value": 7.85, "bound": "exact", "unit": "g/cc", "scope": "material", "conditions": { "basis": "physical properties table; no temperature stated; record titled normalised at 870 C" }, "method": "MatWeb physical properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Physical Properties, Density, 7.85 g/cc (0.284 lb/in3)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "elastic_modulus", "label": "Modulus of elasticity", "value": 205, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "marked Typical for steel on the datasheet; no temperature stated" }, "method": "MatWeb mechanical properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Modulus of Elasticity, 205 GPa (29700 ksi)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "bulk_modulus", "value": 160, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "marked Typical for steel on the datasheet; no temperature stated" }, "method": "MatWeb mechanical properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Bulk Modulus, 160 GPa (23200 ksi)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "shear_modulus", "value": 80, "bound": "exact", "unit": "GPa", "scope": "material", "conditions": { "basis": "marked Typical for steel on the datasheet; no temperature stated" }, "method": "MatWeb mechanical properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Shear Modulus, 80.0 GPa (11600 ksi)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "poissons_ratio", "value": 0.29, "bound": "exact", "unit": "-", "scope": "material", "conditions": { "basis": "marked Calculated on the datasheet; no temperature stated" }, "method": "MatWeb mechanical properties row, value as printed with the Calculated comment", "status": "calculated", "source": "matweb-4130", "where": "Mechanical Properties, Poissons Ratio, 0.29 (comment Calculated)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "impact_energy", "label": "Izod impact energy", "value": 87, "bound": "exact", "unit": "J", "scope": "material", "conditions": { "test": "Izod", "temperature": "not stated on the datasheet", "condition": "record titled normalised at 870 C" }, "method": "MatWeb mechanical properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Izod Impact, 87.0 J (64.2 ft-lb)", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "machinability", "label": "Machinability rating (AISI 1212 = 100 %)", "value": 70, "bound": "exact", "unit": "%", "scope": "material", "conditions": { "condition": "annealed and cold drawn", "reference": "AISI 1212 steel is taken as 100 %" }, "method": "MatWeb mechanical properties row, value as printed with its basis", "status": "ground", "source": "matweb-4130", "where": "Mechanical Properties, Machinability, 70 %", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity at 100 C (212 F)", "value": 42.7, "bound": "exact", "unit": "W/m-K", "scope": "material", "conditions": { "temperature": "100 C (212 F)", "printed_alternative": "296 BTU-in/hr-ft2-F" }, "method": "MatWeb thermal properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Thermal Properties, Thermal Conductivity, 42.7 W/m-K (296 BTU-in/hr-ft2-F) at 100 C", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "thermal_conductivity", "label": "Thermal conductivity at 1200 C (2190 F)", "value": 30.1, "bound": "exact", "unit": "W/m-K", "scope": "material", "conditions": { "temperature": "1200 C (2190 F)", "printed_alternative": "209 BTU-in/hr-ft2-F" }, "method": "MatWeb thermal properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Thermal Properties, Thermal Conductivity, 30.1 W/m-K at 1200 C", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "specific_heat", "label": "Specific heat capacity at 100 C or above", "value": 0.477, "bound": "exact", "unit": "J/g-°C", "scope": "material", "conditions": { "temperature": "100 C (212 F) or above", "printed_alternative": "0.114 BTU/lb-F" }, "method": "MatWeb thermal properties row, metric value as printed", "status": "ground", "source": "matweb-4130", "where": "Thermal Properties, Specific Heat Capacity, 0.477 J/g-C at 100 C or above", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "electrical_resistivity", "label": "Electrical resistivity at 20 C, hardened and tempered specimen", "value": 0.0000223, "bound": "exact", "unit": "ohm-cm", "scope": "material", "conditions": { "condition": "specimen hardened and tempered", "temperature": "20 C (68 F)" }, "method": "MatWeb electrical properties row, value as printed", "status": "ground", "source": "matweb-4130", "where": "Electrical Properties, Electrical Resistivity, 0.0000223 ohm-cm at 20.0 C, specimen hardened and tempered", "source_detail": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, hardened and tempered bar (AMS 6346), temper not stated", "value": 125, "bound": "exact", "unit": "ksi", "scope": "material", "conditions": { "condition": "hardened and tempered bar, AMS 6346; temper temperature not stated" }, "method": "Typical Mechanical Properties table as printed; the table header gives ksi", "status": "ground", "source": "aircraft-4130", "where": "Typical Mechanical Properties table, Bar AMS 6346, Hardened and Tempered, Tensile Strength ksi 125", "source_detail": { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "id": "AISI 4130 Aircraft Steel", "url": "https://aircraftmaterials.com/data/alstst/4130.html", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "yield_strength", "label": "Yield strength, hardened and tempered bar (AMS 6346), temper not stated", "value": 100, "bound": "exact", "unit": "ksi", "scope": "material", "conditions": { "condition": "hardened and tempered bar, AMS 6346; temper temperature not stated" }, "method": "Typical Mechanical Properties table as printed; the table header gives ksi", "status": "ground", "source": "aircraft-4130", "where": "Typical Mechanical Properties table, Bar AMS 6346, Hardened and Tempered, Yield Strength ksi 100", "source_detail": { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "id": "AISI 4130 Aircraft Steel", "url": "https://aircraftmaterials.com/data/alstst/4130.html", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "ultimate_tensile_strength", "label": "Tensile strength, cold drawn tube (AMS 6371)", "value": 95, "bound": "exact", "unit": "ksi", "scope": "material", "conditions": { "condition": "cold drawn tube, AMS 6371" }, "method": "Typical Mechanical Properties table as printed; the table header gives ksi", "status": "ground", "source": "aircraft-4130", "where": "Typical Mechanical Properties table, Tube AMS 6371, Cold Drawn, Tensile Strength ksi 95", "source_detail": { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "id": "AISI 4130 Aircraft Steel", "url": "https://aircraftmaterials.com/data/alstst/4130.html", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "yield_strength", "label": "Yield strength, cold drawn tube (AMS 6371)", "value": 70, "bound": "exact", "unit": "ksi", "scope": "material", "conditions": { "condition": "cold drawn tube, AMS 6371" }, "method": "Typical Mechanical Properties table as printed; the table header gives ksi", "status": "ground", "source": "aircraft-4130", "where": "Typical Mechanical Properties table, Tube AMS 6371, Cold Drawn, Yield Strength ksi 70", "source_detail": { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "id": "AISI 4130 Aircraft Steel", "url": "https://aircraftmaterials.com/data/alstst/4130.html", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "hardness_brinell", "label": "Hardness, annealed bar (AMS 6370), maximum", "value": 29, "bound": "upper", "unit": "HB", "scope": "material", "conditions": { "condition": "annealed bar, AMS 6370" }, "method": "Typical Mechanical Properties table as printed, 29HB Max", "status": "ground", "source": "aircraft-4130", "where": "Typical Mechanical Properties table, Bar AMS 6370, Annealed, Hardness 29HB Max", "source_detail": { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "id": "AISI 4130 Aircraft Steel", "url": "https://aircraftmaterials.com/data/alstst/4130.html", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "hardness_rockwell_c", "label": "Hardness, annealed sheet (AMS 6350), maximum", "value": 25, "bound": "upper", "unit": "HRC", "scope": "material", "conditions": { "condition": "annealed sheet, AMS 6350" }, "method": "Typical Mechanical Properties table as printed, printed as less than 25 HRC", "status": "ground", "source": "aircraft-4130", "where": "Typical Mechanical Properties table, Sheet AMS 6350, Annealed, Hardness less than 25 HRC", "source_detail": { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "id": "AISI 4130 Aircraft Steel", "url": "https://aircraftmaterials.com/data/alstst/4130.html", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "hardness_rockwell_c", "label": "Hardness, round bar as usually supplied (quenched and tempered)", "value": 18, "value_high": 22, "bound": "range", "unit": "HRC", "scope": "material", "conditions": { "condition": "round bar, usually supplied quenched and tempered, as the article states" }, "method": "Range as printed in the Material Welding article; no test method is printed", "status": "ground", "source": "materialwelding-4130", "where": "AISI 4130 Chemical Properties introduction: usually quenched and tempered, hardness 18-22 HRC", "source_detail": { "title": "Material Welding: Welding 4130 Steel: Complete Guidelines", "id": "AISI 4130 Steel aka Chromoly Steel guide", "url": "https://materialwelding.com/how-to-weld-aisi-4130-steel/", "kind": "web", "license": "web article, cited not reproduced" } }, { "benchmark": "melting_point", "label": "Melting point", "value": 2610, "bound": "exact", "unit": "F", "scope": "material", "conditions": { "basis": "physical properties table; no condition stated" }, "method": "Titanium Industries physical properties table, Melting Point (F) as printed", "status": "ground", "source": "titanium-4130", "where": "Table 2, PHYSICAL PROPERTIES, Melting Point (°F), 2610", "source_detail": { "title": "Titanium Industries: Alloy Steel 4130 (UNS G41300) page with physical properties table", "id": "Alloy Steel 4130 | UNS G41300", "url": "https://titanium.com/alloys/alloy-steels/alloy-steel-4130/", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "cte", "label": "Coefficient of thermal expansion (printed per degree F)", "value": 0.0000062, "bound": "exact", "unit": "1/F", "scope": "material", "conditions": { "temperature": "not stated in the table" }, "method": "Titanium Industries physical properties table, Thermal expansion (1/F) as printed; the table prints 0.00000620", "status": "ground", "source": "titanium-4130", "where": "Table 2, PHYSICAL PROPERTIES, Thermal expansion (1/°F), 0.00000620", "source_detail": { "title": "Titanium Industries: Alloy Steel 4130 (UNS G41300) page with physical properties table", "id": "Alloy Steel 4130 | UNS G41300", "url": "https://titanium.com/alloys/alloy-steels/alloy-steel-4130/", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } }, { "benchmark": "electrical_conductivity", "label": "Electrical conductivity", "value": 7.73, "bound": "exact", "unit": "% IACS", "scope": "material", "conditions": { "basis": "physical properties table; no temperature or condition stated" }, "method": "Titanium Industries physical properties table, Electrical conductivity (% IACS) as printed", "status": "ground", "source": "titanium-4130", "where": "Table 2, PHYSICAL PROPERTIES, Electrical conductivity (% IACS), 7.73", "source_detail": { "title": "Titanium Industries: Alloy Steel 4130 (UNS G41300) page with physical properties table", "id": "Alloy Steel 4130 | UNS G41300", "url": "https://titanium.com/alloys/alloy-steels/alloy-steel-4130/", "kind": "datasheet", "license": "supplier web page, cited not reproduced" } } ], "corrosion": [ { "environment": "Aerated aqueous NaCl, CaCl2 and sodium bicarbonate solution at room temperature, corrosion-fatigue at 1 Hz and R = 0.1", "headline": "Salt solution cut the fatigue life of AISI 4130 at every strength level tested, from 837 to 1846 MPa.", "effect": "All specimens tested in the salt solution failed in less than 150,000 cycles, while some tested in air ran out beyond 10^6 cycles. The salt solution lowered the fatigue limit at each strength level. The thesis ties the loss to martensite: the more martensite, the larger the drop. The rating severe is an assistant judgement from these findings.", "rating": "severe", "conditions": { "solution": "aqueous NaCl, CaCl2 and sodium bicarbonate", "temperature": "room temperature, constant aeration", "loading": "1 Hz, stress ratio R = 0.1", "strength_levels": "six levels, 837 to 1846 MPa (121 to 268 ksi)" }, "source": "gatech-cf", "where": "Abstract, findings paragraph (the 10^6 is a superscript in the abstract)" }, { "environment": "Hydrogen gas at 21 to 97 MPa and 286 K, and low-pressure hydrogen at 0.08 MPa", "headline": "Hydrogen gas lowers the threshold stress intensity of quenched and tempered 4130, from 88 MPa√m at 21 MPa H2 to 32 MPa√m at 69 MPa H2.", "effect": "The Sandia reference says hydrogen gas lowers fracture toughness and makes Cr-Mo steels susceptible to crack extension under static loading. For 4130 the threshold falls by a factor of three as yield strength rises from 1050 to 1330 MPa in low-pressure hydrogen, and it rises 40 to 50 percent when the temperature is 50 K above ambient. The printed value at 97 MPa H2 (52 MPa√m) is above the 69 MPa value, and the report prints it that way. The rating severe is an assistant judgement.", "rating": "severe", "conditions": { "temperature": "286 K (about 13 C) for the Table 3.2.2.1 values", "pressure": "21, 41, 62, 69 and 97 MPa H2", "heat_treatment": "austenitize 1144 K, oil quench, temper 908 K (row 4130 [8])" }, "source": "sandia-1211", "where": "Section 1 and Section 3.2.2 text; Table 3.2.2.1, 4130 [8] row; Figure 3.2.2.1" }, { "environment": "Atmosphere, general (no test conditions printed)", "headline": "Titanium Industries describes AISI 4130 as having good atmospheric resistance; no corrosion rate is printed.", "effect": "The supplier says the grade has good atmospheric resistance and good strength at moderately high temperatures. The page gives no exposure time, site or rate, so this is a supplier statement, not a measured result.", "rating": "unknown", "conditions": { "basis": "supplier statement; no test conditions printed" }, "source": "titanium-4130", "where": "Introduction paragraph, Alloy Steel 4130 | UNS G41300" } ], "risks": { "hazards": [ { "text": "PubChem aggregated GHS for elemental chromium (signal word Danger): H317 (20.7%), H319 (19.1%) and H334 (20.3%) are reported codes above 10%. 50% (1202 of 2404) of reports say it does not meet GHS hazard criteria. The data cover the element, not the alloy.", "ghs": [ "H317", "H319", "H334" ], "source": "pubchem-chromium", "where": "Safety and Hazards, GHS Classification (CID 23976)" }, { "text": "PubChem aggregated GHS for elemental molybdenum (signal word Danger): H228 flammable solid (30%), H361 suspected of damaging fertility or the unborn child (29.5%) and H225 (11.6%). 57.4% (874 of 1523) of reports say it does not meet GHS hazard criteria. The data cover the element, not the alloy.", "ghs": [ "H228", "H361", "H225" ], "source": "pubchem-molybdenum", "where": "Safety and Hazards, GHS Classification (CID 23932)" }, { "text": "PubChem aggregated GHS for elemental manganese (signal word Danger): H228 (11.6%), H319 (14.8%), H411 (10.9%) and H412 (10.8%), with H360 (may damage fertility or the unborn child) and H372 (causes damage to organs through prolonged or repeated exposure) also listed. 46.1% (1429 of 3101) of reports say it does not meet GHS hazard criteria. The data cover the element, not the alloy.", "ghs": [ "H228", "H319", "H360", "H372", "H411", "H412" ], "source": "pubchem-manganese", "where": "Safety and Hazards, GHS Classification (CID 23930)" } ], "failure_risks": [ { "mode": "Hydrogen embrittlement under static load", "trigger": "Hydrogen gas at 21 to 97 MPa and 286 K, and low-pressure hydrogen at 0.08 MPa", "consequence": "The threshold stress intensity of the 635 MPa yield strength level fell from 88 MPa√m at 21 MPa H2 to 32 MPa√m at 69 MPa H2. The report ties the loss to yield strength, and says limiting yield strength improves resistance. The threshold also rises 40 to 50 percent when the temperature is 50 K above ambient and falls 25 to 30 percent when it is 70 K below ambient.", "severity": "high", "source": "sandia-1211", "where": "Table 3.2.2.1, 4130 [8] row; Section 3.2.2 (effect of yield strength and temperature)" }, { "mode": "Hydrogen cracking in welds", "trigger": "Welding 4130 without the recommended preheat, with unbaked consumables, or with fast cooling", "consequence": "Material Welding says 4130 is particularly prone to hydrogen cracking, which the filler metal and slow cooling can reduce.", "severity": "high", "source": "materialwelding-4130", "where": "Weldability section (hydrogen cracking paragraph)" }, { "mode": "Corrosion fatigue in salt solutions", "trigger": "Aerated aqueous NaCl and CaCl2 solution under cyclic loading (1 Hz, R = 0.1)", "consequence": "Every specimen tested in the salt solution failed in less than 150,000 cycles, and the salt solution lowered the fatigue limit at each strength level tested.", "severity": "high", "source": "gatech-cf", "where": "Abstract, findings paragraph" }, { "mode": "Loss of tempering effect in post-weld heat treatment", "trigger": "Post-weld heat treatment at a temperature above the tempering temperature", "consequence": "A high PWHT temperature destroys the tempering effect in the base material.", "severity": "moderate", "source": "materialwelding-4130", "where": "4130 Heat Treatment section" } ], "side_effects": [], "handling": [ { "text": "Preheat to about 200 to 300 C (400 to 570 F) before welding. Use the upper end for sections thicker than 25 mm or when working in a cold environment. Slower cooling after welding also reduces the risk of cracking.", "source": "materialwelding-4130", "where": "Weldability and Preheat sections" }, { "text": "Use fully baked welding consumables and an appropriate filler. ER80S-D2 is the recommended filler; ER70S-2 and ER70S-6 are alternatives with slightly lower toughness.", "source": "materialwelding-4130", "where": "Welding consumables and filler questions" }, { "text": "Stress relieve parts thicker than 3 mm (0.120 in) at about 600 C, holding about one hour per inch of thickness, and keep the temperature below the tempering temperature.", "source": "materialwelding-4130", "where": "Heat Treatment section and stress relief question" }, { "text": "Quote the heat-treatment condition with every strength value. The normalised, annealed, hardened and tempered, cold drawn and quenched-and-tempered rows in this file come from different heat treatments.", "source": "aircraft-4130", "where": "Typical Mechanical Properties table and MatWeb record title" } ], "mitigations": [ { "text": "Limit the yield strength of the chosen condition. Sandia states that limiting steel yield strength can improve resistance to hydrogen embrittlement, and the threshold falls as yield strength rises.", "source": "sandia-1211", "where": "Section 1, General (text); Figure 3.2.2.1 and Section 3.2.2" }, { "text": "Avoid hydrogen cracking by using fully baked welding consumables and an appropriate filler, with preheat and slow cooling after welding.", "source": "materialwelding-4130", "where": "Weldability and Consumables sections" } ] }, "uses": [ { "application": "propulsion-and-tanks", "device": "Solid rocket booster case", "example": "NASA's list of heritage launch-vehicle materials names 4130 among the solid rocket booster case materials, with D6AC, 18% nickel maraging steel and titanium.", "source": "nasa-srb", "where": "Launch Vehicle Structures and Solid Rocket Boosters, Case Materials list" }, { "application": "structures", "device": "Aircraft tube, sheet and bar for military and commercial aircraft", "example": "Aircraft Materials lists 4130 tube to AMS 6371, bar to AMS 6346 and sheet to AMS 6350, and names military and commercial aircraft among its applications.", "source": "aircraft-4130", "where": "Applications list; Specifications list" }, { "application": "structures", "device": "Oil and gas wellhead and Christmas tree parts", "example": "Material Welding says quenched and tempered 4130 round bar is used in oil and gas drilling and production components, such as wellhead and Christmas tree parts.", "source": "materialwelding-4130", "where": "AISI 4130 Chemical Properties introduction and the oil and gas sentence" }, { "application": "mechanisms", "device": "Machine tool components and forged valve bodies and pumps", "example": "Aircraft Materials lists machine tools among 4130 applications, and Titanium Industries lists forged valve bodies and pumps.", "source": "aircraft-4130", "where": "Applications list" } ], "supply": [ { "subject": "Chromium", "abundance": "World resources are greater than 12 billion tons of shipping-grade chromite, 95 percent of chromium resources in Kazakhstan and southern Africa (USGS). US net import reliance was 79 percent of apparent consumption in 2025e. Chromite imports in 2021 to 2024 came from South Africa (96%), Turkey (3%) and other (1%). 2025e mine production as printed: South Africa 23,000; Turkey 9,000; Kazakhstan 7,000; India 3,000; Brazil 2,000; Zimbabwe 2,000; Finland 1,900; world total 51,000 (rounded). Producer shares are not printed by USGS and are not calculated here.", "producers": [ { "country": "South Africa", "year": 2025 }, { "country": "Turkey", "year": 2025 }, { "country": "Kazakhstan", "year": 2025 }, { "country": "India", "year": 2025 }, { "country": "Brazil", "year": 2025 }, { "country": "Zimbabwe", "year": 2025 }, { "country": "Finland", "year": 2025 } ], "critical_lists": [], "recycling": "Recycled chromium in reported stainless-steel scrap receipts accounted for 21 percent of apparent consumption in 2025 (USGS).", "substitutes": [ "Chromium has no substitute in stainless steel, the leading end use, or in superalloys (USGS). Chromium-containing scrap can substitute for ferrochromium in some metallurgical uses." ], "source": "usgs-chromium-2026", "where": "Salient Statistics; Import Sources (2021-24); Recycling; World Mine Production and Reserves (2025e); World Resources; Substitutes" }, { "subject": "Molybdenum", "abundance": "Identified resources are about 5.4 million tons in the United States and about 20 million tons in the rest of the world (USGS). World reserves were 17,000 thousand metric tons. Molybdenum is used principally as an alloying agent in cast iron and steel. The United States is a net exporter (E in the USGS table, 2021 to 2025e). In 2025e, China, Chile, the United States, Peru and Mexico account for 90 percent of world production (USGS). 2025e mine production as printed: China 97,000; Chile 42,000; United States 40,000; Peru 39,000; Mexico 17,000; world total 260,000 (rounded). The Government of China imposed export controls on molybdenum powders in February 2025.", "producers": [ { "country": "China", "year": 2025 }, { "country": "Chile", "year": 2025 }, { "country": "United States", "year": 2025 }, { "country": "Peru", "year": 2025 }, { "country": "Mexico", "year": 2025 } ], "critical_lists": [], "recycling": "Molybdenum is recycled from catalysts, ferrous scrap and superalloy scrap. Recycled molybdenum in new and old steel and other scrap may be as much as 30 percent of the apparent supply (USGS).", "substitutes": [ "There is little substitution for molybdenum in steels and cast irons. Potential substitutes in alloy steels include boron, chromium, niobium (columbium) and vanadium (USGS)." ], "source": "usgs-molybdenum-2026", "where": "Salient Statistics; Recycling; Events, Trends and Issues; World Mine Production and Reserves (2025e); World Resources; Substitutes" } ], "media": [], "documents": [ { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "type": "datasheet", "url": "https://aircraftmaterials.com/data/alstst/4130.html" }, { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout (copy hosted on quickparts.com)", "type": "datasheet", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf" }, { "title": "Titanium Industries: Alloy Steel 4130 (UNS G41300) page", "type": "datasheet", "url": "https://titanium.com/alloys/alloy-steels/alloy-steel-4130/" }, { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211), Sandia National Laboratories", "type": "report", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005 }, { "title": "NASA NTRS 20190020090: Heritage Materials for Launch Vehicles and Spacecraft", "type": "report", "url": "https://ntrs.nasa.gov/api/citations/20190020090/downloads/20190020090.pdf" }, { "title": "Material Welding: Welding 4130 Steel: Complete Guidelines", "type": "report", "url": "https://materialwelding.com/how-to-weld-aisi-4130-steel/" }, { "title": "Saarstahl: Werkstoff-Datenblatt 25CrMo4 (1.7218)", "type": "datasheet", "url": "https://www.saarstahl.com/app/uploads/2024/03/20160318114702-25CrMo4-.pdf" }, { "title": "Evins, J. L. (2004): Dependence of Strength on Corrosion-Fatigue Resistance of AISI 4130 Steel, Georgia Tech MS thesis", "type": "paper", "url": "https://repository.gatech.edu/entities/publication/98a0585f-9939-476a-b8e7-986068df1a43", "year": 2004 }, { "title": "PubChem: Chromium (CID 23976), GHS classification", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON/?heading=GHS+Classification" }, { "title": "PubChem: Molybdenum (CID 23932), GHS classification", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23932/JSON/?heading=GHS+Classification" }, { "title": "PubChem: Manganese (CID 23930), GHS classification", "type": "database", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON/?heading=GHS+Classification" }, { "title": "USGS Mineral Commodity Summaries 2026: Chromium", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-chromium.pdf", "year": 2026 }, { "title": "USGS Mineral Commodity Summaries 2026: Molybdenum", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf", "year": 2026 } ], "gaps": [ "identity.cas, crystal_system and space_group: not printed by any source read in this run. A CAS number does not apply to a steel mixture, and no crystal structure source was read for the alloy.", "No standard text was read for SAE J404, AMS 6350, AMS 6360, ASTM A519, A322, A331 or MIL-S-6758. The codes are as the cited pages print them.", "Composition limits disagree between sources. Aircraft Materials prints phosphorus and sulfur at 0.025 max (silicon 0.15 to 0.35 for bar and tube, 0.20 to 0.35 for sheet). MatWeb prints phosphorus 0.035 max, sulfur 0.040 max and silicon 0.15 to 0.30. Material Welding prints sulfur 0.035 max and phosphorus 0.025 max. The recipe uses the allowable ranges in Sandia Table 1.1.1 (phosphorus 0.035 max, sulfur 0.040 max).", "No annealed tensile or yield strength was found. AMS 6370 bar and AMS 6350 sheet give hardness only (29 HB maximum and less than 25 HRC).", "Aircraft Materials prints elongation without a unit, and it prints the normalised sheet hardness without a unit. Neither is recorded. Its tube hardness is printed as less than 25 with no unit, and it is not recorded either.", "Titanium Industries prints density 0.284 and specific heat 0.114 with no unit, so neither is recorded. Its yield, tensile, elongation and hardness ranges combine several conditions, so they are not recorded.", "Material Welding prints tensile 560 MPa and yield 460 MPa with no condition, so they are not recorded. ICAST Alloys prints tensile 480 to 1379 MPa across annealing, normalising and hardening rows, so it is not recorded.", "Sandia gives two strength levels for 4130 [6, 7] under one heat-treatment cell (tempering between 523 K and 813 K). The file records them as lower and high levels, following the text of Section 3.2.2. The report gives no temper temperature for each level.", "Sandia's 4130 rows are all quenched and tempered. The report has no hydrogen tensile or notched-tensile data for 4130; its notched tables cover 4140 only. The 4130 hydrogen data are threshold values from one high-pressure study and one low-pressure study.", "Sandia's 4130 chemistry in Table 1.1.2 (test heats) is not used for the recipe, which uses the allowable ranges in Table 1.1.1.", "Corrosion: no chloride immersion rate, acid immersion rate or atmospheric test value for 4130 was read in this run. The 2020 welded-joint paper (garuda.kemdikbud.go.id/documents/detail/2140279) and the University of Southern Queensland heat-treatment paper did not respond to the fetch.", "Weldability: the preheat, filler and stress-relief values come from Material Welding, a commercial guide, not from a welding procedure specification (AWS D1.1 or ASME IX). Check them against a qualified welding procedure before use.", "Critical minerals: the USGS 2025 critical minerals page returned HTTP 403 in this run, so no critical-list entry is recorded for chromium or molybdenum.", "Supply: USGS prints tonnage, not country shares, so producer shares are not calculated here. The 2025e tonnage is in the abundance text.", "Designations not recorded: JIS SCM430 is printed by MakeItFrom, which returned HTTP 403. MatWeb prints JIS SCM 2 and JIS SCCrM 1 as key words, but neither is confirmed as the same steel. a guessed Elgin 4130 fact sheet URL returned HTTP 404.", "Designations as nearest equivalents: Saarstahl's 25CrMo4 datasheet (1.7218) gives a typical carbon of 0.25 against 0.28 to 0.33 for AISI 4130, so 25CrMo4 and 1.7218 are marked nearest equivalent, not the same grade.", "No safety data sheet for the 4130 bar was read in this run. The hazard entries are PubChem records for elemental chromium, molybdenum and manganese, and welding fume hazards of the steel itself are not sourced.", "No source in this run compares 4130 with 4140 head to head. The Sandia tables list both grades, but their heat treatments differ, so no 4140 value is used in this file.", "Non-canonical benchmark names used: hardness_brinell, hardness_rockwell_c, impact_energy, machinability, electrical_conductivity, threshold_stress_intensity_factor, fracture_toughness, reduction_of_area.", "NASA's heritage list names 4130 for solid rocket booster cases but gives no 4130 data (wall thickness, yield strength or flight history). Launch-vehicle use is recorded as the list entry only." ], "story": { "why": "AISI 4130 (UNS G41300) is a low-alloy chromium-molybdenum steel that aircraft and motorsport builders, oil and gas makers and NASA's heritage list use. Aircraft Materials cites its weldability and ease of fabrication, and Titanium Industries cites good strength, toughness and weldability. Its numbers depend on the heat treatment, so every value in this profile carries its own condition. Hydrogen gas and salt solutions are its weak points, both in laboratory tests.", "uses": [ { "where": "Rocket motors and launch vehicles", "line": "NASA's heritage list for launch vehicles names 4130 as a solid rocket booster case material, alongside D6AC and maraging steel." }, { "where": "Aircraft tube, sheet and bar", "line": "Aircraft Materials lists 4130 tube to AMS 6371, bar to AMS 6346 and sheet to AMS 6350 for military and commercial aircraft." }, { "where": "Oil and gas parts", "line": "Quenched and tempered 4130 round bar goes into oil and gas drilling and production parts, such as wellhead and Christmas tree parts (Material Welding)." } ], "can_do": [ { "label": "Strength", "line": "Quenched and tempered with a temper at about 635 C, the Sandia heat treatment gives 635 MPa yield strength and 820 MPa tensile strength, with 67 percent reduction of area.", "scope": "material" }, { "label": "Normalised", "line": "Normalised at 870 C, the MatWeb record gives 670 MPa tensile strength, 435 MPa yield strength, 25.5 percent elongation in 50 mm and 197 HB.", "scope": "material" }, { "label": "Hardness", "line": "Round bar usually supplied quenched and tempered sits at 18 to 22 HRC (Material Welding).", "scope": "material" }, { "label": "Stiffness", "line": "The modulus of elasticity is 205 GPa, marked typical for steel (MatWeb).", "scope": "material" }, { "label": "Weldability", "line": "Material Welding says it welds well when preheat, interpass temperature and post-weld heat treatment are controlled; Titanium Industries cites good weldability.", "scope": "material" } ], "compare": "No source read in this run compares AISI 4130 with AISI 4140 head to head. The Sandia report prints both grades in the same tables, but their heat treatments differ, so the 4130 and 4140 rows cannot be read as a like-for-like comparison, and no 4140 value is used in this file. To compare the two, first match the heat-treatment condition, then compare the yield strength, elastic modulus and density rows below.", "compare_rows": [ { "label": "Strength (yield)", "benchmark": "yield_strength", "scope": "material" }, { "label": "Stiffness", "benchmark": "elastic_modulus", "scope": "material" }, { "label": "Density", "benchmark": "density", "scope": "material" } ], "handling": [ "Quote the heat-treatment condition with every strength value, because the normalised, annealed, quenched-and-tempered and hydrogen-tested rows differ.", "Preheat before welding to about 200 to 300 C (400 to 570 F), with the upper end for sections thicker than 25 mm, and use fully baked consumables.", "Stress relieve parts thicker than 3 mm (0.120 in) at about 600 C, and keep the temperature below the tempering temperature.", "In hydrogen service, do not assume a high-strength 4130 is safe: the threshold fell from 88 to 32 MPa√m as pressure rose from 21 to 69 MPa in one study.", "Take the safety data sheet for the specific bar before cutting, grinding or welding; no 4130 SDS was read here." ], "good_for": [ "Aircraft and motorsport tube, sheet and bar, where weldability and strength after heat treatment matter (Aircraft Materials).", "Oil and gas wellhead and Christmas tree parts in quenched and tempered round bar (Material Welding).", "Forged valve bodies, pumps and machine tool components (Titanium Industries, Aircraft Materials)." ], "watch_out": [ "Hydrogen gas: the threshold stress intensity of 4130 fell from 88 to 32 MPa√m between 21 and 69 MPa hydrogen (Sandia).", "Salt solutions: every corrosion-fatigue specimen tested in aerated NaCl and CaCl2 solution failed in under 150,000 cycles (Georgia Tech thesis).", "Welding without preheat, post-weld heat treatment or baked consumables risks hydrogen cracking (Material Welding)." ], "verdict": "AISI 4130 is a weldable, heat-treatable chromium-molybdenum steel for aircraft tube and sheet, oil and gas parts and machine parts. Its strength depends on heat treatment, so quote the condition with every value. Hydrogen and salt solutions are the watch points, and the hydrogen data come from laboratory tests, not field service.", "recipe": { "line": "AISI 4130 is an iron-based, low-alloy chromium-molybdenum steel, not a stainless steel. Table 1.1.1 of the Sandia reference gives its allowable ranges as 0.28 to 0.33 carbon, 0.40 to 0.60 manganese, 0.15 to 0.35 silicon, 0.80 to 1.10 chromium and 0.15 to 0.25 molybdenum (wt%), with phosphorus at 0.035 max and sulfur at 0.040 max. Aircraft Materials says bar is vacuum degassed to meet magnetic particle inspection standards. Its strength comes from heat treatment (normalising, annealing, or quenching and tempering).", "parts": [ { "name": "Iron", "symbol": "Fe", "role": "The matrix of the steel; heat treatment turns its structure from austenite to martensite and then to tempered martensite, or to ferrite and carbide when normalised or annealed.", "share_note": "balance (the rest)", "source": "sandia-1211", "where": "Table 1.1.1, row 4130; footnote: balance is Fe" }, { "name": "Carbon", "symbol": "C", "role": "Sets how hard the steel can become when quenched; medium carbon gives the strength range.", "share_percent": 0.28, "share_high": 0.33, "source": "sandia-1211", "where": "Table 1.1.1, row 4130" }, { "name": "Manganese", "symbol": "Mn", "role": "Deoxidiser and hardenability aid.", "share_percent": 0.4, "share_high": 0.6, "source": "sandia-1211", "where": "Table 1.1.1, row 4130" }, { "name": "Silicon", "symbol": "Si", "role": "Deoxidiser.", "share_percent": 0.15, "share_high": 0.35, "source": "sandia-1211", "where": "Table 1.1.1, row 4130" }, { "name": "Chromium", "symbol": "Cr", "role": "Adds hardenability and some corrosion resistance; the grade is still a low-alloy steel.", "share_percent": 0.8, "share_high": 1.1, "source": "sandia-1211", "where": "Table 1.1.1, row 4130" }, { "name": "Molybdenum", "symbol": "Mo", "role": "Adds hardenability and strength at temperature.", "share_percent": 0.15, "share_high": 0.25, "source": "sandia-1211", "where": "Table 1.1.1, row 4130" }, { "name": "Phosphorus", "symbol": "P", "role": "Impurity held low.", "share_note": "max 0.035", "source": "sandia-1211", "where": "Table 1.1.1, row 4130, maximum" }, { "name": "Sulfur", "symbol": "S", "role": "Impurity held low.", "share_note": "max 0.040", "source": "sandia-1211", "where": "Table 1.1.1, row 4130, maximum" } ] }, "risk_groups": [ { "title": "For people", "lead": "PubChem records cover elemental chromium, molybdenum and manganese. No safety data sheet for the 4130 bar was read in this run.", "points": [ { "label": "Chromium", "line": "PubChem lists elemental chromium as Danger, with H317, H319 and H334 among its reported codes. 50 percent of reports say it does not meet GHS hazard criteria." }, { "label": "Molybdenum", "line": "PubChem lists elemental molybdenum as Danger, with H361 (suspected of damaging fertility or the unborn child) and H228 (flammable solid) among its codes." }, { "label": "Manganese", "line": "PubChem lists elemental manganese as Danger, with H360 and H372 among its codes." } ], "level": 1, "verdict": "Element data only, no alloy SDS read" }, { "title": "In service", "lead": "These come from laboratory tests, not from field incidents.", "points": [ { "label": "Hydrogen gas", "line": "At 21 to 69 MPa hydrogen and 286 K, the threshold stress intensity of the 635 MPa yield strength level fell from 88 to 32 MPa√m (Sandia)." }, { "label": "Salt solution", "line": "In aerated NaCl and CaCl2 solution, every corrosion-fatigue specimen failed in under 150,000 cycles (Georgia Tech thesis)." } ], "level": 2, "verdict": "Hydrogen and salt are the watch points" }, { "title": "Welding", "lead": "Welding 4130 is workable, but it is prone to hydrogen cracking if preheat and heat treatment are skipped.", "points": [ { "label": "Hydrogen cracking", "line": "Material Welding says 4130 is particularly prone to hydrogen cracking, which fully baked consumables and slower cooling reduce." }, { "label": "Preheat", "line": "Preheat to about 200 to 300 C (400 to 570 F), with the upper end for sections thicker than 25 mm." } ], "level": 2, "verdict": "Preheat and stress relief are needed" } ] }, "updated": "2026-10-24", "review": { "status": "draft", "method": "assistant", "checked_values": 39, "unreachable": 0, "caveats": 3, "note": "Read by an AI assistant on 2026-10-24 from pages fetched in this run. Each value is tied to its own condition. Caveats: the Sandia KIc is not a standardised measurement; the Sandia 4130 [6, 7] strength levels share one heat-treatment cell; the thermal expansion is printed per degree F. Not reached: a guessed Elgin 4130 fact sheet URL (HTTP 404), MakeItFrom (HTTP 403), Harris Products welding page (HTTP 403), Suppliersonline (HTTP 503), USGS critical minerals page (HTTP 403), two corrosion papers (no response)." }, "sources": { "aircraft-4130": { "title": "Aircraft Materials: 4130 (AMS 6345 / AMS 6346 / AMS 6350) chrome-moly aircraft steel technical data sheet", "id": "AISI 4130 Aircraft Steel", "url": "https://aircraftmaterials.com/data/alstst/4130.html", "kind": "datasheet", "license": "supplier web page, cited not reproduced" }, "matweb-4130": { "title": "MatWeb: AISI 4130 Steel, normalized at 870 C (1600 F), datasheet printout", "id": "MatWeb matguid e1ccebe90cf94502b35c2a4745f63593 (copy on quickparts.com)", "url": "https://quickparts.com/wp-content/uploads/2024/05/Steel-4130.pdf", "kind": "datasheet", "license": "MatWeb terms of use, cited not reproduced" }, "titanium-4130": { "title": "Titanium Industries: Alloy Steel 4130 (UNS G41300) page with physical properties table", "id": "Alloy Steel 4130 | UNS G41300", "url": "https://titanium.com/alloys/alloy-steels/alloy-steel-4130/", "kind": "datasheet", "license": "supplier web page, cited not reproduced" }, "sandia-1211": { "title": "Technical Reference on Hydrogen Compatibility of Materials: Low-Alloy Ferritic Steels, Tempered Fe-Cr-Mo Alloys (code 1211)", "id": "Sandia National Laboratories, code 1211, December 8, 2005", "url": "https://www.sandia.gov/app/uploads/sites/158/2021/12/1211TechRef_FeCrMo_T.pdf", "year": 2005, "kind": "report", "license": "US government report, public" }, "nasa-srb": { "title": "NASA NTRS 20190020090: Heritage Materials for Launch Vehicles and Spacecraft", "id": "NTRS 20190020090", "url": "https://ntrs.nasa.gov/api/citations/20190020090/downloads/20190020090.pdf", "kind": "report", "license": "NASA public document" }, "materialwelding-4130": { "title": "Material Welding: Welding 4130 Steel: Complete Guidelines", "id": "AISI 4130 Steel aka Chromoly Steel guide", "url": "https://materialwelding.com/how-to-weld-aisi-4130-steel/", "kind": "web", "license": "web article, cited not reproduced" }, "saarstahl-25crmo4": { "title": "Saarstahl: Werkstoff-Datenblatt 25CrMo4 (1.7218)", "id": "25CrMo4 / 1.7218", "url": "https://www.saarstahl.com/app/uploads/2024/03/20160318114702-25CrMo4-.pdf", "kind": "datasheet", "license": "manufacturer datasheet, cited not reproduced" }, "gatech-cf": { "title": "Evins, J. L. (2004): Dependence of Strength on Corrosion-Fatigue Resistance of AISI 4130 Steel, Georgia Tech MS thesis", "id": "hdl.handle.net/1853/5265", "url": "https://repository.gatech.edu/entities/publication/98a0585f-9939-476a-b8e7-986068df1a43", "year": 2004, "kind": "paper", "license": "Georgia Tech repository record" }, "pubchem-chromium": { "title": "PubChem: Chromium (CID 23976), Safety and Hazards, GHS Classification", "id": "CID 23976", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23976/JSON/?heading=GHS+Classification", "kind": "database", "license": "PubChem terms (public)" }, "pubchem-molybdenum": { "title": "PubChem: Molybdenum (CID 23932), Safety and Hazards, GHS Classification", "id": "CID 23932", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23932/JSON/?heading=GHS+Classification", "kind": "database", "license": "PubChem terms (public)" }, "pubchem-manganese": { "title": "PubChem: Manganese (CID 23930), Safety and Hazards, GHS Classification", "id": "CID 23930", "url": "https://pubchem.ncbi.nlm.nih.gov/rest/pug_view/data/compound/23930/JSON/?heading=GHS+Classification", "kind": "database", "license": "PubChem terms (public)" }, "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)" }, "usgs-molybdenum-2026": { "title": "USGS Mineral Commodity Summaries 2026: Molybdenum", "id": "mcs2026-molybdenum", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-molybdenum.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/steel-4130/" }