{ "spore": "profile", "id": "galfan-zinc-5-aluminium", "spore_version": "0.2", "family": "zinc-alloys", "name": "Galfan (zinc-5% aluminium hot-dip coating alloy)", "abbreviation": "Zn-5Al", "role": "corrosion-protective hot-dip coating on steel strip and wire", "category": "metals", "type": "heavy-metals", "summary": "Galfan is a hot-dip coating of about 95% zinc and 5% aluminium on steel strip and wire (SSAB). Nyrstar's datasheet gives its density as 6.7 kg/dm³ and its solidification range as 381 to 386 °C. In a neutral salt spray test on Galfan-coated steel wire, white corrosion products covered the whole surface at 510 h, against 264 h for galvanized wire, in one published study.\n", "best_for": "Steel parts that must resist corrosion longer than galvanizing and still bend or deep-draw without the coating cracking (SSAB)", "weakest_at": "No space, vacuum or radiation test found; the corrosion evidence is ground testing, mostly on one study of coated wire", "identity": { "formula": "Zn-5Al hot-dip coating: about 95% zinc and 5% aluminium (SSAB); a eutectic-composition alloy coating on steel", "designations": [ { "system": "Trade name", "code": "Galfan", "source": "nyrstar-galfan", "where": "Title line, Continuous Galvanizing Grade (Galfan)" }, { "system": "EN name", "code": "ZA", "note": "coating designation in EN 10346, as SSAB states", "source": "ssab-galfan", "where": "Introduction paragraph: the EN 10346 standard refers to ZA" }, { "system": "ASTM", "code": "GF", "note": "coating designation, as SSAB states", "source": "ssab-galfan", "where": "Introduction paragraph: ASTM uses the GF designation" } ], "source": "ssab-galfan", "where": "Introduction paragraph: a hot-dip bath of 95% zinc and 5% aluminum; the eutectic composition" }, "tags": { "environments": [], "stresses": [], "applications": [ "structures" ] }, "properties": [ { "benchmark": "density", "label": "Density, Galfan coating alloy (Nyrstar datasheet)", "value": 6.7, "bound": "exact", "unit": "kg/dm3", "scope": "material", "conditions": { "alloy": "Zn-5Al continuous galvanizing grade (Galfan)", "unit_in_source": "kg/dm³", "form": "not stated" }, "method": "Value printed in the physical data table of the Nyrstar Galfan technical datasheet (Nov 2020)", "status": "ground", "source": "nyrstar-galfan", "where": "Physical data table, row Density", "source_detail": { "title": "Continuous Galvanizing Grade (Galfan) Technical Datasheet, Nyrstar Sales & Marketing", "id": "Nyrstar technical datasheet, Nov 2020", "url": "https://www.nyrstar.com/cdn/fe715de8-be03-4787-ac85-587600a28e39/technicaldatasheet-galfan-2020.pdf", "year": 2020, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" } }, { "benchmark": "density", "label": "Density, ZA coating class (EN 10346)", "value": 6.6, "bound": "exact", "unit": "g/cm3", "scope": "material", "conditions": { "coating_class": "ZA095 to ZA300 (one value printed for all six ZA classes)", "unit_in_source": "g/cm³" }, "method": "Value printed once in the Density column of the ZA coating table; the cell is merged across all six ZA rows", "status": "ground", "note": "The two sources differ by 0.1 g/cm3 (6.6 in the standard table, 6.7 kg/dm3 in the manufacturer datasheet); both are kept.", "source": "en10346-commit", "where": "Zinc-aluminium (ZA) coating weight table, Density column", "source_detail": { "title": "UNI EN 10346:2015, zinc-coated steels, zinc-aluminium (ZA) or Galfan: excerpt (Gruppo Commit summary)", "id": "EN 10346:2015 (excerpt)", "url": "https://gruppocommit.it/wp-content/uploads/cit22_GALFAN_eng.pdf", "year": 2015, "kind": "standard", "license": "commercial summary of a European standard, linked not reproduced" } }, { "benchmark": "melting_point", "label": "Melting range, Galfan (solidification range)", "value": 381, "value_high": 386, "bound": "range", "unit": "°C", "scope": "material", "conditions": { "alloy": "Galfan Zn-5Al", "property": "melting point / solidification range, printed as 381~386" }, "method": "Range printed in the physical data table of the Nyrstar datasheet", "status": "ground", "source": "nyrstar-galfan", "where": "Physical data table, row Melting Point/solidification range", "source_detail": { "title": "Continuous Galvanizing Grade (Galfan) Technical Datasheet, Nyrstar Sales & Marketing", "id": "Nyrstar technical datasheet, Nov 2020", "url": "https://www.nyrstar.com/cdn/fe715de8-be03-4787-ac85-587600a28e39/technicaldatasheet-galfan-2020.pdf", "year": 2020, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" } }, { "benchmark": "aluminium_content", "label": "Aluminium content, guaranteed analysis", "value": 5.3, "bound": "exact", "unit": "%", "scope": "material", "conditions": { "tolerance": "±0.3 %", "basis": "guaranteed analysis as printed; weight basis not stated" }, "method": "Value in the chemical specification table ('Guaranteed analysis') of the Nyrstar datasheet", "status": "ground", "note": "The SSAB page gives the nominal split as 5% aluminium; the datasheet guarantee is 5.3% with a ±0.3% tolerance.", "source": "nyrstar-galfan", "where": "Chemical specification table, row Al", "source_detail": { "title": "Continuous Galvanizing Grade (Galfan) Technical Datasheet, Nyrstar Sales & Marketing", "id": "Nyrstar technical datasheet, Nov 2020", "url": "https://www.nyrstar.com/cdn/fe715de8-be03-4787-ac85-587600a28e39/technicaldatasheet-galfan-2020.pdf", "year": 2020, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" } }, { "benchmark": "lead_content_max", "label": "Lead content, maximum (lead-free grade)", "value": 0.005, "bound": "upper", "unit": "%", "scope": "material", "conditions": { "limit": "maximum, as printed (≤ 0.005%)", "grade": "continuous galvanizing grade (described as lead free)" }, "method": "Limit printed in the chemical specification table of the Nyrstar datasheet", "status": "ground", "source": "nyrstar-galfan", "where": "Chemical specification table, row Pb; Uses paragraph (lead free)", "source_detail": { "title": "Continuous Galvanizing Grade (Galfan) Technical Datasheet, Nyrstar Sales & Marketing", "id": "Nyrstar technical datasheet, Nov 2020", "url": "https://www.nyrstar.com/cdn/fe715de8-be03-4787-ac85-587600a28e39/technicaldatasheet-galfan-2020.pdf", "year": 2020, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" } }, { "benchmark": "coating_weight_minimum", "label": "Minimum coating weight, ZA095 (triple spot test)", "value": 95, "bound": "lower", "unit": "g/m2", "scope": "material", "conditions": { "coating_class": "ZA095", "test": "triple spot test", "basis": "both surfaces (table footnote a)", "single_spot_test": "80 g/m2 minimum as printed" }, "method": "Minimum weight printed in the Zinc-aluminium (ZA) coating weight table of the EN 10346:2015 excerpt", "status": "ground", "note": "SSAB prints the same 95 g/m2 minimum (triple spot test) for ZA095.", "source": "en10346-commit", "where": "Zinc-aluminium (ZA) coating weight table, column Minimum weight, triple spot test, row ZA095", "source_detail": { "title": "UNI EN 10346:2015, zinc-coated steels, zinc-aluminium (ZA) or Galfan: excerpt (Gruppo Commit summary)", "id": "EN 10346:2015 (excerpt)", "url": "https://gruppocommit.it/wp-content/uploads/cit22_GALFAN_eng.pdf", "year": 2015, "kind": "standard", "license": "commercial summary of a European standard, linked not reproduced" } }, { "benchmark": "coating_weight_minimum", "label": "Minimum coating weight, ZA300 (triple spot test)", "value": 300, "bound": "lower", "unit": "g/m2", "scope": "material", "conditions": { "coating_class": "ZA300", "test": "triple spot test", "basis": "both surfaces (table footnote a)" }, "method": "Minimum weight printed in the Zinc-aluminium (ZA) coating weight table of the EN 10346:2015 excerpt", "status": "ground", "source": "en10346-commit", "where": "Zinc-aluminium (ZA) coating weight table, column Minimum weight, triple spot test, row ZA300", "source_detail": { "title": "UNI EN 10346:2015, zinc-coated steels, zinc-aluminium (ZA) or Galfan: excerpt (Gruppo Commit summary)", "id": "EN 10346:2015 (excerpt)", "url": "https://gruppocommit.it/wp-content/uploads/cit22_GALFAN_eng.pdf", "year": 2015, "kind": "standard", "license": "commercial summary of a European standard, linked not reproduced" } }, { "benchmark": "coating_thickness_typical", "label": "Typical coating thickness per side, ZA095 (single spot test)", "value": 7, "bound": "exact", "unit": "µm", "scope": "material", "conditions": { "coating_class": "ZA095", "test": "single spot test", "range_printed": "5 to 12 µm" }, "method": "Typical value printed in the Zinc-aluminium (ZA) coating weight table of the EN 10346:2015 excerpt", "status": "ground", "source": "en10346-commit", "where": "Zinc-aluminium (ZA) coating weight table, column Typical value, row ZA095", "source_detail": { "title": "UNI EN 10346:2015, zinc-coated steels, zinc-aluminium (ZA) or Galfan: excerpt (Gruppo Commit summary)", "id": "EN 10346:2015 (excerpt)", "url": "https://gruppocommit.it/wp-content/uploads/cit22_GALFAN_eng.pdf", "year": 2015, "kind": "standard", "license": "commercial summary of a European standard, linked not reproduced" } }, { "benchmark": "corrosion_resistance_vs_gi", "label": "Corrosion resistance relative to hot-dip galvanized (GI) steel, manufacturer statement", "value": 2, "bound": "exact", "unit": "x GI", "scope": "material", "conditions": { "comparison": "hot-dip galvanized (GI) steel", "basis": "manufacturer statement; no test method, exposure or duration printed" }, "method": "Statement printed on the SSAB Galfan product page ('2x the corrosion resistance of GI steel')", "status": "ground", "note": "A manufacturer claim. No test that supports it could be opened from this page.", "source": "ssab-galfan", "where": "Page headline: 2x the corrosion resistance of GI steel", "source_detail": { "title": "Galfan zinc-aluminum steel coating (ZA, GF), SSAB product page", "id": "SSAB, Galfan coated steels", "url": "https://www.ssab.com/en/brands-and-products/steel-categories/metal-coated/galfan-coating", "year": 2026, "kind": "web", "license": "manufacturer web page, linked not reproduced" } }, { "benchmark": "white_corrosion_cover_time", "label": "Time to complete white corrosion product cover, Galfan-coated steel wire", "value": 510, "bound": "exact", "unit": "h", "scope": "material", "conditions": { "test": "neutral salt spray, test room temperature 35 ± 1 °C, NaCl 50 g/L", "specimen": "high-strength steel wire, diameter 5.25 mm, Galfan coating 337 g/m2", "product": "Galfan coated wire" }, "method": "Time at which the wire surface was completely covered by white corrosion products, from the Corrosion Phenomenon section; visual", "status": "ground", "source": "wire2023", "where": "Section 3 (Corrosion Phenomenon), first paragraph; Tables 2 and 5", "source_detail": { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire", "id": "doi:10.3390/ma16020708 (Materials 16(2), 708; PMC9861807)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023, "kind": "paper", "license": "CC BY 4.0 (as listed by PMC)" } }, { "benchmark": "white_corrosion_cover_time", "label": "Time to complete white corrosion product cover, galvanized steel wire (comparison)", "value": 264, "bound": "exact", "unit": "h", "scope": "material", "conditions": { "test": "neutral salt spray, test room temperature 35 ± 1 °C, NaCl 50 g/L", "specimen": "galvanized (pure zinc coating) high-strength steel wire, diameter 5.34 mm" }, "method": "Time at which the galvanized wire was completely covered by white corrosion products, from the Corrosion Phenomenon section; visual", "status": "ground", "note": "Comparison row for galvanized (pure zinc) wire, not Galfan.", "source": "wire2023", "where": "Section 3 (Corrosion Phenomenon), first paragraph; Table 2", "source_detail": { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire", "id": "doi:10.3390/ma16020708 (Materials 16(2), 708; PMC9861807)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023, "kind": "paper", "license": "CC BY 4.0 (as listed by PMC)" } }, { "benchmark": "red_rust_sheet_time", "label": "Time to reddish-brown rust sheets, Galfan-coated steel wire", "value": 1389, "bound": "exact", "unit": "h", "scope": "material", "conditions": { "test": "neutral salt spray, test room temperature 35 ± 1 °C, NaCl 50 g/L", "specimen": "high-strength steel wire, diameter 5.25 mm, Galfan coating 337 g/m2" }, "method": "Time at which reddish-brown corrosion products had connected into sheets, after which uneven pits showed once products were removed; visual", "status": "ground", "source": "wire2023", "where": "Section 3 (Corrosion Phenomenon), paragraph beginning At 510 h", "source_detail": { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire", "id": "doi:10.3390/ma16020708 (Materials 16(2), 708; PMC9861807)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023, "kind": "paper", "license": "CC BY 4.0 (as listed by PMC)" } }, { "benchmark": "red_rust_sheet_time", "label": "Time to reddish-brown rust sheets, galvanized steel wire (comparison)", "value": 510, "bound": "exact", "unit": "h", "scope": "material", "conditions": { "test": "neutral salt spray, test room temperature 35 ± 1 °C, NaCl 50 g/L", "specimen": "galvanized (pure zinc coating) high-strength steel wire, diameter 5.34 mm" }, "method": "Time at which reddish-brown corrosion products had connected into sheets on the galvanized wire; visual", "status": "ground", "note": "Comparison row for galvanized (pure zinc) wire, not Galfan.", "source": "wire2023", "where": "Section 3 (Corrosion Phenomenon), paragraph beginning At 510 h", "source_detail": { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire", "id": "doi:10.3390/ma16020708 (Materials 16(2), 708; PMC9861807)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023, "kind": "paper", "license": "CC BY 4.0 (as listed by PMC)" } }, { "benchmark": "service_life", "label": "Modelled average service life, Galfan suspender wire, comprehensive traffic flow", "value": 28.47, "bound": "exact", "unit": "years", "scope": "material", "conditions": { "basis": "model of a long-span suspension bridge suspender, comprehensive traffic flow; a model output, not a bridge measurement", "coating": "Galfan steel wire" }, "method": "Average life printed by the authors from their corrosion-fatigue model (life distribution, Figure 26)", "status": "calculated", "source": "wire2023", "where": "Corrosion Fatigue of High-Strength Steel Wire section, text on Figure 26", "source_detail": { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire", "id": "doi:10.3390/ma16020708 (Materials 16(2), 708; PMC9861807)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023, "kind": "paper", "license": "CC BY 4.0 (as listed by PMC)" } }, { "benchmark": "service_life", "label": "Modelled average service life, galvanized suspender wire, comprehensive traffic flow (comparison)", "value": 17.24, "bound": "exact", "unit": "years", "scope": "material", "conditions": { "basis": "model of a long-span suspension bridge suspender, comprehensive traffic flow; a model output, not a bridge measurement", "coating": "galvanized steel wire" }, "method": "Average life printed by the authors from their corrosion-fatigue model (life distribution, Figure 26)", "status": "calculated", "note": "Comparison row for galvanized (pure zinc) wire, not Galfan.", "source": "wire2023", "where": "Corrosion Fatigue of High-Strength Steel Wire section, text on Figure 26", "source_detail": { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire", "id": "doi:10.3390/ma16020708 (Materials 16(2), 708; PMC9861807)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023, "kind": "paper", "license": "CC BY 4.0 (as listed by PMC)" } } ], "corrosion": [ { "environment": "Neutral salt spray on Galfan-coated high-strength steel wire (diameter 5.25 mm, coating 337 g/m2)", "headline": "In the same salt spray test, Galfan wire was covered by white corrosion products at 510 h, against 264 h for galvanized wire.", "effect": "The coating is consumed first. Reddish-brown rust sheets appeared on the Galfan wire at 1389 h, and the authors then saw uneven pits once the corrosion products were removed. The authors describe the Galfan coating as corroding more slowly than the pure zinc coating in this test.", "rating": "moderate", "conditions": { "test": "neutral salt spray, test room temperature 35 ± 1 °C, NaCl 50 g/L (Tables 2 and 5 of the study)", "rating_basis": "severity of coating loss and rust in this lab test, not a service life" }, "source": "wire2023", "where": "Section 3 (Corrosion Phenomenon); Table 5" }, { "environment": "Cut edges, scratches and impact damage on Galfan-coated steel", "headline": "The Galfan coating is sacrificial, so it still protects damaged spots to some degree. No test duration is given.", "effect": "SSAB says the coating being sacrificial means it can still provide a level of corrosion resistance to cut edges or to surfaces where the ZA coating has been damaged by scratches or impacts. The page gives no test data for this.", "rating": "unknown", "conditions": { "basis": "manufacturer description; no exposure, duration or test method printed" }, "source": "ssab-galfan", "where": "Section 'ZA coating's tight steel bond'" }, { "environment": "Comparison with hot-dip galvanized steel, general", "headline": "Both the EN 10346 summary and SSAB say Galfan resists corrosion better than galvanized steel. Neither prints test conditions.", "effect": "The UNI EN 10346:2015 summary gives greater corrosion resistance than hot-dip galvanized steels as the main characteristic of the product, because of the combined action of zinc and aluminium. SSAB states about twice the corrosion resistance of hot-dip galvanized steel.", "rating": "unknown", "conditions": { "basis": "general statements in a standard summary and a manufacturer page; no test method printed" }, "source": "en10346-commit", "where": "Zinc-coated steels paragraph (EN 10346:2015 excerpt); SSAB page headline" } ], "risks": { "hazards": [ { "text": "The Steel Dynamics safety data sheet for Zinc-5% Aluminum Alloy-Coated Sheet Steel classifies that product as a mixture hazardous under OSHA's Hazard Communication Standard, with the signal word DANGER.", "ghs": [], "source": "sd-sds", "where": "Section 2(a) and 2(b), classification table" }, { "text": "The same data sheet says 'Suspected of causing cancer.' and lists welding fumes as IARC Group 2B; it advises 'Do not breathe dusts / fume / gas / mist.'", "ghs": [], "source": "sd-sds", "where": "Section 2(b) statements; Section 11(g), Carcinogenicity" } ], "failure_risks": [ { "mode": "Coating consumed, then steel corrodes (wire in salt spray)", "trigger": "Long neutral salt spray exposure of Galfan-coated wire", "consequence": "Reddish-brown rust sheets appeared at 1389 h on the Galfan wire; the steel under the coating corroded once the zinc-aluminium layer was consumed.", "severity": "moderate", "source": "wire2023", "where": "Section 3 (Corrosion Phenomenon)" }, { "mode": "Exposed steel at cut edges and damaged spots", "trigger": "Cutting, scratching or impact that removes the ZA coating", "consequence": "The coating protects exposed steel only sacrificially, while enough zinc-aluminium remains; SSAB prints no duration for this protection.", "severity": "moderate", "source": "ssab-galfan", "where": "Section 'ZA coating's tight steel bond'" } ], "side_effects": [ { "text": "All zinc-based coatings produce zinc oxide welding fumes, so the work area needs proper ventilation (SSAB).", "affects": "Welders and the work area", "source": "ssab-galfan", "where": "Section 'Welding Galfan coated steels'" }, { "text": "Because the coating is thinner than zinc, the welding current and electrode force can be lowered, which extends electrode life (SSAB).", "affects": "Welding equipment and electrodes", "source": "ssab-galfan", "where": "Section 'Welding Galfan coated steels'" } ], "handling": [ { "text": "The EN 10346:2015 summary says that during transportation and storage, galvanized materials should avoid contact with moisture or water as much as possible and be kept in a dry environment.", "source": "en10346-commit", "where": "Technical supply conditions paragraph" }, { "text": "Oils and impurities must be fully removed before painting, and zinc-phosphating or another pretreatment helps paint adhesion (SSAB).", "source": "ssab-galfan", "where": "Section 'Painting of ZA-coated steels'" } ], "mitigations": [ { "text": "Painting further improves the corrosion resistance of the steel part (SSAB).", "source": "ssab-galfan", "where": "Section 'Painting of ZA-coated steels'" } ] }, "uses": [ { "application": "structures", "device": "Cable wire for cable-stayed and suspension bridges (high-strength steel wire)", "example": "Galfan steel wire has recently started to be widely used because of its better corrosion resistance than galvanized steel wire.", "source": "wire2023", "where": "Abstract" }, { "application": "structures", "device": "Roofing, door and window frames and metal wall structures (ZA-coated sheet steel)", "example": "The EN 10346:2015 summary lists construction uses: door and window frames, roofing, metal wall structures, false ceilings and ceilings, shutters, and profiles in general.", "source": "en10346-commit", "where": "Areas of use panel" } ], "supply": [ { "subject": "Zinc", "producers": [ { "country": "China", "share_percent": 31.5, "year": 2025 }, { "country": "Peru", "share_percent": 11.5, "year": 2025 }, { "country": "Australia", "share_percent": 8.5, "year": 2025 }, { "country": "Mexico", "share_percent": 6, "year": 2025 } ], "critical_lists": [ { "list": "EU critical raw materials list (list of 34 on the European Commission page; zinc not on it)", "listed": false } ], "recycling": "USGS: refined zinc produced in the United States was recovered from secondary materials, including galvanizing residues and crude zinc oxide recovered from electric arc furnace dust.", "substitutes": [ "USGS: aluminum and plastics substitute for galvanized sheet in automobiles; aluminum alloys replace zinc coatings in other applications." ], "source": "usgs-mcs2026-zinc", "where": "World Mine Production and Reserves table, 2025e world total 13,000 thousand t (rounded; shares calculated by Space Mushroom from the printed figures); Recycling; Substitutes" }, { "subject": "Aluminium", "producers": [ { "country": "China", "share_percent": 60.8, "year": 2025 }, { "country": "India", "share_percent": 5.7, "year": 2025 }, { "country": "Russia", "share_percent": 5.3, "year": 2025 }, { "country": "Canada", "share_percent": 4.5, "year": 2025 } ], "critical_lists": [ { "list": "EU critical raw materials list (list of 34 on the European Commission page, printed as Bauxite; the page says aluminium and bauxite are merged)", "listed": true } ], "recycling": "USGS (United States): aluminum recovered from old scrap was equivalent to about 28% of apparent consumption in 2025.", "substitutes": [ "USGS: composites, steel, vinyl and wood can substitute for aluminum in construction." ], "source": "usgs-mcs2026-aluminum", "where": "World Smelter Production and Capacity table, 2025e world total 74,000 thousand t (rounded; shares calculated by Space Mushroom from the printed figures); Recycling; Substitutes" } ], "media": [], "documents": [ { "title": "Nyrstar: Continuous Galvanizing Grade (Galfan) technical datasheet", "type": "datasheet", "url": "https://www.nyrstar.com/cdn/fe715de8-be03-4787-ac85-587600a28e39/technicaldatasheet-galfan-2020.pdf", "year": 2020 }, { "title": "SSAB: Galfan zinc-aluminum steel coating (ZA, GF) product page", "type": "datasheet", "url": "https://www.ssab.com/en/brands-and-products/steel-categories/metal-coated/galfan-coating", "year": 2026 }, { "title": "UNI EN 10346:2015 excerpt, zinc-aluminium (ZA) coating table (Gruppo Commit summary)", "type": "standard", "url": "https://gruppocommit.it/wp-content/uploads/cit22_GALFAN_eng.pdf", "year": 2015 }, { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire (Materials 16, 708, open access)", "type": "paper", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023 }, { "title": "Steel Dynamics SDS: Zinc-5% Aluminum Alloy-Coated Sheet Steel (revision 08/31/2018)", "type": "sds", "url": "https://butler.steeldynamics.com/wp-content/uploads/2021/10/Zinc-5-Aluminum-Alloy-Coated-Sheet-Steel-Product-Documents.pdf", "year": 2018 }, { "title": "USGS Mineral Commodity Summaries 2026: Zinc", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf", "year": 2026 }, { "title": "USGS Mineral Commodity Summaries 2026: Aluminum", "type": "report", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf", "year": 2026 }, { "title": "European Commission: Critical raw materials (list of 34 critical raw materials)", "type": "report", "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en", "year": 2023 } ], "gaps": [ "No space, vacuum, radiation, thermal-vacuum or flight result for Galfan was found, and no space use is recorded (the uses are bridge cable wire and building sheet).", "Only one lab study (Materials 2023, 5.25 mm wire, neutral salt spray) gives Galfan-specific corrosion times; the two modelled service lives are the authors' model, not field data.", "Rebar hot-dip Zn-5Al study (MDPI Coatings 2024) was seen only in a search summary and not opened; no value from it is recorded.", "Hardness, thermal conductivity, thermal expansion and electrical conductivity of the Galfan coating itself were not found; the tensile and yield values printed for the coated wire belong to the steel substrate and are not recorded.", "The Nyrstar datasheet prints La+Ce 0.010~0.020 with no unit; the value is not recorded and the mixed rare earth share is not quantified.", "The Materials 2023 Table 3 coating composition prints Zn ≤95 and Al ≤5 with odd entries (Si, Mn), so it is not used; only the text's 5% aluminium is quoted.", "No SDS for a 95/5 zinc-aluminium bath alloy ingot was opened. The Steel Dynamics SDS covers 5% aluminium-zinc coated sheet steel (the steel product), so its hazards are not assigned to the bath alloy alone.", "Aquatic toxicity, GHS H-codes and an exposure limit for the Galfan coating were not found in any source opened.", "The USGS 2025 List of Critical Minerals page returned an access error; zinc and aluminium status on that US list is not recorded.", "Crustal abundance of zinc and aluminium was not read in an open source for this profile.", "The 2 times corrosion claim is a manufacturer statement with no test conditions; it is recorded with a note." ], "story": { "why": "Galfan is a zinc-aluminium coating for steel, made by running the steel through a hot-dip bath of about 95% zinc and 5% aluminium. It is used where a steel part must last longer than with plain galvanizing, and where the coating must still survive bending and deep drawing. SSAB calls its eutectic composition the reason the coating adheres well and forms a lamellar microstructure. The cable-wire study and the manufacturer both describe corrosion resistance above that of galvanized steel.", "uses": [ { "where": "Bridge cables", "line": "In a 2023 study, Galfan steel wire is described as widely used in cable bridges because it resists corrosion better than galvanized wire. The authors' model gives an average life of 28.47 years for a Galfan suspender wire against 17.24 years for galvanized wire under the comprehensive traffic-flow case. That is a model output, not a bridge measurement." }, { "where": "Building sheet", "line": "The EN 10346:2015 summary lists roofing, door and window frames, metal wall structures, false ceilings, shutters and profiles as areas of use for zinc-aluminium coated steel." } ], "can_do": [ { "label": "Corrosion in salt spray", "line": "In a neutral salt spray test, Galfan-coated steel wire was completely covered by white corrosion products at 510 h, against 264 h for galvanized wire. Reddish-brown rust sheets appeared at 1389 h on the Galfan wire, against 510 h on the galvanized wire.", "benchmark": "white_corrosion_cover_time", "scope": "material" }, { "label": "Damaged spots", "line": "Because the coating is sacrificial, it still protects cut edges and scratches to some degree, according to SSAB. The page gives no test duration for that protection.", "scope": "material" }, { "label": "Coating weight", "line": "EN 10346:2015 sets a minimum coating weight from 95 g/m2 for the thinnest class to 300 g/m2 for the thickest class, in the triple spot test.", "scope": "material" }, { "label": "Density", "line": "The density is 6.7 kg/dm3 in the Nyrstar datasheet, and 6.6 g/cm3 for the ZA coating class in the EN 10346 table.", "benchmark": "density", "scope": "material" }, { "label": "Melting range", "line": "The solidification range is 381 to 386 °C, per the Nyrstar datasheet, so the bath runs well above room temperature.", "benchmark": "melting_point", "scope": "material" } ], "compare": "The comparison in these sources is with galvanized (pure zinc) steel. In the same neutral salt spray test, Galfan-coated wire was completely covered by white corrosion products at 510 h, against 264 h for galvanized wire, and showed reddish-brown rust sheets at 1389 h against 510 h. The modelled average bridge-cable life is 28.47 years for Galfan against 17.24 years for galvanized wire. SSAB claims about twice the corrosion resistance of galvanized steel, with no test conditions printed.", "compare_rows": [ { "label": "Density", "benchmark": "density", "scope": "material" }, { "label": "Melting range", "benchmark": "melting_point", "scope": "material" }, { "label": "Time to white corrosion cover in salt spray", "benchmark": "white_corrosion_cover_time", "scope": "material" } ], "handling": [ "Keep coated steel dry in storage and transport; the EN 10346 summary asks to avoid moisture and water.", "Ventilate welding work areas, because zinc oxide fumes form when welding zinc-based coatings (SSAB).", "Remove oil and impurities before painting, and pre-treat with zinc phosphating if the paint shop asks (SSAB)." ], "good_for": [ "Corrosion life beyond plain galvanizing: SSAB's 2x claim, and 510 h against 264 h to full white cover in salt spray.", "Forming and bending: SSAB says the lamellar microstructure suits deep drawing, roll forming, profiling and bending." ], "watch_out": [ "The coating is sacrificial. Once the zinc-aluminium layer is consumed, the steel corrodes, as the wire test showed at 1389 h.", "The two density values differ: 6.7 kg/dm3 in the datasheet and 6.6 g/cm3 in the EN 10346 table.", "No space, vacuum or radiation data were found. All corrosion evidence here is ground testing." ], "verdict": "Galfan is a well-documented corrosion coating for steel on Earth, with lab results better than galvanizing. Nothing yet shows it for space.", "recipe": { "line": "Galfan is a zinc-aluminium alloy coating of about 95% zinc and 5% aluminium (SSAB). Steel coil runs continuously through a hot-dip bath of that alloy, so the coating forms on the steel as it is pulled through (SSAB). The Nyrstar datasheet guarantees 5.3% aluminium with a tolerance of ±0.3%, which is slightly above the nominal 5% that SSAB gives.", "parts": [ { "name": "Zinc", "symbol": "Zn", "role": "The main metal. Zinc is the layer that corrodes first and so protects the steel underneath.", "share_note": "balance, about 95% per SSAB", "source": "ssab-galfan", "where": "Introduction paragraph" }, { "name": "Aluminium", "symbol": "Al", "role": "Raises corrosion resistance and gives a eutectic composition that improves coating adhesion and forming (SSAB).", "share_percent": 5.3, "share_note": "guaranteed analysis, tolerance ±0.3 %", "source": "nyrstar-galfan", "where": "Chemical specification table, row Al" }, { "name": "Mixed rare earth elements", "symbol": "La+Ce", "role": "A small addition in the coated wire of the 2023 study; the amount is not given there.", "share_note": "small amount, not quantified", "source": "wire2023", "where": "Specimens of High-Strength Steel Wire subsection, text on the coating" } ] }, "risk_groups": [ { "title": "For people", "lead": "The coated-steel safety data sheet classifies the product as hazardous. No data sheet for the bath alloy alone was opened, and the coated-steel sheet classification covers the steel as well.", "points": [ { "label": "The data sheet", "line": "The Steel Dynamics data sheet for Zinc-5% Aluminum Alloy-Coated Sheet Steel uses the signal word DANGER and the statement 'Suspected of causing cancer.' It names welding fumes and nickel as the carcinogen notes." }, { "label": "Fume", "line": "All zinc-based coatings produce zinc oxide welding fumes that need ventilation (SSAB). The data sheet advises 'Do not breathe dusts / fume / gas / mist.'" } ], "level": 2, "verdict": "Hazardous as coated steel; welding fumes" }, { "title": "In a fire", "lead": "The coated steel product gives off fumes when it burns.", "points": [ { "label": "Burning", "line": "The data sheet says thermal oxidative decomposition of the steel product can produce fumes containing oxides of iron and manganese." } ], "level": 1, "verdict": "Fumes of iron and manganese oxides" }, { "title": "Handling and storage", "lead": "Ordinary precautions for metal coated steel apply, taken from the sources.", "points": [ { "label": "Storage", "line": "The EN 10346 summary asks that coated steel avoid moisture and water in transport and storage and be kept in a dry environment." }, { "label": "Painting", "line": "Oils and impurities must be removed before painting, and zinc-phosphating helps paint adhesion (SSAB)." } ], "level": 1, "verdict": "Keep dry; ventilate welding" } ] }, "updated": "2026-11-01", "review": { "status": "draft", "method": "assistant", "checked_values": 15, "unreachable": 0, "caveats": 2, "note": "Written by an AI assistant on 2026-11-01 from the sources listed, read in this run. The two density values (6.6 and 6.7) differ and both are kept. The 2x corrosion claim has no test conditions." }, "sources": { "nyrstar-galfan": { "title": "Continuous Galvanizing Grade (Galfan) Technical Datasheet, Nyrstar Sales & Marketing", "id": "Nyrstar technical datasheet, Nov 2020", "url": "https://www.nyrstar.com/cdn/fe715de8-be03-4787-ac85-587600a28e39/technicaldatasheet-galfan-2020.pdf", "year": 2020, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" }, "ssab-galfan": { "title": "Galfan zinc-aluminum steel coating (ZA, GF), SSAB product page", "id": "SSAB, Galfan coated steels", "url": "https://www.ssab.com/en/brands-and-products/steel-categories/metal-coated/galfan-coating", "year": 2026, "kind": "web", "license": "manufacturer web page, linked not reproduced" }, "en10346-commit": { "title": "UNI EN 10346:2015, zinc-coated steels, zinc-aluminium (ZA) or Galfan: excerpt (Gruppo Commit summary)", "id": "EN 10346:2015 (excerpt)", "url": "https://gruppocommit.it/wp-content/uploads/cit22_GALFAN_eng.pdf", "year": 2015, "kind": "standard", "license": "commercial summary of a European standard, linked not reproduced" }, "wire2023": { "title": "Corrosion Fatigue Degradation Characteristics of Galvanized and Galfan High-Strength Steel Wire", "id": "doi:10.3390/ma16020708 (Materials 16(2), 708; PMC9861807)", "url": "https://pmc.ncbi.nlm.nih.gov/articles/PMC9861807/", "year": 2023, "kind": "paper", "license": "CC BY 4.0 (as listed by PMC)" }, "usgs-mcs2026-zinc": { "title": "Mineral Commodity Summaries 2026, Zinc", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zinc.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "usgs-mcs2026-aluminum": { "title": "Mineral Commodity Summaries 2026, Aluminum", "id": "USGS MCS 2026, February 2026", "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-aluminum.pdf", "year": 2026, "kind": "report", "license": "public domain (USGS)" }, "ec-crm": { "title": "Critical raw materials, European Commission (list of 34 critical raw materials, 2023 list)", "id": "EU Critical Raw Materials Act list", "url": "https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en", "year": 2023, "kind": "web", "license": "European Commission web page" }, "sd-sds": { "title": "Safety Data Sheet: Zinc-5% Aluminum Alloy-Coated Sheet Steel, Steel Dynamics Flat Roll Group (revision 08/31/2018)", "id": "Steel Dynamics SDS, product TECHS-002", "url": "https://butler.steeldynamics.com/wp-content/uploads/2021/10/Zinc-5-Aluminum-Alloy-Coated-Sheet-Steel-Product-Documents.pdf", "year": 2018, "kind": "datasheet", "license": "manufacturer document, linked not reproduced" } }, "license": "CC-BY-4.0", "url": "https://spacemushroom.com/profiles/galfan-zinc-5-aluminium/" }