Galfan (zinc-5% aluminium hot-dip coating alloy) Zn-5Al

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.
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'
  source: ssab-galfan
  where: 'Introduction paragraph: a hot-dip bath of 95% zinc and 5% aluminum; the eutectic composition'
  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'
tags:
  environments: []
  stresses: []
  applications:
    - structures
properties:
  - benchmark: density
    label: Density, Galfan coating alloy (Nyrstar datasheet)
    value: 6.7
    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
  - benchmark: density
    label: Density, ZA coating class (EN 10346)
    value: 6.6
    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
  - 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
  - benchmark: aluminium_content
    label: Aluminium content, guaranteed analysis
    value: 5.3
    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
  - 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)
  - 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
  - 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
  - benchmark: coating_thickness_typical
    label: Typical coating thickness per side, ZA095 (single spot test)
    value: 7
    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
  - benchmark: corrosion_resistance_vs_gi
    label: Corrosion resistance relative to hot-dip galvanized (GI) steel, manufacturer statement
    value: 2
    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'
  - benchmark: white_corrosion_cover_time
    label: Time to complete white corrosion product cover, Galfan-coated steel wire
    value: 510
    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
  - benchmark: white_corrosion_cover_time
    label: Time to complete white corrosion product cover, galvanized steel wire (comparison)
    value: 264
    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
  - benchmark: red_rust_sheet_time
    label: Time to reddish-brown rust sheets, Galfan-coated steel wire
    value: 1389
    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
  - benchmark: red_rust_sheet_time
    label: Time to reddish-brown rust sheets, galvanized steel wire (comparison)
    value: 510
    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
  - benchmark: service_life
    label: Modelled average service life, Galfan suspender wire, comprehensive traffic flow
    value: 28.47
    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
  - benchmark: service_life
    label: Modelled average service life, galvanized suspender wire, comprehensive traffic flow (comparison)
    value: 17.24
    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
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.
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
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.
story:
  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
      level: 2
      verdict: Hazardous as coated steel; welding fumes
      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.'
    - title: In a fire
      level: 1
      verdict: Fumes of iron and manganese oxides
      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.
    - title: Handling and storage
      level: 1
      verdict: Keep dry; ventilate welding
      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).
  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
      benchmark: white_corrosion_cover_time
      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.
    - 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.
    - 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.
    - label: Density
      benchmark: 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.
    - label: Melting range
      benchmark: melting_point
      line: The solidification range is 381 to 386 °C, per the Nyrstar datasheet, so the bath runs well above room temperature.
  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
    - label: Melting range
      benchmark: melting_point
    - label: Time to white corrosion cover in salt spray
      benchmark: white_corrosion_cover_time
  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.