{ "@context": "https://schema.org", "@type": "Dataset", "@id": "https://www.z-beam.com/datasets/contaminants/mill-scale-magnetite-laser-cleaning#dataset", "identifier": "mill-scale-magnetite-laser-cleaning", "name": "mill-scale-magnetite", "description": "mill-scale-magnetite", "url": "https://www.z-beam.com/datasets/contaminants/mill-scale-magnetite-laser-cleaning", "includedInDataCatalog": { "@type": "DataCatalog", "name": "Z-Beam Laser Cleaning Entity Registry", "url": "https://www.z-beam.com/datasets" }, "variableMeasured": [ { "@type": "PropertyValue", "name": "millScaleChemistry", "value": "FeO constitutes 85% of the scale at hot rolling temperatures; after cooling, Fe₃O₄ predominates", "propertyID": "contaminant:mill-scale-magnetite/facts.millScaleChemistry", "citation": [ { "@id": "#making-shaping-treating-steel-1985" }, { "@id": "#nippon-steel-oxide-phase-transformation-2016" }, { "@id": "#ispatguru-mill-scale-2017" } ] }, { "@type": "PropertyValue", "name": "millScaleVsRust", "value": "Mill scale (Fe₃O₄, 50-150 μm, dense, crystalline, 570 HV) vs red rust (Fe₂O₃·nH₂O, 10-200 μm, porous, loosely adherent) — mill scale requires 4+ laser passes", "propertyID": "contaminant:mill-scale-magnetite/facts.millScaleVsRust", "citation": [ { "@id": "#making-shaping-treating-steel-1985" }, { "@id": "#guan-mill-scale-vs-rust-2015" }, { "@id": "#yihai-mill-scale-removal-2026" } ] }, { "@type": "PropertyValue", "name": "ablationThresholdMillScale", "value": "200W laser requires 4 passes for mill scale vs 1 pass for rust — the scale's ablation threshold is very high", "propertyID": "contaminant:mill-scale-magnetite/facts.ablationThresholdMillScale", "citation": [ { "@id": "#yihai-mill-scale-removal-2026" }, { "@id": "#fabricator-laser-cleaning-intro-2024" } ] }, { "@type": "PropertyValue", "name": "millScaleThicknessRange", "value": "50–150 μm on hot-rolled steel; <5 μm residual on pickled/cold-rolled; less than 1 mm maximum", "propertyID": "contaminant:mill-scale-magnetite/facts.millScaleThicknessRange", "unitText": "μm", "citation": [ { "@id": "#montipower-mill-scale-steel-2025" } ] }, { "@type": "PropertyValue", "name": "removalMechanismMillScale", "value": "Thermal expansion mismatch between Fe₃O₄ and steel creates compressive stress that fractures the scale at the oxide-metal interface", "propertyID": "contaminant:mill-scale-magnetite/facts.removalMechanismMillScale", "citation": [ { "@id": "#osti-magnetite-thermal-expansion-review" }, { "@id": "#hal-oxide-thermomechanical-behavior" }, { "@id": "#yihai-mill-scale-removal-2026" } ] }, { "@type": "PropertyValue", "name": "patternedRemoval", "value": "Laser cleaning can selectively remove mill scale only from weld zones while leaving protective scale elsewhere — impossible with blasting", "propertyID": "contaminant:mill-scale-magnetite/facts.patternedRemoval", "citation": [ { "@id": "#fabricator-laser-cleaning-intro-2024" } ] }, { "@type": "PropertyValue", "name": "surfaceProfileAfterMillScale", "value": "Laser-cleaned mill scale surfaces have Ra ~4.8 μm — smoother and more uniform profile than abrasive-blasted equivalents", "propertyID": "contaminant:mill-scale-magnetite/facts.surfaceProfileAfterMillScale", "citation": [ { "@id": "#vtrc-lacr-adhesion-2026" }, { "@id": "#tribology-laser-cleaning-adhesion-2025" }, { "@id": "#sspc-sp10-near-white-blast" } ] }, { "@type": "PropertyValue", "name": "coatingAdhesionPullOff", "value": "Laser-cleaned surfaces achieved 318 psi pull-off adhesion — equivalent or superior to grit-blasted at 274 psi", "propertyID": "contaminant:mill-scale-magnetite/facts.coatingAdhesionPullOff", "citation": [ { "@id": "#vtrc-lacr-adhesion-2026" }, { "@id": "#tribology-laser-cleaning-adhesion-2025" } ] }, { "@type": "PropertyValue", "name": "narrowestMarginMillScale", "value": "Thick mill scale on thin-gauge cold-rolled sheet: high fluence needed but low thermal mass causes warping", "propertyID": "contaminant:mill-scale-magnetite/facts.narrowestMarginMillScale" }, { "@type": "PropertyValue", "name": "absorptionProfile", "value": "Mill scale (Fe₃O₄ magnetite, black, 50-150 μm) strongly absorbs 1064 nm — the black oxide layer couples IR energy efficiently. Absorption contrast between the dark mill scale and the bright steel substrate is what drives the selective removal mechanism. However, mill scale is far thicker and denser than atmospheric rust (Fe₂O₃) — the fluence required per unit area is higher because more material must be thermo-mechanically fractured and ejected.", "propertyID": "contaminant:mill-scale-magnetite/facts.absorptionProfile", "citation": [ { "@id": "#making-shaping-treating-steel-1985" }, { "@id": "#yihai-mill-scale-removal-2026" } ] }, { "@type": "PropertyValue", "name": "formationChemistry", "value": "Mill scale: multi-layer iron oxide formed at >570°C during hot rolling of steel. Inner layer = wüstite (FeO, ~85% of thickness, thermodynamically unstable below 570°C), middle layer = magnetite (Fe₃O₄, ~10-15%), outer layer = hematite (Fe₂O₃, ~0.5-2%). FeO disproportionates to Fe₃O₄ + Fe on slow cooling. Mill scale is a thermally-formed manufacturing residue — chemically continuous with the substrate and mechanically interlocked as it thickens. NOT to be confused with atmospheric rust (Fe₂O₃·nH₂O, formed at ambient temperatures).", "propertyID": "contaminant:mill-scale-magnetite/facts.formationChemistry", "citation": [ { "@id": "#making-shaping-treating-steel-1985" }, { "@id": "#nippon-steel-oxide-phase-transformation-2016" } ] }, { "@type": "PropertyValue", "name": "detectionMethods", "value": "ISO 8501-1 rust grades (originally designed for rust, also used for mill scale assessment): Grade A — adherent mill scale intact; Grade B — mill scale beginning to flake; Visual inspection distinguishes mill scale (bluish-black, smooth, adherent) from rust (red-brown, flaky, porous). Magnetic thickness gauge cannot differentiate mill scale from steel — both magnetic. Cross-section microscopy is the definitive method for residual mill scale verification.", "propertyID": "contaminant:mill-scale-magnetite/facts.detectionMethods", "citation": [ { "@id": "#ispatguru-mill-scale-2017" } ] }, { "@type": "PropertyValue", "name": "byproducts", "value": "{\"airborne\":\"Fe₃O₄ (magnetite) / FeO (wüstite) particulate — inert mineral dust, no VOC or combustion gas. HIGH volume compared to thin contaminant removal (50-150 μm mill scale generates significantly more particulate per ft² than 30-50 nm heat tint)\",\"filtration\":\"HEPA/P100 particulate extraction minimum — high-volume removal may require cyclonic pre-separator upstream of HEPA filters\",\"wasteClassification\":\"Iron oxide particulate is generally non-hazardous — same classification as rust particulate. No Cr(VI) concern (unlike stainless mill scale). Lead-based primer underneath older structural steel must be assessed\"}", "propertyID": "contaminant:mill-scale-magnetite/facts.byproducts", "citation": [ { "@id": "#osha-table-z1" } ] }, { "@type": "PropertyValue", "name": "downstreamCompatibility", "value": "{\"recontamination\":\"Bare steel exposed by mill scale removal flashes rust within hours in humid air — coat or prime promptly. Re-formation of mill scale is NOT a concern (requires >570°C, only occurs during hot rolling)\",\"surfaceReadiness\":\"Laser-mill-scale-removed surfaces: Ra ~4.8 μm (VTRC 2026) vs grit-blasted ~12-25 μm. ASTM D4541 pull-off adhesion: laser-cleaned surfaces show comparable or better coating adhesion. SSPC-SP10 (near-white blast) equivalent cleanliness achievable but surface profile is SMOOTHER — verify coating system requirements. If grit-blast profile (40-70 μm to ISO 8503) is specified, laser is out of scope — laser lifts contamination without cutting a profile\"}", "propertyID": "contaminant:mill-scale-magnetite/facts.downstreamCompatibility", "citation": [ { "@id": "#vtrc-lacr-adhesion-2026" }, { "@id": "#tribology-laser-cleaning-adhesion-2025" } ] }, { "@type": "PropertyValue", "name": "laserDamageThreshold", "value": "8–15", "propertyID": "contaminant:mill-scale-magnetite/facts.laserDamageThreshold", "unitText": "J/cm²", "wavelengthNm": 1064, "pulseRegime": "ns", "citation": [ { "@id": "#mdpi-steel-rust-2024" }, { "@id": "#1007-empirical-2020" } ] } ], "measurementTechnique": "Laser cleaning parameter measurement", "license": { "@type": "CreativeWork", "name": "CC BY 4.0", "url": "https://creativecommons.org/licenses/by/4.0/" }, "creator": { "@type": "Organization", "name": "Z-Beam Laser Cleaning" }, "publisher": { "@type": "Organization", "name": "Z-Beam Laser Cleaning", "url": "https://www.z-beam.com" }, "dateModified": "2026-08-31", "version": "3.0", "citation": [ { "@type": "ScholarlyArticle", "@id": "#1007-empirical-2020", "headline": "Empirical Study of Laser Cleaning of Rust, Paint, and Mill Scale from Steel Surface (Deschênes & Fraser, Materials Processing Fundamentals 2020)", "sameAs": "https://doi.org/10.1007/978-3-030-36556-1_17" }, { "@type": "ScholarlyArticle", "@id": "#fabricator-laser-cleaning-intro-2024", "headline": "The Fabricator, \"An Introduction to Laser Cleaning and Laser Texturing,\" Industrial Media, 2024", "sameAs": "https://www.thefabricator.com/thefabricator/article/finishing/an-introduction-to-laser-cleaning-and-laser-texturing" }, { "@type": "ScholarlyArticle", "@id": "#guan-mill-scale-vs-rust-2015", "headline": "Guan, Shiwei William, 'Mill Scale, Rust, and Coating 101,' LinkedIn Article, 2015. Citing 'The Making, Shaping and Treating of Steel,' 10th Ed., p. 1083, 1985.", "sameAs": "https://www.linkedin.com/pulse/mill-scale-rust-coating-101-shiwei-william-guan" }, { "@type": "ScholarlyArticle", "@id": "#hal-oxide-thermomechanical-behavior", "headline": "Various authors, \"Study of the thermo-mechanical and fracture behaviour of iron oxide scales during hot rolling,\" PhD Thesis, PSL University / ArcelorMittal, 2023", "sameAs": "https://pastel.hal.science/tel-04615324v1/file/2023UPSLM082_archivage.pdf" }, { "@type": "ScholarlyArticle", "@id": "#ispatguru-mill-scale-2017", "headline": "IspatGuru, \"Mill Scale,\" Technical Article, May 2017", "sameAs": "https://www.ispatguru.com/mill-scale" }, { "@type": "ScholarlyArticle", "@id": "#making-shaping-treating-steel-1985", "headline": "\"The Making, Shaping and Treating of Steel,\" 10th Edition, p. 1083, AISE Steel Foundation, 1985. ISBN 0930767004.", "sameAs": "https://www.finishing.com/386/57.shtml" }, { "@type": "ScholarlyArticle", "@id": "#mdpi-steel-rust-2024", "headline": "Effect of Different Laser Parameters on Surface Physical Characteristics and Corrosion Resistance of 20 Steel in Laser Cleaning", "sameAs": "https://doi.org/10.3390/app14052058" }, { "@type": "ScholarlyArticle", "@id": "#montipower-mill-scale-steel-2025", "headline": "MontiPower, \"Mill Scale on Steel: What It Is and How to Remove It,\" 2025", "sameAs": "https://montipower.com/blog/mill-scale-steel-what-it-is-how-to-remove-it" }, { "@type": "ScholarlyArticle", "@id": "#nippon-steel-oxide-phase-transformation-2016", "headline": "NIPPON STEEL & SUMITOMO METAL, \"Phase Transformation of Oxide Scale and Its Control,\" NSSMC Technical Report No. 111, March 2016", "sameAs": "https://www.nipponsteel.com/en/tech/report/nssmc/pdf/111-13.pdf" }, { "@type": "ScholarlyArticle", "@id": "#osha-table-z1", "headline": "29 CFR 1910.1000 Table Z-1 — Limits for Air Contaminants", "sameAs": "https://www.osha.gov/annotated-pels/table-z-1" }, { "@type": "ScholarlyArticle", "@id": "#osti-magnetite-thermal-expansion-review", "headline": "Holcomb, G.R. et al., \"A Review of the Thermal Expansion of Magnetite,\" OSTI/DOE Technical Report, NETL-PUB-22426, 2019", "sameAs": "https://www.osti.gov/servlets/purl/1569753" }, { "@type": "ScholarlyArticle", "@id": "#sspc-sp10-near-white-blast", "headline": "SSPC/NACE, \"SSPC-SP 10/NACE No. 2 — Near-White Metal Blast Cleaning,\" Joint Surface Preparation Standard", "sameAs": "https://glavin.net/wp-content/uploads/2020/03/SSPC-SP-10-Near-White-Blast.pdf" }, { "@type": "ScholarlyArticle", "@id": "#tribology-laser-cleaning-adhesion-2025", "headline": "Hadi, E.S. et al., \"Study on the Effect of Laser Cleaning Power and Scanning Frequency on Surface Roughness and Coating Adhesion,\" Tribology in Industry, 2024/2025", "sameAs": "https://www.tribology.rs/journals/aips/1754.pdf" }, { "@type": "ScholarlyArticle", "@id": "#vtrc-lacr-adhesion-2026", "headline": "Virginia Transportation Research Council (VTRC), 'Evaluation of Combining Heat Induction and Laser Ablation for the Removal of Coatings from Steel Bridges,' VTRC 26-R10, 2026.", "sameAs": "https://vtrc.virginia.gov/media/vtrc/vtrc-pdf/vtrc-pdf/26-R10.pdf" }, { "@type": "ScholarlyArticle", "@id": "#yihai-mill-scale-removal-2026", "headline": "YIHAI LASER, \"Laser Mill Scale Removal: Hot Rolled Steel Plates,\" July 2026", "sameAs": "https://yhlaserclean.com/laser-mill-scale-removal" } ] }