ALUMINIUM-BASED COATING FOR STEEL SHEETS OR STEEL STRIPS AND METHOD FOR THE PRODUCTION THEREOF

• Main Authors: KOLL, Thomas, DEBEAUX, Marc, LUTHER, Friedrich, LASS, Jan-Frederik, HARTMANN, Haucke-Frederik, GRAUL, Matthias
• Format: Patent
• Language: English; French; German
• Published: 08.04.2020
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

In an aluminium-based coating for steel sheets or steel strips, the coating includes an aluminium-based coat applied in a hot-dip coating method, a covering layer containing aluminium oxide and/or hydroxide being arranged on the coat. The covering layer is produced by plasma oxidation and/or hot water treatment at temperatures of at least 90° C., advantageously at least 95° C., and/or steam treatment at temperatures of at least 90° C., advantageously at least 95° C. Alternatively, the covering layer containing aluminium oxide and/or hydroxide can be produced by anodic oxidation, the coat being produced in a molten bath with a Si content of between 8 and 12 wt. %, and an Fe content of between 1 and 4 wt. %, the remainder being aluminium.