METHOD FOR HOT-STAMPING GALVANIZED STEEL SHEET

• Main Authors: KOBAYASHI, YOSHIFUMI, YAEKURA, TAKASHI, ITO, YASUNORI, KAWANO, KAZUYUKI
• Format: Patent
• Language: English; French; German
• Published: 12.10.2016
• Subjects: APPARATUS THEREFOR; 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; COLORIMETRY; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; PHYSICS; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS; PUNCHING METAL; RADIATION PYROMETRY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TESTING; TRANSPORTING; WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS ORPROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL

In a cooling a galvanized steel sheet (W), change in emissivity of a surface of the galvanized steel sheet (W) is measured in a temperature range lower than the boiling point of zinc but not lower than the ferrite transformation temperature, using an emissivity sensor (4) with an observation wavelength of 1.4 µm or longer, and pressing and quenching in a pressing and quenching apparatus (2) is started after completion of an alloying reaction has been detected based on the change in emissivity. The emissivity sensor (4) preferably has an InGaAs element or a thermopile as a measuring element.