Verfahren zur Herstellung eines Bauteils aus Stahl durch Warmumformen

• Main Authors: BRAUN, MICHAEL, MUETZE, STEFAN, LUTHER, FRIEDRICH, EVERTZ, THOMAS
• Format: Patent
• Language: German
• Published: 02.10.2013
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; 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; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PERFORMING OPERATIONS; PUNCHING METAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TRANSPORTING; WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS ORPROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL

Die Erfindung betrifft ein Verfahren zur Herstellung eines Bauteils aus umwandlungsfähigem Stahl durch Warmumformen, bei dem zunächst aus einem Band oder Blech als Vormaterial eine Platine zugeschnitten, anschließend auf Umformtemperatur erwärmt und umgeformt wird, aufweisend ein zumindest teilmartensitisches Umwandlungsgefüge nach der Formgebung. Dabei wird anstelle einer Pressformhärtung das zumindest teilmartensitische Umwandlungsgefüge durch Austenitisieren und Abschrecken bereits vor der Formgebung im Vormaterial oder erst in der umzuformenden Platine erzeugt und anschließend die so konditionierte Platine unter Beibehaltung des zumindest teilmartensitischen Umwandlungsgefüges nach der Umformung auf eine Umformtemperatur unterhalb der Ac1-Umwandlungstemperatur wiedererwärmt und bei dieser Temperatur umgeformt. The invention relates to a method for producing a component from transformable steel by hot forming, in which a plate first is cut out of a strip or sheet as the pre-material, and is then heated to forming temperature and pre-formed, having an at least partially martensitic transformation structure after forming. Instead of a press mold hardening, the at least partially martensitic transformation structure is created in the pre-material, or in the plate to be formed, by austenitization and quenching already before forming, and then the thus-conditioned plate is reheated after forming, while maintaining the at least partially martensitic transformation structure, to a temperature below the Ac1 transformation temperature, and formed at this temperature.