MANUFACTURING PROCESS OF PRESS HARDENED PARTS WITH HIGH PRODUCTIVITY

• Main Authors: DRILLET PASCAL, BLAISE ALEXANDRE, STUREL THIERRY
• Format: Patent
• Language: Chinese; English
• Published: 02.10.2020
• 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

A process for manufacturing a non-stamped prealloyed steel coil, sheet or blank, comprising the following successive steps: providing a non-stamped precoated steel coil, sheet or blank composed of a steel substrate covered by a precoating of aluminum, or aluminum-based alloy, or aluminum alloy, wherein the precoating thickness is comprised between 10 and 35 micrometers on each side of the steel coil, sheet or blank, then heating the non-stamped steel coil, sheet or blank in a furnace under an atmosphere containing at least 5% oxygen, up to a temperature theta1 comprised between 750 and 1000 DEG C, for a duration t1 comprised between t1min and t1max, wherein t1min= 23500/( theta1-729.5) and t1max= 4.946*1041*theta1-13.08, t1 designating the total duration in the furnace, theta1 being expressed in DEG C and t1min and t1max being expressed in seconds, then cooling the non-stamped steel coil, sheet or blank at a cooling rate Vr1 down to a temperature theta1, then maintaining the non-stamped steel coil, sheet or b