Verfahren und Vorrichtung zur thermischen oder thermochemischen Behandlung von Stahl

• Main Author: GANTOIS, MICHEL, F-54000 NANCY, FR
• Format: Patent
• Language: German
• Published: 08.10.1998
• Edition: 6
• 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

Process and apparatus for thermal or thermochemical treatment of a steel, permitting the instantaneous and continuous control of the carbon concentration at the surface of the steel, in particular during the carbon enrichment of the surface region of an article. The process provides for circulating in contact with this surface region a gas stream making it possible to obtain the surface carbon saturation concentration at maximum speed and to regulate this stream as a function of time. The apparatus comprises a controlled-atmosphere oven with an entry and an exit for a gas stream, feeding means forming this gas stream and means for regulating the gas stream, and is equipped with means for storing data and/or calculating and the feeding means are designed to form a gas stream capable of obtaining a carbon saturation concentration at the surface of the articles in less than one minute.