VERFAHREN ZUM RANDSCHICHTHAERTEN VON WERKSTUECKEN UND VORRICHTUNG ZUR DURCHFUEHRUNG DES VERFAHRENS

• Main Author: FICHTL,WALTER,.DR
• Format: Patent
• Language: German
• Published: 10.03.1988
• Edition: 4
• 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

Workpieces of metals or metal alloys are edge-hardened by a thermochemical treatment, especially by boronising by means of solid treatment agents in a fluidised bed which is generated in a reaction furnace by distributing a fluidising gas by means of an inflow tray, long tubular or stranded workpieces being moved through the fluidised bed with their surface to be treated being arranged axially in one direction. The figure shows an apparatus for carrying out the process, in which tubular workpieces are thermochemically treated on their inside in discontinuous operation with the use of adaptors. W1 and W2 here designate tubular workpieces with adjoining or interposed adaptors A1 and A2. The stationary tube furnace 5 has a preheating zone 6 and a heating zone 7. An inflow tray 9 is fixed in position in the interior of adaptor A1. At the start of working, the mounted unit of adaptors and workpieces is pushed, with the adaptor A1 at the front, through the preheating zone 6 in the direction of the arrow 15. The fluidising gas is blown in in the direction of the arrow 17 through the inflow tray 9 and the fluidised bed is generated from the granulated treatment material 14.