PROCEDURE FOR THERMO-TREATED METAL ITEMS NON-OXIDATION HEATING IN AIR MEDIUM IN MUFFLE AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2011 - IPC C21D1/74 F27B5/10 

FIELD: metallurgy.

SUBSTANCE: procedure consists in thermo-treated metal items non-oxidation heating in air medium in muffle with gap relative to wall of muffle determined by formula:

where δ is value of gap, B is diametre of circle, area of which is equal to area of cross section of thermo-treated item, and K is biggest internal diametre of muffle, (mm). Further, the procedure consists in placement of the muffle into a heating surface and in items heating above 670°C. Also, the items are set into a preliminary heated muffle where upon an end of the muffle connected with air medium is left open or closed. The muffle is made of material with less potential, than potential of item metal, which form galvanic pair at heating in air medium. The device consists of the heating furnace and the muffle made of material with potential less, than potential of treated metal. The end of the muffle connected with environment is open or is made with a door. According to one version of the group of inventions the muffle can be made of metal with an external layer of oxide or of oxides - quartz or porcelain, or ceramics, or metal ceramics with a substrate of material of potential less, than potential of metal of a thermo-treated item.

EFFECT: thermal treatment of metal without oxidation with reduction of oxides without application of protective mediums and coating.

5 cl, 4 dwg, 5 tbl