| 摘要 |
PURPOSE: A non-oxidation annealing method is provided to prevent an object to be heated from being damaged or broken due to a difference of thermal expansion by uniformly heating inner and outer parts of the object with the same temperature. CONSTITUTION: A nozzle is formed in upper and lower portions of an object to be heated(I). Then, the object is inputted into an annealing furnace(II). After that, a metal flexible hose extending to an exterior of the annealing furnace is coupled to the nozzle(III). Then, nitrogen gas is introduced into the annealing furnace through the hose, thereby lowering oxygen density of the object below 2%(IV). A purge direction of nitrogen gas is converted in such a manner that nitrogen gas is continuously inputted/discharged into/from the annealing furnace(V).
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