| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for operating an electric furnace having a silundum heat generating member and the electric furnace for carrying out the furnace operating method in which the silundum heat generating member can be applied up to a temperature region of a furnace temperature of about 1673 K oxygen in the case that reducing atmosphere with low oxygen content such as a mixture gas atmosphere containing nitrogen and hydrogen is used. SOLUTION: There is provided a method for operating an electric furnace in which a silundum heat generating member is arranged, and heat treatment is carried out in a gas atmosphere containing nitrogen partial pressure of 0.08 MPa or more and hydrogen partial pressure of 0.01 MPa or less. The electric furnace is provided with a controlling mechanism for use in controlling an oxygen concentration in the furnace gas atmosphere in response to a furnace temperature. Oxygen concentration in a temperature range of 1,473 to 1,600 K of the furnace temperature is controlled to 10-18 or more and oxygen concentration in a temperature range of 1,600 K or higher and 1,773 K or lower of the furnace temperature is controlled to 10-17 or more.
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