| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for the stabilization of furnace atmosphere in a furnace at an early time, in applying an annealing treatment with a batch-type annealing furnace to a steel material stuck with oxide of scale, etc. SOLUTION: In the method for the stabilization of the furnace atmosphere in the batch-type annealing furnace, when the steel material stuck with the oxide of scale, etc., is annealed with the batch-type annealing furnace, after replacing the furnace atmosphere into an inert gas atmosphere by supplying the inert gas into the furnace into which the steel material is charged, the furnace atmosphere is changed into a reducing atmosphere by supplying the reducing gas. Under this reducing atmosphere and a temperature zone in which no oxidation and no carburization of the steel material occur, the steel material is heated and held for prescribed time and thereafter, the supply of the reducing gas is stopped. After supplying the inert gas until the furnace atmosphere becomes <1.5 vol.% CO<SB>2</SB>concentration, the reducing gas is again supplied into the furnace. Then, after CO<SB>2</SB>concentration becoming 1.5 vol.% and a carbon potential in the furnace becoming a prescribed value, the steel material is heated to the annealing temperature while controlling the carbon potential in the furnace atmosphere. COPYRIGHT: (C)2003,JPO
|
