| 摘要 |
PURPOSE:To prevent appearance of a temper color on cold rolled steel sheet coils in annealing of the coils in a box annealing furnace, by mounting pure copper on the uppermost coil. CONSTITUTION:In annealing or cold rolled steel sheet coils piled up in a box annealing furnace, iron-framed linear, granular or powdered pure copper is mounted on the uppermost coil. Mixed reducing gas of N2 and H2 is charged into the furnace to carry out annealing. During cooling after the annealing, water in the atmosphere contacts with the pure copper to be dissociated into H2 and O2, and the O2 is converted into Cu oxide. Accordingly, the surfaces of the annealed coils contact with no oxidizing atmosphere, and no temper color appears. |
