| 摘要 |
PURPOSE:To prevent a strip from being scratched in the stage of subjecting the strip to a heat treatment such as annealing in a continuous heat-treating furnace by conveying the strip while suspending the strip in the heating part where the temp. is highest in the U-shaped non-contact state. CONSTITUTION:A strip W is introduced through a charging port 2a into a continuous heat-treating furnace 1 and is passed through a heat-exchanging zone 3 consisting of a preheating zone 3A and the 3rd cooling zone 3B and in succession the strip is passes through the inside of a quick heating zone 4A in the heating and cooling zone bisected vertically to the quick heating zone 4A and a quick cooling zone 4B by a partition wall 13. The strip is then lowered into a vertical zone 5 of the highest temp. by a supporting roll 7a where the strip is suspended into a U shape and after the strip is heated to >=600 deg.C in the final heating zone 5A, the strip is passed through a soaking zone 5C and is cooled in the 1st cooling zone 5B. The cooled strip is passed through a quick cooling zone 4B and the 3rd cooling zone 3B via a supporting roll 7b, by which the heat treatment is completed. The heat-treated strip is taken out of an outlet 2b. Rolls, etc. are not used in the soaking zone 5C where the temp. in the heat treatment is max. and since the strip is held into the U shape without contact in said zone, the strip is prevented from being scratched. |
