| 摘要 |
PURPOSE:To prevent the formation of flaws and strains of a steel strip and decrease the variance in hardness by providing ejection nozzles between a hardening heating furnace and cooling stools to quench the steel strip and providing a mechanism for smoothly cooling the cooling stools. CONSTITUTION:A fog quenching device 4 is provided between a hardening heating furnace 3 and cooling stools 6, 6' and spray nozzles 5 positioned symmetrically at an equal spraying angle on the top and under surfaces of a steel strip 2 are installed therein. A coolant is ejected from the spray nozzles 5 to the steel strip 2 heated in the heating furnace 3, whereby the steel strip is quenched. Thence, the steel strip 2 is led to the stools 6, 6'. Flatly polished surfaces 19, 19' and oil holes 17, 18 and 17', 18' ejecting quenching oil are provided to the stools 6, 6', and further, a cooling water chamber 16 is provided. The nozzles 5 are so made as to permit desired adjustment of the cooling medium such as air or water by using pressure regulating valves. Thereby, the cooling of the steel strip 2 is uniformalized and the formation of flaws by the stools 6, 6' is prevented. |
