| 摘要 |
PURPOSE:To rise heating rate to optimum limit by detecting acoustic emission wave (AE wave) and then by controlling heating rate for object to be heated on the basis of the detected information. CONSTITUTION:The heating of the cast steel roll 10 is started by setting heating rate for the induction heating furnace 34 to nearly upper limit by the current controller 40. A heat stress develops within the roll 10 as the heating proceeds and if AE wave is generated, it is detected by the AE sensor 16 through the wave guide 14. The AE wave so detected is introduced to the time-lag measuring unit 28 through the pre-amplifier 20, the filter 22, the main amplifier 24, and the counter 26 and then the AE wave-generating position is judged throuh the interface 30 in the inside of the microcomputer(MC) 32. According to the judged position, the MC 36 controls the current of inductors (any of 38a to 38c) near the AE wave-generating position to slow down heating rate at the position. Thus, the generation of AE wave can be stopped. |
