| 摘要 |
PURPOSE:To stabilize quality and to improve heat treatment efficiency by calculating a cumulative tempering parameter of a material to be treated at a furnace charging terminal, converting the parameter to temperature, and heating an upset part by a preheater. CONSTITUTION:An artihmetic device 60 controls controllers 40 and 50 to heat a material to be treated in a heat treatment furnace 20. The desired cumulative tempering parameter, furnace staying time and heating temperature of the material on the extraction side of the furnace 20 are estimated. The cumulative tempering parameter of an upset part a certain time before on the extraction side of the furnace 20 is found from the furnace staying time and heating temprature by reversed operation, and on the basis of said cumulative tempering parameter, the temperature prior to a prescribed time is found by reversed operation. Thus, the cumulative tempering parameter of the upset part at the charging terminal of the furnace 20 is found finally. While natural cooling between a preheater 10 and the furnace 20 is considered, the temperature of the upset part on the exit side of the preheater 10 is found, and the preheater 10 performs heating in such a way that the temperature after tempering is equal to the found temperature. |
