| 摘要 |
PURPOSE:To control the equil. carbon concn. of gaseous atmosphere constant by correcting the amount of CO2 corresponding to a desired equil. carbon concn. in accordance with the change in the content of CO in the gaseous atmosphere in a carburizing furnace and the temp. in the furnace. CONSTITUTION:A steel made part W to be carburized is put into a carburizing furnace 1, and after the inside of the furnace is evactuated, gaseous nitrogen is put therein. Next, an org. liquid agent CH3OH is injected dropwise and is decomposed in the furnace, after which the contents of CO2 and CO are analyzed with an analyzer 6. The signals of the analyzed CO value and the in-furnace temp. by a thermocuple 7 are fed to an arithmetic device 10. A desired carbon concn. of the steel material surface is put from a setter 8 into the device 10, and the target amount of CO2 corresponding to the equil. carbon concn. of the gaseous atmosphere is calculated and is inputted as a set value for a CO2 controller 9. The CO2 in the gaseous atmosphere is analyzed with an analyzer 11, and is fed back to the controller 9. The controller 9 compares the target CO2 amount signal and the analyzed CO2 signal, and operates a control valve 4 by the deviation signal thereof, thereby feeding a correct amount of enrich gas into the furnace and maintaining the equil. carbon content in the gaseous atmosphere in the furnace constant. |
