Abstract: In this paper, the ways of the carbon potential central are studied for gas carburizing. It is found that the method of the electrical is effective for controlling carbon potential in drop-feeling well furnace. The construction and the characteristics of the electrical resistance sensor and the instrument, and also the reform way for the well furnace are introduced. A microcomputer system has been built with TP805.Tomperature and carbon potential are controlled by PID model. The method of difference is employed to calculate the case depth. Thus an accurate control of carburizing process can be achieved with this unit for gas carburizing in well furnace. Tests have been repeated more 100 times for fork lift gears. The carburizing quality of the products is satisfactory and agrees with the standard for Japanese TCM fork lift.

Key words: 热处理, 渗碳, 碳热控制