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1、导言近来气体渗碳工艺的发展重点是缩短渗碳时间和减少渗碳气体的需用量,以期节约能源和原材料。这样便导致了过饱和渗碳气体的采用。对于这种气氛,碳势不能定义,从而附带地产生了一个间接测量露点、CO_2或O_2含量的问题。对于这种情况,本文建议采用C—流量控制来补充或替代碳势控制。图1列出了三种渗碳过程的计算和控制模式。在最简单的情况下(a),表层含碳量被视作常数,而渗层的增长按t~(1/2)规律计算。现行的渗碳工艺是以模式b为依据
1, Introduction Recently, the development of gas carburizing process focused on shortening the carburizing time and reducing the amount of carburizing gas needed to save energy and raw materials. This led to the use of supersaturated carburizing gases. For this atmosphere, the carbon potential can not be defined, incidentally resulting in a problem of indirectly measuring the dew point, CO 2 or O 2 content. In this case, this paper suggests using C-flow control to supplement or replace carbon potential control. Figure 1 lists the three carburizing process calculation and control mode. In the simplest case (a), the surface carbon content is taken as a constant, whereas the growth of the permeable layer is calculated as t ~ (1/2) law. The current carburizing process is based on the model b