当前,除了采用常规的渗碳工艺外,越来越广泛地采用了复合循环渗碳工艺(在气氛的碳势可变的条件下)。由于渗碳过程第一阶段建立的气氛碳势比一零件表面层最终碳含量对应的碳势要高得多,所以碳渗入的过程颇为激烈。在渗碳过程第二阶段,当气氛的碳势与表面层最终碳含量的最佳值保持平衡时,工件表面上的碳就出现碳的(氵弥)散。 Currently, in addition to the conventional carburizing process, a composite cyclic carburizing process (under variable carbon potential in the atmosphere) is increasingly used. Since the carbon potential of the atmosphere established in the first stage of the carburizing process is much higher than the carbon potential corresponding to the final carbon content of a part surface layer, the carbon infiltration process is rather fierce. In the second stage of carburizing, the carbon on the surface of the workpiece appears as carbon when the atmosphere’s carbon potential is in balance with the optimum value of the final carbon content of the surface layer.