许多渗碳零件(或是碳氮共渗)往往有一些部位不希望渗碳(或碳氮共渗)。过去常采用的方法是:切去渗碳层或镀铜来达到此目的。切去渗碳层的方法虽然可靠,但费工费料,从而增加工艺的复杂性,也影响到渗碳或炭氮共渗之后不能进行直接淬火。镀铜曾被广泛应用过,但工艺繁锁,成本较高;硷性镀铜还有废液不易处理的问题。因此,目前已有采用抗渗 Many carburizing parts (or carbonitriding) tend to have some parts of carburizing (or carbonitriding) undesirable. In the past, the method used was to cut carburized layer or copper to achieve this purpose. Although the method of cutting the carburized layer is reliable, it takes a lot of work and costs to increase the complexity of the process and also can not directly quench after carburizing or carbonitriding. Copper has been widely used, but the process cumbersome, high cost; alkaline copper and waste is not easy to deal with the problem. Therefore, impermeability has been adopted so far