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我们在与昆明齿轮厂一起研究液体渗碳时,观察到某些渗碳淬火的18CrMnTi钢表层未浸蚀时便存在黑色网,浸蚀后黑网变宽或呈黑色带的现象(图1)。据资料介绍国内外不少人在不同钢种不同渗碳条件下也曾发现过这种黑色组织。目前,对于渗碳表层中黑色网的组织与成因看法极不一致。关于黑色网的组织,有人说是屈氏体,有人说是屈氏体或屈氏体与贝氏体,有人说是恒温转变产物珠光体,有人说是扩散型转变产物,有人统称为非马氏体。至于它们的形成原因,有人认为是表层析出碳化物降低了奥氏体的稳定性,有人认为与脱碳有关,有人认为不能单纯看作脱碳引起的,有人认为是内氧化所产生的结果,也有人认为由石墨夹杂引
When we worked with the Kunming Gear Plant to study liquid carburizing, it was observed that some of the carburized and hardened 18CrMnTi steels showed a black net when they were not etched, and the black net became wider or black after etching (Figure 1) . According to the data, many people both at home and abroad have found this kind of black tissue under the different carburizing conditions of different steels. At present, there is a very different view on the organization and genesis of the black web in the carburized surface. On the black network organization, it was said to be troostite, some say is troostite or troostite and bainite, some people say that the product of constant temperature transformation of pearlite, some people say that diffusion-type transition products, some people collectively referred to as non-horse Body. Some people think that the precipitation of carbides on the surface reduces the stability of austenite. Some people think that it is related to decarburization. Some people think that it can not be simply caused by decarburization. Some people think that it is the result of internal oxidation. Some people think that cited by the graphite mixed