40Cr钢富氮层快速离子渗氮技术的探索  

Study on fast plasma nitriding technology of 40Cr steel with nitrogen-rich layer

作　　者：韩莉[1,2] 赵程[1] 

机构地区：[1]青岛科技大学机电工程学院表面技术研究所,山东青岛266061 [2]海军航空工程学院青岛分院航空机械系,山东青岛266041

出　　处：《材料热处理学报》2009年第4期124-128,共5页Transactions of Materials and Heat Treatment

摘　　要：用活性屏离子渗氮(ASPN)技术对40Cr钢进行快速离子渗氮技术的研究。本项研究是利用氮在奥氏体与铁素体中分别具有不同的溶解度和扩散速度的特性,采用了在共析温度以上短时间溶氮和在共析温度以下长时间扩散渗氮的两种不同的渗氮机制,进行交替渗氮处理。试验结果表明,采用这种新的渗氮工艺不仅可以显著提高渗氮处理中氮在钢中的内扩散速度,而且渗氮层具有较高的硬度。这种快速渗氮工艺可以用"吸收-扩散"渗氮模型进行解释。A new process of fast plasma nitriding on 40Cr steel was investigated using active screen plasma nitriding（ASPN）.The fast nitriding process is based upon the different solubility and diffusion rate of nitrogen atoms in austenite and in ferrite.Firstly,the nitriding samples were heated above the eutectoid temperature for a few minutes to dissolve a large amount of nitrogen on the surface of the nitrided samples to form a nitrogen-rich layer.Then,the nitriding temperature was decreased below the eutectoid temperature and kept for a long time to make the nitrogen atoms in the nitrogen-rich layer diffuse into ferrite. The two different nitriding processes were carried on ahernately. Experimental results indicate that the fast nitriding process not only enhances the nitriding speed remarkably, but also keeps the high hardness of the nitrided layer. The new fast nitriding process can be explained with absorption-diffusion model.

关 键 词：40CR钢 活性屏离子渗氮 快速渗氮 富氮层 

分 类 号：TG156.8[金属学及工艺—热处理]