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.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2009年第4期124-128,共5页
Transactions of Materials and Heat Treatment
关键词
40CR钢
活性屏离子渗氮
快速渗氮
富氮层
40Cr steel
active screen plasma nitriding（ASPN）
fast nitriding
nitrogen-rich layer
