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一、前言氮化(本文的氮化是指气体氮化,下同)是化学热处理方法中的一种。其处理过程是把工件放入内盛有氮化气氛(通常是氨的分解气体)的密封容器内,在500°～600℃范围保温一段时间,让氮化气氛中的活性氮原子向工件内部渗透扩散,即可获得硬度极高的表面层。氮化作为一种工艺方法所以受到很大重视及广泛应用,原因是它具有以下一些独特优点:1)氮化层的表面硬度极高(达 R_068左右),这就使氮化零件的表面具有很高的耐磨性及抗擦伤能力。2)氮化使工件表面获得压应力,从而大大提高了工件的疲劳强度。3)由于氮化前经过消应力处理,氮化温度低及氮化后不需要浸入液体激冷,所以工件氮化后的变形很小。4)即使长时间在500℃高温下工作,氮化层仍能保持很高的表面硬度。5)氮化层具有良好的磨削和抛光性能。我国在解放前没有热处理部门,当然也谈不上采用氮化这种工艺方法。直到解放初
I. Introduction Nitriding (nitriding in this paper means gas nitriding, the same below) is one of the chemical heat treatment methods. The process is to put the workpiece containing a nitriding atmosphere (usually ammonia decomposition gas) in a sealed container, in the range of 500 ° ~ 600 ° C for a period of time so that the nitriding of nitrogen atoms in the atmosphere inside the workpiece Penetration and diffusion, you can get a very high hardness of the surface layer. Nitriding has received great attention as a process method and has been widely used because it has some unique advantages as follows: 1) The nitrided layer has an extremely high surface hardness (up to about R_068), which makes the surface of the nitrided part have High wear resistance and abrasion resistance. 2) nitriding to get the workpiece surface compressive stress, thereby greatly improving the fatigue strength of the workpiece. 3) Since the nitriding before stress relief treatment, nitriding temperature is low and do not need to be immersed in the liquid after nitriding, so the deformation of the workpiece after nitriding is small. 4) The nitrided layer can maintain a high surface hardness even if it is operated at a high temperature of 500 ° C for a long time. 5) nitride layer has good grinding and polishing properties. Before the liberation of our country there is no heat treatment sector, of course, not to mention nitriding this process. Until the liberation of early