【作者】 云腾；

【导师】 周上祺；

【作者基本信息】 重庆大学 ， 材料学， 2002， 硕士

【摘要】 本文采用高电压低气压、闭炉保温的渗氮工艺对合金钢在纯氮气氛下离子渗氮和采用氨气以及不同氮氨比混合气进行普通离子渗氮。利用显微硬度计、金相显微镜和X射线衍射仪测定了渗氮层的硬度梯度、层深、显微组织和相组成。结果表明在相同的渗氮时间里，纯氮离子渗氮获得了比以氨气作为渗氮气源进行离子渗氮更好的效果。而且克服了氨气渗氮容易产生环境污染的缺点。 通过对实验中纯氮离子渗氮系统的研究，发现只有在足够高的电压下才有明显的渗氮效果。分析了纯氮离子渗氮和氮氨混合气体离子渗氮过程中阴极位降区内粒子的行为，计算正离子在电场力作用下一个平均自由程内与中性氮分子发生非弹性碰撞传递给氮分子的能量，找出离子渗氮时氮分子产生活性氮原子的电压临界值，导出了离子渗氮中电压、气压、阴极位降区厚度和离子平均自由程的关系式。从理论上推测了几种混合气体离子渗氮活性氮原子产生的能量要求，理论计算与文献报导的实验结果基本一致。探讨了氮氢、氮氩混合气体离子渗氮中氢和氩的作用，提出了渗氮的机理。更多还原

【Abstract】 In this paper, alloy steel was nitrided under the atmosphere of pure nitrogen, using the ion nitriding technique by high voltage, low air pressure and holding heat with closed furnace, and alloy steel was also nitrided by normal techniques under the atmosphere of the different rate of N2 and NH3 . The hardness gradient, depth , microstructure and phases of nitrided layers were measured with Microhardness Apparatus, Microcopy and X-ray diffractometer . The result shows that under the same nitriding time, better experiment effects was achieved by using pure nitrogen than NH3, and the former technique overcomes the disadvantage of NH3 which is inclined to produce environmental pollutions.After the contrast studies of various techniques of pure nitrogen ion-nitriding , it is found that obvious ion-nitriding effects were achieved only on the condition of sufficiently high voltage. The behavior of molecule or ion around cathode zone on the process of ion nitriding was analyzed, In a mean free path, under the effect of the electric field, positive ion nitrogen has a inelastic collision with neutral nitrogen molecule and releases certain energy that received by the neutral nitrogen molecule, we quantitate this energy. Also we have found out the critical voltage needed in the production of active nitrogen atoms in ion-nitriding. Deduce the relation among the voltage, air pressure and the thickness of cathe zone. It presume the requirement of energy which produce the active nitrogen under some certain mixtured gases in theory, the theoretical quantitation is consistent weith the trial result of literature reports. Meanwhile, the effect of hydrogen and argon in the N2-H2 and N2-Ar ion-nitriding, and the mechanism of pure nitrogen ion nitriding was discussed .更多还原