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在783~843 K温度范围和不同保温时间(30~240 min)对45钢进行了离子氮氧共渗和离子渗氮表面改性处理,对比研究了两种处理方法的动力学。离子氮氧共渗是在离子渗氮的基础上添加流量为0.2 L/min的空气实现的。利用光学显微镜和X射线衍射仪对化合物层显微组织、厚度及物相组成进行了测试和分析。结果表明,添加适量空气可显著促进活性氮原子在基体内的扩散,离子氮氧共渗的扩散系数比普通离子渗氮显著提高,扩散激活能从227.25 k J/mol降低到138.57 k J/mol,从而可达到降低温度或缩短保温时间的效果。同时,计算得到了45钢在783~843 K温度范围内离子氮氧共渗时化合物层厚度与温度T(K)和保温时间t(s)的动力学关系式。
In the temperature range of 783-843 K and different holding time (30 ~ 240 min), ion-nitriding and ion nitriding surface modification of 45 steel was carried out. The kinetics of the two treatments were compared. Ion nitriding is achieved by adding air at a flow rate of 0.2 L / min on the basis of ion nitriding. The microstructure, thickness and phase composition of the compound layer were tested and analyzed by optical microscope and X-ray diffractometer. The results show that the diffusion of active nitrogen atoms in the matrix can be significantly promoted by adding appropriate amount of air. The diffusion coefficient of ion-nitriding is significantly higher than that of common ion nitriding. The diffusion activation energy decreases from 227.25 kJ / mol to 138.57 kJ / mol , Which can achieve the effect of reducing the temperature or shortening the holding time. At the same time, the kinetic relation between the thickness of the compound layer and the temperature T (K) and the holding time t (s) of 45 steel in the temperature range of 783-843 K was calculated.