高氮氮化锰合金的制备及深度氮化机理研究

How to increase the nitrogen content of manganese nitride intermediate alloy(Mn-N) and preparation of high nitrogen Mn-N has become an important problem to be solved in high nitrogen steel smelting industry in China. Resently, we proposes a noval method of preparing high nitrogen(more than 12%) manganese nitride intermediate alloy which called split-step nitridation method. In this project,the IGA-003 dynamic multicomponent adsorption system are used to observe the situ reaction of manganese powder and nitrogen gas ( N2 and H2 ). The thermogravimetric and differential thermal analysis equipment are used to study the thermodynamics process of the reaction. Then, the effect of temperature gas composition and manganese powder particle size on the reaction kinetic parameters are investigated. The phase structure and composition of Mn-N are researched by microstructure analysis methods. Through comprehensive analysis, the thermodynamics regular pattern of metal manganese nitriding process and the mechanism of depth of the nitride are revealed. The evolution regulation of the phase composition and phase structure of Mn-N are found in the process of nitride formation. The optimal preparation synthesis condition and parameters are found out. Finally, the technical prototypes of high nitrogen Mn-N productinn are formed. This work will offer theoretical and technical guidance for the development and production of Mn-N.

如何提高氮化锰中间合金的含氮量，制备出高氮氮化锰合金已成为我国高氮钢冶炼工业中亟待解决的关键问题。基于上述问题，本项目提出了阶梯氮化法制备高氮氮化锰的新方法；利用IGA-003动态多组分吸附系统对锰粉与氮化气体（氮气和氢气）的反应进行原位实验研究，结合热重和差热分析法进行热力学和动力学研究，探讨温度、气相组成和锰粉粒度等对反应动力学参数的影响；利用显微材料分析方法表征Mn-N体系的相结构与组成；经综合分析，揭示金属锰氮化过程的热力学和动力学规律以及深度氮化机理，发现氮化过程中Mn-N系的相组成和相结构形成与演化规律，找出阶梯氮化法制备高氮氮化锰的最佳工艺条件和参数，形成制备高氮氮化锰合金的技术原型，从而对氮化锰合金的研制和生产给予理论和技术指导。

如何提高氮化锰中的含氮量，制备出高氮氮化锰合金已经成为我国高氮钢冶炼工业中亟待解决的关键问题，基于上述问题，本项目提出了阶梯氮化法制备高氮氮化锰合金的新方法，我们利用阶梯氮化的合成方法，首先研究了锰粉粒度、氮化温度、氮化时间等工艺参数对氮化锰合金中含氮量的影响，结合产物的晶相结构检测，发现，单一的中（高温）氮化不能获得高氮含量的氮化锰产物。同时，发现，在氮化过程中引入熔盐前驱体可以有效的抑制氧化，并改善渗氮作用，获得高氮含量的氮化产物，随后我们针对不同熔盐体系，采用阶梯氮化的方法对其晶型结构和形貌的改变进行了讨论，发现在熔盐的作用下，可以改变金属锰表面的形貌，使其界面的结构发生解离，从而提高其对氮原子的吸附作用。同时，在随后的氮化过程中通过提高氮化温度加速氮原子对金属锰的渗透作用，从而提高金属锰的渗氮率。最终我们通过条件的优化，获得了氮含量为12~17%的高氮化锰合金，为高氮锰合金的研制和生产给予理论和技术指导。