热作模具钢中纳米析出物的析出机理及其对钢的强化作用

热作模具钢的强度是制约其应用范围和使用寿命的关键因素。基于钢的综合强化机制和前期研究，钢中纳米级析出物不但能够细化材料组织，而且能够有效提高材料强度。本项目以热作模具钢中纳米析出物为研究对象。研究内容包括：1）研究其形成的热力学和动力学，探明纳米析出物的析出规律，建立相应的理论模型；2）采用微观结构表征技术，研究纳米级析出物的类型，粒度分布，微观结构及其物相的演变规律；3）采用材料测试分析方法，明确纳米级析出物的种类和尺寸对材料组织和强度的影响，并建立适合的评价体系。本项目的研究成果将对于纳米级析出物强化技术在工模具钢领域的应用具有开创性的意义。

The strength of hot work die steel is the key factor in restricting its application scope and long service life. The previous studies show that nano-scale precipitates can not only refine materials structure but also effectively improve materials strength. Nano-scale precipitates in hot work die steel will be chosen as research object. The aim of this study is to: 1) investigate the thermodynamics and kinetics of nano-scale precipitates formation, ascertain the precipitation discipline of nano-scale precipitates, and develop corresponding theoretical model; 2) by using microstructure characterization technique of micromaterials and nanomaterials, study the types, size distribution, microstructure and phase evolution of nano-scale precipitates; 3) By using material testing methods, clarify the effect of the types and size of nano-scale precipitates on materials structure and strength, and develop reasonable evaluation system. The research results of this project will have innovative significance on the application of nano-scale precipitates reinforcement technique to tool and die steels.