Introduction
Nb is a rare element with transition metal properties, and it is one of the transition metals that is most widely used as a material for superconductors, magnets and other high-tech materials. With the development of new technologies and industries, the demand for Nb has been increasing. Many studies have been conducted on the preparation and application of Nb-containing materials. In the process of preparation and application, the thermodynamic and microstructure of Nb-containing materials need to be optimized. Therefore, further research on Nb should focus on how to use heat treatment to obtain its best microstructure and properties.
High temperature and thermal cooling are two common ways to produce microstructures in Nb-containing materials. High temperature treatment is often used to prepare fine microstructure, optimize the physical and mechanical properties and obtain homogeneous microstructures. Thermal cooling is often used to improve the welding performance and reduce the solubility of inclusions. In order to obtain a better microstructure and properties of Nb, heat treatment should be combined with cooling treatment.
In this paper, the results of heat treatment and cooling treatment for the preparation of Nb-containing materials are discussed. It is found that when Nb is cooled from high temperature, it can form carbon or nitrogen compounds. The main compounds are NbC and NbN, which are important in the preparation of Nb-containing materials. NbC is an important hardening phase in Nb-containing materials and its contribution to the strength is related to its content. NbN is an important softening phase in Nb-containing materials, which can reduce the hardness and strength of the material.
High temperature and cooling process
The heat treatment and cooling process of Nb is similar to the heat treatment process of other metals. The high temperature heat treatment of Nb can be divided into two steps: (1) heating to the specific temperature; (2) cooling to the room temperature. The cooling process of Nb is usually carried out by air cooling, water cooling or other methods.
At high temperature, Nb-containing materials react with carbon and nitrogen elements in the air, and carbon and nitrogen atoms can be adsorbed on the surface of Nb. During cooling, the Nb with adsorbed carbon and nitrogen atoms can form carbon or nitrogen compounds, such as NbC or NbN. The formation of carbon and nitrogen compounds can be controlled by controlling the cooling rate. For example, when Nb is cooled by air cooling, carbon compounds such as NbC will be more likely to form and when Nb is cooled by water, nitrogen compounds such as NbN will be more likely to form.
Conclusion
In conclusion, when Nb is cooled from high temperature, it can form carbon or nitrogen compounds. Depending on the cooling method, the compounds formed can be NbC or NbN. NbC is an important hardening phase and its contribution to the strength is related to its content. NbN is an important softening phase and it can reduce the hardness and strength of the material. Heat treatment and cooling treatment are important steps in the preparation of Nb-containing materials and they can be used to optimize the physical and mechanical properties.
