无初生相高铬铸铁固相反应生成机理及其性能研究

High chromium cast iron (HCCI) possessing excellent wear resistance, heat resistance and corrosion resistance, are widely used in mining, cement, electric power, engineering machinery and other industries. Traditional HCCI exhibit poor performance because of bulky dendritic primary austenite and bulky plate-like primary carbide in hypoeutectic and hypereutectic HCCI respectively. How to eliminate primary austenite and carbide in HCCI is a challenging scientific problem all around the world. The present project aim to develop a solution for this problem. A novel HCCI with neither bulky dendritic primary austenite nor bulky plate-like primary carbide was fabricated via a solid-phase reaction between chromium and cast iron.The solid-phase reaction process of different carbon sources (flake graphite and network cementite) and chromium will be researched to explore atomic dissolving, solid diffusion and solid-phase reaction mechanisms; The nucleation and growth process of minisize austenite and tiny carbide will also be studied to disclose the nucleation and growth mechanisms; Meantime, the impact toughness and wear resistance of HCCI with no primary phase will be examined to clarify fracture and worn mechanisms. The successful of implementation of the project will set up new theory and technology system of HCCI with no primary phase produced by solid-phase reaction. The academic significance of present project is huge.

高铬铸铁具有优良的耐磨、耐热和耐腐性能，广泛应用于采矿、水泥、电力、工程机械等行业。目前，由于亚共晶高铬铸铁中存在粗大树枝状初生奥氏体，而过共晶高铬铸铁中存在粗大板块状初生碳化物，直接影响了高铬铸铁的综合性能，因此如何消除粗大的初生奥氏体和初生碳化物是极具挑战性的科学问题。本项目通过固相反应方法制备出新型无粗大初生奥氏体的亚共晶高铬铸铁和无初生碳化物的过共晶高铬铸铁。研究不同碳源（片状石墨和网状渗碳体）与铬的固相反应过程，探索碳原子和铬原子的溶出、固相扩散以及反应机制；分析无初生相高铬铸铁中小尺寸奥氏体和细小碳化物的形成过程，揭示其形核及生长机理；探究新型高铬铸铁的冲击韧性和耐磨特性，阐明其断裂机制与磨损机制。项目的成功实施将有助于构建固相反应生成无初生相高铬铸铁崭新的理论和技术体系，具有重要的科学研究意义。

高铬铸铁具有优良的耐磨、耐热和耐腐性能，广泛应用于采矿、水泥、电力、工程机械等行业。目前，由于亚共晶高铬铸铁中存在粗大树枝状初生奥氏体，而过共晶高铬铸铁中存在粗大板块状初生碳化物，直接影响了高铬铸铁的综合性能，因此如何消除粗大的初生奥氏体和初生碳化物是极具挑战性的科学问题。本项目通过固相反应方法制备出新型无粗大初生奥氏体的亚共晶高铬铸铁和无初生碳化物的过共晶高铬铸铁。研究不同碳源（片状石墨和网状渗碳体）与铬的固相反应过程，探索碳原子和铬原子的溶出、固相扩散以及反应机制；分析无初生相高铬铸铁中小尺寸奥氏体和细小碳化物的形成过程，揭示其形核及生长机理；探究新型高铬铸铁的冲击韧性和耐磨特性，阐明其断裂机制与磨损机制。项目的成功实施将有助于构建固相反应生成无初生相高铬铸铁崭新的理论和技术体系，具有重要的科学研究意义。