喷射成形法制备高速钢及组织性能研究.docVIP

绪论 1 1.高速工具钢简介 3 1.1高速钢的发展史 3 1.2高速钢的组织性能特点 3 1.3高速钢中碳化物类型 4 1.4高速钢近年研究进展： 5 2 高速钢的主要制备方法 6 2.1 传统铸造技术 6 2.2 电渣重熔技术 6 2.3 粉末冶金技术 8 3 喷射成形技术 9 3.1喷射成型简介 9 3.2喷射成形技术发展历程 10 3.3 喷射成形技术优点 11 3.4 喷射成形技术缺点 12 3.5 喷射成型技术基本原理 12 3.6 喷射成形过程 13 3.6.1 喷射成形——金属液的雾化 14 3.6.2 喷射成形——雾滴的沉积 18 3.7 喷射成形工艺控制因素 19 4 喷射成形技术制备高速钢材料的研究进展 20 4.1 喷射成形技术的研究进展和应用 20 4.1.1 喷射成形国外研究现状 20 4.1.2 喷射成形国内研究现状 22 4.2 喷射成形技术在高速钢制备中的应用 22 5 喷射成形发展前景展望 25 6结论 25 参 考 文 献 26 高速钢中碳化物的种类、数量、尺寸、分布及形貌等是决定其性能的关键因素。传统低冷速的铸造易引起严重偏析、一次碳化物粗大，从而严重恶化高速钢性能；而高冷速的喷射成形工艺能极大地抑制宏观偏析的发生，提高固溶度并细化组织，提高材料的强韧性。喷射成形技术在工模具钢方面的研究证明其能有效提高高速钢性能且成本较为低廉，一定程度上了替代粉末冶金制备高速钢。喷射成形工艺对高速钢组织及碳化物形貌、尺寸和分布的显著优化使的喷射成形高速钢表现出良好的热加工变形性能，而同成分的铸态高速钢变形性能差，极易锻造开裂。 关键词 喷射成形；高速钢；性能；组织 Study on microstructures and properties of spray formed high speed steel Zuojinrong School of AMM, University of Science and Technology Beijing, Beijing 100083, China ABSTRACT The properties of the high speed steels are usually determined by the types, amounts, sizes, distributions and shapes of the carbides. The low cooling rate of the traditional cast process can induce macrosegregation and coarse primary carbides, which can greatly deteriorate the properties. However, due to the high cooling rate, the spray-formed metallic materials can be characterised by the absence of macrosegregations, finer microstructures, increased solid solubility, increased strength and toughness, better hot workability. Thus, spray forming has been proven to be a powerful tool for the production of high-alloyed materials. Compared to powder metallurgy, the process chains of spray forming are much shorter.The spray formed high speed steels possess excellent hot workability, which is induced by the microstructures improvement. The cast steel with same chemical composition would be inclined to crack during hot working, due to its coarse dendrites and heterogeneous carbides. KEY WORDS : Spray forming, High speed steel, Properties,Microstructure 绪论 高速