Microstructure simulation of rapidly solidified ASP30 high-speed steel particles by gas atomization  

作　　者：Jie Ma Bo Wang Zhi-liang Yang Guang-xin Wu Jie-yu Zhang Shun-li Zhao 

机构地区：[1]State Key Laboratory of Advanced Special Steel, Shanghai University [2]School of Materials Science and Engineering, Shanghai University [3]Research Institute, Baoshan Iron & Steel Co., Ltd.

出　　处：《International Journal of Minerals,Metallurgy and Materials》2016年第3期294-302,共9页矿物冶金与材料学报（英文版）

基　　金：the National Basic Research Program of China (No. 2011CB012902) for their continuing support to this research

摘　　要：In this study, the microstructure evolution of rapidly solidified ASP30 high-speed steel particles was predicted using a simulation method based on the cellular automaton-finite element （CAFE） model. The dendritic growth kinetics, in view of the characteristics of ASP30 steel, were calculated and combined with macro heat transfer calculations by user-defined functions （UDFs） to simulate the microstructure of gas-atomized particles. The relationship among particle diameter, undercooling, and the convection heat transfer coefficient was also inves- tigated to provide cooling conditions for simulations. The simulated results indicated that a columnar grain microstructure was observed in small particles, whereas an equiaxed microstructure was observed in large particles. In addition, the morphologies and microstructures of gas-atomized ASP30 steel particles were also investigated experimentally using scanning electron microscopy （SEM）. The experimental re- suits showed that four major types ofmicrostructures were formed： dendritic, equiaxed, mixed, and multi-droplet microstructures. The simu- lated results and the available experimental data are in good agreement.In this study, the microstructure evolution of rapidly solidified ASP30 high-speed steel particles was predicted using a simulation method based on the cellular automaton-finite element （CAFE） model. The dendritic growth kinetics, in view of the characteristics of ASP30 steel, were calculated and combined with macro heat transfer calculations by user-defined functions （UDFs） to simulate the microstructure of gas-atomized particles. The relationship among particle diameter, undercooling, and the convection heat transfer coefficient was also inves- tigated to provide cooling conditions for simulations. The simulated results indicated that a columnar grain microstructure was observed in small particles, whereas an equiaxed microstructure was observed in large particles. In addition, the morphologies and microstructures of gas-atomized ASP30 steel particles were also investigated experimentally using scanning electron microscopy （SEM）. The experimental re- suits showed that four major types ofmicrostructures were formed： dendritic, equiaxed, mixed, and multi-droplet microstructures. The simu- lated results and the available experimental data are in good agreement.

关 键 词：high-speed steel rapid solidification MICROSTRUCTURE grain growth gas atomization 

分 类 号：TG142.1[一般工业技术—材料科学与工程]