Nucleation and microstructure development in Cr-Mo-V tool steel during gas atomization

27th Joint Seminar Development of Materials Science in Research and Education

材料科学;教育

Behúlová, M.^1 ; Grga, P.^1 ; ika, R.^1

Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Ulica Jána Bottu . 2781/25, Trnava

917 24, Slovakia^1

关键词: Free-energy difference;    Homogeneous nucleation;    Microstructure development;    Non-equilibrium solidification;    Nucleation temperature;    Numerical calculation;    Rapidly solidified powders;    Undercooled metallic melts;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/266/1/012001/pdf
DOI  :  10.1088/1757-899X/266/1/012001

来源: IOP

【 摘 要 】

Nucleation studies of undercooled metallic melts are of essential interest for the understanding of phase selection, growth kinetics and microstructure development during their rapid non-equilibrium solidification. The paper deals with the modelling of nucleation processes and microstructure development in the hypoeutectic tool steel Ch12MF4 with the chemical composition of 2.37% C, 12.06 % Cr, 1.2% Mo, 4.0% V and balance Fe [wt. %] in the process of nitrogen gas atomization. Based on the classical theory of homogeneous nucleation, the nucleation temperature of molten rapidly cooled spherical particles from this alloy with diameter from 40 μm to 600 μm in the gas atomization process is calculated using various estimations of parameters influencing the nucleation process - the Gibbs free energy difference between solid and liquid phases and the solid/liquid interfacial energy. Results of numerical calculations are compared with experimentally measured nucleation temperatures during levitation experiments and microstructures developed in rapidly solidified powder particles from the investigated alloy.