A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepa...A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepared by common gas atomization and dual-phase flow atomization under similar conditions were compared. The experimental results show that the dual-phase flow-atomized powders have average particle sizes that are one-half that of the common gas-atomized particles;additionally, they possess a finer microstructure and higher cooling rate under the same atomization gas pressure and the same gas flow. The Weber number in the crash criteria of liquid atomization is adopted to measure the crash ability of the atomization media. The Weber number of the dual-phase flow atomization medium is the sum of that of the gas and the solid particles. Furthermore, the critical equation of the crash model in dual-phase flow atomization is established, and the main regularities associated with this process were analyzed.展开更多
Bused on the deformation model of dual phase steels, an expression for the stress of martensite in dual phase steels is derived, it predictes that the onset of plastic deformation of martensite (transition strain) dep...Bused on the deformation model of dual phase steels, an expression for the stress of martensite in dual phase steels is derived, it predictes that the onset of plastic deformation of martensite (transition strain) depends on the strain hardening of ferrite and on the strength of martensile. The relationship between the flow stress and microstructural parameters of a 0.12C-0.9Mn dual phase steel was investigated using the expression for the flow stress of dual phase steel[1] . By calculating the stress ratio and the stress-strain partition coefficient, the loud transition and the stress-strain partition between two phases are studied. It shows that the deformation of dual phase steel lies between the isostress and isostrain states and the stress-strain pratition changes continuously during the deloramtion.展开更多
文摘A self-invented atomization process, in which molten metal is atomized into powder by a high-velocity gas stream carrying solid particles as the atomization medium, was introduced. The characteristics of powders prepared by common gas atomization and dual-phase flow atomization under similar conditions were compared. The experimental results show that the dual-phase flow-atomized powders have average particle sizes that are one-half that of the common gas-atomized particles;additionally, they possess a finer microstructure and higher cooling rate under the same atomization gas pressure and the same gas flow. The Weber number in the crash criteria of liquid atomization is adopted to measure the crash ability of the atomization media. The Weber number of the dual-phase flow atomization medium is the sum of that of the gas and the solid particles. Furthermore, the critical equation of the crash model in dual-phase flow atomization is established, and the main regularities associated with this process were analyzed.
文摘Bused on the deformation model of dual phase steels, an expression for the stress of martensite in dual phase steels is derived, it predictes that the onset of plastic deformation of martensite (transition strain) depends on the strain hardening of ferrite and on the strength of martensile. The relationship between the flow stress and microstructural parameters of a 0.12C-0.9Mn dual phase steel was investigated using the expression for the flow stress of dual phase steel[1] . By calculating the stress ratio and the stress-strain partition coefficient, the loud transition and the stress-strain partition between two phases are studied. It shows that the deformation of dual phase steel lies between the isostress and isostrain states and the stress-strain pratition changes continuously during the deloramtion.
