Some numerical models such as central atoms model （CAM） and superelement model were used to simulate the thermodynamics of austenite decomposition in the Fe-C-Mn-Si TRIP （transformation induced plasticity） steels....Some numerical models such as central atoms model （CAM） and superelement model were used to simulate the thermodynamics of austenite decomposition in the Fe-C-Mn-Si TRIP （transformation induced plasticity） steels. Thermodynamic calculations were carried out under a para-equilibrium （PE） condition. The results show that certain silicon content can accelerate the polygonal ferritic transformation and increase the volume fraction and stability of retained austenite by retarding the precipitation of carbides during the bainitic transformation.展开更多
Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral tec...Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral techniques, and Rose-Dragomethod. Electronic effects in metalloporphrins and effects of ligands, temperature andsolvents were investigated. It was found that equilibrium constants for reactions of ZnT(p-X)PP with ligands follow Hammett equation. The changes of standard molar enthalpy△rHm and the changes of standard molar entropy △rSm of the reactions were obtainedfrom the plots of lnK vs. 1/T.展开更多
In the present paper, a numerical modeling was developed to simulate the growth kinetics of ferrite transformed from austenite in Fe-C-∑X （X denotes substitution elements, such as Mn, Ni, Cr etc.） steels by solving...In the present paper, a numerical modeling was developed to simulate the growth kinetics of ferrite transformed from austenite in Fe-C-∑X （X denotes substitution elements, such as Mn, Ni, Cr etc.） steels by solving the diffusion equation using finite difference method （FDM）. Coupled with the kinetic modeling, thermodynamic calculations were carried out to determine the γ/α phase equilibrium conditions using a para-equilibrium （PE） model. The dissipation of free energy for γ→α phase transformation due to the so-called solute drag effect （SDE） was taken into account in the thermodynamic modeling. With this modeling, simulations on the growth kinetics of ferrite in the steels containing austenite-stabilizing and ferrite-stabilizing elements （such as Ni, Mn and Si, Cr, respectively） were performed, which indicates that it deviates from the parabolic growth rate law after the initial stage of transformation. The results were compared with the experimental values given by Bradley and Aaronson, showing that this model has a reasonably good accuracy to predict the growth kinetics of ferrite.展开更多
The complete miscible solid solution with a minimum freezing point (-50.75℃; 26.88% para-) of the ortho- and para-chlorotoluene has been proved in this paper by many methods as the thermal analysis method, the X-ray ...The complete miscible solid solution with a minimum freezing point (-50.75℃; 26.88% para-) of the ortho- and para-chlorotoluene has been proved in this paper by many methods as the thermal analysis method, the X-ray matter phase analysis, the fractional crystallized separation method and the solidified separation method of solid solution, and by the Fel’dman’s experiential productivity formula compared with the theoretical productivity formula which was obtained from the solidified separation according to the solid solution phase diagram. Therefore, the international official conclusion of simple eutectic type phase diagram of ortho- and para-chlorotoluene mixture does not agree with the experimental facts.The powder diffraction files of ortho- and para-chlorotoluenes are given in this paper.展开更多
基金Item Sponsored by National Natural Science Foundation of China (50334010)
文摘Some numerical models such as central atoms model （CAM） and superelement model were used to simulate the thermodynamics of austenite decomposition in the Fe-C-Mn-Si TRIP （transformation induced plasticity） steels. Thermodynamic calculations were carried out under a para-equilibrium （PE） condition. The results show that certain silicon content can accelerate the polygonal ferritic transformation and increase the volume fraction and stability of retained austenite by retarding the precipitation of carbides during the bainitic transformation.
文摘Equilibrium constants for reactions of ZnT(p-X)PP(para-substituted zinctetraphenylporphyrins) with ligands of the substituted imidazole in CH2Cl2 and several other solvents have been determined by visible spectral techniques, and Rose-Dragomethod. Electronic effects in metalloporphrins and effects of ligands, temperature andsolvents were investigated. It was found that equilibrium constants for reactions of ZnT(p-X)PP with ligands follow Hammett equation. The changes of standard molar enthalpy△rHm and the changes of standard molar entropy △rSm of the reactions were obtainedfrom the plots of lnK vs. 1/T.
基金supported by the National Natural Sci-ence Foundation of China(50474086)the program for New Century Talents in University(NECT)the Ministry of Education,China.
文摘In the present paper, a numerical modeling was developed to simulate the growth kinetics of ferrite transformed from austenite in Fe-C-∑X （X denotes substitution elements, such as Mn, Ni, Cr etc.） steels by solving the diffusion equation using finite difference method （FDM）. Coupled with the kinetic modeling, thermodynamic calculations were carried out to determine the γ/α phase equilibrium conditions using a para-equilibrium （PE） model. The dissipation of free energy for γ→α phase transformation due to the so-called solute drag effect （SDE） was taken into account in the thermodynamic modeling. With this modeling, simulations on the growth kinetics of ferrite in the steels containing austenite-stabilizing and ferrite-stabilizing elements （such as Ni, Mn and Si, Cr, respectively） were performed, which indicates that it deviates from the parabolic growth rate law after the initial stage of transformation. The results were compared with the experimental values given by Bradley and Aaronson, showing that this model has a reasonably good accuracy to predict the growth kinetics of ferrite.
文摘The complete miscible solid solution with a minimum freezing point (-50.75℃; 26.88% para-) of the ortho- and para-chlorotoluene has been proved in this paper by many methods as the thermal analysis method, the X-ray matter phase analysis, the fractional crystallized separation method and the solidified separation method of solid solution, and by the Fel’dman’s experiential productivity formula compared with the theoretical productivity formula which was obtained from the solidified separation according to the solid solution phase diagram. Therefore, the international official conclusion of simple eutectic type phase diagram of ortho- and para-chlorotoluene mixture does not agree with the experimental facts.The powder diffraction files of ortho- and para-chlorotoluenes are given in this paper.
