The aim of the present work was to study the effect of austenite grain size （AGS） on the martensite formation in a high-manganese twinning-induced plasticity （TWIP） steel. The results of a quantitative microstruct...The aim of the present work was to study the effect of austenite grain size （AGS） on the martensite formation in a high-manganese twinning-induced plasticity （TWIP） steel. The results of a quantitative microstructural characterization of the steel by the whole X-ray pattern fitting Rietveld software, materials analysis using diffraction （MAUD）, indicated that the volume fraction of αbcc-martensite increases with increasing AGS. However, the value of the stacking fault probability （Psf） does not show a large variation for samples with different values of AGS under water-quenching conditions.展开更多
By means of X-ray diffraction profile analysis of three different composition Fe?Mn?Si alloys, the relationship between stacking fault probabilityP sf with the concentrations of constituents in alloys, 1/P sf =540.05+...By means of X-ray diffraction profile analysis of three different composition Fe?Mn?Si alloys, the relationship between stacking fault probabilityP sf with the concentrations of constituents in alloys, 1/P sf =540.05+23.70× Mn wt%-138.74×Si wt%, was determined. According to the nucleation mechanism by stacking fault in this alloy, the equation between critical driving force ?G c andP sf ?G c=67.487+0.177 5/P sf (J/mol), was made. Therefore, the relationship between critical driving force and compositions was established. Associated with the thermodynamic calculation, theM s of fcc (γ)→ hcp(ε) martensitic transformation in any suitable composition Fe?Mn?Si shape memory alloys can be predicted and results seem reasonable as compared with some experimental data.展开更多
The stacking fault probability of CoNi alloys with different contents of Ni was measured by X ray diffraction methods. The results show that the stacking fault decreases with increasing Ni content and with increasing ...The stacking fault probability of CoNi alloys with different contents of Ni was measured by X ray diffraction methods. The results show that the stacking fault decreases with increasing Ni content and with increasing temperature. The thermodynamical calculation has found an equation that can express the stacking fault energy γ of CoNi at temperature T . The phase equilibrium temperature depends on the composition of the certain alloy. The relationship between stacking fault energy γ and stacking fault probability P sf is determined.展开更多
The change of microstructure with strain was investigated in a Fe-32Mn-5Si austenitic alloy at room temperature by X-raydiffraction profile analysis.The experimental results show that the Fe-32Mn-5Si alloy is deformed...The change of microstructure with strain was investigated in a Fe-32Mn-5Si austenitic alloy at room temperature by X-raydiffraction profile analysis.The experimental results show that the Fe-32Mn-5Si alloy is deformed by the strain—induced γ→εtransformation and the twinning except dislocation slip at room temperature.The amount of strain-induced ε-martensite,thestacking fault probability and the twinning probability all exhibit parabolic relationship with increasing strain.The stackingfault probability is higher than the twinning probability.展开更多
文摘The aim of the present work was to study the effect of austenite grain size （AGS） on the martensite formation in a high-manganese twinning-induced plasticity （TWIP） steel. The results of a quantitative microstructural characterization of the steel by the whole X-ray pattern fitting Rietveld software, materials analysis using diffraction （MAUD）, indicated that the volume fraction of αbcc-martensite increases with increasing AGS. However, the value of the stacking fault probability （Psf） does not show a large variation for samples with different values of AGS under water-quenching conditions.
基金Project supported by the National Natural Science Foundation of China (Grant No. 59671023).
文摘By means of X-ray diffraction profile analysis of three different composition Fe?Mn?Si alloys, the relationship between stacking fault probabilityP sf with the concentrations of constituents in alloys, 1/P sf =540.05+23.70× Mn wt%-138.74×Si wt%, was determined. According to the nucleation mechanism by stacking fault in this alloy, the equation between critical driving force ?G c andP sf ?G c=67.487+0.177 5/P sf (J/mol), was made. Therefore, the relationship between critical driving force and compositions was established. Associated with the thermodynamic calculation, theM s of fcc (γ)→ hcp(ε) martensitic transformation in any suitable composition Fe?Mn?Si shape memory alloys can be predicted and results seem reasonable as compared with some experimental data.
文摘The stacking fault probability of CoNi alloys with different contents of Ni was measured by X ray diffraction methods. The results show that the stacking fault decreases with increasing Ni content and with increasing temperature. The thermodynamical calculation has found an equation that can express the stacking fault energy γ of CoNi at temperature T . The phase equilibrium temperature depends on the composition of the certain alloy. The relationship between stacking fault energy γ and stacking fault probability P sf is determined.
基金The project was supported by the National Natural Science Foundation of China(grant No.59601007).
文摘The change of microstructure with strain was investigated in a Fe-32Mn-5Si austenitic alloy at room temperature by X-raydiffraction profile analysis.The experimental results show that the Fe-32Mn-5Si alloy is deformed by the strain—induced γ→εtransformation and the twinning except dislocation slip at room temperature.The amount of strain-induced ε-martensite,thestacking fault probability and the twinning probability all exhibit parabolic relationship with increasing strain.The stackingfault probability is higher than the twinning probability.
