Carbon solubility in Mn-Fe melts（xMn=0.161-0.706,xFe=0.034-0.633）was measured experimentally at various temperatures.By thermodynamic derivation and calculation,the relationship between activity coefficient of carbo...Carbon solubility in Mn-Fe melts（xMn=0.161-0.706,xFe=0.034-0.633）was measured experimentally at various temperatures.By thermodynamic derivation and calculation,the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was obtained.Using Gibbs-Duhem relationship,the experimental results of this study,and experimental data reported in references,the relationship between other thermodynamic properties in Mn-C system and temperature were obtained by thermodynamic derivation and calculation.展开更多
Based on the phase diagram, the coexistence theory of the metallic melt structure involving compoundformation and the regularity of melts containing saturated phase, a calculating model of mass action concentrationsfo...Based on the phase diagram, the coexistence theory of the metallic melt structure involving compoundformation and the regularity of melts containing saturated phase, a calculating model of mass action concentrationsfor Mn-C melts was formulated. According to the activities (or activity coefficients AM. and γc.), obtained by theUnified Interaction Parameter Model (UIPM), the thermodynamic parameters G and G at higher temperatures (1628～1873 K) were optimized by the repeated try and error method. It is testified that G G(873～1273 K) and G (298～1623 K), obtained at lower temperatures, can also be used at the above-mentionedhigher temperatures. The calculated N. and N agree well with ac. and ac obtained by UIPM. This result showsthat the deduced model can reflect the structural reality of Mn-C melts.展开更多
根据溶液热力学理论对Fe C Ti Mn体系中TiC增强体的原位合成进行了热力学分析。计算表明,体系中TiC优先于Fe3C和Fe2Ti形成,且在热力学上比Fe3C和Fe2Ti稳定。多数情况下,TiC基体合金在液态未凝固时即可形成,而Fe3C和Fe2Ti则是在合金凝固...根据溶液热力学理论对Fe C Ti Mn体系中TiC增强体的原位合成进行了热力学分析。计算表明,体系中TiC优先于Fe3C和Fe2Ti形成,且在热力学上比Fe3C和Fe2Ti稳定。多数情况下,TiC基体合金在液态未凝固时即可形成,而Fe3C和Fe2Ti则是在合金凝固和冷却过程中才有可能析出。随C含量增加,形成TiC和Fe3C的可能性增大;随Ti含量增加,形成Fe2Ti的可能性增大,而形成Fe3C的可能性减小;高Ti高C时,有利于形成TiC,高Ti低C时有利于形成Fe2Ti;高C低Ti时有利于形成Fe3C;添加适量的Mn既可有效抑制Fe3C的形成,又明显降低TiC的合成温度,使大多数TiC的合成反应发生在合金熔体充满铸型后的冷却、凝固过程中,可能解决TiC过早析出、熔体粘度增大、充型困难等问题。展开更多
Q&P钢的连续退火工艺是一种广泛采用的热处理办法,本文从热力学的角度讨论了连续退火工艺均热过程数种Q&P钢奥氏体化的程度。重新计算了Fe-Si-Mn-C四元系固溶相BCC_A2和FCC_A1的热力学性质。结合连续退火工艺均热段的快速加热,...Q&P钢的连续退火工艺是一种广泛采用的热处理办法,本文从热力学的角度讨论了连续退火工艺均热过程数种Q&P钢奥氏体化的程度。重新计算了Fe-Si-Mn-C四元系固溶相BCC_A2和FCC_A1的热力学性质。结合连续退火工艺均热段的快速加热,短时保温,快速冷却的热处理工艺特点,按照PLE(Partition local equilibrium)和NPLE(Negligible partition local equilibrium)局部平衡计算了当前几种Q&P钢成分的FCC相线和奥氏体体积分数,并根据试验观测结果,提出了一种符合连续退火生产Q&P钢实际需求的准平衡相图计算方法:“准PLE”(Quasi-partition local equilibrium)计算方法,实际观测结果与理论预测结果符合较好。展开更多
基金Item Sponsored by National Natural Science Foundation of China(50374002)
文摘Carbon solubility in Mn-Fe melts（xMn=0.161-0.706,xFe=0.034-0.633）was measured experimentally at various temperatures.By thermodynamic derivation and calculation,the relationship between activity coefficient of carbon in infinite dilute solution of manganese in Mn-C system and temperature was obtained.Using Gibbs-Duhem relationship,the experimental results of this study,and experimental data reported in references,the relationship between other thermodynamic properties in Mn-C system and temperature were obtained by thermodynamic derivation and calculation.
文摘Based on the phase diagram, the coexistence theory of the metallic melt structure involving compoundformation and the regularity of melts containing saturated phase, a calculating model of mass action concentrationsfor Mn-C melts was formulated. According to the activities (or activity coefficients AM. and γc.), obtained by theUnified Interaction Parameter Model (UIPM), the thermodynamic parameters G and G at higher temperatures (1628～1873 K) were optimized by the repeated try and error method. It is testified that G G(873～1273 K) and G (298～1623 K), obtained at lower temperatures, can also be used at the above-mentionedhigher temperatures. The calculated N. and N agree well with ac. and ac obtained by UIPM. This result showsthat the deduced model can reflect the structural reality of Mn-C melts.
文摘根据溶液热力学理论对Fe C Ti Mn体系中TiC增强体的原位合成进行了热力学分析。计算表明,体系中TiC优先于Fe3C和Fe2Ti形成,且在热力学上比Fe3C和Fe2Ti稳定。多数情况下,TiC基体合金在液态未凝固时即可形成,而Fe3C和Fe2Ti则是在合金凝固和冷却过程中才有可能析出。随C含量增加,形成TiC和Fe3C的可能性增大;随Ti含量增加,形成Fe2Ti的可能性增大,而形成Fe3C的可能性减小;高Ti高C时,有利于形成TiC,高Ti低C时有利于形成Fe2Ti;高C低Ti时有利于形成Fe3C;添加适量的Mn既可有效抑制Fe3C的形成,又明显降低TiC的合成温度,使大多数TiC的合成反应发生在合金熔体充满铸型后的冷却、凝固过程中,可能解决TiC过早析出、熔体粘度增大、充型困难等问题。
文摘Q&P钢的连续退火工艺是一种广泛采用的热处理办法,本文从热力学的角度讨论了连续退火工艺均热过程数种Q&P钢奥氏体化的程度。重新计算了Fe-Si-Mn-C四元系固溶相BCC_A2和FCC_A1的热力学性质。结合连续退火工艺均热段的快速加热,短时保温,快速冷却的热处理工艺特点,按照PLE(Partition local equilibrium)和NPLE(Negligible partition local equilibrium)局部平衡计算了当前几种Q&P钢成分的FCC相线和奥氏体体积分数,并根据试验观测结果,提出了一种符合连续退火生产Q&P钢实际需求的准平衡相图计算方法:“准PLE”(Quasi-partition local equilibrium)计算方法,实际观测结果与理论预测结果符合较好。
