材料期刊网

经 LFG(ΔG~(γ→a))-Mogutnov(ΔG_(Fe)~(γ→a))、徐祖耀(Shu-A)(ΔG~(γ→a))-Orr-Chipman(ΔG_(Fe)~(γ→a))、徐祖耀(Shu-B)(ΔG~(γ→a))-Orr-Chipman(ΔG_(Fe)~(γ→a))组合,均可算得 Fe-Mn-C 合金的 Ms 温度且与实验值十分符合.所得结果经数学处理,得 Fe-Mn-C 系 Ms 与成分的关系为:Ms(K)=817.4-7513.4xc-4141.9x_(Mn)-32083.5x_Cx_(Mn)(LFG)Ms(K)=829.9-7580.5x_C-4166.0x_(Mn)-15727.8x_Cx_(Mn)(SHU-A)Ms(K)=829.2-7276.1x_C-2915.4x_(Mn)-43825.7x_Cx_(Mn)(SHU-B)其线性相关系数均大于0.992.C 和 Mn 浓度均使合金的 Ms 线性地降低,而碳的作用几乎是Mn 的两倍.处理中引入了合金元素交互作用项(x_Cx_(Mn)),表明 C,Mn 相互加剧对 Ms 的影响。随含 C,Mn 量的增加,相变驱动力均单调地增加,而不存在奇异点.Ms 和相变驱动力的计算值均依赖于ΔG_(Fe)~(γ→a)项.

The M_s temperatures of Fe-Mn-C alloys have been calculated by the appli- cation of LFG model of △G~(γ→α) with Mogutnov's △G_(Fe)~(γ→α),Hsu-A model with Orr-Chipman's △_(Fe)G~(γ→α) and Hsu-B model with Orr-Chipman's △G_(Fe)~(γ→α) and are in good agreement with the experimental values.Through the mathematical treatment, the relationship between Ms and the composition of Fe-Mn-C alloys can be ob- tained as: M_s(K)=817.4-7513.4x_C-4141.9x_(Mn)-32083.5x_cx_(Mn) (LFG model with Mogutnov's △_(Fe)G~(γ→α)); M_s(K)=829.9-7580.5x_C-4166.0x_(Mn)-15727.Sx_cx_(Mn) (Hsu-A model with Orr-Chipman's △G_(Fe)~(γ→α)); M_s(K)=829.2-7276.1x_C-2915.4x_(Mn)-43825.7x_cx_(Mn) (Hsu-B model with Orr-Chipman's △G_(Fe)~(γ→α)) in which the linear correlation coefficient of these relations are larger than 0.992. Both C and Mn depress M_s linearly and the effect of C is almost two-fold stro- nger than that of Mn.Introduction of an interaction term(x_Cx_(Mn)) between alloying elements in the present treatment shows that C and Mn enhance the effect upon M_s of each other.The driving force for transformation increases monotonically with C and Mn content and there is no singularity.The ealculted M_s and the driving force largely depend on the △G~(γ→α) model and △_(Fe)G~(γ→α) values adopted.