Abstract: By using JMatPro software and according to the 0. 70C steel coil (/%：0. 67C, 0. 17Si, 0. 50Mn, 0. 010P, 0. 010S, 0. 10Cr) produced at steel works, the effect of C (0. 65% ~ 1. 00% ), Si (0. 20% ~ 0. 55% ), Mn(0. 50% ~ 1. 45% , Cr (0. 10% ~0. 75% ), S (0. 010%~0. 070% ) , P (0. 010%~0. 060% ) and austenite grain ratting (5. 0 ~ 8. 0) in high carbon steel rod coil on martensite formation critical cooling rate (CCR_Mf) has been simulate to get the predict high carbon steel CCR_Mf  expression: CCR_Mf/(℃·s^-1 ) =4. 088 -9. 98 x [C]/% -3.58 x [Si]/% -5.12[Mn]/% - 0. 001 [P]/% +23. 45 x [S]/% -7.42 X [Cr]/% +2 x G_m, G_m-austenite grain size rating. Results show that with increasing the C, Mn, Si and Cr content in steel the CCR_Mf decreases, with increasing the S content in steel and original austenite grain size rating the CCR_Mf increases and the effect of P on CCR_Mf is minor； the effect of C and Mn on CCR_Mf  is largest； and the measure value of martensite formation critical cooling rate ( CCR_Mf) of the 70C steel is 8. 51 ℃/s, and its calculated value is 8. 79℃/s with error 0. 28 ℃/s. It is suggested that during high carbon steel casting process the key point is to control C and Mn segregation and to fine austenite grain size during rolling process for decrease of formation of martensite structure.

摘要： 通过JMatPro软件和根据钢厂生产的70钢（/%:0.67C,0.17Si,0.50Mn,0.010P,0.010S,0.10Cr）盘条,模拟对比高碳钢盘条中C（0.65%~1.00%）,Si（0.20%~0.55%）,Mn（0.50%~1.45%）,Cr（0.10%~0.75%）,S（0.010%~0.070%）,P（0.010%~0.060%）和奥氏体晶粒度级别（5.0~8.0）对马氏体形成临界冷却速率(CCR_Mf)的影响,建立了预测高碳钢CCR_Mf的表达式:CCR_Mf/(℃·s^-1)=4.088-9.88×[C]/%-3.58×[Si]/%-5.12×[Mn]/%-0.001×[P]/%+23.45×[S]/%-7.42×[Cr]/%+2×G_m,G_m-奥氏体晶粒度。结果表明,CCR_Mf随C、Mn、Si、Cr含量的增大而减小,随S含量和原奥氏体晶粒度的增大而增大,P对CCR_Mf几乎没有影响;C和Mn对CCR_Mf的影响最大;70钢马氏体临界冷却速率实测值8.51℃/s,计算值8.79℃/s,误差为0.28℃/s。建议高碳钢连铸过程应重点控制C、Mn偏析,并在轧制过程细化奥氏体晶粒尺寸,以减少马氏体组织的形成。 

关键词: 高碳钢盘条, 马氏体, 临界冷却速率, JMatPro软件, 数值模拟