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本文利用温压缩实验，在Gleeble3500热力模拟试验机上测定了中碳钢马氏体（M）和铁素体＋珠光体（F+P）两种组织的流变曲线。对比研究了应变速率对这两种组织流变行为的影响。结果表明：在相同温度下，M组织的应变速率敏感性指数（mM）和加工软化率（s M）都大于F+P组织的相应参数（mF+P）和（s F+P）。应变速率为0.001s-1，变形温度为600℃，650℃，700℃，M组织的流变曲线均低于F+P组织的流变曲线；当应变速率从0.01s-1增加到10s-1，M组织和F+P组织的流变曲线相交，交点应变为临界应变，大于临界应变，M组织的流变应力低于F+P。这表明，对降低钢材温轧或零件温挤压的变形应力和成本来说，M组织可能比F+P更好。此外，对导致M组织上述流变行为的机理进行了初步探讨。

Flow curves of warm deformation performed on martensite structure(M) and ferrite plus pearlite structure (F+P) in a medium carbon steel were determined on Gleeble3500 machine. And the effect of strain rate on the warm flow behavior of the two starting microstructures of M and F+P at various temperatures was studied comparatively. It is found that the strain rate sensitive index(m) and the working softening effect of M are larger than that of F+P. And the flow stress of M is lower than that of F+P under the conditions of strain rate of 0.001s-1 and deformation temperature at 600℃, 650℃ and 700℃. When the strain rate ranges from 0.01 to 10.0s-1, there are critical strain values at which the M flow curves intersect the F+P curves under some conditions. In these cases, if the strain amount is larger than the critical strain, the martensitic flow stress is lower than that of F+P. These results show that, M structure, compared with F+P structure, may be a promising candidator for steel’s warm working. Additional, the mechanisms that result in these characteristics of M flow behavior are also discussed.