摘要
通过研究三种 Fe-Ni-C 合金中珠光体、贝氏体及马氏体的低频相变内耗,发现马氏体相变内耗遵守相界面位错的静滞后损耗机制,珠光体和贝氏体相变内耗不遵守这种机制。在频率基本不变时,随着冷却速度的增加珠光体和贝氏体的相变内耗峰增高,峰温降低,且 Q(?)和(?)/fm 件·T_m 呈正比线性关系;频率增加时,珠光体和贝氏体的内耗峰明显降低,峰温上串。在连续冷却条下,Fe-Ni-C 合金中开始珠光体及贝氏体相变时并不存在点阵软化现象。
The low frequency internal friction of the pearlitic,bainiticand martensitic transformations in three Fe-Ni-C alloys has been studied.Theresults show that the internal friction of the martensitic transformation is incorrespondence with the model based on the hysteresis loss mechanism associ-ated with stress-induced motion of the interface dislocation,while that of thepearlitic and bainitic transformations does not obey this model.At a constantfrequency,the internal friction peaks of the pearlitic and bainitic transforma-tions increase as the cooling rate increases, but the temperature of the internalfriction peaks decreases,and the (?) is directly proportional to the (?)/f_mT_m.When the frequency increases,the (?) of the pearlitic and bainitic transfor-mations lowers apparently,and the temperature of the damping peaks increases.It was revealed that,at the begining of the pearlitic and bainitic transforma-tions under continuous cooling,there is no lattice softening.The internal fric-tion of the isothermal bainitic transformation in a Fe-Ni-C alloy has alsobeen studied,which proves that there appears a damping peak in the incubationperiod,and the damping peak may be attributed to the nucleation ofbainite.Consequently it infers that the mechanism of the bainite reaction seemssimilar to that of pearlite.
关键词
Fe-Ni-C合金
相变
内耗
珠光体
pearlitic transformation
bainitic transformation
martensitic transformation
internal friction
