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采用价电子结构理论计算、微观成分的实验测定和TEM原位动态拉伸变形试验,研究了Fe-Mn-C合金中的C-Mn偏聚及其对相变和形变的影响.结果表明,Fe-8Mn-1.2C合金奥氏体中含C-Mn晶胞的n_A值是不含C晶胞的3.98倍,是含C晶胞的1.40倍;含C-Mn晶胞的n_C~D值是含C晶胞的2.21倍;在Fe-Mn-C合金奥氏体中存在C-Mn原子的微观偏聚,并形成了由-C-Mn-C-Mn-强键络相联结的Fe-Mn-C原子团偏聚区;散乱分布于Fe-Mn-C合金奥氏体中的Fe-Mn-C原子团偏聚区能有效地束缚原子的运动、阻滞滑移系的启动和阻碍位错的运动,强烈影响合金的相交和形变行为.
The effects of C-Mn segregation and deformation on the phase transition and deformation of Fe-Mn-C alloy were investigated by theoretical calculation of valence electron structure, microstructure experiment and TEM in situ tensile deformation test. The value of n_A of C-Mn unit in austenite of Fe-8Mn-1.2C alloy is 3.98 times that of C unit cell, which is 1.40 times of that of C unit cell. The value of n_C ~ D value of C-Mn unit cell Is 2.21 times that of unit cell containing C; micro-segregation of C-Mn atoms exists in the austenite of Fe-Mn-C alloy and forms a Fe-Mn-C-Mn- -Mn-C clusters; the segregation of Fe-Mn-C clusters interspersed in the austenite of Fe-Mn-C alloy can effectively constrain the movement of atoms and retard the activation and blockage of the slip system The wrong movement strongly affects the intersection and deformation behavior of the alloy.