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利用ＳＥＭ,ＴＥＭ及ＥＢＳＤ研究了低碳钢在７５０℃ ,１０ｓ－１应变速率条件下形变过冷奥氏体的组织及取向变化．结果表明,组织演变由二个阶段组成,形变前期是以形变强化相变铁素体转变为主;当应变达到一定时,以铁素体的动态再结晶为主．应变量较小时,形变强化相变铁素体晶粒优先在原奥氏体晶界形核,随应变量的增加,以相界前沿畸变区的反复形核为主,铁素体转变量逐渐提高,同时珠光体等第二组织增多,铁素体晶粒内部位错密度提高．铁素体连续动态再结晶初期亚晶在珠光体与铁素体交界处优先形成．随应变增加频率提高．形变前期＜００１＞织构为相变铁素体在取向上的特征;形变后期＜１１１＞织构是动态再结晶铁素体在取向上的特征．
SEM, TEM and EBSD were used to study the microstructure and orientation change of austenite in low carbon steel under 750 ℃ and 10s-1 strain rate. The results show that the microstructure evolution is composed of two phases, and the deformation is mainly transformed by the transformation of the ferrite during the early stage of deformation. When the strain reaches a certain level, the dynamic recrystallization of the ferrite is dominant. When the strain is small, the deformation strengthened ferrite grains preferentially nucleate in the original austenite grain boundaries. With the increase of the amount of strain, the nucleation is dominated by the repeated nucleation in the frontier of the phase boundary, and the amount of ferrite transformation gradually increases , While the second organization such as pearlite increased, ferrite grain internal dislocation density increased. The initial subgrains of ferrite continuous dynamic recrystallization form preferentially at the junction of pearlite and ferrite. As the strain increases the frequency increases. The texture of pre-deformation <001> texture is characterized by the orientation of the phase transformation ferrite. The texture of the post-deformation <111> texture is characterized by the orientation of the dynamic recrystallized ferrite.