低碳钢过冷奥氏体形变过程中的组织及取向变化  

MICROSTRUCTURE AND MICROTEXTURE CHANGE DURING DEFORMATION OF UNDERCOOLED AUSTENITE IN A LOW CARBON STEEL

作　　者：齐俊杰[1] 杨王玥[1] 孙祖庆[2] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]北京科技大学新金属材料国家重点实验室,北京100083

出　　处：《金属学报》2002年第6期629-634,共6页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展规划G1998061506资助项目

摘　　要：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．Microstructure and ferrite grain orientation evolution in a low carbon steel during deformation of undercooled austenite at 750 ℃ and a strain rate of 10 s-1 were investigated by using SEM, TEM and EBSD. The deformation process consists of two stages: deformation-enhanced transformation is the dominated factor in the early stage of deformation; ferrite dynamic recrystallization plays a major role in the final stage after deformation enhaned transformation nearly complets. The ferrite grains are nucleated at austenite grain boundaries under small strain, then formed repeatedly in front of the ferrite/austenite interface. Pearlite and cementite are also formed in the resulted microstructure. Ferrite sub-grains were observed preferably at the ferrite/pealite interface. The <001> microtexture is the main character of the transformed ferrite grain orientation, and the <111> microtexture is the main character of dynamic recrystallized ferrite.

关 键 词：形变强化相变 低碳钢 铁素体动态再结晶 组织演变 微织构 

分 类 号：TG142.3[一般工业技术—材料科学与工程] TG113.1[金属学及工艺—金属材料]