易艳良
,
梁益龙
,
龙绍檑
材料热处理学报
在DIL805A/D相变仪上对试样进行热处理并测出相变点,应用余氏理论(EET)计算出相结构因子,并采用光学显微镜(OM)、透射电镜(TEM)及AMI-21型奥氏体测量仪对微观组织、亚结构及残留奥氏体量进行了观察与测量.分析了空冷条件下稀土对GDL-1钢连续转变的影响.结果表明:添加一定量稀土后,有τ/t ＜1,形成的核胚不会被侧向迁移的台阶吞并,可以激发形核长大,形成贝氏体多层次精细亚结构.稀土的添加使GDL-1钢中Fe-C-RE的偏聚单元增大(相结构因子nA和FCD值同时增大),造成Fe-C-RE偏聚结构单元对相变的阻力增加,抑制粒状贝氏体形成同时细化贝氏体铁素体组织及亚结构.稀土增加残留奥氏体量,且提高其稳定性.
关键词:
稀土
,
亚结构
,
残留奥氏体
,
相结构因子
H. Zhang
,
Y. Y. Liu
,
D. S. Peng and C. K. Wang (Department of Materials Science and Engineering
,
Central South University of Technology
,
Changsha 410083
,
China)
金属学报(英文版)
Continuous thermo-mechanical processing (CTMP) of 6201 aluminum alloy was simulated on Gleeble-1500. The deformed specimens were analyzed by the observation of TEM and the measurement of hardness. It was shown that rapid solid solution and aging treatment can be effectively combined in one procedure by the strain induced during CTMP. The deformation temperature is ranging from 540* C to 300* C, the hardness increases directly before the 6th pass followed by a slight drop, the amount of precipitates increases with the holding time after deformation. Uniformly distributed and stabilized Mg2Si precipitates, as well as dislocation substructure can be observed on deformed specimens which have been subsequently held at 300℃ for 60 seconds.
关键词:
6201 aluminum alloy
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